Annotation raytracing as overlay

This was the initial attempt at non-scene-geometry annotation raytracing.
Squashed down to one commit for simpler diff review.

Clear Werror=subobject-linkage issue
use bu_strcmp
Make annotation intersections scale independent
Use relative parallel and determinant tests so valid annotations are not rejected after small model transforms.  Carry the caller's model tolerance into visibility decisions and cover both behaviors in the focused annotation semantics test.
Use a strict annotation hit ordering
Compare hit distances exactly before using the path as a tie breaker.  Approximate equality in a std::sort predicate is not transitive and can violate the strict weak ordering required by the C++ standard library.
Preserve hit distance in simple rt lightmodels
Record the first partition distance in viewit, matching colorview.  Annotation compositing uses this value to keep model-space marks behind foreground geometry for lightmodels 1, 2, 4, 5, and 6.
Defer NIRT annotation reporting
Remove the provisional useannot mode instead of emitting records outside NIRT's fmt system.  This preserves existing structured output contracts and avoids extending the public nirt_opt_vals layout until annotation records have a complete formatter design.
Use annotation line styles for render width
Remove the redundant object-wide render_width field, ANR2 payload, and --stroke-width option.  Ray renderers now rely on the established per-segment line_width style over an automatic base width, preserving the public primitive layout and avoiding another database extension.  Document and test the ray coverage behavior.
Name the ADRT model coordinate scale
Replace repeated 1000-to-1 load conversions with ADRT_MODEL_UNITS_PER_TIE_UNIT so geometry and annotation compositing share one documented coordinate convention.
Keep annotations out of the librender camera ABI
Replace camera-resident annotation fields with an additive render_camera_render_annotations entry point.  Per-render private state now carries the scene, coordinate scale, and derived view while the public render_camera_t and thread-data layouts remain unchanged.  Preserve primary rays before shaders mutate them so annotation compositing evaluates the intended sample.
Define ISST annotation scene ownership
Make GFile release its annotation scene and TIE data, destroy the render window before its GFile owner, and clear the renderer under its mutex before reloading.  Queued renders now reject cleared scenes after acquiring the context, preventing use-after-free during reload and shutdown.
Cache rt annotation preparation state
Keep annotation scene and view state private to do.c, expose read-only accessors to workers, and reuse prepared coverage when the database, selected paths, and tolerances are unchanged.  Explicitly invalidate on animation changes and centralize cleanup.
Add a NIRT annotation output format
Add opt-in NIRT annotation reporting
Document NIRT annotation diagnostics
Document annotation and view-object roles
Remove the unused ISST application meta-object
ISSTApp declares no signals, slots, properties, or invokable methods.  Avoid generating a redundant derived meta-object, which also prevents Qt 6 from rejecting the member main-window construction during application startup.
Use Qt 6 OpenGL dependencies for ISST
Qt6::OpenGL and Qt6::OpenGLWidgets already carry the platform OpenGL implementation.  Do not also link the independently discovered host OpenGL target, which can select a different GL ABI and bypass Qt's configured backend.
Keep ISST annotations out of NMG tessellation
ISST renders annotations through its dedicated annotation scene.  Exclude annotation-only roots from the geometry walk and replace annotation leaves in mixed trees with empty nodes so the independent NMG path does not report unsupported tessellation.
Share ADRT annotation tessellation filtering
Frame ISST views using annotation bounds
Gate ART annotation frame processing
Honor inherited colors in annotation renders
Make RTree ray queries const-safe
Composite ordered annotation coverage with RTree indices
Blend all annotation layers in image renderers
Test ordered annotation coverage and alpha blending
Test ADRT annotation filtering and scene framing
Document annotation layering and lookup design
Tighten annotation scene preparation
Test annotation combination color inheritance

annot_viewobj.txt

@@ -0,0 +1,246 @@
+Annotation and view-object rendering notes
+==========================================
+
+Scope
+-----
+
+BRL-CAD has two related, but deliberately distinct, ways to represent visual
+markup:
+
+* An annotation is an ID_ANNOT database primitive.  It is persistent model
+  content with enough semantic and presentation information to be reproduced
+  outside the application that created it.
+* A view object is application-owned scene state.  It is useful for interactive
+  construction and manipulation, but is intentionally not backed by a database
+  object.
+
+They share portions of the interactive display infrastructure, but they do not
+currently have interchangeable ownership, lifetime, or rendering semantics.
+
+
+Annotation capabilities
+-----------------------
+
+An rt_annot_internal stores a model-space anchor, a set of 2D vertices, and
+either a model plane basis or screen-space placement.  Its segment types cover
+lines, circular arcs, NURBS, Beziers, text, and filled polygons.  Segment style
+records include a semantic role, line pattern and width, RGBA color, font or
+symbol, text scaling, and decorative flags.
+
+The libged annotate command can create styled text, leaders, linear/angular/
+radius/diameter/ordinate dimensions, and bounding-box autodim groups.  It can
+regenerate derived annotations from saved attributes and associate them with
+source model objects without making them part of those objects' CSG trees.
+
+Annotations therefore have the properties needed for persistent markup:
+
+* database naming, paths, transforms, and instances;
+* survival across save/reopen and transfer to another application;
+* semantic segment roles and per-segment presentation data;
+* model-space and view-dependent screen-space placement; and
+* high-level generation metadata and source-object associations.
+
+An annotation is informational coverage, not a CSG solid.  The raytracing
+implementation preserves that distinction.  It prepares annotation coverage
+from active database paths and composites it on primary samples after ordinary
+geometry has established color and depth.  Model-space annotation coverage is
+occluded by nearer solid geometry.  Screen-space annotation coverage uses the
+render view and image dimensions.  Annotations do not acquire artificial
+volume, alter model bounds, cast shadows, or participate in reflection and
+refraction rays.
+
+Visible coverage is returned in back-to-front layers.  Model-space layers are
+ordered by ray distance, followed by view-space layers ordered by projected
+anchor depth; segment draw order breaks ties within an annotation.  This lets
+the image renderers apply source-over alpha consistently while retaining the
+single-frontmost-hit query for compatibility.  NIRT continues to report one
+frontmost segment per model-space annotation rather than exposing these
+presentation layers as solid partitions.
+
+Color follows normal database tree state.  An annotation segment with an
+explicit RGBA style wins; otherwise it inherits the resolved combination-path
+color; otherwise it is white.  The legacy region-ID color table is not applied
+to annotation display or coverage, since annotations are informational leaves
+rather than regions.
+
+Prepared coverage uses the existing libbg RTree implementation.  A 3D RTree
+culls model-space annotation instances and a 2D local RTree culls segments
+inside every annotation.  Screen-space instance extents cannot be placed in a
+static world-space index because they change with the view, so those instances
+remain in a compact list while still using their local segment RTree.  This
+avoids a new spatial data structure and keeps prepared scenes immutable and
+safe for concurrent sample queries.
+
+The rt, ART, and ADRT/ISST integrations follow this overlay model.  ERT invokes
+rt with the database, displayed database paths, and view, so database-backed
+annotations can follow that route as well.  ERT does not currently serialize
+or pass application-owned view objects to its subprocess.
+
+NIRT keeps annotation diagnostics opt-in.  `useannot 1` enables model-space
+annotation intersections, and the `fmt a` action reports them.  Default NIRT
+output is unchanged.  Screen-space annotations are deliberately omitted
+because a NIRT ray does not define an image size, pixel footprint, or complete
+model-to-view mapping.
+
+
+View-object capabilities
+------------------------
+
+The core representation is bv_scene_obj.  A view set owns shared view objects,
+and a particular bview can also own local objects.  Independent views force
+local ownership.  bv_obj_put recycles objects when their application lifetime
+ends; the objects are not written to the .g database.
+
+The `view obj` command exposes the principal markup types:
+
+* Lines are model-coordinate polylines represented by vlists.  Generic scene
+  rendering can add arrowheads to segment ends.
+* Labels have a model anchor and optional model-space target/leader.  Their text
+  is projected and drawn as screen-facing HUD text.  If the command omits Z,
+  screen X/Y coordinates are projected onto the current view plane at creation
+  time.
+* Polygons include general polygons, circles, ellipses, rectangles, and
+  squares.  Creation and editing operate on a saved view plane with a view-Z
+  offset.  Selection, movement, open/close, area, overlap, and 2D boolean
+  operations are supported.  A "fill" is currently a set of hatch lines, not
+  an opaque surface.  Polygons can be explicitly imported from or exported to
+  persistent sketch primitives.
+
+Scene objects also provide object color, transparency, pixel line width, dash
+style, and arrow dimensions.  Not all of these properties have a uniform
+command interface for every object type.
+
+There are other visual layers that should not be conflated with these objects.
+Legacy gv_tcl data/sdata arrows, axes, lines, labels, and polygons have a
+separate representation.  Faceplate/HUD elements are screen UI.  Database
+objects temporarily cloned for editing are also transient, but retain database
+primitive semantics and live in the database-object scene containers.
+
+
+Comparison
+----------
+
+Both annotations and view objects eventually produce display-manager pixels,
+often through bv_scene_obj and vlists.  That common final path does not make
+their source representations equivalent.
+
+Annotations are the canonical choice when markup must be saved, named in a
+database, instanced, shared, raytraced from a .g file, or understood by another
+program.  View objects are the right choice for application/session state that
+must be created and manipulated without changing the database.
+
+Some view objects have a direct annotation analogue, but conversion is not
+lossless without type-aware logic:
+
+* A view polyline maps naturally to line segments, including arrowhead style.
+* A polygon outline and its hatch lines can map to annotation coverage, but the
+  existing view "fill" must not silently become an opaque filled polygon.
+* A label is hybrid.  Its target and leader are model-space geometry while its
+  glyphs remain screen-facing at a projected model anchor.
+* Arbitrary vlist extraction is insufficient because display-matrix commands,
+  point and line sizes, child objects, glyph behavior, and semantic roles are
+  otherwise lost or ambiguous.
+
+View-object line width and annotation line width also need an explicit unit
+policy.  View-object widths are display pixels.  Screen-space annotation widths
+are view-dependent coverage widths.  A model-space annotation's line_width is
+used as a scale on the automatically selected model-space stroke width.  In
+other words, removing a separate raytracer "stroke-width" setting does not
+remove width control: the annotation's existing line_width/`--line-width`
+style remains the single user-facing control.  The renderer interprets it in
+the appropriate coordinate system rather than exposing a second competing
+knob.
+
+
+Recommended transient rendering design
+--------------------------------------
+
+Do not make librt or the raytracers depend on bv_scene_obj, libbv application
+containers, or libged.  Do not manufacture tubes, TGCs, meshes, or geometry
+just in front of the view plane.  Artificial geometry would affect bounds,
+depth, shadows, and secondary rays, and would make antialiasing and perspective
+behavior depend on a fabricated distance from the eye.
+
+If transient view objects need to appear in raytraced output, use an explicit
+application-to-renderer snapshot boundary:
+
+1. The GED/application layer snapshots selected live view objects when a render
+   is launched.  This is the only layer that owns their lifetime and semantics.
+2. A type-aware adapter in libged or libbv translates supported objects into a
+   renderer-neutral overlay/coverage description.  It should reuse annotation
+   coverage preparation through an in-memory annotation-instance interface,
+   rather than duplicate line, glyph, and arrow intersection algorithms.
+3. The snapshot travels with the exact view state: model-to-view transform,
+   perspective, image width and height, and sampling convention.  In-process
+   renderers can receive it directly; subprocess rt/ERT needs an explicit
+   serialized side channel.
+4. Raytracers composite this coverage only on primary image samples, after
+   geometry color and depth are known.  It remains outside CSG, model bounds,
+   shadows, reflections, and refractions.
+5. Initial support should be deliberately finite: polyline strokes and
+   arrowheads, label glyphs and leaders, polygon outlines, and polygon hatches.
+   Faceplate elements and legacy gv_tcl overlays should be separately specified
+   opt-in layers rather than being included accidentally.
+6. Snapshot records should preserve object name and type, RGBA, visibility,
+   local/shared ownership, presentation units, and source identity.  Unsupported
+   object types should produce a deliberate diagnostic or documented omission.
+
+Application-side compositing of the interactive display-manager layer over an
+ERT framebuffer is a viable smaller feature if only ERT screen captures need
+view objects.  It would closely reproduce the interactive view, but it would
+not make the objects available to standalone rt, ART, or ISST output and should
+not be presented as the general renderer solution.
+
+Conversion between the two systems should remain explicit.  Automatically
+turning view objects into database annotations would violate their deliberately
+transient contract.  A user command to promote selected view markup to a
+persistent annotation would be reasonable; polygon-to-sketch export is an
+existing precedent.  Conversely, a view-object editor may be used as a front
+end for constructing an annotation, provided the persistence action is clear.
+
+
+Maintenance findings before implementing the adapter
+----------------------------------------------------
+
+Several representation issues should be corrected before type-driven snapshot
+conversion is relied upon:
+
+* Container-selection flags (BV_DB_OBJS, BV_VIEW_OBJS, BV_LOCAL_OBJS, and
+  BV_CHILD_OBJS) reuse numeric bits also used for semantic s_type_flags
+  (BV_DBOBJ_BASED, BV_VIEWONLY, BV_LINES, and others).  bv_obj_create currently
+  assigns its type argument to s_type_flags.  A local view object consequently
+  acquires BV_LINES incidentally, while the line command does not explicitly
+  tag lines.  The namespaces should be separated and every object explicitly
+  typed.
+* Lines, labels, and polygons should have unambiguous type tags and per-type
+  lifecycle/extraction callbacks.  Snapshot conversion must inspect typed data,
+  not infer semantics from a rendered vlist.
+* Label construction should initialize every bv_label field deliberately,
+  including size, line_flag, anchor, arrow, and target.  Current construction
+  does not establish all of those values on every path.
+* The status of legacy gv_tcl overlay data should be decided explicitly:
+  migrate it, support it through a separate adapter, or document its exclusion.
+* Screen-space annotation display and raytrace units need a parity test.  The
+  legacy display-matrix vlist path and the ray coverage path currently express
+  screen offsets through different mechanisms; their apparent agreement must
+  be verified rather than assumed.
+* Per-segment annotation colors exceed the legacy interactive vlist object's
+  single-color model.  Uniform annotate-command colors work today, but true
+  multicolor interactive parity may require split scene objects or a richer
+  display representation.
+
+Tests for a future adapter should cover shared and local ownership, cleanup,
+label anchors and leaders, polygon holes/hatches/view-Z, perspective, pixel
+width, model-space occlusion, screen-space overlay, and serialization across
+the ERT subprocess boundary.
+
+
+Conclusion
+----------
+
+Persistent annotations and transient view objects should continue to coexist.
+The annotation coverage scene is the correct renderer-side abstraction for
+both saved annotations and a future snapshot of transient markup.  The
+application should perform the semantic conversion and transfer a view-complete
+snapshot; the renderer should treat it as primary-ray coverage, never as
+invented scene geometry.

doc/asciidoc/system/man1/nirt.adoc

@@ -132,6 +132,10 @@ Command to set the backout flag. With no option, prints the current value. When
 Sets the _useair_ member of the __rt_i__ structure to the integer _n_. If _n_ is 0, then *nirt* ignores any air in the geometry. If this command is invoked with no arguments, *nirt* prints the current value of _useair_. Default is 0.
 
 
+*useannot [* _n_*]*::
+Enables (_n_=1) or disables (_n_=0) diagnostic annotation intersections. When enabled, *nirt* evaluates all model-space annotations below the active database paths and invokes the *a* output action for each crossing. Screen-space annotations are not evaluated because an individual NIRT ray does not supply a pixel size or model-to-view transform. If this command is invoked with no arguments, *nirt* prints the current value. Default is 0.
+
+
 *overlap_claims [* _n_*]*::
 Specifies how to handle multiple regions' claims to segments of a ray. If _n_ is 0 or "resolve", then all overlaps are resolved in favor of a single region and any other claimants are ignored. If _n_ is 2 or "rebuild_all", then all overlaps are rebuilt, so any overlapping regions along the ray create individual (geometrically intersecting) partitions. If _n_ is 3 or "retain", then all overlaps are retained. In this case, the resulting partitions are always geometrically disjoint, each one is owned by a single region according to the current overlap resolution strategy, but every claimant is recorded. If _n_ is 1 or "rebuild_fastgen", then *nirt* takes on _FASTGEN_ behavior, so overlaps of plate-mode primitives are rebuilt, but other overlaps are retained. This command is useful with the __claimant_count__, __claimant_list__, and __claimant_listn__ output items. Default is "resolve".
 
@@ -197,7 +201,11 @@ Quits *nirt*.
 [[output_statements]]
 == OUTPUT STATEMENTS
 
-*nirt* allows the user a high degree of control, via the _fmt_ command, over what information gets printed out for each ray and in what format. There are six types of output statements, each of which is executed under appropriate circumstances. The types and their use are:
+*nirt* allows the user a high degree of control, via the _fmt_ command, over what information gets printed out for each ray and in what format. There are eight types of output statements, each of which is executed under appropriate circumstances. The types and their use are:
+
+
+*a*::
+Annotation. Executed once for each model-space annotation crossing when *useannot* is enabled. Crossings are reported in ray-distance order after the ordinary solid shotline output. The default format is empty.
 
 
 *r*::
@@ -278,6 +286,41 @@ azimuth of view (i.e., of ray direction).
 elevation of view (i.e., of ray direction).
 
 
+Annotation Information
+
+
+*annot_path*::
+full database path of the annotation primitive.
+
+
+*annot_segment*::
+zero-based annotation segment index.
+
+
+*annot_role*::
+semantic role of the annotation segment, such as `text`, `leader`, `dimension`, or `arrowhead`.
+
+
+*annot_x*::
+_x_ coordinate of the annotation hit point.
+
+
+*annot_y*::
+_y_ coordinate of the annotation hit point.
+
+
+*annot_z*::
+_z_ coordinate of the annotation hit point.
+
+
+*annot_d*::
+_d_ grid-plane coordinate of the annotation hit point.
+
+
+*annot_visible*::
+1 if no non-air solid surface is closer to the ray origin, otherwise 0. Occluded annotation crossings are still reported so they can be inspected during debugging.
+
+
 
 Partition Information
 
@@ -521,6 +564,15 @@ nirt -A material_id -A los_density model.g all
 Each region the ray passes through is reported together with its _material_id_ and _los_density_ attribute values via the *attributes* output item, which is useful for vulnerability and mass-properties analyses.
 ====
 
+.Reporting annotation crossings for debugging
+====
+[source,bash]
+----
+nirt -s -e 'useannot 1;fmt a "%s %d (%g %g %g) visible=%d\n" annot_path annot_segment annot_x annot_y annot_z annot_visible;s' model.g component dimensions
+----
+This opt-in format reports every model-space annotation crossing and whether it is in front of the first solid surface. Ordinary NIRT output is unchanged unless *useannot* is enabled and an *a* format is supplied.
+====
+
 
 [[hints]]
 == HINTS

doc/asciidoc/system/man5/nirt_formatting.adoc

@@ -25,7 +25,7 @@ where the "char" argument is replaced by a single character identifying the cate
 [[nirt_format_categories]]
 == Output Categories
 
-NIRT offers seven categories of output reporting:
+NIRT offers eight categories of output reporting:
 
 [cols="3*"]
 [%noheader]
@@ -33,6 +33,9 @@ NIRT offers seven categories of output reporting:
 |*Category Name*
 |*Char*
 |*Description*
+|*Annotation*
+|*a*
+|Output for each model-space annotation crossing when annotation reporting is enabled with *useannot 1*. The default annotation format is empty.
 |*Ray*
 |*r*
 |Report of ray information. The formatting associated with r will print once per ray, regardless of whether a region is encountered.
@@ -62,7 +65,7 @@ NIRT offers seven categories of output reporting:
 [[nirt_format_str]]
 == Format Strings
 
-NIRT's format specifications are a subset of those found in printf implementations. Specifically, the d, i, and f types are supported, as well as width and precision specifiers.
+NIRT's format specifications are a subset of those found in printf implementations. The d, i, f, e, E, g, G, and s types are supported, as well as width and precision specifiers.
 
 
 [[nirt_format_keys]]
@@ -100,6 +103,33 @@ Unlike the full C/C++ printf, NIRT accepts only pre-defined string keys that ide
 
 Footnote and Miss categories have no particular keys unique to them, although they (like all categories) can use the Ray keys if desired. Partition, Overlap, and Gap, on the other hand, have keys that are unique to their contexts and valid only within those contexts:
 
+.Annotation Variables
+[cols="2*"]
+[%noheader]
+|===
+|annot_path
+|Full database path of the annotation primitive.
+|annot_segment
+|Zero-based annotation segment index.
+|annot_role
+|Semantic role of the annotation segment, such as `text`, `leader`, `dimension`, or `arrowhead`.
+|annot_x
+|x coordinate of the annotation hit point.
+|annot_y
+|y coordinate of the annotation hit point.
+|annot_z
+|z coordinate of the annotation hit point.
+|annot_d
+|d grid-plane coordinate of the annotation hit point.
+|annot_visible
+|1 if no non-air solid surface is closer to the ray origin, otherwise 0.
+|===
+
+Annotation reporting is diagnostic and opt-in. It returns all model-space
+annotation crossings in ray-distance order, including occluded crossings.
+Screen-space annotations are not reported because a NIRT shot does not define
+the pixel dimensions and model-to-view transform needed to evaluate them.
+
 .Partition Variables
 [cols="2*"]
 [%noheader]

doc/asciidoc/system/mann/annotate.adoc

@@ -40,12 +40,11 @@ Coordinates and explicit sizes use the database's current modeling units.
 Creation commands draw the new annotation immediately.  Use *--no-draw* to
 create it without changing the display.  Names must not already exist.
 
-Model-space annotations also participate in raytracing.  Librt expands their
-strokes and filled areas into transient mesh geometry during preparation; the
-generated geometry is not written to the database.  It uses the normal region
-material and color resolved from the containing combination tree.  Screen-space
-annotations remain display-only because primitive preparation has no render
-view or image dimensions with which to place them.
+Ray-traced annotations are zero-thickness informational coverage rather than
+solid regions.  Model-space annotations are depth-tested against ordinary
+geometry.  Screen-space annotations are generated for the current camera and
+composited in the foreground; they do not participate in shadows, reflections,
+line-of-sight thickness, or Boolean evaluation.
 
 The supported dimensions follow the general presentation conventions of ISO
 129-1.  Lettering defaults to OSIFont, an ISO 3098-style technical font shipped
@@ -209,9 +208,9 @@ Set the persistent annotation color using integer red, green, and blue values
 from 0 through 255.
 
 *--line-width width*::
-Set the display line width.  For a model-space raytrace, this value scales the
-physical stroke width inferred from the annotation's text height or overall
-extent.
+Set the presentation line width.  Display and screen-space ray rendering use
+the value as a pixel width.  Model-space ray rendering uses it to scale the
+automatic stroke width derived from the annotation's text height or extent.
 
 *--line-style style*::
 Set semantic line-pattern metadata to *continuous*, *dashed*, *dotted*,

include/rt/func.h

@@ -227,6 +227,32 @@ struct rt_crofton_params {
     double time_ms;      /**< wall-clock time budget (ms); 0 = disabled */
 };
 
+/** One solid partition observed by a Crofton ray. */
+struct rt_crofton_segment {
+    point_t in_point;
+    vect_t in_normal;
+    point_t out_point;
+    vect_t out_normal;
+    fastf_t thickness;
+    size_t ray_id;
+};
+
+/**
+ * Structured samples and estimates produced by rt_crofton_collect().
+ * Release @p segments with rt_crofton_result_free().
+ */
+struct rt_crofton_result {
+    struct rt_crofton_segment *segments;
+    size_t segment_count;
+    size_t ray_count;
+    size_t crossing_count;
+    double surface_area;
+    double volume;
+};
+
+/** Initialize an rt_crofton_result before first use. */
+#define RT_CROFTON_RESULT_INIT { NULL, 0, 0, 0, 0.0, 0.0 }
+
 
 /**
  * Run the Cauchy-Crofton ray-sampling estimator on an already-prepared
@@ -337,6 +363,26 @@ struct rt_crofton_params {
  */
 RT_EXPORT extern int rt_crofton_shoot(double *out_surf_area, double *out_volume, point_t *out_aabb_min, point_t *out_aabb_max, point_t out_obb[8], point_t **out_points, size_t *out_point_count, struct rt_i *rtip, const struct rt_crofton_params *params, const fastf_t *bbox_min, const fastf_t *bbox_max);
 
+/**
+ * Run Crofton sampling while preserving oriented entry/exit pairs.
+ *
+ * @p result must be initialized with RT_CROFTON_RESULT_INIT.  On success it
+ * owns the returned segment array.  @p rtip must already be prepared.
+ * @p ray_offset skips that many samples in the deterministic sequence and
+ * labels the returned rays starting at that value.  This lets successive
+ * calls use disjoint validation streams.
+ */
+RT_EXPORT extern int rt_crofton_collect(struct rt_crofton_result *result,
+					struct rt_i *rtip,
+					const struct rt_crofton_params *params,
+					size_t ray_offset,
+					const fastf_t *bbox_min,
+					const fastf_t *bbox_max);
+
+/** Release storage owned by a structured Crofton result. */
+RT_EXPORT extern void rt_crofton_result_free(
+					struct rt_crofton_result *result);
+
 
 /**
  * Cauchy-Crofton surface-area and/or volume estimator for a primitive.

include/rt/primitives/annot.h

@@ -29,10 +29,19 @@
 #include "bu/list.h"
 #include "bu/vls.h"
 #include "bn/tol.h"
+#include "rt/geom.h"
 #include "rt/defines.h"
 
 __BEGIN_DECLS
 
+struct db_i;
+struct xray;
+
+#define RT_ANNOT_SCREEN_DPI 96.0
+#define RT_ANNOT_MILLIMETERS_PER_INCH 25.4
+#define RT_ANNOT_SCREEN_PIXELS_PER_MM \
+    (RT_ANNOT_SCREEN_DPI / RT_ANNOT_MILLIMETERS_PER_INCH)
+
 RT_EXPORT extern struct rt_annot_internal *rt_copy_annot(const struct rt_annot_internal *annot_ip);
 
 /** Validate annotation topology, model-space placement, and optional segment
@@ -40,6 +49,82 @@ RT_EXPORT extern struct rt_annot_internal *rt_copy_annot(const struct rt_annot_i
 RT_EXPORT extern int rt_annot_validate(const struct rt_annot_internal *annot_ip,
 	struct bu_vls *messages);
 
+/** Opaque, immutable collection of prepared annotation instances. */
+struct rt_annot_scene;
+
+/** Camera state needed to evaluate view-space annotations.  Pixel sample
+ * coordinates use a lower-left origin. */
+struct rt_annot_view {
+    mat_t model2view;
+    size_t width;
+    size_t height;
+    fastf_t perspective;
+};
+
+/** A zero-thickness annotation coverage event.  path is owned by the scene. */
+struct rt_annot_hit {
+    const char *path;
+    size_t segment;
+    uint32_t role;
+    point_t point;
+    fastf_t distance;
+    unsigned char color[4];
+    int screen_space;
+    int visible;
+};
+
+/** Prepare annotations referenced by the supplied top-level database paths.
+ * Boolean operations are intentionally ignored: annotations are
+ * informational leaves, not solids. */
+RT_EXPORT extern struct rt_annot_scene *rt_annot_scene_create(
+	struct db_i *dbip, int path_count, const char * const *paths,
+	const struct bg_tess_tol *ttol, const struct bn_tol *tol);
+
+RT_EXPORT extern void rt_annot_scene_destroy(struct rt_annot_scene *scene);
+RT_EXPORT extern size_t rt_annot_scene_count(const struct rt_annot_scene *scene);
+/** Return model-space bounds for prepared annotations.  Screen-space geometry
+ * contributes its model-space anchor because its extent is view-dependent. */
+RT_EXPORT extern int rt_annot_scene_bounds(const struct rt_annot_scene *scene,
+	point_t minimum, point_t maximum);
+
+/** Return the top visible coverage event for a primary sample. */
+RT_EXPORT extern int rt_annot_scene_query(const struct rt_annot_scene *scene,
+	const struct rt_annot_view *view, const struct xray *ray,
+	fastf_t sample_x, fastf_t sample_y, fastf_t scene_distance,
+	struct rt_annot_hit *hit);
+
+/** Return all visible primary-sample coverage events in back-to-front order.
+ * Model-space events precede screen-space events.  When hits is NULL or
+ * capacity is zero, only the required result count is returned. */
+RT_EXPORT extern size_t rt_annot_scene_query_layers(
+	const struct rt_annot_scene *scene, const struct rt_annot_view *view,
+	const struct xray *ray, fastf_t sample_x, fastf_t sample_y,
+	fastf_t scene_distance, struct rt_annot_hit *hits, size_t capacity);
+
+/** Return all model-space coverage events, sorted by ray distance.  When hits
+ * is NULL or capacity is zero, only the required result count is returned. */
+RT_EXPORT extern size_t rt_annot_scene_query_model(const struct rt_annot_scene *scene,
+	const struct xray *ray, fastf_t scene_distance,
+	struct rt_annot_hit *hits, size_t capacity);
+
+/** Alpha-composite a coverage result over a linear RGB sample. */
+RT_EXPORT extern void rt_annot_hit_blend(fastf_t color[3],
+	const struct rt_annot_hit *hit);
+
+/** Alpha-composite all visible primary-sample coverage over color.  If
+ * front_hit is non-NULL, it receives the frontmost event. */
+RT_EXPORT extern int rt_annot_scene_composite(const struct rt_annot_scene *scene,
+	const struct rt_annot_view *view, const struct xray *ray,
+	fastf_t sample_x, fastf_t sample_y, fastf_t scene_distance,
+	fastf_t color[3], struct rt_annot_hit *front_hit);
+
+/** Generate one annotation segment in annotation-local XY coordinates.  This
+ * is shared by plotting and the coverage preparer to keep curve and font
+ * expansion identical. */
+RT_EXPORT extern int rt_annot_segment_vlist(struct bu_list *vlfree,
+	struct bu_list *vhead, const struct bg_tess_tol *ttol,
+	const struct rt_annot_internal *annot_ip, size_t segment);
+
 __END_DECLS
 
 /** @} */

misc/nirt/default.nrt

@@ -1,5 +1,6 @@
 # default.nrt
 # Description: default   - Standard NIRT Reporting Format
+fmt a ""
 fmt r "Origin (x y z) = (%.8f %.8f %.8f)  (h v d) = (%.4f %.4f %.4f)\nDirection (x y z) = (%.8f %.8f %.8f)  (az el) = (%.8f %.8f)\n" x_orig y_orig z_orig h v d_orig x_dir y_dir z_dir a e
 fmt h "    Region Name               Entry (x y z)              LOS  Obliq_in Attrib\n"
 fmt p "%-20s (%9.4f %9.4f %9.4f) %8.4f %8.4f%s\n" reg_name x_in y_in z_in los obliq_in attributes

src/adrt/CMakeLists.txt

@@ -53,7 +53,7 @@ set(
 )
 
 brlcad_addlib(librender "${LIBRENDER_SRCS}" "" "${ADRT_LOCAL_INCLUDE_DIRS}"
-  PRIVATE_LIBS libgcv ZLIB::ZLIB ${M_LIBRARY}
+  PRIVATE_LIBS libgcv librt ZLIB::ZLIB ${M_LIBRARY}
 )
 set_target_properties(librender PROPERTIES VERSION 20.0.1 SOVERSION 20)
 add_dependencies(librender gcv_plugins)
@@ -109,8 +109,9 @@ cmakefiles(isst.c)
 
 add_subdirectory(master)
 add_subdirectory(slave)
+add_subdirectory(tests)
 
-set(adrt_ignore_files load.h tienet.h)
+set(adrt_ignore_files load.h load_g.h tienet.h)
 cmakefiles(${adrt_ignore_files})
 cmakefiles(CMakeLists.txt)
 

src/adrt/adrt.h

@@ -90,11 +90,19 @@ enum
 
 #define ADRT_NAME_SIZE 256
 
+/* TIE geometry is normalized from millimeters to meters while loading. */
+#define ADRT_MODEL_UNITS_PER_TIE_UNIT 1000.0
+
 #define ADRT_LOAD_FORMAT_G 42
 #define ADRT_LOAD_FORMAT_REG 43
 #define ADRT_LOAD_FORMAT_KDTREE 44
 
+struct rt_annot_scene;
+
 RENDER_EXPORT extern int load_g(struct tie_s *tie, const char *db, int argc, const char **argv, struct adrt_mesh_s **);
+RENDER_EXPORT extern int load_g_annotations(struct tie_s *tie, const char *db,
+	int argc, const char **argv, struct adrt_mesh_s **,
+	struct rt_annot_scene **annotations);
 
 #endif
 

src/adrt/isst.c

@@ -59,6 +59,7 @@ struct isst_s {
     struct render_camera_s camera;
     struct camera_tile_s tile;
     struct adrt_mesh_s *meshes;
+    struct rt_annot_scene *annotations;
     tienet_buffer_t buffer_image;
     int ogl, sflags, w, h, gs, ui;
     double dt, fps, uic;
@@ -67,6 +68,7 @@ struct isst_s {
     void *texdata;
     vect_t camera_pos_init;
     vect_t camera_focus_init;
+    fastf_t scene_radius;
     int64_t t1;
     int64_t t2;
     int dirty;
@@ -119,13 +121,7 @@ resize_isst(struct isst_s *isstp)
     glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
     glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
     glTexEnvf (GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
-    {
-	/* realloc through a temporary so a failure does not leak (and null out)
-	 * the existing buffer. */
-	void *tmp = realloc(isstp->texdata, isstp->camera.w * isstp->camera.h * 3);
-	if (tmp)
-	    isstp->texdata = tmp;
-    }
+    isstp->texdata = realloc(isstp->texdata, isstp->camera.w * isstp->camera.h * 3);
     glTexImage2D (GL_TEXTURE_2D, 0, GL_RGB, isstp->camera.w, isstp->camera.h, 0, GL_RGB, GL_UNSIGNED_BYTE, isstp->texdata);
     glDisable(GL_LIGHTING);
 
@@ -158,11 +154,14 @@ isst_load_g(ClientData UNUSED(clientData), Tcl_Interp *interp, int objc,
     argv = (char **)malloc(sizeof(char *) * (strlen(Tcl_GetString(objv[3])) + 1));	/* allocate way too much. */
     argc = (int)bu_argv_from_string(argv, strlen(Tcl_GetString(objv[3])), Tcl_GetString(objv[3]));
 
-    load_g(isst->tie, Tcl_GetString(objv[2]), argc, (const char **)argv, &(isst->meshes));
+    rt_annot_scene_destroy(isst->annotations);
+    isst->annotations = NULL;
+    load_g_annotations(isst->tie, Tcl_GetString(objv[2]), argc,
+	(const char **)argv, &(isst->meshes), &isst->annotations);
     free(argv);
 
-    VSETALL(isst->camera.pos, isst->tie->radius);
-    VMOVE(isst->camera.focus, isst->tie->mid);
+    isst->scene_radius = render_camera_fit_scene(&isst->camera, isst->tie,
+	isst->annotations, ADRT_MODEL_UNITS_PER_TIE_UNIT);
     VMOVE(isst->camera_pos_init, isst->camera.pos);
     VMOVE(isst->camera_focus_init, isst->camera.focus);
 
@@ -239,7 +238,9 @@ paint_window(ClientData UNUSED(clientData), Tcl_Interp *interp, int objc, Tcl_Ob
 	isst->buffer_image.ind = 0;
 
 	render_camera_prep(&isst->camera);
-	render_camera_render(&isst->camera, isst->tie, &isst->tile, &isst->buffer_image);
+	render_camera_render_annotations(&isst->camera, isst->tie, &isst->tile,
+	    &isst->buffer_image, isst->annotations,
+	    ADRT_MODEL_UNITS_PER_TIE_UNIT);
 
 	isst->t1 = bu_gettime();
 
@@ -282,7 +283,6 @@ set_resolution(ClientData UNUSED(clientData), Tcl_Interp *interp, int objc, Tcl_
     }
 
     CLAMP(resolution, 1, 20);
-    /* gs is the render grid size; 0 means render at full window resolution */
     if (resolution == 20)
 	isst->gs = 0;
     else
@@ -326,13 +326,10 @@ isst_zap(ClientData UNUSED(clientData), Tcl_Interp *interp, int objc, Tcl_Obj *c
 	return TCL_ERROR;
     }
 
-    /* Release the buffers owned directly by the workspace before the struct
-     * itself.  (The tie and mesh list have a more involved lifecycle and are
-     * left for a dedicated teardown.) */
     TIENET_BUFFER_FREE(isst->buffer_image);
     if (isst->texdata)
 	free(isst->texdata);
-
+    rt_annot_scene_destroy(isst->annotations);
     bu_free(isst, "isst free");
     isst = NULL;
 
@@ -354,7 +351,7 @@ render_mode(ClientData UNUSED(clientData), Tcl_Interp *interp, int objc, Tcl_Obj
     if (objc == 4)
 	buf = Tcl_GetString(objv[3]);
 
-    /* pack the 'rest' into buf - probably should use a vls for this */
+    /* pack the 'rest' into buf - probably should use a vls for this*/
     if ( strlen(mode) == 3 && bu_strncmp("cut", mode, 3) == 0 ) {
 	struct adrt_mesh_s *mesh;
 
@@ -391,26 +388,22 @@ zero_view(ClientData UNUSED(clientData), Tcl_Interp *UNUSED(interp), int UNUSED(
 
 
 static int
-move_walk(ClientData UNUSED(clientData), Tcl_Interp *interp, int objc, Tcl_Obj *const *objv)
+move_walk(ClientData UNUSED(clientData), Tcl_Interp *interp, int UNUSED(objc), Tcl_Obj *const *objv)
 {
     vect_t vec;
     int flag;
 
-    if (objc < 3) {
-	Tcl_WrongNumArgs(interp, 1, objv, "pathName flag");
-	return TCL_ERROR;
-    }
     if (Tcl_GetIntFromObj(interp, objv[2], &flag) != TCL_OK)
 	return TCL_ERROR;
 
     if (flag >= 0) {
 	VSUB2(vec, isst->camera.focus, isst->camera.pos);
-	VSCALE(vec, vec, 0.1 * isst->tie->radius);
+	VSCALE(vec, vec, 0.1 * isst->scene_radius);
 	VADD2(isst->camera.pos, isst->camera.pos, vec);
 	VADD2(isst->camera.focus, isst->camera.focus, vec);
     } else {
 	VSUB2(vec, isst->camera.pos, isst->camera.focus);
-	VSCALE(vec, vec, 0.1 * isst->tie->radius);
+	VSCALE(vec, vec, 0.1 * isst->scene_radius);
 	VADD2(isst->camera.pos, isst->camera.pos, vec);
 	VADD2(isst->camera.focus, isst->camera.focus, vec);
     }
@@ -419,16 +412,12 @@ move_walk(ClientData UNUSED(clientData), Tcl_Interp *interp, int objc, Tcl_Obj *
 }
 
 static int
-move_strafe(ClientData UNUSED(clientData), Tcl_Interp *interp, int objc, Tcl_Obj *const *objv)
+move_strafe(ClientData UNUSED(clientData), Tcl_Interp *interp, int UNUSED(objc), Tcl_Obj *const *objv)
 {
     vect_t vec, dir, up;
 
     int flag;
 
-    if (objc < 3) {
-	Tcl_WrongNumArgs(interp, 1, objv, "pathName flag");
-	return TCL_ERROR;
-    }
     if (Tcl_GetIntFromObj(interp, objv[2], &flag) != TCL_OK)
 	return TCL_ERROR;
 
@@ -437,13 +426,13 @@ move_strafe(ClientData UNUSED(clientData), Tcl_Interp *interp, int objc, Tcl_Obj
     if (flag >= 0) {
 	VSUB2(dir, isst->camera.focus, isst->camera.pos);
 	VCROSS(vec, dir, up);
-	VSCALE(vec, vec, 0.1 * isst->tie->radius);
+	VSCALE(vec, vec, 0.1 * isst->scene_radius);
 	VADD2(isst->camera.pos, isst->camera.pos, vec);
 	VADD2(isst->camera.focus, isst->camera.pos, dir);
     } else {
 	VSUB2(dir, isst->camera.focus, isst->camera.pos);
 	VCROSS(vec, dir, up);
-	VSCALE(vec, vec, -0.1 * isst->tie->radius);
+	VSCALE(vec, vec, -0.1 * isst->scene_radius);
 	VADD2(isst->camera.pos, isst->camera.pos, vec);
 	VADD2(isst->camera.focus, isst->camera.pos, dir);
     }
@@ -551,14 +540,10 @@ aerotate(ClientData UNUSED(clientData), Tcl_Interp *interp, int objc, Tcl_Obj *c
 	VSCALE(vecdfoc, vecdfoc, mag_focus);
 	VADD2(isst->camera.focus, isst->camera_focus_init, vecdfoc);
     }
-    /* Update the tcl copies of the az/el vars.  Store them in the same units
-     * as isst_load_g (radians via -DEG2RAD); previously aerotate wrote the raw
-     * degrees from bn_ae_vec, leaving the Tcl vars inconsistent after a drag. */
+    /* Update the tcl copies of the az/el vars */
     VSUB2(vec, isst->camera.focus, isst->camera.pos);
     VUNITIZE(vec);
     bn_ae_vec(&az, &el, vec);
-    az = az * -DEG2RAD;
-    el = el * -DEG2RAD;
     bu_vls_sprintf(&tclstr, "%f", az);
     Tcl_SetVar(interp, "az", bu_vls_addr(&tclstr), 0);
     bu_vls_sprintf(&tclstr, "%f", el);
@@ -576,7 +561,7 @@ open_dm(ClientData UNUSED(cdata), Tcl_Interp *interp, int UNUSED(objc), Tcl_Obj
     dmp = dm_open(NULL, (void *)interp, dm_default_type(), sizeof(av)/sizeof(void*)-1, (const char **)av);
 
     if (dmp == DM_NULL) {
-	printf("Failed to open display manager\n");
+	printf("dm failed?\n");
 	return TCL_ERROR;
     }
 
@@ -654,7 +639,7 @@ const char *fullname;
     argv = __argv;
 #endif
 
-    /* initialize progname for run-time resource finding */
+    /* initialize progname for run-tim resource finding */
     bu_setprogname(argv[0]);
 
 #ifdef HAVE_WINDOWS_H

src/adrt/librender/camera.c

@@ -29,6 +29,7 @@
 #include "bu/dylib.h"
 #include "bu/log.h"
 #include "bu/str.h"
+#include "rt/primitives/annot.h"
 
 #include "./camera.h"
 
@@ -43,13 +44,27 @@ struct render_shader_s {
 
 static struct render_shader_s *shaders = NULL;
 
-/* number of leading characters compared when matching a shader by name */
-#define RENDER_SHADER_NAME_CMP_LEN	8
+struct render_camera_annotation_data {
+    const struct rt_annot_scene *scene;
+    fastf_t model_units_per_tie_unit;
+    struct rt_annot_view view;
+};
+
+
+struct render_camera_parallel_data {
+    render_camera_thread_data_t thread;
+    struct render_camera_annotation_data annotation;
+};
+
+static const fastf_t render_camera_default_scene_radius = 1.0;
+
 
 void render_camera_render_thread(int cpu, void *ptr);	/* for bu_parallel */
 static void render_camera_prep_ortho(render_camera_t *camera);
 static void render_camera_prep_persp(render_camera_t *camera);
 static void render_camera_prep_persp_dof(render_camera_t *camera);
+static void render_camera_annotation_view(const render_camera_t *camera,
+	fastf_t model_units_per_tie_unit, struct rt_annot_view *view);
 
 static struct render_shader_s *render_shader_register (const char *name, int (*init)(render_t *, const char *));
 
@@ -393,20 +408,147 @@ render_camera_prep(render_camera_t *camera)
 }
 
 
-void
-render_camera_render_thread(int UNUSED(cpu), void *ptr)
+fastf_t
+render_camera_fit_scene(render_camera_t *camera, const struct tie_s *tie,
+	const struct rt_annot_scene *annotations,
+	fastf_t model_units_per_tie_unit)
+{
+    point_t annotation_min, annotation_max;
+    point_t scene_min, scene_max;
+    vect_t offset;
+    fastf_t scene_radius;
+
+    if (!camera || !tie)
+	return 0.0;
+
+    if (!annotations || !rt_annot_scene_bounds(annotations,
+	    annotation_min, annotation_max)) {
+	VSETALL(camera->pos, tie->radius);
+	VMOVE(camera->focus, tie->mid);
+	return tie->radius;
+    }
+
+    if (!isfinite(model_units_per_tie_unit) ||
+	    model_units_per_tie_unit <= 0.0)
+	model_units_per_tie_unit = 1.0;
+    VSCALE(annotation_min, annotation_min,
+	1.0 / model_units_per_tie_unit);
+    VSCALE(annotation_max, annotation_max,
+	1.0 / model_units_per_tie_unit);
+    VMOVE(scene_min, annotation_min);
+    VMOVE(scene_max, annotation_max);
+    if (tie->tri_num) {
+	VMINMAX(scene_min, scene_max, tie->amin);
+	VMINMAX(scene_min, scene_max, tie->amax);
+    }
+
+    VADD2SCALE(camera->focus, scene_min, scene_max, 0.5);
+    VSUB2(offset, scene_max, scene_min);
+    scene_radius = 0.5 * MAGNITUDE(offset);
+    if (!isfinite(scene_radius) || scene_radius <= SMALL_FASTF)
+	scene_radius = render_camera_default_scene_radius;
+
+    /* Keep the established isometric initial direction while positioning it
+     * relative to the combined scene center. */
+    VSETALL(offset, scene_radius);
+    VADD2(camera->pos, camera->focus, offset);
+    return scene_radius;
+}
+
+
+static void
+render_camera_annotation_view(const render_camera_t *camera,
+	fastf_t model_units_per_tie_unit, struct rt_annot_view *view)
+{
+    vect_t look, up, side, temp, right;
+    point_t model_position;
+    fastf_t angle, sine, cosine, xy_scale = 1.0;
+    mat_t *matrix = &view->model2view;
+
+    VSUB2(look, camera->focus, camera->pos);
+    VUNITIZE(look);
+    VSET(up, 0.0, 0.0, 1.0);
+    VMOVE(temp, look);
+    angle = VDOT(up, temp);
+    VSCALE(temp, temp, angle);
+    VSUB2(up, up, temp);
+    VUNITIZE(up);
+    VCROSS(side, up, look);
+    sine = sin(-camera->tilt * DEG2RAD);
+    cosine = cos(-camera->tilt * DEG2RAD);
+    VSCALE(up, up, cosine);
+    VSCALE(side, side, sine);
+    VADD2(up, up, side);
+    VCROSS(side, up, look);
+    VREVERSE(right, side);
+
+    MAT_IDN(*matrix);
+    if (camera->type == RENDER_CAMERA_ORTHOGRAPHIC &&
+	    camera->aspect > 0.0 && camera->gridsize > 0.0) {
+	xy_scale = 2.0 / (camera->aspect * camera->gridsize *
+		model_units_per_tie_unit);
+    } else if (camera->aspect > 0.0) {
+	xy_scale = 1.0 / camera->aspect;
+    }
+    for (size_t axis = 0; axis < 3; ++axis) {
+	(*matrix)[axis] = right[axis] * xy_scale;
+	(*matrix)[4 + axis] = up[axis] * xy_scale;
+	(*matrix)[8 + axis] = -look[axis];
+    }
+    VSCALE(model_position, camera->pos, model_units_per_tie_unit);
+    (*matrix)[3] = -VDOT(&(*matrix)[0], model_position);
+    (*matrix)[7] = -VDOT(&(*matrix)[4], model_position);
+    (*matrix)[11] = -VDOT(&(*matrix)[8], model_position);
+    view->width = camera->w;
+    view->height = camera->h;
+    view->perspective =
+	camera->type == RENDER_CAMERA_PERSPECTIVE ? 2.0 * camera->fov : 0.0;
+}
+
+
+static void
+render_camera_composite_annotation(render_camera_thread_data_t *td,
+	const struct render_camera_annotation_data *annotation,
+	const struct tie_ray_s *tie_ray, fastf_t sample_x, fastf_t sample_y,
+	vect_t *pixel)
+{
+    struct rt_annot_hit back_layer = {0};
+    struct xray ray;
+    fastf_t scene_distance = INFINITY;
+
+    if (!annotation || !annotation->scene)
+	return;
+    VSCALE(ray.r_pt, tie_ray->pos, annotation->model_units_per_tie_unit);
+    VMOVE(ray.r_dir, tie_ray->dir);
+    if (!rt_annot_scene_query_layers(annotation->scene, &annotation->view,
+	    &ray, sample_x, sample_y, INFINITY, &back_layer, 1))
+	return;
+
+    if (!back_layer.screen_space) {
+	struct tie_id_s id;
+	struct tie_ray_s depth_ray = *tie_ray;
+	if (TIE_WORK(td->tie, &depth_ray, &id, render_hit, NULL))
+	    scene_distance = id.dist * annotation->model_units_per_tie_unit;
+    }
+    (void)rt_annot_scene_composite(annotation->scene, &annotation->view,
+	&ray, sample_x, sample_y, scene_distance, *pixel, NULL);
+}
+
+
+static void
+render_camera_render_thread_impl(int UNUSED(cpu), render_camera_thread_data_t *td,
+	const struct render_camera_annotation_data *annotation)
 {
-    render_camera_thread_data_t *td;
     int d, n, res_ind, scanline, v_scanline;
     vect_t pixel, accum;
     vect_t v1 = VINIT_ZERO;
     vect_t v2 = VINIT_ZERO;
     struct tie_ray_s ray;
+    struct tie_ray_s annotation_ray;
     fastf_t view_inv;
 
     VSETALL(v1, 0);
 
-    td = (render_camera_thread_data_t *)ptr;
     view_inv = 1.0 / td->camera->view_num;
 
     td->camera->render.tie = td->tie;
@@ -457,9 +599,15 @@ render_camera_render_thread(int UNUSED(cpu), void *ptr)
 		    VMOVE(ray.pos, td->camera->view_list[d].pos);
 		    ray.depth = 0;
 		    VUNITIZE(ray.dir);
+		    annotation_ray = ray;
 
 		    /* Compute pixel value using this ray */
 		    td->camera->render.work(&td->camera->render, td->tie, &ray, &pixel);
+		    render_camera_composite_annotation(td, annotation,
+			&annotation_ray,
+			(fastf_t)n + 0.5,
+			(fastf_t)td->camera->h - (fastf_t)v_scanline - 0.5,
+			&pixel);
 
 		    VADD2(accum, accum, pixel);
 		}
@@ -476,6 +624,7 @@ render_camera_render_thread(int UNUSED(cpu), void *ptr)
 		    VMOVE(ray.pos, td->camera->view_list[0].pos);
 		    ray.depth = 0;
 		    VUNITIZE(ray.dir);
+		    annotation_ray = ray;
 
 		    /* Compute pixel value using this ray */
 		    td->camera->render.work(&td->camera->render, td->tie, &ray, &pixel);
@@ -490,12 +639,19 @@ render_camera_render_thread(int UNUSED(cpu), void *ptr)
 
 		    VSET(pixel, (TFLOAT)RENDER_CAMERA_BGR, (TFLOAT)RENDER_CAMERA_BGG, (TFLOAT)RENDER_CAMERA_BGB);
 		    ray.depth = 0;
+		    annotation_ray = ray;
 
 		    /* Compute pixel value using this ray */
 		    td->camera->render.work(&td->camera->render, td->tie, &ray, &pixel);
 		}
 	    }
 
+	    if (td->camera->view_num == 1)
+		render_camera_composite_annotation(td, annotation,
+		    &annotation_ray, (fastf_t)n + 0.5,
+		    (fastf_t)td->camera->h - (fastf_t)v_scanline - 0.5,
+		    &pixel);
+
 
 	    if (td->tile->format == RENDER_CAMERA_BIT_DEPTH_24) {
 		V_MIN(pixel[0], 1);
@@ -523,9 +679,30 @@ render_camera_render_thread(int UNUSED(cpu), void *ptr)
 
 
 void
-render_camera_render(render_camera_t *camera, struct tie_s *tie, camera_tile_t *tile, tienet_buffer_t *result)
+render_camera_render_thread(int cpu, void *ptr)
 {
-    render_camera_thread_data_t td;
+    render_camera_render_thread_impl(cpu, (render_camera_thread_data_t *)ptr,
+	NULL);
+}
+
+
+static void
+render_camera_render_annotations_thread(int cpu, void *ptr)
+{
+    struct render_camera_parallel_data *data =
+	(struct render_camera_parallel_data *)ptr;
+
+    render_camera_render_thread_impl(cpu, &data->thread, &data->annotation);
+}
+
+
+static void
+render_camera_render_internal(render_camera_t *camera, struct tie_s *tie,
+	camera_tile_t *tile, tienet_buffer_t *result,
+	const struct rt_annot_scene *annotations,
+	fastf_t model_units_per_tie_unit)
+{
+    struct render_camera_parallel_data data = {0};
     unsigned int scanline;
     uint32_t ind;
 
@@ -543,19 +720,47 @@ render_camera_render(render_camera_t *camera, struct tie_s *tie, camera_tile_t *
     TCOPY(camera_tile_t, tile, 0, result->data, result->ind);
     result->ind += sizeof(camera_tile_t);
 
-    td.tie = tie;
-    td.camera = camera;
-    td.tile = tile;
-    td.res_buf = &((char *)result->data)[result->ind];
+    data.thread.tie = tie;
+    data.thread.camera = camera;
+    data.thread.tile = tile;
+    data.thread.res_buf = &((char *)result->data)[result->ind];
     scanline = 0;
-    td.scanline = &scanline;
-    td.sem_tie_worker = bu_semaphore_register("sem_tie_worker");
+    data.thread.scanline = &scanline;
+    data.thread.sem_tie_worker = bu_semaphore_register("sem_tie_worker");
+    data.annotation.scene = annotations;
+    data.annotation.model_units_per_tie_unit =
+	model_units_per_tie_unit > 0.0 ? model_units_per_tie_unit : 1.0;
+    if (annotations)
+	render_camera_annotation_view(camera,
+	    data.annotation.model_units_per_tie_unit, &data.annotation.view);
 
-    bu_parallel(render_camera_render_thread, camera->thread_num, &td);
+    if (annotations)
+	bu_parallel(render_camera_render_annotations_thread,
+	    camera->thread_num, &data);
+    else
+	bu_parallel(render_camera_render_thread, camera->thread_num,
+	    &data.thread);
 
     result->ind = ind;
+}
 
-    return;
+
+void
+render_camera_render(render_camera_t *camera, struct tie_s *tie,
+	camera_tile_t *tile, tienet_buffer_t *result)
+{
+    render_camera_render_internal(camera, tie, tile, result, NULL, 1.0);
+}
+
+
+void
+render_camera_render_annotations(render_camera_t *camera, struct tie_s *tie,
+	camera_tile_t *tile, tienet_buffer_t *result,
+	const struct rt_annot_scene *annotations,
+	fastf_t model_units_per_tie_unit)
+{
+    render_camera_render_internal(camera, tie, tile, result, annotations,
+	model_units_per_tie_unit);
 }
 
 
@@ -620,9 +825,9 @@ render_shader_unload_plugin(render_t *r, const char *name)
 {
 #ifdef HAVE_DLFCN_H
     struct render_shader_s *t, *s = shaders, *meh;
-    if (!bu_strncmp(s->name, name, RENDER_SHADER_NAME_CMP_LEN)) {
+    if (!bu_strncmp(s->name, name, 8)) {
 	t = s->next;
-	if (r && r->shader && !bu_strncmp(r->shader, name, RENDER_SHADER_NAME_CMP_LEN)) {
+	if (r && r->shader && !bu_strncmp(r->shader, name, 8)) {
 	    meh = s->next;
 	    while (meh) {
 		if (render_shader_init(r, meh->name, NULL) != -1)
@@ -641,7 +846,7 @@ LOADED:
     }
 
     while (s->next) {
-	if (!bu_strncmp(s->next->name, name, RENDER_SHADER_NAME_CMP_LEN)) {
+	if (!bu_strncmp(s->next->name, name, 8)) {
 	    if (r)
 		render_shader_init(r, s->name, NULL);
 	    if (s->next->dlh)
@@ -651,7 +856,6 @@ LOADED:
 	    bu_free(t, "unload shader");
 	    return 0;
 	}
-	s = s->next;
     }
 
     bu_log("Could not find shader \"%s\"\n", name);
@@ -667,7 +871,7 @@ render_shader_init(render_t *r, const char *name, const char *buf)
 {
     struct render_shader_s *s = shaders;
     while (s) {
-	if (!bu_strncmp(s->name, name, RENDER_SHADER_NAME_CMP_LEN)) {
+	if (!bu_strncmp(s->name, name, 8)) {
 	    s->init(r, buf);
 	    r->shader = s->name;
 	    return 0;

src/adrt/librender/camera.h

@@ -99,7 +99,18 @@ __BEGIN_DECLS
 RENDER_EXPORT extern void render_camera_init(render_camera_t *camera, size_t threads);
 RENDER_EXPORT extern void render_camera_free(render_camera_t *camera);
 RENDER_EXPORT extern void render_camera_prep(render_camera_t *camera);
+/** Center a camera on TIE geometry and any prepared annotations.  Returns the
+ * effective scene radius in TIE coordinates. */
+RENDER_EXPORT extern fastf_t render_camera_fit_scene(render_camera_t *camera,
+	const struct tie_s *tie, const struct rt_annot_scene *annotations,
+	fastf_t model_units_per_tie_unit);
 RENDER_EXPORT extern void render_camera_render(render_camera_t *camera, struct tie_s *tie, camera_tile_t *tile, tienet_buffer_t *result);
+/** Render with an externally owned annotation scene.  The coordinate scale
+ * converts TIE coordinates to database model coordinates. */
+RENDER_EXPORT extern void render_camera_render_annotations(render_camera_t *camera,
+	struct tie_s *tie, camera_tile_t *tile, tienet_buffer_t *result,
+	const struct rt_annot_scene *annotations,
+	fastf_t model_units_per_tie_unit);
 
 RENDER_EXPORT extern int render_shader_init(render_t *, const char *name, const char *buf);
 RENDER_EXPORT extern const char *render_shader_load_plugin(const char *filename);

src/adrt/load_g.c

@@ -40,11 +40,13 @@
 #include "vmath.h"
 #include "nmg.h"
 #include "rt/geom.h"
+#include "rt/search.h"
 #include "raytrace.h"
 
 #include "rt/tie.h"
 #include "adrt.h"
 #include "adrt_struct.h"
+#include "load_g.h"
 
 
 static struct bn_tol tol;		/* calculation tolerance */
@@ -104,6 +106,42 @@ struct gcv_data {
 static struct gcv_data gcvwriter = {{load_nmg_to_adrt_gcvwrite, NULL, NULL}, NULL};
 
 
+int
+adrt_path_has_geometry(struct db_i *database, const char *path)
+{
+    static const char *geometry_search = "! -type comb ! -type annot";
+    struct directory *root;
+
+    if (!database || !path)
+	return 0;
+    root = db_lookup(database, path, LOOKUP_QUIET);
+
+    /* Let db_walk_tree report a missing path rather than hiding the error. */
+    if (!root)
+	return 1;
+
+    return db_search(NULL, DB_SEARCH_QUIET, geometry_search, 1, &root,
+	database, NULL, NULL, NULL) != 0;
+}
+
+
+union tree *
+adrt_leaf_tess(struct db_tree_state *tsp, const struct db_full_path *pathp,
+	struct rt_db_internal *ip, void *client_data)
+{
+    union tree *result;
+
+    if (!ip || ip->idb_type != ID_ANNOT)
+	return rt_booltree_leaf_tess(tsp, pathp, ip, client_data);
+
+    /* Annotations are rendered directly and have no NMG representation. */
+    BU_GET(result, union tree);
+    RT_TREE_INIT(result);
+    result->tr_op = OP_NOP;
+    return result;
+}
+
+
 /* load the region into the tie image */
 static void
 load_nmg_to_adrt_internal(struct adrt_mesh_s *mesh, struct nmgregion *r)
@@ -153,7 +191,8 @@ load_nmg_to_adrt_internal(struct adrt_mesh_s *mesh, struct nmgregion *r)
 		    NMG_CK_VERTEX(v);
 
 		    /* convert mm to m */
-		    VSCALE((*tribuf[vert_count]).v, v->vg_p->coord, 1.0/1000.0);
+		    VSCALE((*tribuf[vert_count]).v, v->vg_p->coord,
+			1.0 / ADRT_MODEL_UNITS_PER_TIE_UNIT);
 		    vert_count++;
 		}
 		if (vert_count > 3)
@@ -248,9 +287,12 @@ load_nmg_to_adrt_regstart(struct db_tree_state *ts, const struct db_full_path *p
 
 	for (i=0;i<bot->num_faces;i++)
 	{
-	    VSCALE((*tribuf[0]).v, (bot->vertices+3*bot->faces[3*i+0]), 1.0/1000.0);
-	    VSCALE((*tribuf[1]).v, (bot->vertices+3*bot->faces[3*i+1]), 1.0/1000.0);
-	    VSCALE((*tribuf[2]).v, (bot->vertices+3*bot->faces[3*i+2]), 1.0/1000.0);
+	    VSCALE((*tribuf[0]).v, (bot->vertices+3*bot->faces[3*i+0]),
+		1.0 / ADRT_MODEL_UNITS_PER_TIE_UNIT);
+	    VSCALE((*tribuf[1]).v, (bot->vertices+3*bot->faces[3*i+1]),
+		1.0 / ADRT_MODEL_UNITS_PER_TIE_UNIT);
+	    VSCALE((*tribuf[2]).v, (bot->vertices+3*bot->faces[3*i+2]),
+		1.0 / ADRT_MODEL_UNITS_PER_TIE_UNIT);
 
 	    TIE_VAL(tie_push)(cur_tie, tribuf, 1, mesh, 0);
 	}
@@ -298,11 +340,16 @@ load_nmg_to_adrt_gcvwrite(struct nmgregion *r, const struct db_full_path *pathp,
 
 
 int
-load_g(struct tie_s *tie, const char *db, int argc, const char **argv, struct adrt_mesh_s **meshes)
+load_g_annotations(struct tie_s *tie, const char *db, int argc,
+	const char **argv, struct adrt_mesh_s **meshes,
+	struct rt_annot_scene **annotations)
 {
     struct model *the_model;
     struct bg_tess_tol ttol;		/* tessellation tolerance in mm */
     struct db_tree_state tree_state;	/* includes tol & model */
+    const char **geometry_paths = NULL;
+    int geometry_count = 0;
+    int walk_result = 0;
 
     cur_tie = tie;	/* NOTE: cur_tie is a file-scope global; this is not
 			 * reentrant and would need locking to be thread-safe. */
@@ -338,13 +385,21 @@ load_g(struct tie_s *tie, const char *db, int argc, const char **argv, struct ad
     if ((dbip = db_open(db, DB_OPEN_READONLY)) == DBI_NULL) {
 	perror(db);
 	bu_log("Unable to open geometry database file (%s)\n", db);
+	nmg_km(the_model);
 	return -1;
     }
     if (db_dirbuild(dbip)) {
 	bu_log("ERROR: db_dirbuild failed\n");
+	db_close(dbip);
+	dbip = DBI_NULL;
+	nmg_km(the_model);
 	return -1;
     }
 
+    if (annotations) {
+	*annotations = rt_annot_scene_create(dbip, argc, argv, &ttol, &tol);
+    }
+
     BN_CK_TOL(tree_state.ts_tol);
     BG_CK_TESS_TOL(tree_state.ts_ttol);
 
@@ -362,15 +417,26 @@ load_g(struct tie_s *tie, const char *db, int argc, const char **argv, struct ad
     tribuf[1] = (TIE_3 *)bu_malloc(sizeof(TIE_3) * 3, "triangle tribuffer");
     tribuf[2] = (TIE_3 *)bu_malloc(sizeof(TIE_3) * 3, "triangle tribuffer");
 
-    (void) db_walk_tree(dbip,
-			argc,			/* number of toplevel regions */
-			argv,			/* region names */
+    if (argc > 0) {
+	geometry_paths = (const char **)bu_calloc((size_t)argc,
+	    sizeof(const char *), "ADRT geometry paths");
+	for (int i = 0; i < argc; ++i) {
+	    if (adrt_path_has_geometry(dbip, argv[i]))
+		geometry_paths[geometry_count++] = argv[i];
+	}
+    }
+
+    if (geometry_count) {
+	walk_result = db_walk_tree(dbip,
+			geometry_count,		/* number of toplevel regions */
+			geometry_paths,		/* region names */
 			1,			/* ncpu */
 			&tree_state,		/* initial tree state */
 			load_nmg_to_adrt_regstart,	/* region start function */
 			gcv_region_end,		/* region end function */
-			rt_booltree_leaf_tess,	/* leaf func */
+			adrt_leaf_tess,		/* leaf func */
 			(void *)&gcvwriter);	/* client data */
+    }
 
     /* Release dynamic storage */
     nmg_km(the_model);
@@ -380,10 +446,20 @@ load_g(struct tie_s *tie, const char *db, int argc, const char **argv, struct ad
     bu_free(tribuf[1], "vert");
     bu_free(tribuf[2], "vert");
     bu_free(tribuf, "tri");
+    if (geometry_paths)
+	bu_free(geometry_paths, "ADRT geometry paths");
 
     TIE_VAL(tie_prep)(cur_tie);
 
-    return 0;
+    return walk_result;
+}
+
+
+int
+load_g(struct tie_s *tie, const char *db, int argc, const char **argv,
+	struct adrt_mesh_s **meshes)
+{
+    return load_g_annotations(tie, db, argc, argv, meshes, NULL);
 }
 
 /*

src/adrt/load_g.h

@@ -0,0 +1,43 @@
+/*                      L O A D _ G . H
+ * BRL-CAD / ADRT
+ *
+ * Copyright (c) 2026 United States Government as represented by
+ * the U.S. Army Research Laboratory.
+ *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ */
+
+#ifndef ADRT_LOAD_G_H
+#define ADRT_LOAD_G_H
+
+#include "common.h"
+
+#include "adrt.h"
+
+struct db_i;
+struct db_tree_state;
+struct db_full_path;
+struct rt_db_internal;
+union tree;
+
+__BEGIN_DECLS
+
+RENDER_EXPORT extern int adrt_path_has_geometry(struct db_i *dbip,
+	const char *path);
+RENDER_EXPORT extern union tree *adrt_leaf_tess(struct db_tree_state *tsp,
+	const struct db_full_path *pathp, struct rt_db_internal *ip,
+	void *client_data);
+
+__END_DECLS
+
+#endif /* ADRT_LOAD_G_H */
+
+/*
+ * Local Variables:
+ * tab-width: 8
+ * mode: C
+ * indent-tabs-mode: t
+ * c-file-style: "stroustrup"
+ * End:
+ * ex: shiftwidth=4 tabstop=8
+ */

src/adrt/tests/CMakeLists.txt

@@ -0,0 +1,16 @@
+brlcad_addexec(adrt_annotation_test annotation.c
+  "librender;libwdb;librt;libbu;${M_LIBRARY}" TEST)
+target_include_directories(adrt_annotation_test PRIVATE
+  ${BRLCAD_SOURCE_DIR}/src/adrt
+  ${BRLCAD_SOURCE_DIR}/src/adrt/librender
+)
+brlcad_add_test(NAME adrt_annotation_test COMMAND adrt_annotation_test)
+
+cmakefiles(annotation.c CMakeLists.txt)
+
+# Local Variables:
+# tab-width: 8
+# mode: cmake
+# indent-tabs-mode: t
+# End:
+# ex: shiftwidth=2 tabstop=8

src/adrt/tests/annotation.c

@@ -0,0 +1,179 @@
+/*                 A N N O T A T I O N . C
+ * BRL-CAD
+ *
+ * Copyright (c) 2026 United States Government as represented by
+ * the U.S. Army Research Laboratory.
+ *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ */
+
+#include "common.h"
+
+#include <math.h>
+#include <stdio.h>
+
+#include "bu/app.h"
+#include "bu/file.h"
+#include "raytrace.h"
+#include "rt/primitives/annot.h"
+#include "wdb.h"
+
+#include "load_g.h"
+#include "librender/camera.h"
+
+
+static void
+write_test_database(struct db_i *dbip)
+{
+    struct rt_wdb *wdbp = wdb_dbopen(dbip, RT_WDB_TYPE_DB_DISK);
+    struct rt_annot_internal annot = {0};
+    point2d_t vertices[2];
+    struct line_seg line = {0};
+    void *segments[1];
+    int reverse[1] = {0};
+    point_t center = VINIT_ZERO;
+    struct wmember members;
+
+    if (wdbp == RT_WDB_NULL)
+	bu_exit(1, "unable to open ADRT annotation test database\n");
+    annot.magic = RT_ANNOT_INTERNAL_MAGIC;
+    VSET(annot.V, 10.0, 0.0, 0.0);
+    annot.flags = RT_ANNOT_MODEL_SPACE;
+    VSET(annot.u_vec, 0.0, 1.0, 0.0);
+    VSET(annot.v_vec, 0.0, 0.0, 1.0);
+    annot.vert_count = 2;
+    annot.verts = vertices;
+    V2SET(vertices[0], -1.0, 0.0);
+    V2SET(vertices[1], 1.0, 0.0);
+    annot.ant.count = 1;
+    annot.ant.reverse = reverse;
+    annot.ant.segments = segments;
+    line.magic = CURVE_LSEG_MAGIC;
+    line.start = 0;
+    line.end = 1;
+    segments[0] = &line;
+    if (rt_annot_validate(&annot, NULL) ||
+	    mk_annot(wdbp, "test.annot", &annot) < 0 ||
+	    mk_sph(wdbp, "test.sph", center, 1.0) < 0)
+	bu_exit(1, "unable to write ADRT annotation test objects\n");
+
+    BU_LIST_INIT(&members.l);
+    if (!mk_addmember("test.annot", &members.l, NULL, WMOP_UNION) ||
+	    mk_lcomb(wdbp, "annotation-only.c", &members, 0, NULL, NULL,
+		NULL, 0))
+	bu_exit(1, "unable to write annotation-only test combination\n");
+
+    BU_LIST_INIT(&members.l);
+    if (!mk_addmember("test.annot", &members.l, NULL, WMOP_UNION) ||
+	    !mk_addmember("test.sph", &members.l, NULL, WMOP_UNION) ||
+	    mk_lcomb(wdbp, "mixed.c", &members, 0, NULL, NULL, NULL, 0))
+	bu_exit(1, "unable to write mixed test combination\n");
+}
+
+
+static void
+check_geometry_filter(struct db_i *dbip)
+{
+    struct rt_db_internal intern;
+    union tree *leaf;
+
+    if (adrt_path_has_geometry(dbip, "test.annot") ||
+	    adrt_path_has_geometry(dbip, "annotation-only.c") ||
+	    !adrt_path_has_geometry(dbip, "test.sph") ||
+	    !adrt_path_has_geometry(dbip, "mixed.c"))
+	bu_exit(1, "ADRT annotation geometry filtering failed\n");
+
+    RT_DB_INTERNAL_INIT(&intern);
+    intern.idb_type = ID_ANNOT;
+    leaf = adrt_leaf_tess(NULL, NULL, &intern, NULL);
+    if (!leaf || leaf->tr_op != OP_NOP)
+	bu_exit(1, "ADRT annotation leaf did not become a no-op\n");
+    db_free_tree(leaf);
+}
+
+
+static void
+check_camera_fit(struct db_i *dbip)
+{
+    const char *paths[] = {"test.annot"};
+    struct bg_tess_tol ttol = BG_TESS_TOL_INIT_TOL;
+    struct bn_tol tol = BN_TOL_INIT_TOL;
+    struct rt_annot_scene *scene = rt_annot_scene_create(dbip, 1, paths,
+	&ttol, &tol);
+    render_camera_t camera = {0};
+    struct tie_s tie = {0};
+    fastf_t radius;
+    const fastf_t combined_radius = 0.5 * sqrt(41.0);
+
+    if (!scene || rt_annot_scene_count(scene) != 1)
+	bu_exit(1, "unable to prepare ADRT annotation test scene\n");
+    tie.radius = 2.0;
+    VSET(tie.mid, 1.0, 2.0, 3.0);
+    radius = render_camera_fit_scene(&camera, &tie, NULL, 1.0);
+    if (!NEAR_EQUAL(radius, 2.0, BN_TOL_DIST) ||
+	    !VNEAR_EQUAL(camera.focus, tie.mid, BN_TOL_DIST) ||
+	    !NEAR_EQUAL(camera.pos[X], 2.0, BN_TOL_DIST) ||
+	    !NEAR_EQUAL(camera.pos[Y], 2.0, BN_TOL_DIST) ||
+	    !NEAR_EQUAL(camera.pos[Z], 2.0, BN_TOL_DIST))
+	bu_exit(1, "ADRT geometry-only camera framing changed\n");
+
+    radius = render_camera_fit_scene(&camera, &tie, scene, 10.0);
+    if (radius <= SMALL_FASTF ||
+	    !NEAR_EQUAL(camera.focus[X], 1.0, BN_TOL_DIST) ||
+	    !NEAR_ZERO(camera.focus[Y], BN_TOL_DIST) ||
+	    !NEAR_ZERO(camera.focus[Z], BN_TOL_DIST) ||
+	    !NEAR_EQUAL(camera.pos[X] - camera.focus[X], radius, BN_TOL_DIST) ||
+	    !NEAR_EQUAL(camera.pos[Y] - camera.focus[Y], radius, BN_TOL_DIST) ||
+	    !NEAR_EQUAL(camera.pos[Z] - camera.focus[Z], radius, BN_TOL_DIST))
+	bu_exit(1, "ADRT annotation-only camera framing failed: radius=%g "
+	    "focus=(%g %g %g) pos=(%g %g %g)\n", radius,
+	    V3ARGS(camera.focus), V3ARGS(camera.pos));
+
+    tie.tri_num = 1;
+    VSET(tie.amin, -2.0, -2.0, -2.0);
+    VSET(tie.amax, 0.0, 2.0, 2.0);
+    radius = render_camera_fit_scene(&camera, &tie, scene, 10.0);
+    if (!NEAR_EQUAL(radius, combined_radius, BN_TOL_DIST) ||
+	    !NEAR_EQUAL(camera.focus[X], -0.5, BN_TOL_DIST) ||
+	    !NEAR_ZERO(camera.focus[Y], BN_TOL_DIST) ||
+	    !NEAR_ZERO(camera.focus[Z], BN_TOL_DIST))
+	bu_exit(1, "ADRT combined geometry and annotation framing failed\n");
+    rt_annot_scene_destroy(scene);
+}
+
+
+int
+main(int argc, char **argv)
+{
+    char path[MAXPATHLEN];
+    struct db_i *dbip;
+
+    bu_setprogname(argv[0]);
+    if (argc != 1)
+	return 1;
+    {
+	FILE *fp = bu_temp_file(path, MAXPATHLEN);
+	if (!fp)
+	    bu_exit(1, "unable to create ADRT annotation test path\n");
+	fclose(fp);
+    }
+    dbip = db_create(path, 5);
+    if (dbip == DBI_NULL)
+	bu_exit(1, "unable to create ADRT annotation test database\n");
+    write_test_database(dbip);
+    check_geometry_filter(dbip);
+    check_camera_fit(dbip);
+    db_close(dbip);
+    bu_file_delete(path);
+    return 0;
+}
+
+/*
+ * Local Variables:
+ * tab-width: 8
+ * mode: C
+ * indent-tabs-mode: t
+ * c-file-style: "stroustrup"
+ * End:
+ * ex: shiftwidth=4 tabstop=8
+ */

src/art/tile.cpp

@@ -64,16 +64,17 @@ ArtTileCallback::on_tile_end(const renderer::Frame* frame, const size_t tile_x,
 {
     foundation::Tile& t = frame->image().tile(tile_x, tile_y);
     const foundation::Tile rgb(t, PixelFormatUInt8);
+    const foundation::CanvasProperties& properties = frame->image().properties();
     // fb_write(fbp, tile_x, tile_y, rgb.get_storage(), rgb.get_size());
     // printf("yay!\n");
     // printf("%lu %lu \n", tile_x, tile_y);
     // printf("%lu %lu \n", rgb.get_width(), rgb.get_height());
     for (size_t y = 0; y < rgb.get_height(); y++) {
 	for (size_t x = 0; x < rgb.get_width(); x++) {
-	    size_t x_coord = tile_x * rgb.get_width() + x;
-	    size_t y_coord = tile_y * rgb.get_height() + y;
-	    size_t img_h = frame->image().properties().m_canvas_height;
-	    fb_write(fbp, (int)x_coord, (int)(img_h - y_coord), rgb.get_storage()+((y * rgb.get_width() * 4) + (x * 4)), 1);
+	    size_t x_coord = tile_x * properties.m_tile_width + x;
+	    size_t y_coord = tile_y * properties.m_tile_height + y;
+	    size_t img_h = properties.m_canvas_height;
+	    fb_write(fbp, (int)x_coord, (int)(img_h - y_coord - 1), rgb.get_storage()+((y * rgb.get_width() * 4) + (x * 4)), 1);
 	}
     }
 }

src/isst/CMakeLists.txt

@@ -42,7 +42,6 @@ if(BRLCAD_ENABLE_QT AND OPENGL_TARGETS)
       Qt6::Widgets
       Qt6::OpenGL
       Qt6::OpenGLWidgets
-      ${OPENGL_TARGETS}
     )
   else(Qt6Widgets_FOUND)
     qt5_wrap_cpp(moc_srcs ${isst_headers})

src/isst/gfile.cpp

@@ -26,6 +26,7 @@
 #include <QFile>
 #include <QPlainTextEdit>
 #include <QTextStream>
+#include <vector>
 #include "gfile.h"
 
 #include "bu/malloc.h"
@@ -33,6 +34,7 @@
 #include "gcv.h"
 #include "nmg.h"
 #include "rt/geom.h"
+#include "load_g.h"
 
 /* Replace the load_g globals from adrt with a struct that is
  * passed through the callers. */
@@ -102,7 +104,8 @@ nmg_to_adrt_internal(TIE_3 **tribuf, struct tie_s *cur_tie, struct adrt_mesh_s *
 		    NMG_CK_VERTEX(v);
 
 		    /* convert mm to m */
-		    VSCALE((*tribuf[vert_count]).v, v->vg_p->coord, 1.0/1000.0);
+		    VSCALE((*tribuf[vert_count]).v, v->vg_p->coord,
+			1.0 / ADRT_MODEL_UNITS_PER_TIE_UNIT);
 		    vert_count++;
 		}
 		if (vert_count > 3)
@@ -185,9 +188,12 @@ nmg_to_adrt_regstart(struct db_tree_state *ts, const struct db_full_path *path,
 
 	for (i=0;i<bot->num_faces;i++)
 	{
-	    VSCALE((*d->tribuf[0]).v, (bot->vertices+3*bot->faces[3*i+0]), 1.0/1000.0);
-	    VSCALE((*d->tribuf[1]).v, (bot->vertices+3*bot->faces[3*i+1]), 1.0/1000.0);
-	    VSCALE((*d->tribuf[2]).v, (bot->vertices+3*bot->faces[3*i+2]), 1.0/1000.0);
+	    VSCALE((*d->tribuf[0]).v, (bot->vertices+3*bot->faces[3*i+0]),
+		1.0 / ADRT_MODEL_UNITS_PER_TIE_UNIT);
+	    VSCALE((*d->tribuf[1]).v, (bot->vertices+3*bot->faces[3*i+1]),
+		1.0 / ADRT_MODEL_UNITS_PER_TIE_UNIT);
+	    VSCALE((*d->tribuf[2]).v, (bot->vertices+3*bot->faces[3*i+2]),
+		1.0 / ADRT_MODEL_UNITS_PER_TIE_UNIT);
 
 	    TIE_VAL(tie_push)(d->cur_tie, d->tribuf, 1, mesh, 0);
 	}
@@ -233,6 +239,13 @@ nmg_to_adrt_gcvwrite(struct nmgregion *r, const struct db_full_path *pathp, stru
     nmg_to_adrt_internal(d->tribuf, d->cur_tie, mesh, r);
 }
 
+
+GFile::~GFile()
+{
+    closedb();
+}
+
+
 int
 GFile::load_g(const char *filename, int argc, const char *argv[])
 {
@@ -241,6 +254,9 @@ GFile::load_g(const char *filename, int argc, const char *argv[])
     struct bg_tess_tol ttol;		/* tessellation tolerance in mm */
     struct db_tree_state tree_state;	/* includes tol & model */
     struct isst_nmg_data d;
+    std::vector<const char *> geometry_paths;
+
+    closedb();
 
     RT_DBTS_INIT(&tree_state);
     tree_state.ts_tol = &tol;
@@ -278,6 +294,8 @@ GFile::load_g(const char *filename, int argc, const char *argv[])
     }
     if (db_dirbuild(dbip)) {
 	bu_log("ERROR: db_dirbuild failed\n");
+	db_close(dbip);
+	dbip = NULL;
 	return -1;
     }
     d.dbip = dbip;
@@ -304,20 +322,30 @@ GFile::load_g(const char *filename, int argc, const char *argv[])
     tribuf[2] = (TIE_3 *)bu_malloc(sizeof(TIE_3) * 3, "triangle tribuffer");
     d.tribuf = this->tribuf;
 
-    (void) db_walk_tree(dbip,
-			argc,			/* number of toplevel regions */
-			argv,			/* region names */
-			1,			/* ncpu */
-			&tree_state,		/* initial tree state */
-			nmg_to_adrt_regstart,	/* region start function */
-			gcv_region_end,		/* region end function */
-			rt_booltree_leaf_tess,	/* leaf func */
-			(void *)&gcvwriter);	/* client data */
+    annotations = rt_annot_scene_create(dbip, argc, argv, &ttol, &tol);
+
+    for (int i = 0; i < argc; ++i) {
+	if (adrt_path_has_geometry(dbip, argv[i]))
+	    geometry_paths.push_back(argv[i]);
+    }
+
+    if (!geometry_paths.empty()) {
+	(void) db_walk_tree(dbip,
+		(int)geometry_paths.size(), /* number of toplevel regions */
+		geometry_paths.data(),	/* region names */
+		1,			/* ncpu */
+		&tree_state,		/* initial tree state */
+		nmg_to_adrt_regstart,	/* region start function */
+		gcv_region_end,		/* region end function */
+		adrt_leaf_tess,		/* leaf func */
+		(void *)&gcvwriter);	/* client data */
+    }
 
     /* Release dynamic storage */
     nmg_km(the_model);
     rt_vlist_cleanup();
     db_close(dbip);
+    dbip = NULL;
     bu_free(tribuf[0], "vert");
     bu_free(tribuf[1], "vert");
     bu_free(tribuf[2], "vert");
@@ -331,7 +359,17 @@ GFile::load_g(const char *filename, int argc, const char *argv[])
 void
 GFile::closedb()
 {
-    bu_free(tie, "free tie");
+    rt_annot_scene_destroy(annotations);
+    annotations = NULL;
+    if (tie) {
+	TIE_FREE(tie);
+	bu_free(tie, "free tie");
+	tie = NULL;
+    }
+    if (dbip) {
+	db_close(dbip);
+	dbip = NULL;
+    }
     current_file.clear();
 }
 
@@ -345,4 +383,3 @@ GFile::closedb()
  * End:
  * ex: shiftwidth=4 tabstop=8
  */
-

src/isst/gfile.h

@@ -32,6 +32,7 @@
 extern "C" {
 #include "bn/tol.h"
 #include "raytrace.h"
+#include "rt/primitives/annot.h"
 
 #include "rt/tie.h"
 #include "adrt.h"
@@ -43,13 +44,16 @@ class GFile : public QObject
     Q_OBJECT
 
     public:
+	~GFile() override;
+
 	int load_g(const char *filename, int argc, const char **argv);
 	void closedb();
 
-	struct tie_s *tie;
-	struct adrt_mesh_s *meshes;
-	struct db_i *dbip;
-	TIE_3 **tribuf;
+	struct tie_s *tie = NULL;
+	struct adrt_mesh_s *meshes = NULL;
+	struct db_i *dbip = NULL;
+	struct rt_annot_scene *annotations = NULL;
+	TIE_3 **tribuf = NULL;
 
 	QString current_file;
 };
@@ -66,4 +70,3 @@ class GFile : public QObject
  * End:
  * ex: shiftwidth=4 tabstop=8
  */
-

src/isst/isstapp.cpp

@@ -28,6 +28,9 @@
 int
 ISSTApp::load_g(const char *filename, int argc, const char *argv[])
 {
+    /* Synchronize with the render thread before GFile releases the old
+     * annotation scene and TIE data. */
+    w.canvas->clear_tie();
     if (g.load_g(filename, argc, argv)) {
 	w.statusBar()->showMessage("open failed");
 	return -1;
@@ -35,7 +38,7 @@ ISSTApp::load_g(const char *filename, int argc, const char *argv[])
 
     // The OpenGL widget manages the rendering, so let it know about the
     // TIE data structure associated with the current model
-    w.canvas->set_tie(g.tie);
+    w.canvas->set_tie(g.tie, g.annotations);
 
     return 0;
 }
@@ -51,4 +54,3 @@ ISSTApp::load_g(const char *filename, int argc, const char *argv[])
  * End:
  * ex: shiftwidth=4 tabstop=8
  */
-

src/isst/isstapp.h

@@ -36,16 +36,14 @@
 
 class ISSTApp : public QApplication
 {
-    Q_OBJECT
-
     public:
 	ISSTApp(int &argc, char *argv[]) :QApplication(argc, argv) {};
 	~ISSTApp() {};
 
 	int load_g(const char *filename, int argc, const char **argv);
 
-	ISST_MainWindow w;
 	GFile g;
+	ISST_MainWindow w;
 };
 
 #endif // ISSTAPP_H
@@ -60,4 +58,3 @@ class ISSTApp : public QApplication
  * End:
  * ex: shiftwidth=4 tabstop=8
  */
-

src/isst/isstgl.cpp

@@ -159,8 +159,13 @@ void TIERenderer::render()
     m_grabCond.wait(&m_grabMutex);
     QMutexLocker lock(&m_renderMutex);
     m_grabMutex.unlock();
-    if (m_exiting)
+
+    /* The GUI may clear a scene while a queued render is waiting for the
+     * context.  Return the context before leaving that stale request. */
+    if (m_exiting || !tie) {
+	ctx->moveToThread(qGuiApp->thread());
 	return;
+    }
     Q_ASSERT(ctx->thread() == QThread::currentThread());
 
 
@@ -183,7 +188,8 @@ void TIERenderer::render()
 
     // Core TIE render
     render_camera_prep(&camera);
-    render_camera_render(&camera, tie, &tile, &buffer_image);
+    render_camera_render_annotations(&camera, tie, &tile, &buffer_image,
+	annotations, ADRT_MODEL_UNITS_PER_TIE_UNIT);
 
     glDisable(GL_LIGHTING);
 
@@ -297,17 +303,31 @@ void isstGL::grabContext()
 }
 
 void
-isstGL::set_tie(struct tie_s *in_tie)
+isstGL::clear_tie()
 {
-    m_renderer->tie = in_tie;
+    m_renderer->lockRenderer();
+    m_renderer->tie = NULL;
+    m_renderer->annotations = NULL;
+    m_renderer->changed = false;
+    m_renderer->unlockRenderer();
+}
 
-    // Initialize the camera position
-    VSETALL(m_renderer->camera.pos, m_renderer->tie->radius);
-    VMOVE(m_renderer->camera.focus, m_renderer->tie->mid);
+
+void
+isstGL::set_tie(struct tie_s *in_tie, struct rt_annot_scene *annotations)
+{
+    m_renderer->lockRenderer();
+    m_renderer->tie = in_tie;
+    m_renderer->annotations = annotations;
+
+    render_camera_fit_scene(&m_renderer->camera, m_renderer->tie, annotations,
+	ADRT_MODEL_UNITS_PER_TIE_UNIT);
 
     // Record the initial settings for use in subsequent calculations
-    VSETALL(m_renderer->camera_pos_init, m_renderer->tie->radius);
-    VMOVE(m_renderer->camera_focus_init, m_renderer->tie->mid);
+    VMOVE(m_renderer->camera_pos_init, m_renderer->camera.pos);
+    VMOVE(m_renderer->camera_focus_init, m_renderer->camera.focus);
+    m_renderer->changed = true;
+    m_renderer->unlockRenderer();
 
     // Having just loaded a new TIE scene,
     // we need a new image
@@ -369,4 +389,3 @@ void isstGL::save_image() {
 // c-file-style: "stroustrup"
 // End:
 // ex: shiftwidth=4 tabstop=8
-

src/isst/isstgl.h

@@ -77,6 +77,7 @@ class TIERenderer : public QObject, protected QOpenGLFunctions
 
     public:
 	struct tie_s *tie = NULL; // From parent app
+	struct rt_annot_scene *annotations = NULL; // Owned by the parent app
 	struct render_camera_s camera;
 	vect_t camera_pos_init;
 	vect_t camera_focus_init;
@@ -113,7 +114,8 @@ class isstGL : public QOpenGLWidget
 	explicit isstGL(QWidget *parent = nullptr);
 	~isstGL();
 
-	void set_tie(struct tie_s *in_tie);
+	void clear_tie();
+	void set_tie(struct tie_s *in_tie, struct rt_annot_scene *annotations);
 
 	void save_image();
 
@@ -153,4 +155,3 @@ class isstGL : public QOpenGLWidget
 // c-file-style: "stroustrup"
 // End:
 // ex: shiftwidth=4 tabstop=8
-

src/libanalyze/nirt/nirt.cpp

@@ -480,6 +480,22 @@ _nirt_get_resource(struct nirt_state *nss)
 }
 
 
+static void
+_nirt_annotation_result_clear(struct nirt_state *nss)
+{
+    delete nss->i->vals->annotation;
+    nss->i->vals->annotation = NULL;
+}
+
+
+static void
+_nirt_annotation_scene_clear(struct nirt_state *nss)
+{
+    rt_annot_scene_destroy(nss->i->annotation_scene);
+    nss->i->annotation_scene = NULL;
+}
+
+
 int
 _nirt_raytrace_prep(struct nirt_state *nss)
 {
@@ -517,11 +533,17 @@ _nirt_raytrace_prep(struct nirt_state *nss)
 	bu_free(attrs, "objs");
 	return -1;
     }
-    bu_free(objs, "objs");
     bu_free(attrs, "objs");
 
     nmsg(nss, "Prepping the geometry...\n");
     rt_prep(nss->i->ap->a_rt_i);
+    _nirt_annotation_scene_clear(nss);
+    if (nss->i->use_annotations) {
+	nss->i->annotation_scene = rt_annot_scene_create(nss->i->dbip,
+	    ocnt, objs, &nss->i->ap->a_rt_i->rti_ttol,
+	    &nss->i->ap->a_rt_i->rti_tol);
+    }
+    bu_free(objs, "objs");
     nmsg(nss, "%s ", (nss->i->active_paths.size() == 1) ? "Object" : "Objects");
     for (size_t i = 0; i < nss->i->active_paths.size(); i++) {
 	if (i == 0) {
@@ -960,6 +982,17 @@ _nirt_print_fmt_substr(struct nirt_state *nss, struct bu_vls *ostr, const char *
     nirt_print_key("a", r->a);
     nirt_print_key("e", r->e);
 
+    if (r->annotation) {
+	nirt_print_key("annot_path", r->annotation->path.c_str());
+	nirt_print_key("annot_segment", r->annotation->segment);
+	nirt_print_key("annot_role", r->annotation->role.c_str());
+	nirt_print_key("annot_x", r->annotation->point[X] * base2local);
+	nirt_print_key("annot_y", r->annotation->point[Y] * base2local);
+	nirt_print_key("annot_z", r->annotation->point[Z] * base2local);
+	nirt_print_key("annot_d", r->annotation->d * base2local);
+	nirt_print_key("annot_visible", r->annotation->visible);
+    }
+
     if (!r->seg || r->seg->type == 0) return;
 
     if (r->seg->type == NIRT_PARTITION_SEG || r->seg->type == NIRT_ALL_SEG) {
@@ -1056,6 +1089,9 @@ _nirt_report(struct nirt_state *nss, char type, struct nirt_output_record *r)
     std::vector<std::pair<std::string,std::string> >::iterator f_it;
 
     switch (type) {
+	case 'a':
+	    fmt_vect = &nss->i->fmt.annotation;
+	    break;
 	case 'r':
 	    fmt_vect = &nss->i->fmt.ray;
 	    break;
@@ -1091,6 +1127,75 @@ _nirt_report(struct nirt_state *nss, char type, struct nirt_output_record *r)
 }
 
 
+static const char *
+_nirt_annotation_role(uint32_t role)
+{
+    switch (role) {
+	case RT_ANNOT_ROLE_UNSPECIFIED:
+	    return "unspecified";
+	case RT_ANNOT_ROLE_GEOMETRY:
+	    return "geometry";
+	case RT_ANNOT_ROLE_TEXT:
+	    return "text";
+	case RT_ANNOT_ROLE_LEADER:
+	    return "leader";
+	case RT_ANNOT_ROLE_EXTENSION:
+	    return "extension";
+	case RT_ANNOT_ROLE_DIMENSION:
+	    return "dimension";
+	case RT_ANNOT_ROLE_ARROWHEAD:
+	    return "arrowhead";
+	case RT_ANNOT_ROLE_SYMBOL:
+	    return "symbol";
+	case RT_ANNOT_ROLE_MASK:
+	    return "mask";
+	case RT_ANNOT_ROLE_CENTERMARK:
+	    return "centermark";
+	case RT_ANNOT_ROLE_PLACEHOLDER:
+	    return "placeholder";
+	case RT_ANNOT_ROLE_TEXT_DECORATION:
+	    return "text-decoration";
+	default:
+	    return "unknown";
+    }
+}
+
+
+static void
+_nirt_report_annotations(struct nirt_state *nss)
+{
+    const size_t count = rt_annot_scene_query_model(nss->i->annotation_scene,
+	&nss->i->ap->a_ray, nss->i->first_solid_distance, NULL, 0);
+    if (!count)
+	return;
+
+    std::vector<struct rt_annot_hit> hits(count);
+    const size_t found = rt_annot_scene_query_model(nss->i->annotation_scene,
+	&nss->i->ap->a_ray, nss->i->first_solid_distance, hits.data(),
+	hits.size());
+    nirt_seg *saved_segment = nss->i->vals->seg;
+    nss->i->vals->seg = NULL;
+    for (size_t i = 0; i < std::min(found, hits.size()); ++i) {
+	const struct rt_annot_hit &hit = hits[i];
+	if (hit.segment > (size_t)std::numeric_limits<int>::max()) {
+	    nerr(nss, "Annotation segment index is too large for NIRT reporting\n");
+	    continue;
+	}
+	if (!nss->i->vals->annotation)
+	    nss->i->vals->annotation = new nirt_annotation_record;
+	nirt_annotation_record *record = nss->i->vals->annotation;
+	record->path = hit.path ? hit.path : "";
+	record->segment = (int)hit.segment;
+	record->role = _nirt_annotation_role(hit.role);
+	VMOVE(record->point, hit.point);
+	record->d = d_calc(nss, record->point);
+	record->visible = hit.visible;
+	_nirt_report(nss, 'a', nss->i->vals);
+    }
+    nss->i->vals->seg = saved_segment;
+}
+
+
 /************************
  * Raytracing Callbacks *
  ************************/
@@ -1213,6 +1318,21 @@ _nirt_if_hit(struct application *ap, struct partition *part_head, struct seg *UN
     int ev_odd = 1; /* first partition is colored as "odd" */
     point_t out_old = VINIT_ZERO;
     double d_out_old = 0.0;
+
+    nss->i->first_solid_distance = INFINITY;
+    for (part = part_head->pt_forw; part != part_head; part = part->pt_forw) {
+	if (part->pt_regionp->reg_aircode)
+	    continue;
+	if (part->pt_inhit->hit_dist >= 0.0) {
+	    nss->i->first_solid_distance = part->pt_inhit->hit_dist;
+	    break;
+	}
+	if (part->pt_outhit->hit_dist >= 0.0) {
+	    nss->i->first_solid_distance = part->pt_outhit->hit_dist;
+	    break;
+	}
+    }
+
     nirt_seg *s = new nirt_seg;
     if (vals->seg) {
 	delete vals->seg;
@@ -1549,9 +1669,10 @@ static const struct nirt_cmd_desc nirt_descs[] = {
     { "s",              "shoot a ray at the target",                     NULL },
     { "backout",        "back out of model",                             NULL },
     { "useair",         "set/query use of air",                          "<0|1|2|...>" },
+    { "useannot",       "set/query annotation reporting",                "<0|1>" },
     { "units",          "set/query local units",                         "<mm|cm|m|in|ft>" },
     { "overlap_claims", "set/query overlap rebuilding/retention",        "<0|1|2|3>" },
-    { "fmt",            "set/query output formats",                      "{rhpfmog} format item item ..." },
+    { "fmt",            "set/query output formats",                      "{arhpfmog} format item item ..." },
     { "plotfile",       "designate an output file to hold plot data",    "file" },
     { "print",          "query an output item",                          "item" },
     { "debug",          "set/query nirt debug flags",                    "[-h] [-l [lib]] [-C [lib]] [-V [lib] [val]] [lib [flag]]" },
@@ -1828,6 +1949,9 @@ _nirt_cmd_shoot(void *ns, int argc, const char **UNUSED(argv))
 	return -1;
     }
 
+    _nirt_annotation_result_clear(nss);
+    nss->i->first_solid_distance = INFINITY;
+
     /* If we have no active rtip, we don't need to prep or shoot */
     if (!_nirt_get_rtip(nss)) {
 	return 0;
@@ -1860,9 +1984,10 @@ _nirt_cmd_shoot(void *ns, int argc, const char **UNUSED(argv))
 	    nss->i->ap->a_ray.r_pt[2] * nss->i->base2local,
 	    V3ARGS(nss->i->ap->a_ray.r_dir));
 
-    // TODO - any necessary initialization for data collection by callbacks
     _nirt_init_ovlp(nss);
     (void)rt_shootray(nss->i->ap);
+    if (nss->i->use_annotations)
+	_nirt_report_annotations(nss);
 
     // Undo backout
     for (i = 0; i < 3; ++i) {
@@ -1965,6 +2090,45 @@ _nirt_cmd_use_air(void *ns, int argc, const char *argv[])
 }
 
 
+extern "C" int
+_nirt_cmd_use_annotations(void *ns, int argc, const char *argv[])
+{
+    struct nirt_state *nss = (struct nirt_state *)ns;
+    struct bu_vls optparse_msg = BU_VLS_INIT_ZERO;
+    int enabled = 0;
+
+    if (!ns) return -1;
+    if (argc == 1) {
+	nout(nss, "use_annotations = %d\n", nss->i->use_annotations);
+	return 0;
+    }
+    if (argc > 2) {
+	nerr(nss, "Usage:  useannot %s\n", _nirt_get_desc_args("useannot"));
+	return -1;
+    }
+    if (bu_opt_int(&optparse_msg, 1, (const char **)&argv[1],
+	    (void *)&enabled) == -1) {
+	nerr(nss, "Error: bu_opt value read failure: %s\n\nUsage:  useannot %s\n",
+	    bu_vls_cstr(&optparse_msg), _nirt_get_desc_args("useannot"));
+	bu_vls_free(&optparse_msg);
+	return -1;
+    }
+    bu_vls_free(&optparse_msg);
+    if (enabled != 0 && enabled != 1) {
+	nerr(nss, "useannot must be set to 0 (off) or 1 (on)\n");
+	return -1;
+    }
+    if (enabled != nss->i->use_annotations) {
+	nss->i->use_annotations = enabled;
+	_nirt_annotation_scene_clear(nss);
+	_nirt_annotation_result_clear(nss);
+	if (enabled)
+	    nss->i->need_reprep = 1;
+    }
+    return 0;
+}
+
+
 extern "C" int
 _nirt_cmd_units(void *ns, int argc, const char *argv[])
 {
@@ -2085,6 +2249,9 @@ _nirt_cmd_format_output(void *ns, int argc, const char **argv)
 	// print out current fmt str for the specified type
 	struct bu_vls ostr = BU_VLS_INIT_ZERO;
 	switch (type) {
+	    case 'a':
+		_nirt_print_fmt_str(&ostr, nss->i->fmt.annotation);
+		break;
 	    case 'r':
 		_nirt_print_fmt_str(&ostr, nss->i->fmt.ray);
 		break;
@@ -2191,6 +2358,10 @@ _nirt_cmd_format_output(void *ns, int argc, const char **argv)
 	 * formatting instructions with the new. */
 set_fmt:
 	switch (type) {
+	    case 'a':
+		nss->i->fmt.annotation.clear();
+		nss->i->fmt.annotation = fmt_tmp;
+		break;
 	    case 'r':
 		nss->i->fmt.ray.clear();
 		nss->i->fmt.ray = fmt_tmp;
@@ -2543,6 +2714,7 @@ _nirt_cmd_state(void *ns, int argc, const char *argv[])
 	bu_vls_printf(&dumpstr, "xyz %g %g %g\n", V3ARGS(nss->i->vals->orig));
 	bu_vls_printf(&dumpstr, "dir %g %g %g\n", V3ARGS(nss->i->vals->dir));
 	bu_vls_printf(&dumpstr, "useair %d\n", nss->i->use_air);
+	bu_vls_printf(&dumpstr, "useannot %d\n", nss->i->use_annotations);
 	bu_vls_printf(&dumpstr, "units %s\n", bu_units_string(nss->i->local2base));
 	bu_vls_printf(&dumpstr, "overlap_claims ");
 	switch (nss->i->overlap_claims) {
@@ -2563,6 +2735,8 @@ _nirt_cmd_state(void *ns, int argc, const char *argv[])
 		break;
 	}
 	struct bu_vls ostr = BU_VLS_INIT_ZERO;
+	_nirt_print_fmt_cmd(&ostr, 'a', nss->i->fmt.annotation);
+	bu_vls_printf(&dumpstr, "%s", bu_vls_cstr(&ostr));
 	_nirt_print_fmt_cmd(&ostr, 'r', nss->i->fmt.ray);
 	bu_vls_printf(&dumpstr, "%s", bu_vls_cstr(&ostr));
 	_nirt_print_fmt_cmd(&ostr, 'h', nss->i->fmt.head);
@@ -2617,6 +2791,7 @@ const struct bu_cmdtab _libanalyze_nirt_cmds[] = {
     { "state",          _nirt_cmd_state},
     { "units",          _nirt_cmd_units},
     { "useair",         _nirt_cmd_use_air},
+    { "useannot",       _nirt_cmd_use_annotations},
     { "xyz",            _nirt_cmd_target_coor},
     { (char *)NULL,     NULL}
 };
@@ -2783,6 +2958,14 @@ static const char *nirt_cmd_tbl_defs =
 "z_dir,          FNOUNIT,       Ray direction unit vector z component,"
 "a,              FNOUNIT,       Azimuth,"
 "e,              FNOUNIT,       Elevation,"
+"annot_path,     STRING,        Annotation database path,"
+"annot_segment,  INT,           Annotation segment index,"
+"annot_role,     STRING,        Annotation segment role,"
+"annot_x,        FLOAT,         Annotation hit X coordinate,"
+"annot_y,        FLOAT,         Annotation hit Y coordinate,"
+"annot_z,        FLOAT,         Annotation hit Z coordinate,"
+"annot_d,        FLOAT,         Annotation hit gridplane distance,"
+"annot_visible,  INT,           Annotation hit visibility,"
 "x_in,           FLOAT,         ,"
 "y_in,           FLOAT,         ,"
 "z_in,           FLOAT,         ,"
@@ -2895,6 +3078,7 @@ nirt_init(struct nirt_state *ns)
     n->base2local = 0.0;
     n->local2base = 0.0;
     n->use_air = 0;
+    n->use_annotations = 0;
     n->backout = 1;
 
     n->b_state = false;
@@ -2909,6 +3093,8 @@ nirt_init(struct nirt_state *ns)
     BU_GET(n->res_air, struct resource);
     n->rtip = RTI_NULL;
     n->rtip_air = RTI_NULL;
+    n->annotation_scene = NULL;
+    n->first_solid_distance = INFINITY;
     n->need_reprep = 1;
 
     BU_GET(n->val_types, struct bu_attribute_value_set);
@@ -2922,6 +3108,7 @@ nirt_init(struct nirt_state *ns)
     n->vals->h = 0.0;
     n->vals->v = 0.0;
     n->vals->d_orig = 0.0;
+    n->vals->annotation = NULL;
     n->vals->seg = NULL;
 
     _nirt_diff_create(ns);
@@ -3025,6 +3212,8 @@ nirt_clear_dbip(struct nirt_state *ns)
 {
     if (!ns) return -1;
 
+    _nirt_annotation_scene_clear(ns);
+    _nirt_annotation_result_clear(ns);
     db_close(ns->i->dbip);
     ns->i->dbip = NULL;
 
@@ -3045,6 +3234,9 @@ void
 nirt_destroy(struct nirt_state *ns)
 {
     if (!ns) return;
+
+    _nirt_annotation_scene_clear(ns);
+    _nirt_annotation_result_clear(ns);
     bu_vls_free(&ns->nirt_cmd);
     bu_vls_free(ns->i->err);
     bu_vls_free(ns->i->msg);
@@ -3057,6 +3249,7 @@ nirt_destroy(struct nirt_state *ns)
 
     db_close(ns->i->dbip);
 
+    delete ns->i->vals->seg;
     BU_PUT(ns->i->vals, struct nirt_output_record);
 
     BU_PUT(ns->i->res, struct resource);

src/libanalyze/nirt/nirt.h

@@ -83,7 +83,7 @@ extern "C" b_off_t ftello(FILE *);
 #define NIRT_OVLP_RETAIN             3
 
 #define NIRT_PRINTF_SPECIFIERS "difeEgGs"
-#define NIRT_OUTPUT_TYPE_SPECIFIERS "rhpfmog"
+#define NIRT_OUTPUT_TYPE_SPECIFIERS "arhpfmog"
 
 #define HELPFLAG "--print-help"
 #define PURPOSEFLAG "--print-purpose"
@@ -274,6 +274,16 @@ class nirt_seg {
 	}
 };
 
+class nirt_annotation_record {
+    public:
+	std::string path;
+	int segment;
+	std::string role;
+	point_t point;
+	fastf_t d;
+	int visible;
+};
+
 /* This record structure doesn't have to correspond exactly to the above list
  * of available values, but it needs to retain sufficient information to
  * support the ability to generate all of them upon request. */
@@ -286,6 +296,7 @@ struct nirt_output_record {
     fastf_t a;
     fastf_t e;
     struct nirt_overlap ovlp_list;
+    nirt_annotation_record *annotation;
     nirt_seg *seg;
 };
 
@@ -294,6 +305,7 @@ struct nirt_diff_state;
 
 class nirt_fmt_state {
     public:
+	std::vector<std::pair<std::string,std::string> > annotation;
 	std::vector<std::pair<std::string,std::string> > ray;
 	std::vector<std::pair<std::string,std::string> > head;
 	std::vector<std::pair<std::string,std::string> > part;
@@ -303,6 +315,7 @@ class nirt_fmt_state {
 	std::vector<std::pair<std::string,std::string> > gap;
 
 	void clear() {
+	    annotation.clear();
 	    ray.clear();
 	    head.clear();
 	    part.clear();
@@ -347,6 +360,7 @@ struct nirt_state_impl {
     int backout;
     int overlap_claims;
     int use_air;
+    int use_annotations;
     std::set<std::string> attrs;        // active attributes
     std::vector<std::string> active_paths; // active paths for raytracer
     struct nirt_output_record *vals;
@@ -368,6 +382,8 @@ struct nirt_state_impl {
     struct resource *res;
     struct rt_i *rtip_air;
     struct resource *res_air;
+    struct rt_annot_scene *annotation_scene;
+    fastf_t first_solid_distance;
     int need_reprep;
 
     /* internal format specifier arrays */

src/libanalyze/tests/CMakeLists.txt

@@ -1,6 +1,9 @@
 brlcad_addexec(analyze_raydiff raydiff.c "libanalyze;librt;libbu" TEST)
 brlcad_addexec(analyze_sp solid_partitions.c "libanalyze;librt;libbu" TEST)
 brlcad_addexec(analyze_nhit nhit.cpp "libanalyze;librt;libbu" TEST_USESDATA)
+brlcad_addexec(analyze_nirt_annotations nirt_annotations.cpp
+  "libanalyze;libwdb;librt;libbu" TEST_USESDATA)
+brlcad_add_test(NAME analyze_nirt_annotations COMMAND analyze_nirt_annotations)
 
 #####################################
 #      analyze_densities testing    #

src/libanalyze/tests/nirt_annotations.cpp

@@ -0,0 +1,191 @@
+/*              N I R T _ A N N O T A T I O N S . C P P
+ * BRL-CAD
+ *
+ * Copyright (c) 2026 United States Government as represented by the
+ * U.S. Army Research Laboratory.
+ *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ */
+
+#include "common.h"
+
+#include <cstdio>
+#include <cstdlib>
+
+#include "analyze.h"
+#include "bu/app.h"
+#include "bu/file.h"
+#include "bu/malloc.h"
+#include "raytrace.h"
+#include "wdb.h"
+
+
+static constexpr fastf_t FRONT_ANNOTATION_X = 18.0;
+static constexpr fastf_t REAR_ANNOTATION_X = 10.0;
+static constexpr fastf_t SCREEN_ANNOTATION_X = 19.0;
+static constexpr fastf_t OCCLUDER_MINIMUM_X = 15.0;
+static constexpr fastf_t OCCLUDER_MAXIMUM_X = 16.0;
+static constexpr fastf_t RAY_ORIGIN_X = 20.0;
+static constexpr fastf_t TEST_HALF_EXTENT = 1.0;
+
+
+static int
+capture_output(struct nirt_state *state, void *data)
+{
+    struct bu_vls current = BU_VLS_INIT_ZERO;
+    struct bu_vls *captured = (struct bu_vls *)data;
+
+    nirt_log(&current, state, NIRT_OUT);
+    bu_vls_vlscat(captured, &current);
+    bu_vls_free(&current);
+    return 0;
+}
+
+
+static void
+write_annotation(struct rt_wdb *wdbp, const char *name, fastf_t x,
+	bool screen_space)
+{
+    struct rt_annot_internal annotation = {};
+    struct line_seg line = {};
+    struct rt_annot_seg_style style = {};
+    int reverse = 0;
+    void *segment = &line;
+    point2d_t vertices[2] = {{0.0, 0.0}, {TEST_HALF_EXTENT, 0.0}};
+
+    annotation.magic = RT_ANNOT_INTERNAL_MAGIC;
+    VSET(annotation.V, x, 0.0, 0.0);
+    annotation.flags = screen_space ? RT_ANNOT_SCREEN_SPACE :
+	RT_ANNOT_MODEL_SPACE;
+    VSET(annotation.u_vec, 0.0, 1.0, 0.0);
+    VSET(annotation.v_vec, 0.0, 0.0, 1.0);
+    annotation.vert_count = 2;
+    annotation.verts = vertices;
+    annotation.ant.count = 1;
+    annotation.ant.reverse = &reverse;
+    annotation.ant.segments = &segment;
+    annotation.styles = &style;
+
+    line.magic = CURVE_LSEG_MAGIC;
+    line.start = 0;
+    line.end = 1;
+    style.role = RT_ANNOT_ROLE_LEADER;
+    style.line_pattern = RT_ANNOT_LINE_CONTINUOUS;
+
+    if (rt_annot_validate(&annotation, NULL) ||
+	    mk_annot(wdbp, name, &annotation) < 0)
+	bu_exit(EXIT_FAILURE, "unable to write %s\n", name);
+}
+
+
+static void
+clear_standard_formats(struct nirt_state *state)
+{
+    const char *commands[] = {
+	"fmt r \"\"", "fmt h \"\"", "fmt p \"\"", "fmt f \"\"",
+	"fmt m \"\"", "fmt o \"\"", "fmt g \"\""
+    };
+
+    for (size_t i = 0; i < sizeof(commands) / sizeof(commands[0]); ++i)
+	if (nirt_exec(state, commands[i]))
+	    bu_exit(EXIT_FAILURE, "NIRT rejected command: %s\n", commands[i]);
+}
+
+
+static void
+get_output(struct bu_vls *output, struct bu_vls *captured)
+{
+    bu_vls_sprintf(output, "%s", bu_vls_cstr(captured));
+    bu_vls_trunc(captured, 0);
+}
+
+
+int
+main(int argc, char **argv)
+{
+    char path[MAXPATHLEN];
+    struct db_i *dbip;
+    struct rt_wdb *wdbp;
+    struct nirt_state *state;
+    struct bu_vls captured = BU_VLS_INIT_ZERO;
+    struct bu_vls output = BU_VLS_INIT_ZERO;
+    struct wmember members;
+    point_t minimum, maximum;
+
+    bu_setprogname(argv[0]);
+    if (argc != 1)
+	return EXIT_FAILURE;
+    {
+	FILE *fp = bu_temp_file(path, sizeof(path));
+	if (!fp)
+	    bu_exit(EXIT_FAILURE, "unable to create temporary database path\n");
+	fclose(fp);
+    }
+    dbip = db_create(path, 5);
+    if (!dbip)
+	bu_exit(EXIT_FAILURE, "unable to create temporary database\n");
+    wdbp = wdb_dbopen(dbip, RT_WDB_TYPE_DB_DISK);
+    if (!wdbp)
+	bu_exit(EXIT_FAILURE, "unable to open temporary database for writing\n");
+
+    write_annotation(wdbp, "front.annot", FRONT_ANNOTATION_X, false);
+    write_annotation(wdbp, "rear.annot", REAR_ANNOTATION_X, false);
+    write_annotation(wdbp, "screen.annot", SCREEN_ANNOTATION_X, true);
+    VSET(minimum, OCCLUDER_MINIMUM_X, -TEST_HALF_EXTENT,
+	-TEST_HALF_EXTENT);
+    VSET(maximum, OCCLUDER_MAXIMUM_X, TEST_HALF_EXTENT,
+	TEST_HALF_EXTENT);
+    if (mk_rpp(wdbp, "occluder.s", minimum, maximum) < 0)
+	bu_exit(EXIT_FAILURE, "unable to write occluder\n");
+    BU_LIST_INIT(&members.l);
+    if (!mk_addmember("occluder.s", &members.l, NULL, WMOP_UNION) ||
+	    mk_lcomb(wdbp, "occluder.r", &members, 1, NULL, NULL, NULL, 0))
+	bu_exit(EXIT_FAILURE, "unable to write occluding region\n");
+
+    BU_GET(state, struct nirt_state);
+    if (nirt_init(state))
+	bu_exit(EXIT_FAILURE, "unable to initialize NIRT\n");
+    nirt_udata(state, &captured);
+    nirt_hook(state, capture_output, NIRT_OUT);
+    if (nirt_exec(state,
+	    "draw front.annot rear.annot screen.annot occluder.r") ||
+	    nirt_init_dbip(state, dbip))
+	bu_exit(EXIT_FAILURE, "unable to prepare NIRT test database\n");
+    clear_standard_formats(state);
+    if (nirt_exec(state,
+	    "fmt a \"%s|%d|%s|%.1f|%.1f|%d\\n\" annot_path annot_segment annot_role annot_x annot_d annot_visible"))
+	bu_exit(EXIT_FAILURE, "unable to set annotation report format\n");
+    struct bu_vls shot = BU_VLS_INIT_ZERO;
+    bu_vls_sprintf(&shot, "backout 0;xyz %g 0 0;dir -1 0 0;s",
+	RAY_ORIGIN_X);
+    if (nirt_exec(state, bu_vls_cstr(&shot)))
+	bu_exit(EXIT_FAILURE, "unable to shoot default NIRT ray\n");
+    bu_vls_free(&shot);
+    get_output(&output, &captured);
+    if (bu_vls_strlen(&output))
+	bu_exit(EXIT_FAILURE,
+	    "annotations were reported without useannot: %s\n",
+	    bu_vls_cstr(&output));
+
+    if (nirt_exec(state, "useannot 1;s"))
+	bu_exit(EXIT_FAILURE, "unable to shoot annotation NIRT ray\n");
+    get_output(&output, &captured);
+    struct bu_vls expected = BU_VLS_INIT_ZERO;
+    bu_vls_sprintf(&expected,
+	"/front.annot|0|leader|%.1f|%.1f|1\n"
+	"/rear.annot|0|leader|%.1f|%.1f|0\n",
+	FRONT_ANNOTATION_X, FRONT_ANNOTATION_X,
+	REAR_ANNOTATION_X, REAR_ANNOTATION_X);
+    if (!BU_STR_EQUAL(bu_vls_cstr(&output), bu_vls_cstr(&expected)))
+	bu_exit(EXIT_FAILURE, "unexpected annotation report:\n%s",
+	    bu_vls_cstr(&output));
+    bu_vls_free(&expected);
+
+    nirt_destroy(state);
+    BU_PUT(state, struct nirt_state);
+    bu_vls_free(&captured);
+    bu_vls_free(&output);
+    db_close(dbip);
+    bu_file_delete(path);
+    return EXIT_SUCCESS;
+}

src/libbg/RTree.h

@@ -419,7 +419,7 @@ protected:
     ListNode* AllocListNode();
     void FreeListNode(ListNode* a_listNode);
     bool Overlap(Rect* a_rectA, Rect* a_rectB) const;
-    bool Intersect(Rect* a_rect, Ray* a_ray) const;
+    bool Intersect(const Rect* a_rect, const Ray* a_ray) const;
     void ReInsert(Node* a_node, ListNode** a_listNode);
     bool Search(Node* a_node, Rect* a_rect, int& a_foundCount, std::function<bool(const DataType&, void *)> callback, void *a_context) const;
     void RemoveAllRec(Node* a_node);
@@ -433,14 +433,15 @@ protected:
     size_t CheckNodes(Node *a_nodeA, Node *a_nodeB, std::set<DataType> *a_result, std::set<DataType> *b_result);
     size_t CheckNodes(Node *a_nodeA, Node *a_nodeB, std::set<std::pair<DataType, DataType>> *result);
 
-    size_t IsectNode(Node *a_node, Ray *a_ray, std::set<DataType> *result);
+    size_t IsectNode(const Node *a_node, const Ray *a_ray,
+	    std::set<DataType> *result) const;
 
     Node* m_root = nullptr;                                         ///< Root of tree
     ElementTypeReal m_unitSphereVolume = kElementTypeRealZero;      ///< Unit sphere constant for required number of dimensions
 
 public:
     // Find the leaves intersected by a ray, returning the data from the leaves in a set.
-    size_t Intersects(Ray *a_ray, std::set<DataType> *result);
+    size_t Intersects(const Ray *a_ray, std::set<DataType> *result) const;
 
     void plot(const char *fname);
     void plot2d(const char *fname);
@@ -1551,7 +1552,7 @@ bool RTREE_QUAL::Overlap(Rect* a_rectA, Rect* a_rectB) const
 
 // Decide whether a ray intersect a Rect.
 RTREE_TEMPLATE
-bool RTREE_QUAL::Intersect(Rect* a_rect, Ray* a_ray) const
+bool RTREE_QUAL::Intersect(const Rect* a_rect, const Ray* a_ray) const
 {
     RTreeAssert(a_rect);
     if (kNumDimensions != 3) return false;
@@ -1685,7 +1686,8 @@ size_t RTREE_QUAL::Overlaps(RTree &other, std::set<std::pair<DataType, DataType>
 
 
 RTREE_TEMPLATE
-size_t RTREE_QUAL::IsectNode(Node *a_node, Ray *a_ray, std::set<DataType> *result)
+size_t RTREE_QUAL::IsectNode(const Node *a_node, const Ray *a_ray,
+	std::set<DataType> *result) const
 {
     size_t ocnt = 0;
     for (int index = 0; index < a_node->m_count; ++index) {
@@ -1703,7 +1705,8 @@ size_t RTREE_QUAL::IsectNode(Node *a_node, Ray *a_ray, std::set<DataType> *resul
 
 // Loosely based on the idea from the openNURBS code to search two R-trees for all pairs elements whose bounding boxes overlap.
 RTREE_TEMPLATE
-size_t RTREE_QUAL::Intersects(Ray *a_ray, std::set<DataType> *result)
+size_t RTREE_QUAL::Intersects(const Ray *a_ray,
+	std::set<DataType> *result) const
 {
     if (!m_root) return 0;
     size_t ovlp_cnt = IsectNode(m_root, a_ray, result);
@@ -1800,6 +1803,9 @@ void RTREE_QUAL::plot2d(const char *fname)
 }
 
 
+#undef BB_PLOT2D
+#undef BB_PLOT
+#undef TREE_LEAF_FACE_3D
 #undef RTREE_TEMPLATE
 #undef RTREE_QUAL
 

src/libbu/CMakeLists.txt

@@ -234,7 +234,7 @@ set(
   mime.cmake
   parallel.h
   parallel_cpp11thread.cpp
-  process.h
+  process_private.h
   sha1.h
   struetype.h
   vfont.h

src/libbu/process.c

@@ -49,7 +49,7 @@
 #include "bu/str.h"
 #include "bu/datetime.h"
 #include "bu/vls.h"
-#include "./process.h"
+#include "./process_private.h"
 
 #ifndef HAVE_KILL
 #  include <TlHelp32.h>

src/libbu/process_private.h

@@ -1,4 +1,4 @@
-/*                      P R O C E S S . H
+/*              P R O C E S S _ P R I V A T E . H
  * BRL-CAD
  *
  * Copyright (c) 2013-2026 United States Government as represented by
@@ -20,8 +20,8 @@
 
 /* Private libbu process related definitions shared between multiple files */
 
-#ifndef LIBBU_PROCESS_H
-#define LIBBU_PROCESS_H
+#ifndef LIBBU_PROCESS_PRIVATE_H
+#define LIBBU_PROCESS_PRIVATE_H
 
 /* Apparently the termination code on Windows is arbitrary and somewhat
  * ill-defined - see https://bugs.python.org/issue31863 for more info.  Try our
@@ -29,7 +29,7 @@
  * abort identification. */
 #define BU_MSVC_ABORT_EXIT 97101  /* ascii - a == 97 && e == 101 */
 
-#endif /* LIBBU_PROCESS_H */
+#endif /* LIBBU_PROCESS_PRIVATE_H */
 
 /*
  * Local Variables:

src/libgcv/plugins/iges/tests/test_iges_orientation.cpp

@@ -188,8 +188,7 @@ test_uncertain()
     require(result.shells.empty() || (result.shells.front().orientation == ShellOrientation::Indeterminate &&
 	!result.shells.front().corrected), "invalid parameter-loop senses caused an incorrect face repair");
     auto flat = box();
-    ON_Xform flatten;
-    flatten.DiagonalTransformation(1.0);
+    ON_Xform flatten = ON_Xform::DiagonalTransformation(1.0);
     flatten[2][2] = 1.0e-13;
     require(flat->Transform(flatten), "could not construct thin shell");
     result = repair_brep_orientation(*flat);

src/libged/annotate/annotate.cpp

@@ -62,9 +62,8 @@ constexpr fastf_t DEFAULT_LEADER_MARGIN_SCALE = 2.0;
 constexpr fastf_t DEFAULT_SCREEN_TEXT_HEIGHT_MM = 3.0;
 /* The display-plane renderer uses this nominal density.  --dpi makes the
  * physical size explicit for displays whose effective density differs. */
-constexpr fastf_t DEFAULT_SCREEN_DPI = 96.0;
-constexpr fastf_t MILLIMETERS_PER_INCH = 25.4;
-constexpr fastf_t DISPLAY_PIXELS_PER_MM = DEFAULT_SCREEN_DPI / MILLIMETERS_PER_INCH;
+constexpr fastf_t DEFAULT_SCREEN_DPI = RT_ANNOT_SCREEN_DPI;
+constexpr fastf_t DISPLAY_PIXELS_PER_MM = RT_ANNOT_SCREEN_PIXELS_PER_MM;
 constexpr double AUTODIM_TEXT_WIDTH_SCALE = 0.65;
 /* Layout penalties deliberately dominate the smaller rewards so avoiding
  * collisions and crossings wins over merely moving a label farther out. */
@@ -473,10 +472,12 @@ parse_options(struct ged *gedp, int argc, const char **argv,
 	bu_vls_printf(gedp->ged_result_str, "Precision must be between 0 and 15");
 	return -1;
     }
-    if (opts.text_height < 0.0 || opts.line_width < 0.0 ||
+    if (!std::isfinite(opts.text_height) || !std::isfinite(opts.line_width) ||
+	opts.text_height < 0.0 || opts.line_width < 0.0 ||
+	std::isinf(opts.offset) ||
 	(std::isfinite(opts.offset) && opts.offset < 0.0)) {
 	bu_vls_printf(gedp->ged_result_str,
-	    "Text height, line width, and offset must not be negative");
+	    "Text height and line width must be finite and non-negative; offset must be finite and non-negative when specified");
 	return -1;
     }
     if (!std::isfinite(opts.dpi) || opts.dpi <= 0.0) {
@@ -2904,7 +2905,8 @@ cmd_info(void *data, int argc, const char **argv)
 	if (rt_db_get_internal(&intern, dp, gedp->dbip, NULL) == ID_ANNOT) {
 	    struct rt_annot_internal *annotation =
 		static_cast<struct rt_annot_internal *>(intern.idb_ptr);
-	    bu_vls_printf(gedp->ged_result_str, "\nspace: %s\nsegments: %zu",
+	    bu_vls_printf(gedp->ged_result_str,
+		"\nspace: %s\nsegments: %zu",
 		(annotation->flags & RT_ANNOT_MODEL_SPACE) ? "model" : "view",
 		annotation->ant.count);
 	    rt_db_free_internal(&intern);

src/librt/CMakeLists.txt

@@ -150,6 +150,7 @@ set(
   prep.cpp
   ${LIBRT_PRIMEDIT_SOURCES}
   primitives/annot/annot.c
+  primitives/annot/annot_render.cpp
   primitives/arb8/arb8.c
   primitives/arb8/arb8_brep.cpp
   primitives/arb8/arb8_mirror.c
@@ -427,6 +428,7 @@ endif(BRLCAD_ENABLE_SPR)
 set(LIBRT_PUBLIC_LIBS ${librt_deps} OPENNURBS::OPENNURBS)
 set(
   LIBRT_PRIVATE_LIBS
+  Threads::Threads
   ${OPENCL_LIBS}
   mmesh::mmesh
   REGEX::REGEX

src/librt/primitives/annot/annot.c

@@ -49,7 +49,6 @@
 #include "nmg.h"
 #include "rt/geom.h"
 #include "rt/primitives/annot.h"
-#include "rt/primitives/bot.h"
 #include "raytrace.h"
 
 #if defined(__GNUC__) && !defined(__clang__)
@@ -77,46 +76,8 @@
 #define ANNOT_PRES_MAGIC 0x414e5032u /* "ANP2" */
 #define ANNOT_PRES_VERSION 1u
 
-/* Stored line widths are display-scale multipliers, not model distances.
- * Primitive prep has no view pixel scale, so infer a stable model-space base
- * width from the annotation content before applying that multiplier. */
-#define ANNOT_TEXT_STROKE_RATIO (1.0 / 14.0)
-#define ANNOT_GEOMETRY_STROKE_RATIO 0.01
-#define ANNOT_MIN_WIDTH_TOL_FACTOR 4.0
-
-struct annot_mesh {
-    point_t *vertices;
-    size_t vertex_count;
-    size_t vertex_capacity;
-    int *faces;
-    fastf_t *thickness;
-    size_t face_count;
-    size_t face_capacity;
-};
-
 C_DECL void rt_annot_ifree(struct rt_db_internal *ip);
 
-/* Annotation prep uses BOT as a transient raytrace representation, as ARS
- * does.  These callbacks are internal to librt rather than public BOT APIs. */
-C_DECL int rt_bot_prep(struct soltab *stp, struct rt_db_internal *ip,
-	struct rt_i *rtip);
-C_DECL int rt_bot_shot(struct soltab *stp, struct xray *rp,
-	struct application *ap, struct seg *seghead);
-C_DECL void rt_bot_print(const struct soltab *stp);
-C_DECL void rt_bot_norm(struct hit *hitp, struct soltab *stp,
-	struct xray *rp);
-C_DECL void rt_bot_curve(struct curvature *cvp, struct hit *hitp,
-	struct soltab *stp);
-C_DECL void rt_bot_uv(struct application *ap, struct soltab *stp,
-	struct hit *hitp, struct uvcoord *uvp);
-C_DECL void rt_bot_free(struct soltab *stp);
-C_DECL void rt_bot_ifree(struct rt_db_internal *ip);
-
-static int annot_to_bot(struct rt_bot_internal **result,
-	const struct rt_annot_internal *annot_ip,
-	const struct bg_tess_tol *ttol, const struct bn_tol *tol,
-	unsigned char bot_mode);
-
 static uint32_t
 annot_get_uint32(const unsigned char *cp)
 {
@@ -473,8 +434,9 @@ rt_annot_validate(const struct rt_annot_internal *annot_ip,
 		    annot_validation_message(messages, i, "fill has no compatible outline segments");
 		    ret++;
 		} else {
-		    for (j = (size_t)fsg->legacy_start;
-			    j < (size_t)(fsg->legacy_start + fsg->legacy_count); ++j)
+		    size_t legacy_end = (size_t)fsg->legacy_start +
+			(size_t)fsg->legacy_count;
+		    for (j = (size_t)fsg->legacy_start; j < legacy_end; ++j)
 			if (!ant->segments[j] ||
 				*(uint32_t *)ant->segments[j] != CURVE_LSEG_MAGIC) {
 			    annot_validation_message(messages, i,
@@ -541,59 +503,25 @@ rt_annot_validate(const struct rt_annot_internal *annot_ip,
 C_DECL int
 rt_annot_prep(struct soltab *stp, struct rt_db_internal *ip, struct rt_i *rtip)
 {
-    struct bg_tess_tol default_ttol = BG_TESS_TOL_INIT_TOL;
-    struct bn_tol default_tol = BN_TOL_INIT_TOL;
-    const struct rt_annot_internal *annot_ip;
-    struct rt_bot_internal *bot = NULL;
-    struct rt_db_internal bot_intern;
-    const struct bg_tess_tol *ttol = &default_ttol;
-    const struct bn_tol *tol = &default_tol;
-    int ret;
-
     if (!stp)
 	return -1;
     RT_CK_SOLTAB(stp);
-    if (!ip)
-	return -1;
-    RT_CK_DB_INTERNAL(ip);
-    if (rtip) {
-	RT_CK_RTI(rtip);
-	ttol = &rtip->rti_ttol;
-	tol = &rtip->rti_tol;
-    }
+    if (ip) RT_CK_DB_INTERNAL(ip);
+    if (rtip) RT_CK_RTI(rtip);
 
-    annot_ip = (const struct rt_annot_internal *)ip->idb_ptr;
-    if (rt_annot_validate(annot_ip, NULL))
+    if (ip && rt_annot_validate(
+	    (const struct rt_annot_internal *)ip->idb_ptr, NULL))
 	return -1;
 
-    /* View-space annotations need camera state, which primitive prep does not
-     * have.  Leave them non-intersecting until a view-aware prep API exists. */
     stp->st_specific = (void *)NULL;
-    if (!(annot_ip->flags & RT_ANNOT_MODEL_SPACE))
-	return 0;
-
-    if (annot_to_bot(&bot, annot_ip, ttol, tol, RT_BOT_PLATE) || !bot)
-	return -1;
-
-    RT_DB_INTERNAL_INIT(&bot_intern);
-    bot_intern.idb_major_type = DB5_MAJORTYPE_BRLCAD;
-    bot_intern.idb_type = ID_BOT;
-    bot_intern.idb_meth = &OBJ[ID_BOT];
-    bot_intern.idb_ptr = bot;
-    ret = rt_bot_prep(stp, &bot_intern, rtip);
-    rt_bot_ifree(&bot_intern);
-    return ret;
+    return 0;
 }
 
 
 C_DECL void
 rt_annot_print(const struct soltab *stp)
 {
-    if (!stp)
-	return;
-    RT_CK_SOLTAB(stp);
-    if (stp->st_specific)
-	rt_bot_print(stp);
+    if (stp) RT_CK_SOLTAB(stp);
 }
 
 
@@ -615,18 +543,25 @@ rt_annot_shot(struct soltab *stp, struct xray *rp, struct application *ap, struc
     RT_CK_RAY(rp);
     RT_CK_APPLICATION(ap);
 
-    return stp->st_specific ? rt_bot_shot(stp, rp, ap, seghead) : 0;
+    /* Annotation coverage is evaluated separately from solid partitions. */
+
+    return 0;			/* MISS */
 }
 
 
 /**
- * Vectorized annotation shooting uses the scalar wrapper so view-space
- * annotations without prepared geometry continue to miss safely.
+ * Vectorized rt_annot_shot(): annotations do not create solid partitions, so
+ * every ray in the batch misses.
  */
 C_DECL void
-rt_annot_vshot(struct soltab **stp, struct xray **rp, struct seg *segp, int n, struct application *ap)
+rt_annot_vshot(struct soltab **stp, struct xray **UNUSED(rp), struct seg *segp, int n, struct application *ap)
 {
-    rt_vshot_via_shot(rt_annot_shot, stp, rp, segp, n, ap);
+    int i;
+    if (ap) RT_CK_APPLICATION(ap);
+    for (i = 0; i < n; i++) {
+	if (stp[i] == 0) continue;		/* skip this ray */
+	segp[i].seg_stp = (struct soltab *)0;	/* always MISS */
+    }
 }
 
 
@@ -643,10 +578,6 @@ rt_annot_norm(struct hit *hitp, struct soltab *stp, struct xray *rp)
     if (stp) RT_CK_SOLTAB(stp);
     RT_CK_RAY(rp);
 
-    if (stp && stp->st_specific) {
-	rt_bot_norm(hitp, stp, rp);
-	return;
-    }
     VJOIN1(hitp->hit_point, rp->r_pt, hitp->hit_dist, rp->r_dir);
 }
 
@@ -663,10 +594,6 @@ rt_annot_curve(struct curvature *cvp, struct hit *hitp, struct soltab *stp)
     RT_CK_HIT(hitp);
     if (stp) RT_CK_SOLTAB(stp);
 
-    if (stp && stp->st_specific) {
-	rt_bot_curve(cvp, hitp, stp);
-	return;
-    }
     cvp->crv_c1 = cvp->crv_c2 = 0;
 
     bn_vec_ortho(cvp->crv_pdir, hitp->hit_normal);
@@ -681,19 +608,13 @@ rt_annot_uv(struct application *ap, struct soltab *stp, struct hit *hitp, struct
     if (hitp) RT_CK_HIT(hitp);
     if (!uvp)
 	return;
-    if (stp && stp->st_specific)
-	rt_bot_uv(ap, stp, hitp, uvp);
 }
 
 
 C_DECL void
 rt_annot_free(struct soltab *stp)
 {
-    if (!stp)
-	return;
-    RT_CK_SOLTAB(stp);
-    if (stp->st_specific)
-	rt_bot_free(stp);
+    if (stp) RT_CK_SOLTAB(stp);
 }
 
 
@@ -1605,6 +1526,29 @@ seg_to_vlist(struct bu_list *vlfree, struct bu_list *vhead, const struct bg_tess
 }
 
 
+int
+rt_annot_segment_vlist(struct bu_list *vlfree, struct bu_list *vhead,
+	const struct bg_tess_tol *ttol,
+	const struct rt_annot_internal *annot_ip, size_t segment)
+{
+    struct rt_annot_internal local;
+    point_t base = VINIT_ZERO;
+
+    if (!vlfree || !vhead || !ttol || !annot_ip ||
+	    segment >= annot_ip->ant.count || !annot_ip->ant.segments ||
+	    !annot_ip->ant.segments[segment])
+	return 1;
+
+    RT_ANNOT_CK_MAGIC(annot_ip);
+    local = *annot_ip;
+    local.flags = RT_ANNOT_SCREEN_SPACE;
+    VSETALL(local.V, 0.0);
+    return seg_to_vlist(vlfree, vhead, ttol, base, &local,
+	annot_ip->ant.segments[segment], annot_ip->styles ?
+	&annot_ip->styles[segment] : NULL);
+}
+
+
 static int
 annot_is_fill_compatibility_outline(const struct rt_ant *ant, size_t seg_no)
 {
@@ -1691,489 +1635,6 @@ ant_to_vlist(struct bu_list *vlfree, struct bu_list *vhead, const struct bg_tess
 }
 
 
-static void
-annot_mesh_free(struct annot_mesh *mesh)
-{
-    if (!mesh)
-	return;
-    if (mesh->vertices)
-	bu_free(mesh->vertices, "annotation mesh vertices");
-    if (mesh->faces)
-	bu_free(mesh->faces, "annotation mesh faces");
-    if (mesh->thickness)
-	bu_free(mesh->thickness, "annotation mesh thickness");
-    memset(mesh, 0, sizeof(*mesh));
-}
-
-
-static int
-annot_mesh_reserve_vertices(struct annot_mesh *mesh, size_t additional)
-{
-    size_t capacity;
-    size_t required;
-
-    if (additional > SIZE_MAX - mesh->vertex_count)
-	return 1;
-    required = mesh->vertex_count + additional;
-    if (required <= mesh->vertex_capacity)
-	return 0;
-    capacity = mesh->vertex_capacity ? mesh->vertex_capacity : 64;
-    while (capacity < required) {
-	if (capacity > SIZE_MAX / 2) {
-	    capacity = required;
-	    break;
-	}
-	capacity *= 2;
-    }
-    if (capacity > SIZE_MAX / sizeof(point_t))
-	return 1;
-    mesh->vertices = (point_t *)bu_realloc(mesh->vertices,
-	capacity * sizeof(point_t), "annotation mesh vertices");
-    mesh->vertex_capacity = capacity;
-    return 0;
-}
-
-
-static int
-annot_mesh_reserve_faces(struct annot_mesh *mesh, size_t additional)
-{
-    size_t capacity;
-    size_t required;
-
-    if (additional > SIZE_MAX - mesh->face_count)
-	return 1;
-    required = mesh->face_count + additional;
-    if (required <= mesh->face_capacity)
-	return 0;
-    capacity = mesh->face_capacity ? mesh->face_capacity : 96;
-    while (capacity < required) {
-	if (capacity > SIZE_MAX / 2) {
-	    capacity = required;
-	    break;
-	}
-	capacity *= 2;
-    }
-    if (capacity > SIZE_MAX / (3 * sizeof(int)) ||
-	capacity > SIZE_MAX / sizeof(fastf_t))
-	return 1;
-    mesh->faces = (int *)bu_realloc(mesh->faces,
-	capacity * 3 * sizeof(int), "annotation mesh faces");
-    mesh->thickness = (fastf_t *)bu_realloc(mesh->thickness,
-	capacity * sizeof(fastf_t), "annotation mesh thickness");
-    mesh->face_capacity = capacity;
-    return 0;
-}
-
-
-static int
-annot_mesh_add_triangle(struct annot_mesh *mesh, const point_t a,
-	const point_t b, const point_t c, const vect_t normal, fastf_t thickness,
-	const struct bn_tol *tol)
-{
-    point_t ordered[3];
-    vect_t ab, ac, bc, face_normal;
-    size_t base;
-
-    if (VINVALID(a) || VINVALID(b) || VINVALID(c)) {
-	bu_log("annotation mesh contains a non-finite triangle\n");
-	return 1;
-    }
-    VSUB2(ab, b, a);
-    VSUB2(ac, c, a);
-    VSUB2(bc, c, b);
-    VCROSS(face_normal, ab, ac);
-    if (INVALID(MAGSQ(ab)) || INVALID(MAGSQ(ac)) || INVALID(MAGSQ(bc)) ||
-	INVALID(MAGSQ(face_normal))) {
-	bu_log("annotation mesh triangle exceeds the numeric range\n");
-	return 1;
-    }
-    if (MAGNITUDE(face_normal) <= tol->dist_sq)
-	return 0;
-    VMOVE(ordered[0], a);
-    if (VDOT(face_normal, normal) >= 0.0) {
-	VMOVE(ordered[1], b);
-	VMOVE(ordered[2], c);
-    } else {
-	VMOVE(ordered[1], c);
-	VMOVE(ordered[2], b);
-    }
-
-    if (!mesh || mesh->vertex_count > (size_t)INT_MAX - 3 ||
-	annot_mesh_reserve_vertices(mesh, 3) ||
-	annot_mesh_reserve_faces(mesh, 1))
-	return 1;
-    base = mesh->vertex_count;
-    VMOVE(mesh->vertices[base], ordered[0]);
-    VMOVE(mesh->vertices[base + 1], ordered[1]);
-    VMOVE(mesh->vertices[base + 2], ordered[2]);
-    mesh->vertex_count += 3;
-    mesh->faces[3 * mesh->face_count] = (int)base;
-    mesh->faces[3 * mesh->face_count + 1] = (int)base + 1;
-    mesh->faces[3 * mesh->face_count + 2] = (int)base + 2;
-    mesh->thickness[mesh->face_count++] = thickness;
-    return 0;
-}
-
-
-static int
-annot_mesh_add_stroke_span(struct annot_mesh *mesh, const point_t start,
-	const point_t end, const vect_t normal, fastf_t width,
-	const struct bn_tol *tol)
-{
-    point_t corners[4];
-    point_t first, last;
-    vect_t direction, side;
-    fastf_t half_width;
-    fastf_t length;
-
-    VSUB2(direction, end, start);
-    length = MAGNITUDE(direction);
-    if (INVALID(length))
-	return 1;
-    if (length <= tol->dist)
-	return 0;
-    VSCALE(direction, direction, 1.0 / length);
-    VCROSS(side, normal, direction);
-    if (VINVALID(side))
-	return 1;
-    if (MAGNITUDE(side) <= SMALL_FASTF)
-	return 0;
-    VUNITIZE(side);
-
-    half_width = 0.5 * width;
-    VJOIN1(first, start, -half_width, direction);
-    VJOIN1(last, end, half_width, direction);
-
-    VJOIN1(corners[0], first, -half_width, side);
-    VJOIN1(corners[1], last, -half_width, side);
-    VJOIN1(corners[2], last, half_width, side);
-    VJOIN1(corners[3], first, half_width, side);
-
-    if (annot_mesh_add_triangle(mesh, corners[0], corners[1], corners[2],
-	    normal, width, tol))
-	return 1;
-    return annot_mesh_add_triangle(mesh, corners[0], corners[2], corners[3],
-	normal, width, tol);
-}
-
-
-static void
-annot_line_pattern(uint32_t pattern, const fastf_t **intervals,
-	size_t *interval_count)
-{
-    /* Entries alternate mark and gap lengths in stroke-width units. */
-    static const fastf_t dashed[] = {8.0, 4.0};
-    static const fastf_t dotted[] = {1.0, 3.0};
-    static const fastf_t center[] = {8.0, 3.0, 2.0, 3.0};
-    static const fastf_t phantom[] = {8.0, 3.0, 2.0, 3.0, 2.0, 3.0};
-
-    *intervals = NULL;
-    *interval_count = 0;
-    switch (pattern) {
-	case RT_ANNOT_LINE_DASHED:
-	    *intervals = dashed;
-	    *interval_count = sizeof(dashed) / sizeof(dashed[0]);
-	    break;
-	case RT_ANNOT_LINE_DOTTED:
-	    *intervals = dotted;
-	    *interval_count = sizeof(dotted) / sizeof(dotted[0]);
-	    break;
-	case RT_ANNOT_LINE_CENTER:
-	    *intervals = center;
-	    *interval_count = sizeof(center) / sizeof(center[0]);
-	    break;
-	case RT_ANNOT_LINE_PHANTOM:
-	    *intervals = phantom;
-	    *interval_count = sizeof(phantom) / sizeof(phantom[0]);
-	    break;
-	default:
-	    break;
-    }
-}
-
-
-static int
-annot_mesh_add_stroke(struct annot_mesh *mesh, const point_t start,
-	const point_t end, const vect_t normal, fastf_t width, uint32_t pattern,
-	fastf_t *path_distance, const struct bn_tol *tol)
-{
-    const fastf_t *intervals;
-    size_t interval_count;
-    vect_t delta;
-    fastf_t length;
-    fastf_t period = 0.0;
-    fastf_t position = 0.0;
-    fastf_t phase;
-    size_t interval = 0;
-    size_t i;
-
-    VSUB2(delta, end, start);
-    length = MAGNITUDE(delta);
-    if (INVALID(length))
-	return 1;
-    if (length <= tol->dist)
-	return 0;
-    annot_line_pattern(pattern, &intervals, &interval_count);
-    if (!interval_count) {
-	*path_distance += length;
-	return annot_mesh_add_stroke_span(mesh, start, end, normal, width, tol);
-    }
-
-    for (i = 0; i < interval_count; ++i)
-	period += intervals[i] * width;
-    phase = fmod(*path_distance, period);
-    while (phase >= intervals[interval] * width) {
-	phase -= intervals[interval] * width;
-	interval = (interval + 1) % interval_count;
-    }
-
-    while (position < length) {
-	fastf_t available = intervals[interval] * width - phase;
-	fastf_t run = available < length - position ? available : length - position;
-	if (!(interval & 1) && run > tol->dist) {
-	    point_t run_start, run_end;
-	    VJOIN1(run_start, start, position / length, delta);
-	    VJOIN1(run_end, start, (position + run) / length, delta);
-	    if (annot_mesh_add_stroke_span(mesh, run_start, run_end, normal,
-		    width, tol))
-		return 1;
-	}
-	position += run;
-	phase = 0.0;
-	interval = (interval + 1) % interval_count;
-    }
-    *path_distance += length;
-    return 0;
-}
-
-
-static fastf_t
-annot_default_width(const struct rt_annot_internal *annot_ip,
-	const struct bn_tol *tol)
-{
-    fastf_t largest_text = 0.0;
-    fastf_t local_width = 0.0;
-    fastf_t plane_scale;
-    point2d_t minimum, maximum;
-    vect_t normal;
-    size_t i;
-
-    for (i = 0; i < annot_ip->ant.count; ++i) {
-	if (annot_ip->ant.segments[i] &&
-		*(uint32_t *)annot_ip->ant.segments[i] == ANN_TSEG_MAGIC) {
-	    const struct txt_seg *text =
-		(const struct txt_seg *)annot_ip->ant.segments[i];
-	    if (text->txt_size > largest_text)
-		largest_text = text->txt_size;
-	}
-    }
-    if (largest_text > 0.0) {
-	local_width = largest_text * ANNOT_TEXT_STROKE_RATIO;
-    } else if (annot_ip->vert_count) {
-	V2MOVE(minimum, annot_ip->verts[0]);
-	V2MOVE(maximum, annot_ip->verts[0]);
-	for (i = 1; i < annot_ip->vert_count; ++i) {
-	    V_MIN(minimum[X], annot_ip->verts[i][X]);
-	    V_MIN(minimum[Y], annot_ip->verts[i][Y]);
-	    V_MAX(maximum[X], annot_ip->verts[i][X]);
-	    V_MAX(maximum[Y], annot_ip->verts[i][Y]);
-	}
-	local_width = hypot(maximum[X] - minimum[X],
-	    maximum[Y] - minimum[Y]) * ANNOT_GEOMETRY_STROKE_RATIO;
-    }
-
-    VCROSS(normal, annot_ip->u_vec, annot_ip->v_vec);
-    plane_scale = sqrt(MAGNITUDE(normal));
-    local_width *= plane_scale;
-    if (local_width < ANNOT_MIN_WIDTH_TOL_FACTOR * tol->dist)
-	local_width = ANNOT_MIN_WIDTH_TOL_FACTOR * tol->dist;
-    return local_width;
-}
-
-
-static int
-annot_segment_mesh(struct annot_mesh *mesh,
-	const struct rt_annot_internal *annot_ip, size_t segment,
-	const struct bg_tess_tol *ttol, const struct bn_tol *tol,
-	const vect_t normal, fastf_t base_width)
-{
-    struct bu_list vhead;
-    struct bu_list vlfree;
-    struct bv_vlist *vp;
-    const struct rt_annot_seg_style *style = annot_ip->styles ?
-	&annot_ip->styles[segment] : NULL;
-    uint32_t magic = *(uint32_t *)annot_ip->ant.segments[segment];
-    uint32_t pattern = style ? style->line_pattern : RT_ANNOT_LINE_CONTINUOUS;
-    fastf_t width = base_width;
-    point_t line_start = VINIT_ZERO;
-    point_t polygon[3];
-    fastf_t path_distance = 0.0;
-    size_t polygon_count = 0;
-    int have_line_start = 0;
-    int ret = 0;
-
-    if (style && (style->flags & RT_ANNOT_STYLE_WIDTH))
-	width *= style->line_width;
-    else if (style && magic == ANN_TSEG_MAGIC &&
-	    (style->flags & RT_ANNOT_STYLE_BOLD))
-	width *= 2.0;
-    if (!isfinite(width) || width <= 0.0)
-	return 1;
-
-    BU_LIST_INIT(&vhead);
-    BU_LIST_INIT(&vlfree);
-    ret = seg_to_vlist(&vlfree, &vhead, ttol,
-	(fastf_t *)annot_ip->V, (struct rt_annot_internal *)annot_ip,
-	annot_ip->ant.segments[segment], style);
-    if (ret)
-	goto cleanup;
-
-    for (BU_LIST_FOR(vp, bv_vlist, &vhead)) {
-	size_t i;
-	for (i = 0; i < vp->nused; ++i) {
-	    switch (vp->cmd[i]) {
-		case BV_VLIST_LINE_MOVE:
-		    VMOVE(line_start, vp->pt[i]);
-		    have_line_start = 1;
-		    path_distance = 0.0;
-		    break;
-		case BV_VLIST_LINE_DRAW:
-		    if (have_line_start && annot_mesh_add_stroke(mesh,
-			    line_start, vp->pt[i], normal, width, pattern,
-			    &path_distance, tol)) {
-			ret = 1;
-			goto cleanup;
-		    }
-		    VMOVE(line_start, vp->pt[i]);
-		    have_line_start = 1;
-		    break;
-		case BV_VLIST_POLY_MOVE:
-		case BV_VLIST_TRI_MOVE:
-		    VMOVE(polygon[0], vp->pt[i]);
-		    polygon_count = 1;
-		    break;
-		case BV_VLIST_POLY_DRAW:
-		case BV_VLIST_TRI_DRAW:
-		    if (polygon_count < 3) {
-			VMOVE(polygon[polygon_count], vp->pt[i]);
-			polygon_count++;
-		    }
-		    break;
-		case BV_VLIST_POLY_END:
-		case BV_VLIST_TRI_END:
-		    if (polygon_count == 3 && annot_mesh_add_triangle(mesh,
-			    polygon[0], polygon[1], polygon[2], normal,
-			    base_width, tol)) {
-			ret = 1;
-			goto cleanup;
-		    }
-		    polygon_count = 0;
-		    break;
-		default:
-		    break;
-	    }
-	}
-    }
-
-cleanup:
-    BV_FREE_VLIST(&vlfree, &vhead);
-    bv_vlist_cleanup(&vlfree);
-    return ret;
-}
-
-
-static int
-annot_to_bot(struct rt_bot_internal **result,
-	const struct rt_annot_internal *annot_ip,
-	const struct bg_tess_tol *ttol, const struct bn_tol *tol,
-	unsigned char bot_mode)
-{
-    struct annot_mesh mesh = {0};
-    struct rt_bot_internal *bot;
-    vect_t normal;
-    fastf_t base_width;
-    size_t i;
-
-    if (!result)
-	return 1;
-    *result = NULL;
-
-    if (!annot_ip || !ttol || !tol ||
-	(bot_mode != RT_BOT_PLATE && bot_mode != RT_BOT_SURFACE) ||
-	!(annot_ip->flags & RT_ANNOT_MODEL_SPACE))
-	return 1;
-    VCROSS(normal, annot_ip->u_vec, annot_ip->v_vec);
-    if (VINVALID(normal) || MAGNITUDE(normal) <= SMALL_FASTF)
-	return 1;
-    VUNITIZE(normal);
-    base_width = annot_default_width(annot_ip, tol);
-    if (!isfinite(base_width) || base_width <= 0.0)
-	return 1;
-
-    for (i = 0; i < annot_ip->ant.count; ++i) {
-	if (!annot_ip->ant.segments[i] ||
-		annot_is_fill_compatibility_outline(&annot_ip->ant, i))
-	    continue;
-	if (annot_segment_mesh(&mesh, annot_ip, i, ttol, tol, normal,
-		base_width)) {
-	    annot_mesh_free(&mesh);
-	    return 1;
-	}
-    }
-    if (!mesh.vertex_count || !mesh.face_count) {
-	annot_mesh_free(&mesh);
-	return 1;
-    }
-
-    BU_ALLOC(bot, struct rt_bot_internal);
-    bot->magic = RT_BOT_INTERNAL_MAGIC;
-    bot->mode = bot_mode;
-    bot->orientation = RT_BOT_UNORIENTED;
-    bot->num_vertices = mesh.vertex_count;
-    bot->vertices = (fastf_t *)mesh.vertices;
-    bot->num_faces = mesh.face_count;
-    bot->faces = mesh.faces;
-    if (bot_mode == RT_BOT_PLATE)
-	bot->thickness = mesh.thickness;
-    else
-	bu_free(mesh.thickness, "annotation mesh thickness");
-    mesh.vertices = NULL;
-    mesh.faces = NULL;
-    mesh.thickness = NULL;
-    *result = bot;
-    return 0;
-}
-
-
-C_DECL int
-rt_annot_tess(struct nmgregion **r, struct model *m,
-	struct rt_db_internal *ip, const struct bg_tess_tol *ttol,
-	const struct bn_tol *tol)
-{
-    struct rt_bot_internal *bot = NULL;
-    struct rt_db_internal bot_intern;
-    const struct rt_annot_internal *annot_ip;
-    int ret;
-
-    if (!r || !m || !ip || !ttol || !tol)
-	return -1;
-    RT_CK_DB_INTERNAL(ip);
-    annot_ip = (const struct rt_annot_internal *)ip->idb_ptr;
-    if (rt_annot_validate(annot_ip, NULL) ||
-	annot_to_bot(&bot, annot_ip, ttol, tol, RT_BOT_SURFACE))
-	return -1;
-
-    RT_DB_INTERNAL_INIT(&bot_intern);
-    bot_intern.idb_major_type = DB5_MAJORTYPE_BRLCAD;
-    bot_intern.idb_type = ID_BOT;
-    bot_intern.idb_meth = &OBJ[ID_BOT];
-    bot_intern.idb_ptr = bot;
-    ret = rt_bot_tess(r, m, &bot_intern, ttol, tol);
-    rt_bot_ifree(&bot_intern);
-    return ret;
-}
-
-
 C_DECL int
 rt_annot_plot(struct bu_list *vhead, struct rt_db_internal *ip, const struct bg_tess_tol *ttol, const struct bn_tol *UNUSED(tol), const struct bview *UNUSED(info))
 {
@@ -4066,11 +3527,11 @@ rt_annot_adjust(struct bu_vls *logstr, struct rt_db_internal *intern, int argc,
 	    fastf_t *new_vert;
 
 	    vert_no = atol(argv[0] + 1);
-	    new_vert = annot_ip->verts[vert_no];
-	    if (vert_no < 0 || (size_t)vert_no > annot_ip->vert_count) {
+	    if (vert_no < 0 || (size_t)vert_no >= annot_ip->vert_count) {
 		bu_vls_printf(logstr, "ERROR: Illegal vertex number\n");
 		return BRLCAD_ERROR;
 	    }
+	    new_vert = annot_ip->verts[vert_no];
 	    array_len = 2;
 	    if (_rt_tcl_list_to_fastf_array(argv[1], &new_vert, &array_len) != array_len) {
 		bu_vls_printf(logstr, "ERROR: Incorrect number of coordinates for vertex\n");

src/librt/primitives/crofton.cpp

@@ -45,24 +45,28 @@
  * intersecting closed surface), and total_chord is the sum of solid
  * segment lengths.
  *
- * References:
- *   Li et al. (2003), "Using low-discrepancy sequences and the Crofton
- *   formula to compute surface areas of geometric models",
- *   Computer-Aided Design 35, 771-782.
- *
- *   Liu et al. (2010), "Surface area estimation of digitized 3D objects
- *   using quasi-Monte Carlo methods", Pattern Recognition 43, 3900-3909.
+ * Chord endpoints are independent pseudorandom points on the bounding
+ * sphere.  Reinitializing the generator with a fixed seed makes sampling
+ * reproducible without changing the ordinary Monte Carlo convergence
+ * behavior on which the estimator's stability checks rely.
  */
 
 #include "common.h"
 
+#include <chrono>
 #include <climits>
+#include <condition_variable>
 #include <cstdint>
+#include <exception>
+#include <mutex>
+#include <random>
 #include <stdlib.h>
 #include <math.h>
-#include <random>
+#include <stdexcept>
 #include <string.h>
+#include <thread>
 #include <time.h>
+#include <vector>
 
 #include "vmath.h"
 #include "bu/log.h"
@@ -100,8 +104,15 @@
 #define RT_CROFTON_STABILITY_MIN_WINDOWS   2u
 
 /** Fixed seed for reproducible estimates in tests and cross-platform runs. */
-#define RT_CROFTON_RNG_SEED 0x9e3779b97f4a7c15ULL
+#define RT_CROFTON_RNG_SEED UINT64_C(0x9e3779b97f4a7c15)
 
+/** Two sphere coordinates for each of two chord endpoints. */
+#define RT_CROFTON_RANDOM_VALUES_PER_RAY 4u
+
+/** Convert the high 53 random bits exactly to a double in [0, 1). */
+static constexpr unsigned int CROFTON_RANDOM_SHIFT = 11u;
+static constexpr double CROFTON_RANDOM_SCALE =
+    1.0 / 9007199254740992.0;
 
 /* ------------------------------------------------------------------ */
 /* Internal types                                                       */
@@ -110,6 +121,7 @@
 struct crofton_ray {
     point_t r_pt;
     vect_t  r_dir;
+    size_t  id;
 };
 
 struct crofton_shared {
@@ -117,14 +129,19 @@ struct crofton_shared {
     size_t  total_crossings; /* in+out hit events */
     double  total_chord;     /* solid segment length sum (mm) */
     size_t  total_rays;      /* rays fired (hits + misses) */
+    size_t  ray_offset;      /* first identifier in this sample stream */
     point_t *points;
     size_t point_count;
     size_t point_capacity;
+    struct rt_crofton_segment *segments;
+    size_t segment_count;
+    size_t segment_capacity;
     bool collect_points;
+    bool collect_segments;
 };
 
 struct crofton_worker_data {
-    struct application    *ap;        /* per-CPU application struct */
+    struct application     ap;        /* per-CPU application struct */
     struct crofton_ray    *rays;      /* shared ray array (read-only) */
     size_t                 start;
     size_t                 end;
@@ -135,6 +152,10 @@ struct crofton_worker_data {
     point_t               *local_points;
     size_t                 local_point_count;
     size_t                 local_point_capacity;
+    struct rt_crofton_segment *local_segments;
+    size_t                 local_segment_count;
+    size_t                 local_segment_capacity;
+    size_t                 current_ray;
 };
 
 
@@ -143,46 +164,88 @@ struct crofton_worker_data {
 /* ------------------------------------------------------------------ */
 
 static int
-crofton_hit(struct application *ap, struct partition *PartHeadp, struct seg *UNUSED(segs))
+crofton_hit(struct application *ap, struct partition *PartHeadp,
+    struct seg *UNUSED(segs))
 {
-    struct crofton_worker_data *wd = (struct crofton_worker_data *)ap->a_uptr;
-
+    struct crofton_worker_data *worker =
+        (struct crofton_worker_data *)ap->a_uptr;
     size_t crossings = 0;
-    double chord     = 0.0;
+    double chord = 0.0;
 
-    struct partition *pp;
-    for (pp = PartHeadp->pt_forw; pp != PartHeadp; pp = pp->pt_forw) {
-	/* Each partition contributes an in-hit and an out-hit */
-	crossings += 2;
-	chord += pp->pt_outhit->hit_dist - pp->pt_inhit->hit_dist;
-	if (wd->shared->collect_points) {
-	    if (wd->local_point_count + 2 > wd->local_point_capacity) {
-		const size_t initial_capacity = 1024;
-		size_t new_capacity = wd->local_point_capacity ?
-		    2 * wd->local_point_capacity : initial_capacity;
-		while (new_capacity < wd->local_point_count + 2)
-		    new_capacity *= 2;
-		wd->local_points = (point_t *)bu_realloc(wd->local_points,
-		    new_capacity * sizeof(point_t), "Crofton worker hit points");
-		wd->local_point_capacity = new_capacity;
-	    }
-	    VJOIN1(wd->local_points[wd->local_point_count], ap->a_ray.r_pt,
-		pp->pt_inhit->hit_dist, ap->a_ray.r_dir);
-	    wd->local_point_count++;
-	    VJOIN1(wd->local_points[wd->local_point_count], ap->a_ray.r_pt,
-		pp->pt_outhit->hit_dist, ap->a_ray.r_dir);
-	    wd->local_point_count++;
-	}
+    struct partition *partition;
+    for (partition = PartHeadp->pt_forw; partition != PartHeadp;
+         partition = partition->pt_forw) {
+        fastf_t thickness = partition->pt_outhit->hit_dist -
+            partition->pt_inhit->hit_dist;
+        crossings += 2;
+        chord += thickness;
+
+        if (worker->shared->collect_points) {
+            if (worker->local_point_count + 2 >
+                worker->local_point_capacity) {
+                const size_t initial_capacity = 1024;
+                size_t new_capacity = worker->local_point_capacity ?
+                    2 * worker->local_point_capacity : initial_capacity;
+                while (new_capacity < worker->local_point_count + 2)
+                    new_capacity *= 2;
+                worker->local_points = (point_t *)bu_realloc(
+                    worker->local_points,
+                    new_capacity * sizeof(point_t),
+                    "Crofton worker hit points");
+                worker->local_point_capacity = new_capacity;
+            }
+            VJOIN1(worker->local_points[worker->local_point_count],
+                ap->a_ray.r_pt, partition->pt_inhit->hit_dist,
+                ap->a_ray.r_dir);
+            worker->local_point_count++;
+            VJOIN1(worker->local_points[worker->local_point_count],
+                ap->a_ray.r_pt, partition->pt_outhit->hit_dist,
+                ap->a_ray.r_dir);
+            worker->local_point_count++;
+        }
+
+        if (worker->shared->collect_segments) {
+            if (worker->local_segment_count + 1 >
+                worker->local_segment_capacity) {
+                const size_t initial_capacity = 512;
+                size_t new_capacity = worker->local_segment_capacity ?
+                    2 * worker->local_segment_capacity : initial_capacity;
+                worker->local_segments =
+                    (struct rt_crofton_segment *)bu_realloc(
+                        worker->local_segments,
+                        new_capacity * sizeof(struct rt_crofton_segment),
+                        "Crofton worker segments");
+                worker->local_segment_capacity = new_capacity;
+            }
+
+            struct rt_crofton_segment *sample =
+                &worker->local_segments[worker->local_segment_count];
+            struct soltab *in_solid =
+                partition->pt_inseg->seg_stp;
+            struct soltab *out_solid =
+                partition->pt_outseg->seg_stp;
+            VJOIN1(sample->in_point, ap->a_ray.r_pt,
+                partition->pt_inhit->hit_dist, ap->a_ray.r_dir);
+            VJOIN1(sample->out_point, ap->a_ray.r_pt,
+                partition->pt_outhit->hit_dist, ap->a_ray.r_dir);
+            RT_HIT_NORMAL(sample->in_normal, partition->pt_inhit,
+                in_solid, &ap->a_ray, partition->pt_inflip);
+            RT_HIT_NORMAL(sample->out_normal, partition->pt_outhit,
+                out_solid, &ap->a_ray, partition->pt_outflip);
+            sample->thickness = thickness;
+            sample->ray_id = worker->rays[worker->current_ray].id;
+            if (!VNEAR_ZERO(sample->in_normal, VUNITIZE_TOL) &&
+                !VNEAR_ZERO(sample->out_normal, VUNITIZE_TOL))
+                worker->local_segment_count++;
+        }
     }
 
-    wd->local_crossings += crossings;
-    wd->local_chord     += chord;
-    wd->local_rays      += 1;
-
+    worker->local_crossings += crossings;
+    worker->local_chord += chord;
+    worker->local_rays++;
     return 1;
 }
 
-
 static int
 crofton_miss(struct application *ap)
 {
@@ -193,159 +256,273 @@ crofton_miss(struct application *ap)
 }
 
 
-/* ------------------------------------------------------------------ */
-/* Parallel worker                                                      */
-/* ------------------------------------------------------------------ */
-
-static void
-crofton_worker(int id, void *data)
-{
-    struct crofton_worker_data *wd = &((struct crofton_worker_data *)data)[id - 1];
-    struct application         *ap = wd->ap;
-    struct crofton_ray         *rays = wd->rays;
-
-    for (size_t i = wd->start; i < wd->end; i++) {
-	VMOVE(ap->a_ray.r_pt,  rays[i].r_pt);
-	VMOVE(ap->a_ray.r_dir, rays[i].r_dir);
-	/* r_dir is already unit-length (set during ray generation) */
-	rt_shootray(ap);
-    }
-}
-
-
 /* ------------------------------------------------------------------ */
 /* Point / ray generation                                               */
 /* ------------------------------------------------------------------ */
 
 static double
-crofton_rand01(std::mt19937_64 &rng)
+crofton_random01(std::mt19937_64 &rng)
 {
-    return std::generate_canonical<double, 53>(rng);
+    return static_cast<double>(rng() >> CROFTON_RANDOM_SHIFT) *
+        CROFTON_RANDOM_SCALE;
 }
 
-
 static void
-random_point_on_sphere(double radius, const point_t center, point_t out, std::mt19937_64 &rng)
+random_point_on_sphere(double radius, const point_t center, double u,
+    double v, point_t point)
 {
-    double theta = 2.0 * M_PI * crofton_rand01(rng);
-    double phi   = acos(2.0 * crofton_rand01(rng) - 1.0);
-    double sp    = sin(phi);
-    out[X] = center[X] + radius * sp * cos(theta);
-    out[Y] = center[Y] + radius * sp * sin(theta);
-    out[Z] = center[Z] + radius * cos(phi);
+    double z = 1.0 - 2.0 * u;
+    double radial = sqrt(std::max(0.0, 1.0 - z * z));
+    double angle = 2.0 * M_PI * v;
+    point[X] = center[X] + radius * radial * cos(angle);
+    point[Y] = center[Y] + radius * radial * sin(angle);
+    point[Z] = center[Z] + radius * z;
 }
 
-
 /**
- * Generate @p nrays chord rays from 2*nrays random points on the
- * bounding sphere.  Each ray connects one randomly chosen point to
- * another.
+ * Generate independent random chord endpoints.  Pairing consecutive IID
+ * sphere points has the same distribution as shuffling a point array before
+ * pairing, but consumes exactly four random values per ray.  That fixed
+ * stride lets callers continue the deterministic stream with ray_offset.
  */
 static void
-generate_rays(struct crofton_ray *rays, size_t nrays,
-	      double radius, const point_t center, std::mt19937_64 &rng)
+generate_rays(struct crofton_ray *rays, size_t ray_count, size_t first_id,
+    double radius, const point_t center, std::mt19937_64 &rng)
 {
-    size_t npts = nrays * 2;
-
-    point_t *pts = (point_t *)bu_calloc(npts, sizeof(point_t), "crofton pts");
-    for (size_t i = 0; i < npts; i++)
-	random_point_on_sphere(radius, center, pts[i], rng);
-
-    /* Shuffle so pairing is random */
-    for (size_t i = npts - 1; i > 0; i--) {
-	size_t j = (size_t)(crofton_rand01(rng) * (i + 1));
-	if (j > i) j = i;
-	point_t tmp;
-	VMOVE(tmp, pts[i]);
-	VMOVE(pts[i], pts[j]);
-	VMOVE(pts[j], tmp);
+    for (size_t i = 0; i < ray_count; i++) {
+        point_t endpoint;
+        random_point_on_sphere(radius, center, crofton_random01(rng),
+            crofton_random01(rng), rays[i].r_pt);
+        random_point_on_sphere(radius, center, crofton_random01(rng),
+            crofton_random01(rng), endpoint);
+        VSUB2(rays[i].r_dir, endpoint, rays[i].r_pt);
+        VUNITIZE(rays[i].r_dir);
+        rays[i].id = first_id + i;
     }
-
-    for (size_t i = 0; i < nrays; i++) {
-	VMOVE(rays[i].r_pt, pts[i * 2]);
-	VSUB2(rays[i].r_dir, pts[i * 2 + 1], pts[i * 2]);
-	VUNITIZE(rays[i].r_dir);
-    }
-
-    bu_free(pts, "crofton pts");
 }
 
+/* ------------------------------------------------------------------ */
+/* Reusable parallel workers                                            */
+/* ------------------------------------------------------------------ */
+
+class CroftonWorkerPool
+{
+    public:
+	CroftonWorkerPool(const struct application *ap_template,
+		struct resource *resources, size_t worker_count) :
+		count(worker_count), data(worker_count)
+	{
+	    for (size_t i = 0; i < count; i++) {
+		data[i].ap = *ap_template;
+		data[i].ap.a_resource = &resources[i];
+		data[i].shared = NULL;
+		data[i].ap.a_uptr = &data[i];
+	    }
+
+	    try {
+		executor = std::thread(&CroftonWorkerPool::run_workers, this);
+	    } catch (...) {
+		free_worker_points();
+		throw;
+	    }
+
+	    std::unique_lock<std::mutex> lock(mutex);
+	    if (!workers_started.wait_for(lock, worker_start_timeout,
+		    [this]() { return registered == count; })) {
+		stopping = true;
+		work_ready.notify_all();
+		lock.unlock();
+		executor.join();
+		free_worker_points();
+		throw std::runtime_error("worker startup timed out");
+	    }
+	}
+
+	~CroftonWorkerPool()
+	{
+	    stop_and_join();
+	    free_worker_points();
+	}
+
+	CroftonWorkerPool(const CroftonWorkerPool &) = delete;
+	CroftonWorkerPool &operator=(const CroftonWorkerPool &) = delete;
+
+	void run(struct crofton_ray *rays, size_t nrays,
+		struct crofton_shared *shared)
+	{
+	    const size_t rays_per_worker = nrays / count;
+	    std::unique_lock<std::mutex> lock(mutex);
+	    for (size_t i = 0; i < count; i++) {
+		struct crofton_worker_data &wd = data[i];
+		wd.rays = rays;
+		wd.start = i * rays_per_worker;
+		wd.end = (i == count - 1) ? nrays : (i + 1) * rays_per_worker;
+		wd.shared = shared;
+		wd.local_crossings = 0;
+		wd.local_chord = 0.0;
+		wd.local_rays = 0;
+		wd.local_point_count = 0;
+		wd.local_segment_count = 0;
+	    }
+	    completed = 0;
+	    generation++;
+	    work_ready.notify_all();
+	    work_done.wait(lock, [this]() { return completed == count; });
+	}
+
+	const std::vector<struct crofton_worker_data> &worker_data() const
+	{
+	    return data;
+	}
+
+    private:
+	/* Native thread creation should complete promptly.  A bounded startup wait
+	 * turns partial bu_parallel startup into a reported failure, not a hang. */
+	static constexpr std::chrono::seconds worker_start_timeout{5};
+
+	static void worker_entry(int UNUSED(id), void *context)
+	{
+	    CroftonWorkerPool *pool = static_cast<CroftonWorkerPool *>(context);
+	    size_t slot = 0;
+	    {
+		std::lock_guard<std::mutex> lock(pool->mutex);
+		slot = pool->registered++;
+		if (pool->registered == pool->count)
+		    pool->workers_started.notify_one();
+	    }
+	    pool->worker(slot);
+	}
+
+	void run_workers()
+	{
+	    bu_parallel(worker_entry, count, this);
+	}
+
+	void worker(size_t slot)
+	{
+	    size_t observed_generation = 0;
+	    std::unique_lock<std::mutex> lock(mutex);
+	    while (true) {
+		work_ready.wait(lock, [this, observed_generation]() {
+		    return stopping || generation != observed_generation;
+		});
+		if (stopping)
+		    return;
+
+		observed_generation = generation;
+		struct crofton_worker_data *wd = &data[slot];
+		lock.unlock();
+		for (size_t i = wd->start; i < wd->end; i++) {
+		    wd->current_ray = i;
+		    VMOVE(wd->ap.a_ray.r_pt, wd->rays[i].r_pt);
+		    VMOVE(wd->ap.a_ray.r_dir, wd->rays[i].r_dir);
+		    rt_shootray(&wd->ap);
+		}
+		lock.lock();
+		completed++;
+		if (completed == count)
+		    work_done.notify_one();
+	    }
+	}
+
+	void stop_and_join()
+	{
+	    {
+		std::lock_guard<std::mutex> lock(mutex);
+		stopping = true;
+		work_ready.notify_all();
+	    }
+	    if (executor.joinable())
+		executor.join();
+	}
+
+	void free_worker_points()
+	{
+	    for (struct crofton_worker_data &wd : data) {
+		if (wd.local_points)
+		    bu_free(wd.local_points, "Crofton worker hit points");
+		if (wd.local_segments)
+		    bu_free(wd.local_segments, "Crofton worker segments");
+		wd.local_points = NULL;
+		wd.local_segments = NULL;
+	    }
+	}
+
+	size_t count;
+	std::vector<struct crofton_worker_data> data;
+	std::thread executor;
+	std::mutex mutex;
+	std::condition_variable workers_started;
+	std::condition_variable work_ready;
+	std::condition_variable work_done;
+	size_t registered = 0;
+	size_t generation = 0;
+	size_t completed = 0;
+	bool stopping = false;
+};
 
-/* ------------------------------------------------------------------ */
-/* One iteration: fire nrays, accumulate into shared                   */
-/* ------------------------------------------------------------------ */
 
 static void
-do_one_iteration(struct application *ap_template,
-		 struct resource    *resources,
-		 size_t              nrays,
-		 double              radius,
-		 const point_t       center,
-		 struct crofton_shared *shared,
-		 std::mt19937_64      &rng)
+do_one_iteration(CroftonWorkerPool &pool, size_t ray_count, double radius,
+    const point_t center, struct crofton_shared *shared,
+    std::mt19937_64 &rng)
 {
     struct crofton_ray *rays = (struct crofton_ray *)bu_calloc(
-	nrays, sizeof(struct crofton_ray), "crofton rays");
+        ray_count, sizeof(struct crofton_ray), "Crofton rays");
+    generate_rays(rays, ray_count, shared->ray_offset + shared->total_rays,
+        radius, center, rng);
+    pool.run(rays, ray_count, shared);
 
-    generate_rays(rays, nrays, radius, center, rng);
+    for (const struct crofton_worker_data &worker : pool.worker_data()) {
+        shared->total_crossings += worker.local_crossings;
+        shared->total_chord += worker.local_chord;
+        shared->total_rays += worker.local_rays;
 
-    size_t ncpus = bu_avail_cpus();
-    if (ncpus < 1) ncpus = 1;
-    if (ncpus > MAX_PSW) ncpus = MAX_PSW;
+        if (worker.local_point_count) {
+            const size_t needed =
+                shared->point_count + worker.local_point_count;
+            if (needed > shared->point_capacity) {
+                size_t new_capacity = shared->point_capacity ?
+                    2 * shared->point_capacity : needed;
+                if (new_capacity < needed)
+                    new_capacity = needed;
+                shared->points = (point_t *)bu_realloc(shared->points,
+                    new_capacity * sizeof(point_t),
+                    "Crofton hit points");
+                shared->point_capacity = new_capacity;
+            }
+            memcpy(&shared->points[shared->point_count],
+                worker.local_points,
+                worker.local_point_count * sizeof(point_t));
+            shared->point_count = needed;
+        }
 
-    struct crofton_worker_data *wdata = (struct crofton_worker_data *)bu_calloc(
-	ncpus, sizeof(struct crofton_worker_data), "crofton wdata");
-
-    size_t per_cpu = nrays / ncpus;
-
-    for (size_t i = 0; i < ncpus; i++) {
-	struct application *a = (struct application *)bu_calloc(
-	    1, sizeof(struct application), "crofton app");
-	*a = *ap_template;                  /* struct copy */
-	a->a_resource = &resources[i];
-
-	struct crofton_worker_data *wd = &wdata[i];
-	wd->ap     = a;
-	wd->rays   = rays;
-	wd->start  = i * per_cpu;
-	wd->end    = (i == ncpus - 1) ? nrays : (i + 1) * per_cpu;
-	wd->shared = shared;
-	a->a_uptr  = wd;
+        if (worker.local_segment_count) {
+            const size_t needed =
+                shared->segment_count + worker.local_segment_count;
+            if (needed > shared->segment_capacity) {
+                size_t new_capacity = shared->segment_capacity ?
+                    2 * shared->segment_capacity : needed;
+                if (new_capacity < needed)
+                    new_capacity = needed;
+                shared->segments =
+                    (struct rt_crofton_segment *)bu_realloc(
+                        shared->segments,
+                        new_capacity * sizeof(struct rt_crofton_segment),
+                        "Crofton segments");
+                shared->segment_capacity = new_capacity;
+            }
+            memcpy(&shared->segments[shared->segment_count],
+                worker.local_segments,
+                worker.local_segment_count *
+                    sizeof(struct rt_crofton_segment));
+            shared->segment_count = needed;
+        }
     }
 
-    bu_parallel(crofton_worker, (int)ncpus, (void *)wdata);
-
-    for (size_t i = 0; i < ncpus; i++) {
-	shared->total_crossings += wdata[i].local_crossings;
-	shared->total_chord     += wdata[i].local_chord;
-	shared->total_rays      += wdata[i].local_rays;
-	if (wdata[i].local_point_count) {
-	    const size_t needed = shared->point_count + wdata[i].local_point_count;
-	    if (needed > shared->point_capacity) {
-		size_t new_capacity = shared->point_capacity ?
-		    2 * shared->point_capacity : needed;
-		if (new_capacity < needed)
-		    new_capacity = needed;
-		shared->points = (point_t *)bu_realloc(shared->points,
-		    new_capacity * sizeof(point_t), "Crofton hit points");
-		shared->point_capacity = new_capacity;
-	    }
-	    memcpy(&shared->points[shared->point_count], wdata[i].local_points,
-		wdata[i].local_point_count * sizeof(point_t));
-	    shared->point_count = needed;
-	}
-    }
-
-    for (size_t i = 0; i < ncpus; i++) {
-	if (wdata[i].local_points)
-	    bu_free(wdata[i].local_points, "Crofton worker hit points");
-	bu_free(wdata[i].ap, "crofton app");
-    }
-    bu_free(wdata, "crofton wdata");
-    bu_free(rays,  "crofton rays");
+    bu_free(rays, "Crofton rays");
 }
 
-
 /* ------------------------------------------------------------------ */
 /* Public API: rt_crofton_shoot                                         */
 /* ------------------------------------------------------------------ */
@@ -375,7 +552,8 @@ do_one_iteration(struct application *ap_template,
  *          sampling (>= 0) on success; -1 on bad arguments.
  */
 static int
-crofton_shoot_impl(point_t                        **out_points,
+crofton_shoot_impl(struct rt_crofton_result       *out_result,
+                   point_t                        **out_points,
 		   size_t                          *out_point_count,
 		   double                          *out_surf_area,
 		   double                          *out_volume,
@@ -384,13 +562,22 @@ crofton_shoot_impl(point_t                        **out_points,
 		   point_t                          out_obb[8],
 		 struct rt_i                    *rtip,
 		 const struct rt_crofton_params *params,
+		 size_t                         ray_offset,
 		 const fastf_t                  *bbox_min,
 		 const fastf_t                  *bbox_max)
 {
-    if (!rtip || (!out_surf_area && !out_volume && !out_aabb_min && !out_obb && !out_points) ||
-	((out_points == NULL) != (out_point_count == NULL)) ||
-	((out_aabb_min == NULL) != (out_aabb_max == NULL)))
-	return -1;
+    if (!rtip ||
+        (!out_result && !out_surf_area && !out_volume && !out_aabb_min &&
+            !out_obb && !out_points) ||
+        ((out_points == NULL) != (out_point_count == NULL)) ||
+        ((out_aabb_min == NULL) != (out_aabb_max == NULL)) ||
+        (out_result && out_result->segments) ||
+        ray_offset > UINT64_MAX / RT_CROFTON_RANDOM_VALUES_PER_RAY)
+        return -1;
+    if (out_result) {
+        struct rt_crofton_result empty = RT_CROFTON_RESULT_INIT;
+        *out_result = empty;
+    }
     if (out_points) {
 	*out_points = NULL;
 	*out_point_count = 0;
@@ -473,10 +660,14 @@ crofton_shoot_impl(point_t                        **out_points,
     if (!use_default && max_rays > 0 && stability_mm <= 0.0 && time_ms <= 0.0)
 	batch = max_rays;   /* single-iteration mode */
 
+    size_t ncpus = bu_avail_cpus();
+    if (ncpus < 1) ncpus = 1;
+    if (ncpus > MAX_PSW) ncpus = MAX_PSW;
+
     /* ---- Initialize per-CPU resources ---- */
     struct resource *resources = (struct resource *)bu_calloc(
-	MAX_PSW, sizeof(struct resource), "crofton resources");
-    for (int i = 0; i < MAX_PSW; i++)
+	ncpus, sizeof(struct resource), "crofton resources");
+    for (size_t i = 0; i < ncpus; i++)
 	rt_init_resource(&resources[i], i, rtip);
 
     /* ---- Set up application template ---- */
@@ -494,10 +685,32 @@ crofton_shoot_impl(point_t                        **out_points,
     /* ---- Shared accumulator ---- */
     struct crofton_shared shared;
     memset(&shared, 0, sizeof(shared));
-    shared.collect_points = out_points != NULL || out_aabb_min != NULL || out_obb != NULL;
-    const bool stabilize_surface = out_surf_area != NULL || shared.collect_points;
+    shared.ray_offset = ray_offset;
+    shared.collect_points =
+        out_points != NULL || out_aabb_min != NULL || out_obb != NULL;
+    shared.collect_segments = out_result != NULL;
+    const bool stabilize_surface =
+        out_surf_area != NULL || out_result != NULL ||
+        shared.collect_points;
+
+    CroftonWorkerPool *pool = NULL;
+    try {
+	pool = new CroftonWorkerPool(&ap, resources, ncpus);
+    } catch (const std::exception &e) {
+	bu_log("rt_crofton: unable to start worker pool: %s\n", e.what());
+	for (size_t i = 0; i < ncpus; i++) {
+	    if (resources[i].re_magic == RESOURCE_MAGIC) {
+		rt_clean_resource_basic(rtip, &resources[i]);
+		BU_PTBL_SET(&rtip->rti_resources, i, NULL);
+	    }
+	}
+	bu_free(resources, "crofton resources");
+	return -1;
+    }
 
     std::mt19937_64 rng(RT_CROFTON_RNG_SEED);
+    rng.discard(static_cast<uint64_t>(ray_offset) *
+        RT_CROFTON_RANDOM_VALUES_PER_RAY);
 
     const double FOUR_PI    = 4.0 * M_PI;
     const double PI         = M_PI;
@@ -521,7 +734,7 @@ crofton_shoot_impl(point_t                        **out_points,
 		    curr_rays = batch;
 	    }
 
-	    do_one_iteration(&ap, resources, curr_rays, R, center, &shared, rng);
+	    do_one_iteration(*pool, curr_rays, R, center, &shared, rng);
 	    iteration++;
 
 	    if (shared.total_rays == 0) break;
@@ -562,9 +775,12 @@ crofton_shoot_impl(point_t                        **out_points,
     } else {
 	/* ---- Parametric loop: n_rays / stability_mm / time_ms ---- */
 	double prev_r_sa = -1.0, prev_r_v = -1.0;
+	double prev_sa = -1.0, prev_v = -1.0;
 	size_t total_fired = 0;
 	size_t stable_windows = 0;
 	int64_t t0 = (time_ms > 0.0) ? bu_gettime() : 0;
+	const bool use_relative_stability = out_result && time_ms > 0.0 &&
+	    stability_mm <= 0.0;
 
 	for (;;) {
 	    /* Time-budget check before firing */
@@ -581,7 +797,7 @@ crofton_shoot_impl(point_t                        **out_points,
 		if (fire > remaining) fire = remaining;
 	    }
 
-	    do_one_iteration(&ap, resources, fire, R, center, &shared, rng);
+	    do_one_iteration(*pool, fire, R, center, &shared, rng);
 	    total_fired += fire;
 
 	    if (shared.total_rays == 0) break;
@@ -594,27 +810,39 @@ crofton_shoot_impl(point_t                        **out_points,
 		/ (double)shared.total_rays;
 
 	    /* Stability check */
-	    if (stability_mm > 0.0 &&
+	    if ((stability_mm > 0.0 || use_relative_stability) &&
 		shared.total_rays >= RT_CROFTON_STABILITY_MIN_RAYS &&
 		shared.total_crossings >= RT_CROFTON_STABILITY_MIN_CROSSINGS) {
-		double r_sa = (curr_est_sa > 0.0) ? sqrt(curr_est_sa * INV_4PI)  : 0.0;
-		double r_v  = (curr_est_v  > 0.0) ? cbrt(curr_est_v  * INV_4PI3) : 0.0;
-
-		if (prev_r_sa >= 0.0) {
-		    int sa_ok = (!stabilize_surface) ||
-			fabs(r_sa - prev_r_sa) < stability_mm;
-		    int v_ok  = (!out_volume) ||
-			fabs(r_v  - prev_r_v)  < stability_mm;
-		    if (sa_ok && v_ok) {
-			stable_windows++;
-			if (stable_windows >= RT_CROFTON_STABILITY_MIN_WINDOWS)
-			    break;
-		    } else {
-			stable_windows = 0;
-		    }
+		bool sa_ok = false;
+		bool v_ok = false;
+		if (use_relative_stability) {
+		    sa_ok = !stabilize_surface || (prev_sa > 0.0 &&
+			fabs(curr_est_sa - prev_sa) / prev_sa * 100.0 <=
+			RT_CROFTON_DEFAULT_THRESHOLD);
+		    v_ok = !out_volume || (prev_v > 0.0 &&
+			fabs(curr_est_v - prev_v) / prev_v * 100.0 <=
+			RT_CROFTON_DEFAULT_THRESHOLD);
+		    prev_sa = curr_est_sa;
+		    prev_v = curr_est_v;
+		} else {
+		    double r_sa = (curr_est_sa > 0.0) ?
+			sqrt(curr_est_sa * INV_4PI) : 0.0;
+		    double r_v = (curr_est_v > 0.0) ?
+			cbrt(curr_est_v * INV_4PI3) : 0.0;
+		    sa_ok = !stabilize_surface || (prev_r_sa >= 0.0 &&
+			fabs(r_sa - prev_r_sa) < stability_mm);
+		    v_ok = !out_volume || (prev_r_v >= 0.0 &&
+			fabs(r_v - prev_r_v) < stability_mm);
+		    prev_r_sa = r_sa;
+		    prev_r_v = r_v;
+		}
+		if (sa_ok && v_ok) {
+		    stable_windows++;
+		    if (stable_windows >= RT_CROFTON_STABILITY_MIN_WINDOWS)
+			break;
+		} else {
+		    stable_windows = 0;
 		}
-		prev_r_sa = r_sa;
-		prev_r_v  = r_v;
 	    }
 
 	    /* Time-budget check after firing */
@@ -624,8 +852,16 @@ crofton_shoot_impl(point_t                        **out_points,
 	}
     }
 
-    if (out_surf_area) *out_surf_area = curr_est_sa;
-    if (out_volume)    *out_volume    = curr_est_v;
+    if (out_surf_area)
+        *out_surf_area = curr_est_sa;
+    if (out_volume)
+        *out_volume = curr_est_v;
+    if (out_result) {
+        out_result->surface_area = curr_est_sa;
+        out_result->volume = curr_est_v;
+        out_result->ray_count = shared.total_rays;
+        out_result->crossing_count = shared.total_crossings;
+    }
     if (out_aabb_min) {
 	for (size_t i = 0; i < shared.point_count; ++i)
 	    VMINMAX(*out_aabb_min, *out_aabb_max, shared.points[i]);
@@ -641,11 +877,19 @@ crofton_shoot_impl(point_t                        **out_points,
 	    bounds_ret = -1;
     }
     if (out_points && !bounds_ret) {
-	*out_points = shared.points;
-	*out_point_count = shared.point_count;
+        *out_points = shared.points;
+        *out_point_count = shared.point_count;
     } else if (shared.points) {
-	bu_free(shared.points, "Crofton hit points");
+        bu_free(shared.points, "Crofton hit points");
     }
+    if (out_result && !bounds_ret) {
+        out_result->segments = shared.segments;
+        out_result->segment_count = shared.segment_count;
+    } else if (shared.segments) {
+        bu_free(shared.segments, "Crofton segments");
+    }
+
+    delete pool;
 
     /* Clean each resource and NULL out its slot in rtip->rti_resources.
      * This is necessary because crofton_from_ip calls rt_i_destroy(rtip)
@@ -657,7 +901,7 @@ crofton_shoot_impl(point_t                        **out_points,
      *
      * By setting the slot to NULL we let rt_i_destroy's cleanup skip it,
      * and then we can safely bu_free the resources array.                */
-    for (int i = 0; i < MAX_PSW; i++) {
+    for (size_t i = 0; i < ncpus; i++) {
 	if (resources[i].re_magic == RESOURCE_MAGIC) {
 	    rt_clean_resource_basic(rtip, &resources[i]);
 	    BU_PTBL_SET(&rtip->rti_resources, i, NULL);
@@ -681,9 +925,31 @@ rt_crofton_shoot(double *out_surf_area, double *out_volume,
 		 const struct rt_crofton_params *params,
 		 const fastf_t *bbox_min, const fastf_t *bbox_max)
 {
-    return crofton_shoot_impl(out_points, out_point_count, out_surf_area,
-	out_volume, out_aabb_min, out_aabb_max, out_obb, rtip, params,
-	bbox_min, bbox_max);
+    return crofton_shoot_impl(NULL, out_points, out_point_count,
+        out_surf_area, out_volume, out_aabb_min, out_aabb_max, out_obb,
+        rtip, params, 0, bbox_min, bbox_max);
+}
+
+int
+rt_crofton_collect(struct rt_crofton_result *result, struct rt_i *rtip,
+    const struct rt_crofton_params *params, size_t ray_offset,
+    const fastf_t *bbox_min, const fastf_t *bbox_max)
+{
+    if (!result)
+        return -1;
+    return crofton_shoot_impl(result, NULL, NULL, NULL, NULL, NULL, NULL,
+        NULL, rtip, params, ray_offset, bbox_min, bbox_max);
+}
+
+void
+rt_crofton_result_free(struct rt_crofton_result *result)
+{
+    if (!result)
+        return;
+    if (result->segments)
+        bu_free(result->segments, "Crofton segments");
+    struct rt_crofton_result empty = RT_CROFTON_RESULT_INIT;
+    *result = empty;
 }
 
 
@@ -821,7 +1087,7 @@ crofton_from_ip_n(const struct rt_db_internal    *ip,
     double sa  = 0.0;
     double vol = 0.0;
     (void)rt_crofton_shoot(&sa, &vol, NULL, NULL, NULL, NULL, NULL,
-	rtip, params, NULL, NULL);
+        rtip, params, NULL, NULL);
 
     if (out_sa)  *out_sa  = sa;
     if (out_vol) *out_vol = vol;

src/librt/primitives/dsp/dsp.c

@@ -1543,8 +1543,7 @@ permute_cell(point_t A,
 	     struct dsp_specific *dsp,
 	     struct dsp_rpp *dsp_rpp)
 {
-    int x, y;
-
+    point_t tmp;
 
 #ifdef FULL_DSP_DEBUGGING
     if (RT_G_DEBUG & RT_DEBUG_HF) {
@@ -1558,10 +1557,8 @@ permute_cell(point_t A,
     switch (dsp->dsp_i.dsp_cuttype) {
 	case DSP_CUT_DIR_llUR:
 	    return DSP_CUT_DIR_llUR;
-	    break;
 
 	case DSP_CUT_DIR_ADAPT: {
-	    point_t tmp;
 	    size_t cx = (size_t)dsp_rpp->dsp_min[X];
 	    size_t cy = (size_t)dsp_rpp->dsp_min[Y];
 
@@ -1570,28 +1567,8 @@ permute_cell(point_t A,
 		       dsp_rpp->dsp_min[X],
 		       dsp_rpp->dsp_min[Y]);
 
-	    /*
-	     * We look at the points in the diagonal next cells to
-	     * determine the curvature along each diagonal of this
-	     * cell.  This cell is divided into two triangles by
-	     * cutting across the cell in the direction of least
-	     * curvature.
-	     *
-	     *	*  *  *	 *
-	     *	 \      /
-	     *	  \C  D/
-	     *	*  *--*  *
-	     *	   |\/|
-	     *	   |/\|
-	     *	*  *--*  *
-	     *	  /A  B\
-	     *	 /	\
-	     *	*  *  *	 *
-	     */
-
-	    /* leaf-cell precondition: the rpp spans exactly one grid unit, so
-	     * (cx, cy) plus the cell counts fully describe the curvature
-	     * stencil that rt_dsp_cell_cut() recomputes.
+	    /* The rpp spans one grid cell; use its indices to select the
+	     * lower-curvature diagonal.
 	     */
 	    BU_ASSERT(dsp_rpp->dsp_max[X] == dsp_rpp->dsp_min[X] + 1);
 	    BU_ASSERT(dsp_rpp->dsp_max[Y] == dsp_rpp->dsp_min[Y] + 1);
@@ -1599,15 +1576,16 @@ permute_cell(point_t A,
 	    if (rt_dsp_cell_cut(&dsp->dsp_i, cx, cy,
 			     (size_t)dsp->xsiz, (size_t)dsp->ysiz)
 		== DSP_CUT_DIR_llUR) {
-		/* A-D cut is fine, no need to permute */
 		if (RT_G_DEBUG & RT_DEBUG_HF)
 		    bu_log("A-D cut\n");
-
 		return DSP_CUT_DIR_llUR;
-
 	    }
-
-	    /* prefer the B-C cut */
+	}
+	/* fall through */
+	case DSP_CUT_DIR_ULlr:
+	    /* Both B-C modes need the same corner order.  The top triangles
+	     * must keep outward (+Z) normals for the entry/exit state machine.
+	     */
 	    VMOVE(tmp, A);
 	    VMOVE(A, B);
 	    VMOVE(B, D);
@@ -1615,35 +1593,7 @@ permute_cell(point_t A,
 	    VMOVE(C, tmp);
 	    if (RT_G_DEBUG & RT_DEBUG_HF)
 		bu_log("B-C cut\n");
-
 	    return DSP_CUT_DIR_ULlr;
-
-	    break;
-	}
-	case DSP_CUT_DIR_ULlr:
-	    /* assign the values for the corner points
-	     *
-	     *  D----C
-	     *  |    |
-	     *  |    |
-	     *  |    |
-	     *  B----A
-	     */
-	    x = dsp_rpp->dsp_min[X];
-	    y = dsp_rpp->dsp_min[Y];
-	    VSET(B, x, y, DSP(&dsp->dsp_i, x, y));
-
-	    x = dsp_rpp->dsp_max[X];
-	    VSET(A, x, y, DSP(&dsp->dsp_i, x, y));
-
-	    y = dsp_rpp->dsp_max[Y];
-	    VSET(C, x, y, DSP(&dsp->dsp_i, x, y));
-
-	    x = dsp_rpp->dsp_min[X];
-	    VSET(D, x, y, DSP(&dsp->dsp_i, x, y));
-
-	    return DSP_CUT_DIR_ULlr;
-	    break;
     }
     bu_log("%s:%d Unknown DSP cut direction: %d\n",
 	   __FILE__, __LINE__, dsp->dsp_i.dsp_cuttype);

src/librt/tests/crofton.c

@@ -43,6 +43,18 @@ rel_err(double estimated, double exact)
 }
 
 
+static int
+crofton_segments_equal(const struct rt_crofton_segment *left,
+		       const struct rt_crofton_segment *right)
+{
+    return left->ray_id == right->ray_id &&
+	NEAR_EQUAL(left->thickness, right->thickness, SMALL_FASTF) &&
+	VNEAR_EQUAL(left->in_point, right->in_point, SMALL_FASTF) &&
+	VNEAR_EQUAL(left->in_normal, right->in_normal, SMALL_FASTF) &&
+	VNEAR_EQUAL(left->out_point, right->out_point, SMALL_FASTF) &&
+	VNEAR_EQUAL(left->out_normal, right->out_normal, SMALL_FASTF);
+}
+
 static int
 verify_crofton_estimates(void)
 {
@@ -379,6 +391,102 @@ run_convergence_case(struct db_i *dbip,
 	    &sample_points, &sample_count,
 	    rtip, &p, NULL, NULL);
 	run_sec = (double)(bu_gettime() - t0) / 1000000.0;
+
+	if (i == 0) {
+	    struct rt_crofton_result samples = RT_CROFTON_RESULT_INIT;
+	    const size_t ray_offset = 4096u;
+	    const size_t continuation_rays = 256u;
+	    struct rt_crofton_params sample_params =
+		{ray_offset + continuation_rays, 0.0, 0.0};
+	    int sample_ret = rt_crofton_collect(&samples, rtip,
+		&sample_params, 0, NULL, NULL);
+	    int full_samples_valid = sample_ret > 0 && samples.segments &&
+		samples.segment_count * 2 == samples.crossing_count &&
+		samples.ray_count == sample_params.n_rays;
+	    if (!full_samples_valid) {
+		printf("  %-24s  invalid structured Crofton output\\n", label);
+		failures++;
+	    } else {
+		for (size_t sample_index = 0;
+		     sample_index < samples.segment_count; sample_index++) {
+		    struct rt_crofton_segment *segment =
+			&samples.segments[sample_index];
+		    if (segment->thickness <= 0.0 ||
+			!NEAR_EQUAL(DIST_PNT_PNT(segment->in_point,
+				segment->out_point), segment->thickness, RT_LEN_TOL) ||
+			!NEAR_EQUAL(MAGNITUDE(segment->in_normal), 1.0,
+				VUNITIZE_TOL) ||
+			!NEAR_EQUAL(MAGNITUDE(segment->out_normal), 1.0,
+				VUNITIZE_TOL) ||
+			segment->ray_id >= samples.ray_count) {
+			printf("  %-24s  invalid structured segment\\n", label);
+			failures++;
+			break;
+		    }
+		}
+	    }
+
+	    struct rt_crofton_result offset_samples =
+		RT_CROFTON_RESULT_INIT;
+	    struct rt_crofton_params offset_params =
+		{continuation_rays, 0.0, 0.0};
+	    sample_ret = rt_crofton_collect(&offset_samples, rtip,
+		&offset_params, ray_offset, NULL, NULL);
+	    int offset_samples_valid = sample_ret > 0 &&
+		offset_samples.ray_count == offset_params.n_rays;
+	    if (!offset_samples_valid) {
+		printf("  %-24s  invalid offset Crofton output\\n", label);
+		failures++;
+	    } else {
+		for (size_t sample_index = 0;
+		     sample_index < offset_samples.segment_count;
+		     sample_index++) {
+		    size_t ray_id = offset_samples.segments[sample_index].ray_id;
+		    if (ray_id < ray_offset ||
+			    ray_id >= ray_offset + offset_params.n_rays) {
+			printf("  %-24s  invalid offset ray identifier\\n",
+			    label);
+			failures++;
+			break;
+		    }
+		}
+	    }
+
+	    if (full_samples_valid && offset_samples_valid) {
+		size_t suffix_start = 0;
+		while (suffix_start < samples.segment_count &&
+		       samples.segments[suffix_start].ray_id < ray_offset)
+		    suffix_start++;
+		size_t suffix_count = samples.segment_count - suffix_start;
+
+		if (suffix_count != offset_samples.segment_count) {
+		    printf("  %-24s  random stream continuation count mismatch\\n",
+			label);
+		    failures++;
+		} else {
+		    for (size_t sample_index = 0;
+			 sample_index < suffix_count; sample_index++) {
+			const struct rt_crofton_segment *full_segment =
+			    &samples.segments[suffix_start + sample_index];
+			const struct rt_crofton_segment *offset_segment =
+			    &offset_samples.segments[sample_index];
+			if (!crofton_segments_equal(full_segment, offset_segment)) {
+			    printf("  %-24s  random stream continuation mismatch\\n",
+				label);
+			    failures++;
+			    break;
+			}
+		    }
+		}
+	    }
+
+	    rt_crofton_result_free(&samples);
+	    if (samples.segments || samples.segment_count)
+		failures++;
+	    rt_crofton_result_free(&offset_samples);
+	    if (offset_samples.segments || offset_samples.segment_count)
+		failures++;
+	}
 	rt_i_destroy(rtip);
 
 	if (elapsed_total_sec)

src/librt/tests/datum_annot_semantics.c

@@ -19,13 +19,14 @@
 #include "bu/malloc.h"
 #include "bu/str.h"
 #include "bv/vlist.h"
-#include "nmg.h"
 #include "raytrace.h"
 #include "rt/geom.h"
 #include "rt/primitives/annot.h"
 #include "rt/primitives/datum.h"
 #include "wdb.h"
 
+enum { LAYER_TEST_MAX_SEGMENTS = 2 };
+
 
 static void
 check_vector(const char *name, const fastf_t *actual, const fastf_t *expected)
@@ -46,79 +47,46 @@ lookup(struct db_i *dbip, const char *name)
 }
 
 
-struct annot_ray_result {
-    fastf_t in_dist;
-    fastf_t out_dist;
-    fastf_t color[3];
-    int color_valid;
-    int partitions;
-};
-
-
-static int
-annot_ray_hit(struct application *ap, struct partition *part_head,
-	struct seg *UNUSED(finished_segs))
-{
-    struct annot_ray_result *result = (struct annot_ray_result *)ap->a_uptr;
-    struct partition *part;
-
-    for (part = part_head->pt_forw; part != part_head;
-	    part = part->pt_forw) {
-	if (!result->partitions) {
-	    result->in_dist = part->pt_inhit->hit_dist;
-	    result->out_dist = part->pt_outhit->hit_dist;
-	    result->color_valid = part->pt_regionp->reg_mater.ma_color_valid;
-	    VMOVE(result->color, part->pt_regionp->reg_mater.ma_color);
-	}
-	result->partitions++;
-    }
-    return result->partitions > 0;
-}
-
-
-static int
-annot_ray_miss(struct application *UNUSED(ap))
-{
-    return 0;
-}
-
-
 static void
-check_annot_ray(struct db_i *dbip, const char *object,
-	const fastf_t *expected_color)
+write_layer_annotation(struct rt_wdb *wdbp, const char *name,
+    fastf_t anchor_x, uint32_t space, size_t segment_count,
+    const unsigned char colors[][4])
 {
-    struct rt_i *rtip = rt_i_create(dbip);
-    struct resource resource = RT_RESOURCE_INIT_ZERO;
-    struct application ap;
-    struct annot_ray_result result = {0};
-    const fastf_t expected_thickness = 0.2;
-    int shot_result;
+    struct rt_annot_internal annot = {0};
+    point2d_t vertices[2];
+    struct line_seg lines[LAYER_TEST_MAX_SEGMENTS] = {{0}};
+    void *segments[LAYER_TEST_MAX_SEGMENTS] = {NULL, NULL};
+    int reverse[LAYER_TEST_MAX_SEGMENTS] = {0, 0};
+    struct rt_annot_seg_style styles[LAYER_TEST_MAX_SEGMENTS] = {{0}};
+    size_t i;
 
-    if (!rtip || rt_gettree(rtip, object))
-	bu_exit(1, "unable to prepare annotation raytrace object %s\n", object);
-    rt_prep(rtip);
-    rt_init_resource(&resource, 0, rtip);
-    RT_APPLICATION_INIT(&ap);
-    ap.a_rt_i = rtip;
-    ap.a_resource = &resource;
-    ap.a_hit = annot_ray_hit;
-    ap.a_miss = annot_ray_miss;
-    ap.a_uptr = &result;
-    VSET(ap.a_ray.r_pt, 0.0, -2.0, 0.03);
-    VSET(ap.a_ray.r_dir, 1.0, 0.0, 0.0);
-    shot_result = rt_shootray(&ap);
-    if (shot_result != 1 || result.partitions != 1 ||
-	    !result.color_valid ||
-	    !NEAR_EQUAL(result.out_dist - result.in_dist,
-		expected_thickness, rtip->rti_tol.dist) ||
-	    !VNEAR_EQUAL(result.color, expected_color, VUNITIZE_TOL)) {
-	bu_log("%s: shot=%d partitions=%d LOS=%g color-valid=%d color=%g/%g/%g\n",
-	    object, shot_result, result.partitions,
-	    result.out_dist - result.in_dist, result.color_valid,
-	    V3ARGS(result.color));
-	bu_exit(1, "annotation did not produce the expected colored partition\n");
+    if (!wdbp || !name || !colors || segment_count < 1 ||
+	    segment_count > LAYER_TEST_MAX_SEGMENTS)
+	bu_exit(1, "invalid ordered-layer test annotation\n");
+    annot.magic = RT_ANNOT_INTERNAL_MAGIC;
+    VSET(annot.V, anchor_x, 0.0, 0.0);
+    annot.flags = space;
+    VSET(annot.u_vec, 0.0, 1.0, 0.0);
+    VSET(annot.v_vec, 0.0, 0.0, 1.0);
+    annot.vert_count = 2;
+    annot.verts = vertices;
+    V2SET(vertices[0], -1.0, 0.0);
+    V2SET(vertices[1], 1.0, 0.0);
+    annot.ant.count = segment_count;
+    annot.ant.reverse = reverse;
+    annot.ant.segments = segments;
+    annot.styles = styles;
+    for (i = 0; i < segment_count; ++i) {
+	lines[i].magic = CURVE_LSEG_MAGIC;
+	lines[i].start = 0;
+	lines[i].end = 1;
+	segments[i] = &lines[i];
+	styles[i].flags = RT_ANNOT_STYLE_COLOR;
+	styles[i].line_pattern = RT_ANNOT_LINE_CONTINUOUS;
+	memcpy(styles[i].color, colors[i], sizeof(styles[i].color));
     }
-    rt_i_destroy(rtip);
+    if (rt_annot_validate(&annot, NULL) || mk_annot(wdbp, name, &annot) < 0)
+	bu_exit(1, "unable to write ordered-layer test annotation\n");
 }
 
 
@@ -257,48 +225,78 @@ main(int argc, char **argv)
     annot.styles[10].role = RT_ANNOT_ROLE_MASK;
     annot.styles[10].flags = RT_ANNOT_STYLE_FILLED;
     annot.styles[10].symbol = (char *)"owned fill with hole";
+    {
+	const size_t segment_count = annot.ant.count;
+	annot.ant.count = 1;
+	annot.styles[0].line_pattern = RT_ANNOT_LINE_CONTINUOUS;
+	annot.styles[0].line_width = 1.0;
+	if (rt_annot_validate(&annot, NULL) ||
+		mk_annot(wdbp, "thin.annot", &annot) < 0)
+	    bu_exit(1, "unable to write default-width annotation\n");
+	annot.styles[0].line_width = 2.5;
+	if (rt_annot_validate(&annot, NULL) ||
+		mk_annot(wdbp, "wide.annot", &annot) < 0)
+	    bu_exit(1, "unable to write wide annotation\n");
+	annot.ant.count = segment_count;
+	annot.styles[0].line_pattern = RT_ANNOT_LINE_DASHED;
+    }
     if (rt_annot_validate(&annot, NULL) ||
 	    mk_annot(wdbp, "leader.annot", &annot) < 0)
 	bu_exit(1, "unable to write enhanced annotation\n");
-
     {
-	struct rt_annot_internal ray_annot = {0};
-	point2d_t ray_vertices[2];
-	struct line_seg ray_line = {0};
-	void *ray_segments[1];
-	int ray_reverse[1] = {0};
-	struct rt_annot_seg_style ray_style[1] = {{0}};
-	struct wmember member;
-	unsigned char region_color[3] = {90, 80, 70};
-
-	ray_annot.magic = RT_ANNOT_INTERNAL_MAGIC;
-	VSET(ray_annot.V, 10.0, 0.0, 0.0);
-	ray_annot.flags = RT_ANNOT_MODEL_SPACE;
-	VSET(ray_annot.u_vec, 0.0, 1.0, 0.0);
-	VSET(ray_annot.v_vec, 0.0, 0.0, 1.0);
-	ray_annot.vert_count = 2;
-	ray_annot.verts = ray_vertices;
-	V2SET(ray_vertices[0], -5.0, 0.0);
-	V2SET(ray_vertices[1], 5.0, 0.0);
-	ray_line.magic = CURVE_LSEG_MAGIC;
-	ray_line.start = 0;
-	ray_line.end = 1;
-	ray_segments[0] = &ray_line;
-	ray_annot.ant.count = 1;
-	ray_annot.ant.reverse = ray_reverse;
-	ray_annot.ant.segments = ray_segments;
-	ray_style[0].flags = RT_ANNOT_STYLE_WIDTH;
-	ray_style[0].line_pattern = RT_ANNOT_LINE_CONTINUOUS;
-	ray_style[0].line_width = 2.0;
-	ray_annot.styles = ray_style;
-	if (rt_annot_validate(&ray_annot, NULL) ||
-		mk_annot(wdbp, "ray.annot", &ray_annot) < 0)
-	    bu_exit(1, "unable to write raytrace annotation\n");
-	BU_LIST_INIT(&member.l);
-	if (!mk_addmember("ray.annot", &member.l, NULL, WMOP_UNION) ||
-		mk_lcomb(wdbp, "ray.r", &member, 1, NULL, NULL,
-		region_color, 0))
-	    bu_exit(1, "unable to write raytrace annotation region\n");
+	struct wmember members;
+	mat_t member_transform = MAT_INIT_IDN;
+	unsigned char inherited_color[3] = {90, 80, 70};
+	BU_LIST_INIT(&members.l);
+	MAT_DELTAS(member_transform, 100.0, 0.0, 0.0);
+	if (!mk_addmember("leader.annot", &members.l, member_transform,
+		WMOP_UNION) ||
+		mk_lcomb(wdbp, "annotation-group", &members, 0, NULL, NULL,
+		    inherited_color, 0))
+	    bu_exit(1, "unable to write annotation instance combination\n");
+    }
+    {
+	struct wmember members;
+	unsigned char inherited_color[3] = {21, 31, 41};
+	BU_LIST_INIT(&members.l);
+	if (!mk_addmember("annotation-group", &members.l, NULL, WMOP_UNION) ||
+		mk_lcomb(wdbp, "inherited-annotation-group", &members, 0,
+		    NULL, NULL, inherited_color, 1))
+	    bu_exit(1, "unable to write inherited annotation combination\n");
+    }
+    {
+	struct wmember members;
+	mat_t member_transform = MAT_INIT_IDN;
+	BU_LIST_INIT(&members.l);
+	MAT_SCALE_ALL(member_transform, 1000.0);
+	if (!mk_addmember("leader.annot", &members.l, member_transform,
+		WMOP_UNION) ||
+		mk_lcomb(wdbp, "scaled-annotation-group", &members, 0, NULL,
+		    NULL, NULL, 0))
+	    bu_exit(1, "unable to write scaled annotation instance combination\n");
+    }
+    {
+	point_t saved_anchor;
+	VMOVE(saved_anchor, annot.V);
+	VSETALL(annot.V, 0.0);
+	annot.flags = RT_ANNOT_SCREEN_SPACE;
+	if (mk_annot(wdbp, "screen.annot", &annot) < 0)
+	    bu_exit(1, "unable to write screen annotation\n");
+	VMOVE(annot.V, saved_anchor);
+	annot.flags = RT_ANNOT_MODEL_SPACE;
+    }
+    {
+	const unsigned char far_color[][4] = {{0, 0, 255, 128}};
+	const unsigned char near_colors[][4] = {
+	    {255, 0, 0, 128}, {0, 255, 0, 128}
+	};
+	const unsigned char screen_color[][4] = {{255, 255, 255, 128}};
+	write_layer_annotation(wdbp, "alpha-far.annot", 20.0,
+	    RT_ANNOT_MODEL_SPACE, 1, far_color);
+	write_layer_annotation(wdbp, "alpha-near.annot", 10.0,
+	    RT_ANNOT_MODEL_SPACE, 2, near_colors);
+	write_layer_annotation(wdbp, "alpha-screen.annot", 0.0,
+	    RT_ANNOT_SCREEN_SPACE, 1, screen_color);
     }
 
     /* ANP2 is deliberately appended after the main-branch ANT2 body.  A
@@ -398,12 +396,7 @@ main(int argc, char **argv)
 	struct bu_list vhead;
 	struct bg_tess_tol ttol = BG_TESS_TOL_INIT_TOL;
 	struct bn_tol tol = BN_TOL_INIT_TOL;
-	if (!loaded || !loaded->styles || !loaded->ant.segments ||
-		loaded->ant.count != 11 || !loaded->ant.segments[10])
-	    bu_exit(1,
-		"enhanced annotation structure did not round trip\n");
-
-	if (!(loaded->flags & RT_ANNOT_MODEL_SPACE) ||
+	if (!(loaded->flags & RT_ANNOT_MODEL_SPACE) || !loaded->styles ||
 		loaded->styles[0].role != RT_ANNOT_ROLE_CENTERMARK ||
 		loaded->styles[0].line_pattern != RT_ANNOT_LINE_DASHED ||
 		!loaded->styles[0].font ||
@@ -422,6 +415,7 @@ main(int argc, char **argv)
 		!NEAR_EQUAL(loaded->styles[1].xy_scale, 0.25, SMALL_FASTF) ||
 		!NEAR_EQUAL(loaded->styles[1].yx_scale, 0.1, SMALL_FASTF) ||
 		!NEAR_EQUAL(loaded->styles[1].y_scale, 0.75, SMALL_FASTF) ||
+		loaded->ant.count != 11 ||
 		*(uint32_t *)loaded->ant.segments[10] != ANN_FSEG_MAGIC ||
 		loaded->styles[10].role != RT_ANNOT_ROLE_MASK ||
 		!loaded->styles[10].symbol ||
@@ -473,36 +467,222 @@ main(int argc, char **argv)
 	}
 	check_vector("annotation plot anchor", loaded->V, original_anchor);
 	BV_FREE_VLIST(&rt_vlfree, &vhead);
-	{
-	    struct model *model = nmg_mm();
-	    struct nmgregion *region = NULL;
-	    if (rt_obj_tess(&region, model, &intern, &ttol, &tol) || !region)
-		bu_exit(1, "unable to tessellate model-space annotation\n");
-	    nmg_km(model);
-	}
     }
     rt_db_free_internal(&intern);
 
     {
-	const fastf_t default_color[3] = {1.0, 1.0, 1.0};
-	const fastf_t annotation_color[3] = {
-	    12.0 / 255.0, 34.0 / 255.0, 56.0 / 255.0
+	const char *paths[] = {"leader.annot"};
+	struct bg_tess_tol ttol = BG_TESS_TOL_INIT_TOL;
+	struct bn_tol tol = BN_TOL_INIT_TOL;
+	struct rt_annot_scene *scene = rt_annot_scene_create(dbip, 1, paths,
+	    &ttol, &tol);
+	struct xray ray;
+	struct rt_annot_hit hit = {0};
+	struct rt_annot_hit all_hit = {0};
+	point_t render_min, render_max, width_sample;
+	const fastf_t line_offset = 0.12;
+	const fastf_t inverse_line_length = 1.0 / sqrt(41.0);
+	const fastf_t offset_x = 2.0 - 5.0 * line_offset * inverse_line_length;
+	const fastf_t offset_y = 2.5 + 4.0 * line_offset * inverse_line_length;
+	VSET(ray.r_pt, 0.0, 24.0, 37.5);
+	VSET(ray.r_dir, 1.0, 0.0, 0.0);
+	if (!scene || rt_annot_scene_count(scene) != 1)
+	    bu_exit(1, "annotation render scene did not collect its leaf\n");
+	if (!rt_annot_scene_bounds(scene, render_min, render_max) ||
+		!NEAR_EQUAL(render_min[X], 10.0, SMALL_FASTF) ||
+		!NEAR_EQUAL(render_max[X], 10.0, SMALL_FASTF) ||
+		render_min[Y] >= render_max[Y] ||
+		render_min[Z] >= render_max[Z])
+	    bu_exit(1, "annotation render scene bounds are invalid\n");
+	if (!rt_annot_scene_query(scene, NULL, &ray, 0.0, 0.0,
+		INFINITY, &hit) || hit.screen_space || !hit.visible ||
+		!NEAR_EQUAL(hit.distance, 10.0, SMALL_FASTF) ||
+		hit.color[0] != 12 || hit.color[1] != 34 || hit.color[2] != 56)
+	    bu_exit(1, "model annotation coverage query failed\n");
+	if (rt_annot_scene_query(scene, NULL, &ray, 0.0, 0.0, 5.0, &hit))
+	    bu_exit(1, "occluded annotation was returned as visible\n");
+	if (!rt_annot_scene_query(scene, NULL, &ray, 0.0, 0.0,
+		9.99975, &hit))
+	    bu_exit(1, "annotation visibility ignored model tolerance\n");
+	if (rt_annot_scene_query(scene, NULL, &ray, 0.0, 0.0,
+		9.999, &hit))
+	    bu_exit(1, "annotation visibility exceeded model tolerance\n");
+	if (rt_annot_scene_query_model(scene, &ray, 5.0, &all_hit, 1) != 1 ||
+		all_hit.visible)
+	    bu_exit(1, "annotation diagnostic query lost occluded coverage\n");
+	VSET(ray.r_pt, 0.0, 12.0, 18.0);
+	if (!rt_annot_scene_query(scene, NULL, &ray, 0.0, 0.0,
+		INFINITY, &hit) || hit.segment != 10)
+	    bu_exit(1, "filled annotation coverage was not returned\n");
+	VSET(ray.r_pt, 0.0, 17.0, 25.5);
+	if (rt_annot_scene_query(scene, NULL, &ray, 0.0, 0.0,
+		INFINITY, &hit))
+	    bu_exit(1, "annotation fill hole unexpectedly reported coverage\n");
+	rt_annot_scene_destroy(scene);
+	VSET(width_sample, 0.0, 20.0 + 2.0 * offset_x,
+	    30.0 + 3.0 * offset_y);
+	paths[0] = "wide.annot";
+	scene = rt_annot_scene_create(dbip, 1, paths, &ttol, &tol);
+	VMOVE(ray.r_pt, width_sample);
+	if (!scene || !rt_annot_scene_query(scene, NULL, &ray, 0.0, 0.0,
+		INFINITY, &hit) || hit.segment != 0)
+	    bu_exit(1, "annotation line width did not expand ray coverage\n");
+	rt_annot_scene_destroy(scene);
+	paths[0] = "thin.annot";
+	scene = rt_annot_scene_create(dbip, 1, paths, &ttol, &tol);
+	VMOVE(ray.r_pt, width_sample);
+	if (!scene || rt_annot_scene_query(scene, NULL, &ray, 0.0, 0.0,
+		INFINITY, &hit))
+	    bu_exit(1, "default line width unexpectedly covered wide sample\n");
+	rt_annot_scene_destroy(scene);
+    }
+
+    {
+	const char *paths[] = {"scaled-annotation-group"};
+	struct bg_tess_tol ttol = BG_TESS_TOL_INIT_TOL;
+	struct bn_tol tol = BN_TOL_INIT_TOL;
+	struct rt_annot_scene *scene = rt_annot_scene_create(dbip, 1, paths,
+	    &ttol, &tol);
+	struct xray ray;
+	struct rt_annot_hit hit = {0};
+	VSET(ray.r_pt, 0.0, 0.028, 0.045);
+	VSET(ray.r_dir, 1.0, 0.0, 0.0);
+	if (!scene || rt_annot_scene_count(scene) != 1 ||
+		!rt_annot_scene_query(scene, NULL, &ray, 0.0, 0.0,
+		    INFINITY, &hit) ||
+		!NEAR_EQUAL(hit.distance, 0.01, SMALL_FASTF))
+	    bu_exit(1, "scaled annotation instance coverage failed\n");
+	rt_annot_scene_destroy(scene);
+    }
+
+    {
+	const char *paths[] = {"annotation-group"};
+	struct bg_tess_tol ttol = BG_TESS_TOL_INIT_TOL;
+	struct bn_tol tol = BN_TOL_INIT_TOL;
+	struct rt_annot_scene *scene = rt_annot_scene_create(dbip, 1, paths,
+	    &ttol, &tol);
+	struct xray ray;
+	struct rt_annot_hit hit = {0};
+	VSET(ray.r_pt, 0.0, 28.0, 45.0);
+	VSET(ray.r_dir, 1.0, 0.0, 0.0);
+	if (!scene || rt_annot_scene_count(scene) != 1 ||
+		!rt_annot_scene_query(scene, NULL, &ray, 0.0, 0.0,
+		    INFINITY, &hit) ||
+		!NEAR_EQUAL(hit.distance, 110.0, SMALL_FASTF) ||
+		hit.segment != 10 || hit.color[0] != 90 ||
+		hit.color[1] != 80 || hit.color[2] != 70)
+	    bu_exit(1, "annotation instance transform was not applied\n");
+	VSET(ray.r_pt, 0.0, 24.0, 37.5);
+	if (!rt_annot_scene_query(scene, NULL, &ray, 0.0, 0.0,
+		INFINITY, &hit) || hit.segment != 0 || hit.color[0] != 12 ||
+		hit.color[1] != 34 || hit.color[2] != 56)
+	    bu_exit(1, "annotation segment color did not override inherited color\n");
+	rt_annot_scene_destroy(scene);
+    }
+
+    {
+	const char *paths[] = {"inherited-annotation-group"};
+	struct bg_tess_tol ttol = BG_TESS_TOL_INIT_TOL;
+	struct bn_tol tol = BN_TOL_INIT_TOL;
+	struct rt_annot_scene *scene = rt_annot_scene_create(dbip, 1, paths,
+	    &ttol, &tol);
+	struct xray ray;
+	struct rt_annot_hit hit = {0};
+	VSET(ray.r_pt, 0.0, 28.0, 45.0);
+	VSET(ray.r_dir, 1.0, 0.0, 0.0);
+	if (!scene || !rt_annot_scene_query(scene, NULL, &ray, 0.0, 0.0,
+		INFINITY, &hit) || hit.segment != 10 || hit.color[0] != 21 ||
+		hit.color[1] != 31 || hit.color[2] != 41)
+	    bu_exit(1, "annotation color did not follow tree inheritance\n");
+	rt_annot_scene_destroy(scene);
+    }
+
+    {
+	const char *paths[] = {"screen.annot"};
+	struct bg_tess_tol ttol = BG_TESS_TOL_INIT_TOL;
+	struct bn_tol tol = BN_TOL_INIT_TOL;
+	struct rt_annot_scene *scene = rt_annot_scene_create(dbip, 1, paths,
+	    &ttol, &tol);
+	struct rt_annot_view view = {MAT_INIT_IDN, 100, 100, 0.0};
+	struct xray ray;
+	struct rt_annot_hit hit = {0};
+	VSET(ray.r_pt, 0.0, 0.0, 10.0);
+	VSET(ray.r_dir, 0.0, 0.0, -1.0);
+	if (!scene || !rt_annot_scene_query(scene, &view, &ray, 50.0, 50.0,
+		0.0, &hit) || !hit.screen_space || !hit.visible)
+	    bu_exit(1, "screen annotation coverage query failed\n");
+	rt_annot_scene_destroy(scene);
+    }
+
+    {
+	const char *paths[] = {
+	    "alpha-far.annot", "alpha-near.annot", "alpha-screen.annot"
 	};
-	const fastf_t region_color[3] = {
-	    90.0 / 255.0, 80.0 / 255.0, 70.0 / 255.0
+	struct bg_tess_tol ttol = BG_TESS_TOL_INIT_TOL;
+	struct bn_tol tol = BN_TOL_INIT_TOL;
+	struct rt_annot_scene *scene = rt_annot_scene_create(dbip, 3, paths,
+	    &ttol, &tol);
+	struct rt_annot_view view = {MAT_INIT_IDN, 100, 100, 0.0};
+	struct rt_annot_hit layers[4] = {{0}};
+	struct rt_annot_hit diagnostic_hits[2] = {{0}};
+	struct rt_annot_hit top = {0};
+	struct xray ray;
+	size_t layer_count;
+	fastf_t color[3] = {0.0, 0.0, 0.0};
+	const fastf_t alpha = 128.0 / 255.0;
+	const fastf_t remainder = 1.0 - alpha;
+	const fastf_t expected_color[3] = {
+	    alpha + remainder * remainder * alpha,
+	    alpha + remainder * alpha,
+	    alpha + remainder * remainder * remainder * alpha
 	};
-
-	/* m35.g has this broad table entry, which includes the synthetic ID 0
-	 * assigned to bare solids.  It must not replace annotation colors. */
-	db_mater_add(dbip, 0, 15000, 210, 146, 1, MATER_NO_ADDR);
-	check_annot_ray(dbip, "ray.annot", default_color);
-	if (db5_update_attribute("ray.annot", "rgb", "12/34/56", dbip))
-	    bu_exit(1, "unable to set annotation raytrace color\n");
-	check_annot_ray(dbip, "ray.annot", annotation_color);
-	check_annot_ray(dbip, "ray.r", region_color);
+	VSET(ray.r_pt, 0.0, 0.0, 0.0);
+	VSET(ray.r_dir, 1.0, 0.0, 0.0);
+	layer_count = rt_annot_scene_query_layers(scene, &view, &ray,
+	    50.0, 50.0, INFINITY, layers, 2);
+	if (!scene || layer_count != 4 ||
+		bu_strcmp(layers[0].path, "/alpha-far.annot") ||
+		bu_strcmp(layers[1].path, "/alpha-near.annot") ||
+		layers[1].segment != 0)
+	    bu_exit(1, "annotation layer count or capacity handling failed: "
+		"count=%zu first=%s second=%s/%zu\n", layer_count,
+		layers[0].path ? layers[0].path : "(null)",
+		layers[1].path ? layers[1].path : "(null)", layers[1].segment);
+	if (rt_annot_scene_query_layers(scene, &view, &ray, 50.0, 50.0,
+		INFINITY, layers, 4) != 4 ||
+		!NEAR_EQUAL(layers[0].distance, 20.0, SMALL_FASTF) ||
+		!NEAR_EQUAL(layers[1].distance, 10.0, SMALL_FASTF) ||
+		layers[1].segment != 0 ||
+		layers[2].segment != 1 || !layers[3].screen_space)
+	    bu_exit(1, "annotation layers are not back-to-front\n");
+	if (!rt_annot_scene_query(scene, &view, &ray, 50.0, 50.0,
+		INFINITY, &top) || !top.screen_space ||
+		bu_strcmp(top.path, "/alpha-screen.annot"))
+	    bu_exit(1, "annotation top-layer compatibility query changed\n");
+	if (rt_annot_scene_query_layers(scene, &view, &ray, 50.0, 50.0,
+		15.0, NULL, 0) != 3)
+	    bu_exit(1, "annotation layer visibility filtering failed\n");
+	if (rt_annot_scene_query_model(scene, &ray, INFINITY,
+		diagnostic_hits, 2) != 2 ||
+		bu_strcmp(diagnostic_hits[0].path, "/alpha-near.annot") ||
+		diagnostic_hits[0].segment != 1 ||
+		bu_strcmp(diagnostic_hits[1].path, "/alpha-far.annot"))
+	    bu_exit(1, "annotation diagnostic hits changed layer semantics\n");
+	if (!rt_annot_scene_composite(scene, &view, &ray, 50.0, 50.0,
+		INFINITY, color, &top) ||
+		!VNEAR_EQUAL(color, expected_color, SMALL_FASTF) ||
+		!top.screen_space)
+	    bu_exit(1, "annotation alpha compositing order failed\n");
+	MAT_DELTAS(view.model2view, 0.0, 0.0, -2.0);
+	view.width = 160;
+	view.height = 90;
+	view.perspective = 60.0;
+	if (rt_annot_scene_query_layers(scene, &view, &ray, 80.0, 45.0,
+		INFINITY, NULL, 0) != 4)
+	    bu_exit(1, "perspective screen annotation coverage failed\n");
+	rt_annot_scene_destroy(scene);
     }
 
-    dp = lookup(dbip, "leader.annot");
     MAT_DELTAS(transform, -5.0, 6.0, 7.0);
     RT_DB_INTERNAL_INIT(&intern);
     if (rt_db_get_internal(&intern, dp, dbip, transform) != ID_ANNOT)

src/librt/tests/dsp_raytrace_check.c

@@ -414,13 +414,20 @@ flat_dsp_analytic(uint32_t xcnt, uint32_t ycnt, unsigned short h,
 /* Build an in-memory DB, prep, and run comparison                     */
 /* ------------------------------------------------------------------ */
 
+enum dsp_ray_check_mode {
+    DSP_RAY_CHECK_NONE,
+    DSP_RAY_CHECK_FLAT,
+    DSP_RAY_CHECK_SMOOTH,
+    DSP_RAY_CHECK_BC_CUT
+};
+
 struct dsp_case {
     const char     *label;
     uint32_t        xcnt, ycnt;
     const unsigned short *buf;
     int             cuttype;
     int             smooth;
-    int             ray_checks;
+    enum dsp_ray_check_mode ray_checks;
     /* stom diagonal (identity: dx=dy=dz=1): */
     double          dx, dy, dz;
     /* analytic SA/vol (-1 if not available): */
@@ -550,7 +557,7 @@ check_smooth_normal(const struct dsp_case *tc, struct soltab *stp)
 static int
 run_prepped_ray_checks(const struct dsp_case *tc, struct rt_i *rtip)
 {
-    if (!tc->ray_checks)
+    if (tc->ray_checks == DSP_RAY_CHECK_NONE)
 	return 0;
 
     int failures = 0;
@@ -562,16 +569,14 @@ run_prepped_ray_checks(const struct dsp_case *tc, struct rt_i *rtip)
 
     double x_extent = (tc->xcnt - 1) * tc->dx;
     double y_extent = (tc->ycnt - 1) * tc->dy;
-    /* ray_checks == 1 is reserved for flat DSP cases, so buf[0] is the
-     * expected terrain height for the deterministic vertical/side rays.
-     */
-    double top_z = (double)tc->buf[0] * tc->dz;
-    double expected_vertical_in = 10.0;
-    double expected_vertical_out = expected_vertical_in + top_z;
     point_t o;
     vect_t d;
 
-    if (tc->ray_checks == 1) {
+    if (tc->ray_checks == DSP_RAY_CHECK_FLAT) {
+	/* Flat cases use buf[0] as the terrain height for direct rays. */
+	double top_z = (double)tc->buf[0] * tc->dz;
+	double expected_vertical_in = 10.0;
+	double expected_vertical_out = expected_vertical_in + top_z;
 	VSET(o, 0.5 * x_extent, 0.5 * y_extent, top_z + 10.0);
 	VSET(d, 0.0, 0.0, -1.0);
 	failures += check_direct_ray("vertical down flat DSP", stp, rtip,
@@ -598,12 +603,22 @@ run_prepped_ray_checks(const struct dsp_case *tc, struct rt_i *rtip)
 	failures += check_direct_ray("vertical up flat DSP", stp, rtip,
 		o, d, 1, expected_vertical_in,
 		expected_vertical_out, 0);
-    } else if (tc->ray_checks == 2) {
+    } else if (tc->ray_checks == DSP_RAY_CHECK_SMOOTH) {
 	VSET(o, 0.5 * x_extent, 0.5 * y_extent, 10000.0);
 	VSET(d, 0.0, 0.0, -1.0);
 	failures += check_direct_ray("smooth-mode direct vertical shot", stp, rtip,
 		o, d, 1, -1.0, -1.0, 0);
 	failures += check_smooth_normal(tc, stp);
+    } else if (tc->ray_checks == DSP_RAY_CHECK_BC_CUT) {
+	/* In cell (3,3), the B-C triangle rises from 315 at y=3.25 by
+	 * 68 per x.  A horizontal ray at z=330 enters at x=3+15/68
+	 * and exits through the outer wall at x=4.  This also checks
+	 * that the explicit B-C cut gives the top an outward normal.
+	 */
+	VSET(o, 2.5, 3.25, 330.0);
+	VSET(d, 1.0, 0.0, 0.0);
+	failures += check_direct_ray("explicit B-C top-to-side shot", stp, rtip,
+		o, d, 1, 0.5 + 15.0 / 68.0, 1.5, 1);
     }
 
     return failures;
@@ -782,7 +797,7 @@ test_synthetic(void)
 
 	struct dsp_case tc = {
 	    "flat 5x5 h=100 (4x4 cells, identity stom)",
-	    GW, GH, buf, DSP_CUT_DIR_llUR, 0, 1, 1.0, 1.0, 1.0, asa, avol
+	    GW, GH, buf, DSP_CUT_DIR_llUR, 0, DSP_RAY_CHECK_FLAT, 1.0, 1.0, 1.0, asa, avol
 	};
 	failures += run_inmem_case(&tc);
     }
@@ -798,7 +813,7 @@ test_synthetic(void)
 
 	struct dsp_case tc = {
 	    "flat 10x10 h=200 (9x9 cells)",
-	    GW, GH, buf, DSP_CUT_DIR_llUR, 0, 0, 1.0, 1.0, 1.0, asa, avol
+	    GW, GH, buf, DSP_CUT_DIR_llUR, 0, DSP_RAY_CHECK_NONE, 1.0, 1.0, 1.0, asa, avol
 	};
 	failures += run_inmem_case(&tc);
     }
@@ -814,7 +829,7 @@ test_synthetic(void)
 
 	struct dsp_case tc = {
 	    "flat 10x10 h=50 (stom dx=5 dy=5 dz=2)",
-	    GW, GH, buf, DSP_CUT_DIR_llUR, 0, 1, 5.0, 5.0, 2.0, asa, avol
+	    GW, GH, buf, DSP_CUT_DIR_llUR, 0, DSP_RAY_CHECK_FLAT, 5.0, 5.0, 2.0, asa, avol
 	};
 	failures += run_inmem_case(&tc);
     }
@@ -829,7 +844,7 @@ test_synthetic(void)
 
 	struct dsp_case tc = {
 	    "ramp 9x9 (h=100+20x+10y)",
-	    GW, GH, buf, DSP_CUT_DIR_llUR, 0, 0, 1.0, 1.0, 1.0, -1.0, -1.0
+	    GW, GH, buf, DSP_CUT_DIR_llUR, 0, DSP_RAY_CHECK_NONE, 1.0, 1.0, 1.0, -1.0, -1.0
 	};
 	failures += run_inmem_case(&tc);
     }
@@ -844,7 +859,7 @@ test_synthetic(void)
 
 	struct dsp_case tc = {
 	    "asymmetric 5x5 explicit ULlr cut",
-	    GW, GH, buf, DSP_CUT_DIR_ULlr, 0, 0, 1.0, 1.0, 1.0, -1.0, -1.0
+	    GW, GH, buf, DSP_CUT_DIR_ULlr, 0, DSP_RAY_CHECK_BC_CUT, 1.0, 1.0, 1.0, -1.0, -1.0
 	};
 	failures += run_inmem_case(&tc);
     }
@@ -859,7 +874,7 @@ test_synthetic(void)
 
 	struct dsp_case tc = {
 	    "asymmetric 5x5 adaptive cut",
-	    GW, GH, buf, DSP_CUT_DIR_ADAPT, 0, 0, 1.0, 1.0, 1.0, -1.0, -1.0
+	    GW, GH, buf, DSP_CUT_DIR_ADAPT, 0, DSP_RAY_CHECK_NONE, 1.0, 1.0, 1.0, -1.0, -1.0
 	};
 	failures += run_inmem_case(&tc);
     }
@@ -874,7 +889,7 @@ test_synthetic(void)
 
 	struct dsp_case tc = {
 	    "smooth=1 ramp normal check",
-	    GW, GH, buf, DSP_CUT_DIR_llUR, 1, 2, 1.0, 1.0, 1.0, -1.0, -1.0
+	    GW, GH, buf, DSP_CUT_DIR_llUR, 1, DSP_RAY_CHECK_SMOOTH, 1.0, 1.0, 1.0, -1.0, -1.0
 	};
 	failures += run_inmem_case(&tc);
     }
@@ -889,7 +904,7 @@ test_synthetic(void)
 
 	struct dsp_case tc = {
 	    "smooth=2 ramp normal check",
-	    GW, GH, buf, DSP_CUT_DIR_llUR, 2, 2, 1.0, 1.0, 1.0, -1.0, -1.0
+	    GW, GH, buf, DSP_CUT_DIR_llUR, 2, DSP_RAY_CHECK_SMOOTH, 1.0, 1.0, 1.0, -1.0, -1.0
 	};
 	failures += run_inmem_case(&tc);
     }
@@ -908,7 +923,7 @@ test_synthetic(void)
 
 	struct dsp_case tc = {
 	    "sinusoidal 16x16",
-	    GW, GH, buf, DSP_CUT_DIR_llUR, 0, 0, 1.0, 1.0, 1.0, -1.0, -1.0
+	    GW, GH, buf, DSP_CUT_DIR_llUR, 0, DSP_RAY_CHECK_NONE, 1.0, 1.0, 1.0, -1.0, -1.0
 	};
 	failures += run_inmem_case(&tc);
     }
@@ -928,7 +943,7 @@ test_synthetic(void)
 
 	struct dsp_case tc = {
 	    "complex 33x33 wave",
-	    GW, GH, buf, DSP_CUT_DIR_llUR, 0, 0, 1.0, 1.0, 1.0, -1.0, -1.0
+	    GW, GH, buf, DSP_CUT_DIR_llUR, 0, DSP_RAY_CHECK_NONE, 1.0, 1.0, 1.0, -1.0, -1.0
 	};
 	failures += run_inmem_case(&tc);
 	bu_free(buf, "33x33 buf");
@@ -971,7 +986,7 @@ test_synthetic(void)
 
 	struct dsp_case tc = {
 	    "larger 129x129 mixed ramp/wave terrain",
-	    grid_width, grid_height, buf, DSP_CUT_DIR_llUR, 0, 0, 1.0, 1.0, 1.0, -1.0, -1.0
+	    grid_width, grid_height, buf, DSP_CUT_DIR_llUR, 0, DSP_RAY_CHECK_NONE, 1.0, 1.0, 1.0, -1.0, -1.0
 	};
 	failures += run_inmem_case(&tc);
 	bu_free(sin_x, "129x129 sin x");

src/nirt/main.cpp

@@ -889,4 +889,3 @@ done:
 // c-file-style: "stroustrup"
 // End:
 // ex: shiftwidth=4 tabstop=8
-

src/rt/CMakeLists.txt

@@ -56,6 +56,7 @@ add_target_deps(rtscale dm_plugins)
 
 brlcad_addexec(rt "${LIBRTUIF_SOURCES};view.c" "${OPENCL_LIBS};${RT_STD_LIBS}" FOLDER Rt)
 target_include_directories(rt BEFORE PRIVATE ${CMAKE_CURRENT_SOURCE_DIR})
+set_property(TARGET rt APPEND PROPERTY COMPILE_DEFINITIONS "RT_ANNOT_OVERLAY")
 add_target_deps(rt dm_plugins dm-txt)
 
 brlcad_addexec(rtarea "${LIBRTUIF_SOURCES};viewarea.c" "${RT_STD_LIBS}" FOLDER Rt)

src/rt/do.c

@@ -80,6 +80,15 @@ extern void worker(int cpu, void *arg);
 
 extern struct icv_image *bif;
 unsigned char *pixmap = NULL; /**< Pixel Map for rerendering of black pixels */
+#ifdef RT_ANNOT_OVERLAY
+static struct rt_annot_scene *annotation_scene = NULL;
+static struct rt_annot_view annotation_view = {MAT_INIT_IDN, 0, 0, 0.0};
+static struct db_i *annotation_dbip = DBI_NULL;
+static struct bu_ptbl annotation_paths = BU_PTBL_INIT_ZERO;
+static struct bg_tess_tol annotation_ttol = BG_TESS_TOL_INIT_ZERO;
+static struct bn_tol annotation_tol = BN_TOL_INIT_ZERO;
+static int annotation_cache_valid = 0;
+#endif
 
 enum view_command_flag {
     VIEW_COMMAND_EYE_SET = 1u << 0,
@@ -320,6 +329,9 @@ int cm_end(const int UNUSED(argc), const char **UNUSED(argv))
 	return -1;
     }
 
+#ifdef RT_ANNOT_OVERLAY
+    rtuif_prepare_annotations(rtip);
+#endif
     do_view_finalize(azimuth, elevation);
 
     if (do_frame(curframe) < 0)
@@ -472,6 +484,9 @@ int cm_multiview(const int UNUSED(argc), const char **UNUSED(argv))
     if (rtip && BU_LIST_IS_EMPTY(&rtip->HeadRegion) && !def_tree(rtip, NULL)) {
 	return -1;
     }
+#ifdef RT_ANNOT_OVERLAY
+    rtuif_prepare_annotations(rtip);
+#endif
     for (i = 0; i < (sizeof(a)/sizeof(a[0])); i++) {
 	do_ae((double)a[i], (double)e[i]);
 	(void)do_frame(curframe++);
@@ -492,6 +507,9 @@ int cm_anim(const int argc, const char **argv)
 	bu_log("cm_anim:  %s %s failed\n", argv[1], argv[2]);
 	return -1;		/* BAD */
     }
+#ifdef RT_ANNOT_OVERLAY
+    rtuif_clear_annotations();
+#endif
     return 0;
 }
 
@@ -887,11 +905,19 @@ validate_raytrace(struct rt_i *rtip)
 	bu_log("ERROR: No raytracing instance.\n");
 	return 1;
     }
-    if (rtip->stats.nsolids <= 0) {
+    if (rtip->stats.nsolids <= 0
+#ifdef RT_ANNOT_OVERLAY
+	    && (!annotation_scene || !rt_annot_scene_count(annotation_scene))
+#endif
+	    ) {
 	bu_log("ERROR: No primitives remaining.\n");
 	return 2;
     }
-    if (rtip->stats.nregions <= 0) {
+    if (rtip->stats.nregions <= 0
+#ifdef RT_ANNOT_OVERLAY
+	    && (!annotation_scene || !rt_annot_scene_count(annotation_scene))
+#endif
+	    ) {
 	bu_log("ERROR: No regions remaining.\n");
 	return 3;
     }
@@ -900,6 +926,152 @@ validate_raytrace(struct rt_i *rtip)
 }
 
 
+#ifdef RT_ANNOT_OVERLAY
+static void
+annotation_cache_clear(void)
+{
+    size_t i;
+
+    rt_annot_scene_destroy(annotation_scene);
+    annotation_scene = NULL;
+    if (BU_PTBL_TEST(&annotation_paths)) {
+	for (i = 0; i < BU_PTBL_LEN(&annotation_paths); ++i)
+	    bu_free((char *)BU_PTBL_GET(&annotation_paths, i),
+		"cached annotation path");
+	bu_ptbl_free(&annotation_paths);
+    }
+    annotation_dbip = DBI_NULL;
+    annotation_cache_valid = 0;
+}
+
+
+static int
+annotation_scalar_equal(double a, double b)
+{
+    return a <= b && a >= b;
+}
+
+
+static int
+annotation_tolerances_match(const struct rt_i *rtip)
+{
+    const struct bg_tess_tol *ttol = &rtip->rti_ttol;
+    const struct bn_tol *tol = &rtip->rti_tol;
+
+    return annotation_ttol.magic == ttol->magic &&
+	annotation_scalar_equal(annotation_ttol.abs, ttol->abs) &&
+	annotation_scalar_equal(annotation_ttol.rel, ttol->rel) &&
+	annotation_scalar_equal(annotation_ttol.norm, ttol->norm) &&
+	annotation_scalar_equal(annotation_ttol.absmax, ttol->absmax) &&
+	annotation_scalar_equal(annotation_ttol.absmin, ttol->absmin) &&
+	annotation_scalar_equal(annotation_ttol.relmax, ttol->relmax) &&
+	annotation_scalar_equal(annotation_ttol.relmin, ttol->relmin) &&
+	annotation_scalar_equal(annotation_ttol.rel_lmax, ttol->rel_lmax) &&
+	annotation_scalar_equal(annotation_ttol.rel_lmin, ttol->rel_lmin) &&
+	annotation_tol.magic == tol->magic &&
+	annotation_scalar_equal(annotation_tol.dist, tol->dist) &&
+	annotation_scalar_equal(annotation_tol.dist_sq, tol->dist_sq) &&
+	annotation_scalar_equal(annotation_tol.perp, tol->perp) &&
+	annotation_scalar_equal(annotation_tol.para, tol->para);
+}
+
+
+static int
+annotation_cache_matches(const struct rt_i *rtip, int path_count,
+	const char * const *paths)
+{
+    int i;
+
+    if (!annotation_cache_valid || annotation_dbip != rtip->rti_dbip ||
+	    path_count < 0 ||
+	    (size_t)path_count != BU_PTBL_LEN(&annotation_paths) ||
+	    !annotation_tolerances_match(rtip))
+	return 0;
+    for (i = 0; i < path_count; ++i)
+	if (!BU_STR_EQUAL((const char *)BU_PTBL_GET(&annotation_paths, i),
+		paths[i]))
+	    return 0;
+    return 1;
+}
+
+
+static void
+annotation_cache_store(const struct rt_i *rtip, int path_count,
+	const char * const *paths)
+{
+    int i;
+
+    bu_ptbl_init(&annotation_paths, (size_t)path_count,
+	"cached annotation paths");
+    for (i = 0; i < path_count; ++i)
+	bu_ptbl_ins(&annotation_paths, (long *)bu_strdup(paths[i]));
+    annotation_dbip = rtip->rti_dbip;
+    annotation_ttol = rtip->rti_ttol;
+    annotation_tol = rtip->rti_tol;
+    annotation_cache_valid = 1;
+}
+
+
+const struct rt_annot_scene *
+rtuif_annotations(void)
+{
+    return annotation_scene;
+}
+
+
+const struct rt_annot_view *
+rtuif_annotation_view(void)
+{
+    return &annotation_view;
+}
+
+
+void
+rtuif_clear_annotations(void)
+{
+    annotation_cache_clear();
+    MAT_IDN(annotation_view.model2view);
+    annotation_view.width = 0;
+    annotation_view.height = 0;
+    annotation_view.perspective = 0.0;
+}
+
+
+size_t
+rtuif_prepare_annotations(struct rt_i *rtip)
+{
+    const char **treev = NULL;
+    int treec = 0;
+    size_t count;
+
+    if (!rtip) {
+	rtuif_clear_annotations();
+	return 0;
+    }
+
+    if (cmd_objs && BU_PTBL_LEN(cmd_objs)) {
+	treec = (int)BU_PTBL_LEN(cmd_objs);
+	treev = (const char **)cmd_objs->buffer;
+    } else if (!rtuif_tree_list(rtip, &treec, &treev, NULL)) {
+	rtuif_clear_annotations();
+	return 0;
+    }
+    if (!annotation_cache_matches(rtip, treec, treev)) {
+	annotation_cache_clear();
+	annotation_scene = rt_annot_scene_create(rtip->rti_dbip, treec, treev,
+	    &rtip->rti_ttol, &rtip->rti_tol);
+	annotation_cache_store(rtip, treec, treev);
+    }
+    count = rt_annot_scene_count(annotation_scene);
+    if (opencl_mode && count) {
+	bu_log("rt: annotations require primary-sample compositing; using the CPU renderer\n");
+	opencl_mode = 0;
+    }
+    return count;
+}
+#endif
+
+
 /**
  * Do all the actual work to run a frame.
  *
@@ -924,6 +1096,10 @@ do_frame(int framenumber)
     /* Compute model RPP, etc. */
     do_prep(rtip);
 
+#ifdef RT_ANNOT_OVERLAY
+    rtuif_prepare_annotations(rtip);
+#endif
+
     if (rt_verbosity & VERBOSE_VIEWDETAIL)
 	bu_log("Tree: %zu solids in %zu regions\n", rtip->stats.nsolids, rtip->stats.nregions);
 
@@ -958,6 +1134,13 @@ do_frame(int framenumber)
 	bu_vls_free(&msg);
     }
 
+#ifdef RT_ANNOT_OVERLAY
+    MAT_COPY(annotation_view.model2view, model2view);
+    annotation_view.width = width;
+    annotation_view.height = height;
+    annotation_view.perspective = rt_perspective;
+#endif
+
     /* az/el 0, 0 is when screen +Z is model +X */
     VSET(work, 0, 0, 1);
     MAT3X3VEC(temp, view2model, work);
@@ -1406,22 +1589,32 @@ do_ae_internal(double azim, double elev, int center_eye)
 {
     struct rt_i *rtip = APP.a_rt_i;
     point_t view_min, view_max;
+#ifdef RT_ANNOT_OVERLAY
+    point_t annotation_min, annotation_max;
+    int have_annotation_bounds;
+#endif
 
     if (rtip == NULL)
 	return;
 
-    if (rtip->mdl_max[X] >= INFINITY) {
-	bu_log("do_ae: infinite model bounds? setting a unit minimum\n");
-	VSETALL(rtip->mdl_min, -1);
-    }
-    if (rtip->mdl_max[X] <= -INFINITY) {
+    if (rtip->mdl_min[X] >= INFINITY || rtip->mdl_max[X] <= -INFINITY) {
 	/* Model not yet loaded (librt initial state: mdl_min=+INF, mdl_max=-INF).
 	 * Reset both bounds to a unit box so that autoviewsize() does not
 	 * propagate +INFINITY through mdl_min into cell_width (which causes a
 	 * bu_bomb("bad cell size") crash when work is dispatched). */
-	bu_log("do_ae: infinite model bounds? setting unit bounds\n");
-	VSETALL(rtip->mdl_min, -1);
-	VSETALL(rtip->mdl_max, 1);
+#ifdef RT_ANNOT_OVERLAY
+	have_annotation_bounds = rt_annot_scene_bounds(annotation_scene,
+	    annotation_min, annotation_max);
+	if (have_annotation_bounds) {
+	    VMOVE(rtip->mdl_min, annotation_min);
+	    VMOVE(rtip->mdl_max, annotation_max);
+	} else
+#endif
+	{
+	    bu_log("do_ae: infinite model bounds? setting unit bounds\n");
+	    VSETALL(rtip->mdl_min, -1);
+	    VSETALL(rtip->mdl_max, 1);
+	}
     }
 
     /*
@@ -1443,6 +1636,14 @@ do_ae_internal(double azim, double elev, int center_eye)
      */
     VMOVE(view_min, rtip->mdl_min);
     VMOVE(view_max, rtip->mdl_max);
+#ifdef RT_ANNOT_OVERLAY
+    have_annotation_bounds = rt_annot_scene_bounds(annotation_scene,
+	annotation_min, annotation_max);
+    if (have_annotation_bounds) {
+	VMINMAX(view_min, view_max, annotation_min);
+	VMINMAX(view_min, view_max, annotation_max);
+    }
+#endif
     if (autoview_argc > 0) {
 	point_t sub_min, sub_max;
 	if (rt_obj_bounds(NULL, rtip->rti_dbip, autoview_argc,

src/rt/ext.h

@@ -151,6 +151,9 @@ extern vect_t dx_model;			/* view delta-X as model-space vect (width of pixel as
 extern vect_t dx_unit;			/* unit-len dir vector of pixel side-to-side */
 extern vect_t dy_model;			/* view delta-Y as model-space vect (height of pixel as vector) */
 extern vect_t dy_unit;			/* unit-len dir vector of pixel top-to-bottom */
+#ifdef RT_ANNOT_OVERLAY
+#  define RTUIF_ANNOTATION_ONLY 2
+#endif
 /** 'jitter' variable values **/
 #define JITTER_CELL 0x1			/* jitter position of ray in each cell */
 #define JITTER_FRAME 0x2		/* jitter position of entire frame */
@@ -197,6 +200,12 @@ extern void do_ae(double azim, double elev);
 extern void do_view_finalize(double azim, double elev);
 extern int old_way(FILE *fp);
 extern int do_frame(int framenumber);
+#ifdef RT_ANNOT_OVERLAY
+extern size_t rtuif_prepare_annotations(struct rt_i *rtip);
+extern const struct rt_annot_scene *rtuif_annotations(void);
+extern const struct rt_annot_view *rtuif_annotation_view(void);
+extern void rtuif_clear_annotations(void);
+#endif
 
 #ifdef USE_OPENCL
 enum {

src/rt/main.c

@@ -620,6 +620,9 @@ int main(int argc, char *argv[])
 	    }
 	}
 
+#ifdef RT_ANNOT_OVERLAY
+	rtuif_prepare_annotations(APP.a_rt_i);
+#endif
 	do_view_finalize(azimuth, elevation);
 
 	if (need_fb != 0 && !fbp) {
@@ -739,6 +742,9 @@ int main(int argc, char *argv[])
     }
 
 rt_cleanup:
+#ifdef RT_ANNOT_OVERLAY
+    rtuif_clear_annotations();
+#endif
     /* Clean up objv memory, if necessary */
     if (objs_free_argv) {
 	for (i = 0; i < objc; i++) {

src/rt/view.c

@@ -267,6 +267,14 @@ view_pixel(struct application *ap)
 		    fp->ff_frame = -1;		/* Don't cache misses */
 		    return;
 		}
+#ifdef RT_ANNOT_OVERLAY
+		if (ap->a_flag == RTUIF_ANNOTATION_ONLY) {
+		    /* Annotation coverage has no region or reusable model hit. */
+		    fp->ff_dist = -INFINITY;
+		    fp->ff_regp = NULL;
+		    return;
+		}
+#endif
 		/* XXX a_dist is negative and misleading when eye is in air */
 		fp->ff_dist = (float)ap->a_dist;
 		VJOIN1(fp->ff_hitpt, ap->a_ray.r_pt,
@@ -1230,6 +1238,7 @@ viewit(struct application *ap, struct partition *PartHeadp, struct seg *UNUSED(s
     }
 
     hitp = pp->pt_inhit;
+    ap->a_dist = hitp->hit_dist;
     RT_HIT_NORMAL(normal, hitp, pp->pt_inseg->seg_stp, &(ap->a_ray), pp->pt_inflip);
 
     /*

src/rt/worker.c

@@ -151,6 +151,46 @@ jitter_start_pnt(vect_t point, struct application *a, int samplenum, int pat_num
 }
 
 
+#ifdef RT_ANNOT_OVERLAY
+static int
+annotation_overlay_active(void)
+{
+    const struct rt_annot_scene *scene = rtuif_annotations();
+
+    return scene && rt_annot_scene_count(scene);
+}
+
+
+static void
+annotate_primary_sample(struct application *ap, const point_t viewplane_point)
+{
+    point_t view_point;
+    struct rt_annot_hit hit = {0};
+    fastf_t sample_x;
+    fastf_t sample_y;
+    fastf_t scene_distance;
+    const struct rt_annot_scene *scene = rtuif_annotations();
+    const struct rt_annot_view *view = rtuif_annotation_view();
+
+    if (!scene || !rt_annot_scene_count(scene))
+	return;
+    MAT4X3PNT(view_point, model2view, viewplane_point);
+    sample_x = (view_point[X] + 1.0) * (fastf_t)width * 0.5;
+    sample_y = view_point[Y] * (fastf_t)width * 0.5 +
+	(fastf_t)height * 0.5;
+    scene_distance = ap->a_user ? ap->a_dist : INFINITY;
+    if (rt_annot_scene_composite(scene, view, &ap->a_ray,
+	    sample_x, sample_y, scene_distance, ap->a_color, &hit)) {
+	if (!ap->a_user) {
+	    ap->a_user = 1;
+	    ap->a_flag = RTUIF_ANNOTATION_ONLY;
+	    ap->a_dist = hit.screen_space ? INFINITY : hit.distance;
+	}
+    }
+}
+#endif
+
+
 void
 do_pixel(int cpu, int pat_num, int pixelnum)
 {
@@ -239,7 +279,11 @@ do_pixel(int cpu, int pat_num, int pixelnum)
     if (fullfloat_mode) {
 	register struct floatpixel *fp;
 	fp = &curr_float_frame[a.a_y*width + a.a_x];
-	if (fp->ff_frame >= 0) {
+	if (fp->ff_frame >= 0
+#ifdef RT_ANNOT_OVERLAY
+		&& !annotation_overlay_active()
+#endif
+		) {
 	    return;	/* pixel was reprojected */
 	}
     }
@@ -247,7 +291,11 @@ do_pixel(int cpu, int pat_num, int pixelnum)
     /* Check the pixel map to determine if this image should be
      * rendered or not.
      */
-    if (pixmap) {
+    if (pixmap
+#ifdef RT_ANNOT_OVERLAY
+	    && !annotation_overlay_active()
+#endif
+	    ) {
 	a.a_user= 1;	/* Force Shot Hit */
 
 	if (pixmap[pindex + RED] + pixmap[pindex + GRN] + pixmap[pindex + BLU]) {
@@ -328,7 +376,12 @@ do_pixel(int cpu, int pat_num, int pixelnum)
 
 	a.a_level = 0;		/* recursion level */
 	a.a_purpose = "main ray";
+	a.a_flag = 0;
+	a.a_dist = INFINITY;
 	(void)rt_shootray(&a);
+#ifdef RT_ANNOT_OVERLAY
+	annotate_primary_sample(&a, point);
+#endif
 
 	if (stereo) {
 	    fastf_t right, left;
@@ -350,7 +403,12 @@ do_pixel(int cpu, int pat_num, int pixelnum)
 	    }
 	    a.a_level = 0;		/* recursion level */
 	    a.a_purpose = "left eye ray";
+	    a.a_flag = 0;
+	    a.a_dist = INFINITY;
 	    (void)rt_shootray(&a);
+#ifdef RT_ANNOT_OVERLAY
+	    annotate_primary_sample(&a, point);
+#endif
 
 	    left = CRT_BLEND(a.a_color);
 	    VSET(a.a_color, left, 0, right);
@@ -413,7 +471,12 @@ do_pixel(int cpu, int pat_num, int pixelnum)
 
 	    a.a_level = 0;		/* recursion level */
 	    a.a_purpose = "main ray";
+	    a.a_flag = 0;
+	    a.a_dist = INFINITY;
 	    (void)rt_shootray(&a);
+#ifdef RT_ANNOT_OVERLAY
+	    annotate_primary_sample(&a, point);
+#endif
 
 	    if (stereo) {
 		fastf_t right, left;
@@ -435,7 +498,12 @@ do_pixel(int cpu, int pat_num, int pixelnum)
 		}
 		a.a_level = 0;		/* recursion level */
 		a.a_purpose = "left eye ray";
+		a.a_flag = 0;
+		a.a_dist = INFINITY;
 		(void)rt_shootray(&a);
+#ifdef RT_ANNOT_OVERLAY
+		annotate_primary_sample(&a, point);
+#endif
 
 		left = CRT_BLEND(a.a_color);
 		VSET(a.a_color, left, 0, right);