Add load-time initialization to LIBRT

Like libbu, libged, etc. use an rt_init.cpp file to definite load time
initializations for librt.  Historically, applications have needed to
initialize the RTG.rtg_vlfree list themselves before being able to
successfully use draw routines.  Rather than keep requiring that, we
instead initialize it ourselves at library load time.

Ironically, if we do eventually succeed in eliminating the global
completely applications will be back to having to initialize their own
vlfree lists, but at least in that scenario they will be managing the
list themselves and will need to know about it - unlike the current
situation, where the only awareness of rtg_vlfree in application code
comes from them needing to know to initialize it a-priori.

In principle this should also remove the need for initializing
rt_uniresource, but deliberately focusing this commit on the rtg_vlfree
initializations to limit how much changes at once for testing.

src/adrt/load_g.c

@@ -271,7 +271,6 @@ load_g(struct tie_s *tie, const char *db, int argc, const char **argv, struct ad
 
     /* make empty NMG model */
     the_model = nmg_mm();
-    BU_LIST_INIT(&RTG.rtg_vlfree);	/* for vlist macros */
 
     /*
      * these should probably encode so the result can be passed back to client

src/conv/dxf/g-dxf.c

@@ -409,8 +409,6 @@ main(int argc, char *argv[])
     tol.perp = 1e-6;
     tol.para = 1 - tol.perp;
 
-    BU_LIST_INIT(&RTG.rtg_vlfree);	/* for vlist macros */
-
     /* Get command line arguments. */
     while ((c = bu_getopt(argc, argv, "a:n:o:pr:vx:D:P:X:ih?")) != -1) {
 	switch (c) {

src/conv/g-acad.c

@@ -512,7 +512,6 @@ main(int argc, char **argv)
 
     the_model = nmg_mm();
     struct bu_list *vlfree = &RTG.rtg_vlfree;
-    BU_LIST_INIT(vlfree);      /* for vlist macros */
 
     /* Get command line arguments. */
     while ((c = bu_getopt(argc, argv, "a:n:o:r:vx:D:P:X:e:ih?")) != -1) {
@@ -639,7 +638,7 @@ main(int argc, char **argv)
 			0,			/* take all regions */
 			do_region_end,
 			rt_booltree_leaf_tess,
-			(void *)NULL);	/* in librt/nmg_bool.c */
+			(void *)vlfree);	/* in librt/nmg_bool.c */
 
     if (regions_tried>0) {
 	percent = ((double)regions_converted * 100) / regions_tried;

src/conv/g-egg.c

@@ -225,7 +225,6 @@ main(int argc, char *argv[])
     /* make empty NMG model */
     the_model = nmg_mm();
     conv_data.vlfree = &RTG.rtg_vlfree;
-    BU_LIST_INIT(conv_data.vlfree);	/* for vlist macros */
 
     /* Get command line arguments. */
     while ((i = bu_getopt(argc, argv, "a:89n:o:r:vx:D:P:X:h?")) != -1) {

src/conv/g-nff.c

@@ -390,7 +390,6 @@ main(int argc, char *argv[])
 
     the_model = nmg_mm();
     struct bu_list *vlfree = &RTG.rtg_vlfree;
-    BU_LIST_INIT(vlfree);      /* for vlist macros */
 
     /* Get command line arguments. */
     while ((c = bu_getopt(argc, argv, "a:n:o:r:vx:D:X:e:ih?")) != -1) {

src/conv/g-obj.c

@@ -215,7 +215,6 @@ main(int argc, const char **argv)
 
     the_model = nmg_mm();
     struct bu_list *vlfree = &RTG.rtg_vlfree;
-    BU_LIST_INIT(vlfree);	/* for vlist macros */
 
     /* Get command line arguments. */
     ++argv; --argc;

src/conv/g-shell-rect.c

@@ -1638,7 +1638,6 @@ main(int argc, char **argv)
     fastf_t x_start, y_start, z_start;
     fastf_t bb_area[3];
     struct bu_list *vlfree = &RTG.rtg_vlfree;
-    BU_LIST_INIT(vlfree);      /* for vlist macros */
 
     bu_setprogname(argv[0]);
 

src/conv/g-vrml.c

@@ -629,9 +629,7 @@ main(int argc, char **argv)
 	nmg_eue_dist = 2.0;
     }
 
-    struct bu_list *vlfree = &RTG.rtg_vlfree;
-    BU_LIST_INIT(vlfree);      /* for vlist macros */
-    pm.vlfree = vlfree;
+    pm.vlfree = &RTG.rtg_vlfree;
 
     /* Get command line arguments. */
     while ((c = bu_getopt(argc, argv, "a:bd:en:o:r:vx:X:u:h?")) != -1) {
@@ -754,7 +752,7 @@ main(int argc, char **argv)
 			   0,
 			   nmg_region_end,
 			   rt_booltree_leaf_tess,
-			   (void *)vlfree);	/* in librt/nmg_bool.c */
+			   (void *)pm.vlfree);	/* in librt/nmg_bool.c */
 	goto out;
     }
 

src/conv/g-x3d.c

@@ -380,7 +380,6 @@ main(int argc, char **argv)
     }
 
     pm.vlfree = &RTG.rtg_vlfree;
-    BU_LIST_INIT(pm.vlfree);	/* for vlist macros */
 
     /* Get command line arguments. */
     while ((c = bu_getopt(argc, argv, "d:a:n:o:r:vx:P:X:u:h?")) != -1) {

src/conv/g-xxx_facets.c

@@ -119,7 +119,6 @@ main(int argc, char **argv)
     the_model = nmg_mm();
 
     struct bu_list *vlfree = &RTG.rtg_vlfree;
-    BU_LIST_INIT(vlfree);      /* for vlist macros */
 
     /* Get command line arguments. */
     while ((c = bu_getopt(argc, argv, "r:a:n:o:vx:D:X:h?")) != -1) {

src/conv/iges/conv_drawings.c

@@ -411,7 +411,6 @@ Draw_entities(struct model *m, int de_list[], size_t no_of_des, fastf_t x, fastf
     s = BU_LIST_FIRST(shell, &r->s_hd);
 
     BU_LIST_INIT(&vhead);
-    BU_LIST_INIT(vlfree);
 
     sina = sin(ang);
     cosa = cos(ang);

src/conv/iges/g-iges.c

@@ -224,7 +224,6 @@ main(int argc, char *argv[])
 
     the_model = nmg_mm();
     struct bu_list *vlfree = &RTG.rtg_vlfree;
-    BU_LIST_INIT(vlfree);	/* for vlist macros */
 
     prog_name = argv[0];
 

src/conv/iges/main.c

@@ -153,7 +153,6 @@ main(int argc, char *argv [])
     int c;
     int file_count = 0;
     char *output_file = (char *)NULL;
-    BU_LIST_INIT(&RTG.rtg_vlfree);
     struct bu_list *vlfree = &RTG.rtg_vlfree;
 
     bu_setprogname(argv[0]);

src/conv/nastran-g.c

@@ -1113,7 +1113,6 @@ main(int argc, char **argv)
     char *nastran_file = "Converted from NASTRAN file (stdin)";
 
     struct bu_list *vlfree = &RTG.rtg_vlfree;
-    BU_LIST_INIT(vlfree);      /* for vlist macros */
 
     bu_setprogname(argv[0]);
     fpin = stdin;

src/conv/nmg/asc-nmg.c

@@ -60,7 +60,6 @@ main(int argc, char **argv)
     FILE		*fpin;
     struct rt_wdb	*fpout;
     struct bu_list *vlfree = &RTG.rtg_vlfree;
-    BU_LIST_INIT(vlfree);      /* for vlist macros */
 
     if ( BU_STR_EQUAL(argv[1],"-h") || BU_STR_EQUAL(argv[1],"-?")) {
 	usage();

src/conv/obj-g.c

@@ -3194,7 +3194,6 @@ main(int argc, char **argv)
     char bot_orientation = RT_BOT_UNORIENTED;
     int fuse_vertices = 0;
     struct bu_list *vlfree = &RTG.rtg_vlfree;
-    BU_LIST_INIT(vlfree);      /* for vlist macros */
 
     bu_setprogname(argv[0]);
 

src/conv/off/g-off.c

@@ -104,7 +104,6 @@ main(int argc, char **argv)
 
     the_model = nmg_mm();
     struct bu_list *vlfree = &RTG.rtg_vlfree;
-    BU_LIST_INIT(vlfree);	/* for vlist macros */
 
     /* Get command line arguments. */
     while ((c = bu_getopt(argc, argv, "a:dn:p:r:vx:P:X:h?")) != -1) {

src/conv/off/off-g.c

@@ -228,7 +228,6 @@ int main(int argc, char **argv)
     bu_setprogname(argv[0]);
 
     struct bu_list *vlfree = &RTG.rtg_vlfree;
-    BU_LIST_INIT(vlfree);      /* for vlist macros */
 
     tol.magic = BN_TOL_MAGIC;	/* Copied from proc-db/nmgmodel.c */
     tol.dist = 0.01;

src/conv/patch/patch-g.c

@@ -3379,7 +3379,6 @@ main(int argc, char **argv)
     int stop, num;
     char name[NAMESIZE+1];
     struct bu_list *vlfree = &RTG.rtg_vlfree;
-    BU_LIST_INIT(vlfree);      /* for vlist macros */
 
     /* This size is dictated by the specific format output by the
      * 'rpatch' tool and expected material file.  They are

src/conv/raw/g-raw.c

@@ -248,8 +248,6 @@ main(int argc, char *argv[])
 
     /* make empty NMG model */
     the_model = nmg_mm();
-    struct bu_list *vlfree = &RTG.rtg_vlfree;
-    BU_LIST_INIT(vlfree);	/* for vlist macros */
 
     /* Get command line arguments. */
     while ((c = bu_getopt(argc, argv, "a:b8m:n:o:r:vx:D:X:i")) != -1) {

src/conv/stl/g-stl.c

@@ -341,8 +341,6 @@ main(int argc, char *argv[])
 
     /* make empty NMG model */
     the_model = nmg_mm();
-    struct bu_list *vlfree = &RTG.rtg_vlfree;
-    BU_LIST_INIT(vlfree);      /* for vlist macros */
 
     /* Get command line arguments. */
     while ((c = bu_getopt(argc, argv, "a:b8m:n:o:r:vx:D:X:ih?")) != -1) {

src/conv/tankill/tankill-g.c

@@ -158,7 +158,6 @@ main(int argc, char **argv)
     int group_len[100];
     int all_len=0;
     struct bu_list *vlfree = &RTG.rtg_vlfree;
-    BU_LIST_INIT(vlfree);      /* for vlist macros */
 
     bu_setprogname(argv[0]);
 

src/gtools/gsh/gsh.cpp

@@ -754,9 +754,6 @@ main(int argc, const char **argv)
 	fprintf(stderr, "%s", ged_init_str);
     }
 
-    /* FIXME: To draw, we need to init this LIBRT global */
-    BU_LIST_INIT(&RTG.rtg_vlfree);
-
     // Use a C++ class to manage info we will need
     std::shared_ptr<GshState> gs = std::make_shared<GshState>();
 

src/isst/gfile.cpp

@@ -268,7 +268,6 @@ GFile::load_g(const char *filename, int argc, const char *argv[])
     /* make empty NMG model */
     the_model = nmg_mm();
     d.vlfree = &RTG.rtg_vlfree;
-    BU_LIST_INIT(d.vlfree);	/* for vlist macros */
 
     /*
      * these should probably encode so the result can be passed back to client

src/libgcv/plugins/assetimport/assetimport_write.cpp

@@ -414,7 +414,6 @@ assetimport_write(struct gcv_context *context, const struct gcv_opts *gcv_option
     /* make empty NMG model */
     state.the_model = nmg_mm();
     state.vlfree = &RTG.rtg_vlfree;
-    BU_LIST_INIT(state.vlfree);	/* for vlist macros */
 
     /* Walk indicated tree(s).  Each region will be output separately */
     if (state.assetimport_write_options->model_workaround) {

src/libgcv/plugins/fastgen4/fastgen4_write.cpp

@@ -2462,7 +2462,6 @@ do_conversion(db_i &db, const struct gcv_opts &gcv_options,
 			   facetize_regions);
 
     data.vlfree = &RTG.rtg_vlfree;
-    //BU_LIST_INIT(data.vlfree); /* for vlist macros */
 
     const int ret = db_walk_tree(&db,
 				 static_cast<int>(gcv_options.num_objects),

src/libgcv/plugins/obj/obj_write.c

@@ -528,7 +528,6 @@ obj_write(struct gcv_context *context, const struct gcv_opts *gcv_options, const
 
     the_model = nmg_mm();
     state.vlfree = &RTG.rtg_vlfree;
-    BU_LIST_INIT(state.vlfree);	/* for vlist macros */
 
     /* Write out header */
     if (NEAR_EQUAL(state.gcv_options->scale_factor, 1.0 / 25.4, RT_LEN_TOL))

src/libgcv/plugins/ply/ply_write.c

@@ -650,7 +650,6 @@ ply_write_gcv(struct gcv_context* context, const struct gcv_opts* gcv_options, c
     state.the_model = nmg_mm();
 
     state.vlfree = &RTG.rtg_vlfree;
-    BU_LIST_INIT(state.vlfree);      /* for vlist macros */
 
     if (!state.ply_write_options->separate) {
         /* open outputfile using specified type */

src/libgcv/plugins/stl/stl_write.cpp

@@ -418,7 +418,6 @@ stl_write(struct gcv_context *context, const struct gcv_opts *gcv_options, const
     /* make empty NMG model */
     state.the_model = nmg_mm();
     state.vlfree = &RTG.rtg_vlfree;
-    BU_LIST_INIT(state.vlfree);	/* for vlist macros */
 
     /* Walk indicated tree(s).  Each region will be output separately */
     (void) db_walk_tree(state.dbip, gcv_options->num_objects, (const char **)gcv_options->object_names,

src/libgcv/plugins/vrml/vrml_write.c

@@ -1258,7 +1258,6 @@ vrml_write(struct gcv_context *context, const struct gcv_opts *gcv_options, cons
     }
 
     region_end_data.vlfree = &RTG.rtg_vlfree;
-    BU_LIST_INIT(region_end_data.vlfree);	/* for vlist macros */
 
     fprintf(state.fp_out, "#VRML V2.0 utf8\n");
     fprintf(state.fp_out, "#Units are %s\n", vrml_write_make_units_str(gcv_options->scale_factor));

src/libged/tests/draw/aet.cpp

@@ -166,9 +166,6 @@ main(int ac, char *av[]) {
 	return 2;
     }
 
-    /* FIXME: To draw, we need to init this LIBRT global */
-    BU_LIST_INIT(&RTG.rtg_vlfree);
-
     /* make a temporary copy of moss */
     bu_vls_sprintf(&fname, "%s/moss.g", av[1]);
     std::ifstream orig(bu_vls_cstr(&fname), std::ios::binary);

src/libged/tests/draw/draw.cpp

@@ -233,9 +233,6 @@ main(int ac, char *av[]) {
     bu_mkdir(lcache);
     bu_setenv("BU_DIR_CACHE", lcache, 1);
 
-    /* FIXME: To draw, we need to init this LIBRT global */
-    BU_LIST_INIT(&RTG.rtg_vlfree);
-
     /* We are going to generate geometry from the basic moss data,
      * so we make a temporary copy */
     bu_vls_sprintf(&fname, "%s/moss.g", av[1]);

src/libged/tests/draw/faceplate.cpp

@@ -77,9 +77,6 @@ main(int ac, char *av[]) {
 	return 2;
     }
 
-    /* FIXME: To draw, we need to init this LIBRT global */
-    BU_LIST_INIT(&RTG.rtg_vlfree);
-
     /* Open the temp file, then dbconcat argv[1] into it */
     bu_vls_sprintf(&fname, "%s/moss.g", av[1]);
     dbp = ged_open("db", bu_vls_cstr(&fname), 1);

src/libged/tests/draw/lod.cpp

@@ -84,9 +84,6 @@ main(int ac, char *av[]) {
     bu_mkdir(lcache);
     bu_setenv("BU_DIR_CACHE", lcache, 1);
 
-    /* FIXME: To draw, we need to init this LIBRT global */
-    BU_LIST_INIT(&RTG.rtg_vlfree);
-
     /* We are going to generate geometry from the basic moss data,
      * so we make a temporary copy */
     bu_vls_sprintf(&fname, "%s/moss.g", av[1]);

src/libged/tests/draw/quad.cpp

@@ -417,9 +417,6 @@ main(int ac, char *av[]) {
     bu_mkdir(lcache);
     bu_setenv("BU_DIR_CACHE", lcache, 1);
 
-    /* FIXME: To draw, we need to init this LIBRT global */
-    BU_LIST_INIT(&RTG.rtg_vlfree);
-
     /* We are going to generate geometry from the basic moss data,
      * so we make a temporary copy */
     bu_vls_sprintf(&fname, "%s/moss.g", av[1]);

src/libged/tests/draw/select.cpp

@@ -84,9 +84,6 @@ main(int ac, char *av[]) {
     bu_mkdir(lcache);
     bu_setenv("BU_DIR_CACHE", lcache, 1);
 
-    /* FIXME: To draw, we need to init this LIBRT global */
-    BU_LIST_INIT(&RTG.rtg_vlfree);
-
     /* We are going to generate geometry from the basic moss data,
      * so we make a temporary copy */
     bu_vls_sprintf(&fname, "%s/moss.g", av[1]);

src/librt/CMakeLists.txt

@@ -214,6 +214,7 @@ set(
   reduce_db.cpp
   regionfix.c
   roots.c
+  rt_init.cpp
   search.cpp
   search_old.cpp
   shoot.c

src/librt/prep.cpp

@@ -74,25 +74,9 @@ rt_new_rti(struct db_i *dbip)
 {
     struct rt_i *rtip;
     int i;
-    struct bu_list *vlfree = &RTG.rtg_vlfree;
 
     RT_CK_DBI(dbip);
 
-    /* XXX Move to rt_global_init() ? */
-    if (BU_LIST_FIRST(bu_list, vlfree) == 0) {
-	char *debug_flags;
-	debug_flags = getenv("LIBRT_DEBUG");
-	if (debug_flags) {
-	    if (rt_debug) {
-		bu_log("WARNING: discarding LIBRT_DEBUG value in favor of application-specified flags\n");
-	    } else {
-		rt_debug = strtol(debug_flags, NULL, 0x10);
-	    }
-	}
-
-	BU_LIST_INIT(vlfree);
-    }
-
     BU_ALLOC(rtip, struct rt_i);
     rtip->rti_magic = RTI_MAGIC;
     for (i=0; i < RT_DBNHASH; i++) {

src/librt/primitives/extrude/extrude.c

@@ -2216,8 +2216,6 @@ rt_extrude_tess(struct nmgregion **r, struct model *m, struct rt_db_internal *ip
     }
 
     BU_LIST_INIT(&vhead);
-    if (!BU_LIST_IS_INITIALIZED(vlfree))
-	BU_LIST_INIT(vlfree);
 
     for (i = 0; outer_loop && i<(size_t)BU_PTBL_LEN(outer_loop); i++) {
 	void *seg;

src/librt/rt_init.cpp

@@ -0,0 +1,77 @@
+/*                     R T _ I N I T . C P P
+ * BRL-CAD
+ *
+ * Copyright (c) 2019-2024 United States Government as represented by
+ * the U.S. Army Research Laboratory.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public License
+ * version 2.1 as published by the Free Software Foundation.
+ *
+ * This library is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this file; see the file named COPYING for more
+ * information.
+ */
+/** @file rt_init.cpp
+ *
+ * NOTE: as this init is global to ALL applications before main(),
+ * care must be taken to not write to STDOUT or STDERR or app output
+ * may be corrupted, signals can be raised, or worse.
+ *
+ */
+
+#include "common.h"
+
+#include "rt/defines.h"
+#include "rt/debug.h"
+#include "rt/global.h"
+#include "rt/resource.h"
+#include "rt/rt_instance.h"
+
+static void
+librt_init(void)
+{
+    BU_LIST_INIT(&RTG.rtg_vlfree);
+    rt_init_resource(&rt_uniresource, 0, NULL);
+
+    // NOTE - rt_new_rti used to do this, checking if the rtg_vlfree list was
+    // initialized.  Since we're doing that initialization in this routine,
+    // handle reading LIBRT_DEBUG here as well.
+    const char *debug_flags = getenv("LIBRT_DEBUG");
+    if (debug_flags)
+	rt_debug = strtol(debug_flags, NULL, 0x10);
+}
+
+static void
+librt_clear(void)
+{
+}
+
+struct librt_initializer {
+    /* constructor */
+    librt_initializer() {
+	librt_init();
+    }
+    /* destructor */
+    ~librt_initializer() {
+	librt_clear();
+    }
+};
+
+static librt_initializer LIBRT;
+
+
+// Local Variables:
+// tab-width: 8
+// mode: C++
+// c-basic-offset: 4
+// indent-tabs-mode: t
+// c-file-style: "stroustrup"
+// End:
+// ex: shiftwidth=4 tabstop=8
+

src/libtclcad/rt.c

@@ -699,15 +699,6 @@ tclcad_rt_import_from_path(Tcl_Interp *interp, struct rt_db_internal *ip, const
 int
 Rt_Init(Tcl_Interp *interp)
 {
-    /*XXX how much will this break? */
-    if (!BU_LIST_IS_INITIALIZED(&RTG.rtg_vlfree)) {
-	/* initialize RT's global state */
-	BU_LIST_INIT(&RTG.rtg_vlfree);
-	if (rt_uniresource.re_magic != RESOURCE_MAGIC) {
-	    rt_init_resource(&rt_uniresource, 0, NULL);
-	}
-    }
-
     Tcl_PkgProvide(interp,  "Rt", brlcad_version());
 
     return TCL_OK;

src/mged/mged.c

@@ -1838,7 +1838,6 @@ main(int argc, char *argv[])
 
     /* Set up linked lists */
     s->vlfree = &RTG.rtg_vlfree;
-    BU_LIST_INIT(s->vlfree);
     BU_LIST_INIT(&rtg_headwdb.l);
 
     // Start out in an initialization state

src/proc-db/nmgmodel.c

@@ -519,7 +519,6 @@ main(int ac, char *av[])
     struct bn_tol tol;
     FILE *fdplot;
     struct rt_wdb *fdmodel;
-    BU_LIST_INIT(&RTG.rtg_vlfree);
     struct bu_list *vlfree = &RTG.rtg_vlfree;
 
     bu_setprogname(av[0]);

src/proc-db/tea_nmg.c

@@ -189,7 +189,6 @@ main(int argc, char **argv)
     bu_log("Writing out geometry to file [tea_nmg.g] ...");
 
     struct bu_list *vlfree = &RTG.rtg_vlfree;
-    BU_LIST_INIT(vlfree);
 
     outfp = wdb_fopen("tea_nmg.g");
 

src/qged/QgEdApp.cpp

@@ -167,7 +167,6 @@ QgEdApp::QgEdApp(int &argc, char *argv[], int swrast_mode, int quad_mode) :QAppl
     bu_setenv("GED_TEST_NEW_CMD_FORMS", "1", 1);
 
     mdl = new QgModel();
-    BU_LIST_INIT(&RTG.rtg_vlfree);
 
     // Install a filter to handle the top level key bindings and other
     // interactive event management requiring global application knowledge.