1 // obj.cxx -- routines to handle "sorta" WaveFront .obj format files.
3 // Written by Curtis Olson, started October 1997.
5 // Copyright (C) 1997 Curtis L. Olson - curt@infoplane.com
7 // This program is free software; you can redistribute it and/or
8 // modify it under the terms of the GNU General Public License as
9 // published by the Free Software Foundation; either version 2 of the
10 // License, or (at your option) any later version.
12 // This program is distributed in the hope that it will be useful, but
13 // WITHOUT ANY WARRANTY; without even the implied warranty of
14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 // General Public License for more details.
17 // You should have received a copy of the GNU General Public License
18 // along with this program; if not, write to the Free Software
19 // Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
22 // (Log is kept at end of this file)
38 #if defined ( __sun__ )
39 extern "C" void *memmove(void *, const void *, size_t);
40 extern "C" void *memset(void *, int, size_t);
43 #include <string> // Standard C++ library
45 #include <ctype.h> // isdigit()
47 #ifdef NEEDNAMESPACESTD
51 #include <Debug/fg_debug.h>
52 #include <Include/fg_constants.h>
53 #include <Include/fg_zlib.h>
54 #include <Main/options.hxx>
55 #include <Math/mat3.h>
56 #include <Math/fg_random.h>
57 #include <Math/polar3d.hxx>
58 #include <Misc/stopwatch.hxx>
59 #include <Misc/fgstream.hxx>
60 #include <Scenery/tile.hxx>
62 #include "material.hxx"
66 static double normals[MAX_NODES][3];
69 // given three points defining a triangle, calculate the normal
70 static void calc_normal(double p1[3], double p2[3],
71 double p3[3], double normal[3])
76 v1[0] = p2[0] - p1[0]; v1[1] = p2[1] - p1[1]; v1[2] = p2[2] - p1[2];
77 v2[0] = p3[0] - p1[0]; v2[1] = p3[1] - p1[1]; v2[2] = p3[2] - p1[2];
79 MAT3cross_product(normal, v1, v2);
80 MAT3_NORMALIZE_VEC(normal,temp);
82 // fgPrintf( FG_TERRAIN, FG_DEBUG, " Normal = %.2f %.2f %.2f\n",
83 // normal[0], normal[1], normal[2]);
87 #define FG_TEX_CONSTANT 128.0
90 // Calculate texture coordinates for a given point.
91 fgPoint3d calc_tex_coords(double *node, fgPoint3d *ref) {
95 cp.x = node[0] + ref->x;
96 cp.y = node[1] + ref->y;
97 cp.z = node[2] + ref->z;
99 pp = fgCartToPolar3d(cp);
101 pp.lon = fmod(RAD_TO_DEG * FG_TEX_CONSTANT * pp.lon, 25.0);
102 pp.lat = fmod(RAD_TO_DEG * FG_TEX_CONSTANT * pp.lat, 25.0);
108 // Load a .obj file and build the GL fragment list
109 int fgObjLoad( const string& path, fgTILE *t) {
112 double approx_normal[3], normal[3], scale;
113 // double x, y, z, xmax, xmin, ymax, ymin, zmax, zmin;
114 // GLfloat sgenparams[] = { 1.0, 0.0, 0.0, 0.0 };
117 int in_fragment, in_faces, vncount, n1, n2, n3, n4;
118 int last1, last2, odd;
122 // printf("loading %s\n", path.c_str() );
124 // Attempt to open "path.gz" or "path"
125 fg_gzifstream in( path );
128 // Attempt to open "path.obj" or "path.obj.gz"
129 in.open( path + ".obj" );
132 fgPrintf( FG_TERRAIN, FG_ALERT,
133 "Cannot open file: %s\n", path.c_str() );
138 shading = current_options.get_shading();
143 t->bounding_radius = 0.0;
150 // ignore initial comments and blank lines. (priming the pump)
157 in.stream() >> token;
159 // printf("token = %s\n", token.c_str() );
161 if ( token == "gbs" )
163 // reference point (center offset)
164 in.stream() >> t->center.x
167 >> t->bounding_radius;
169 else if ( token == "bs" )
171 // reference point (center offset)
172 in.stream() >> fragment.center.x
175 >> fragment.bounding_radius;
177 else if ( token == "vn" )
180 if ( vncount < MAX_NODES ) {
181 in.stream() >> normals[vncount][0]
182 >> normals[vncount][1]
183 >> normals[vncount][2];
186 fgPrintf( FG_TERRAIN, FG_EXIT,
187 "Read too many vertex normals ... dying :-(\n");
190 else if ( token[0] == 'v' )
193 if ( t->ncount < MAX_NODES ) {
194 in.stream() >> t->nodes[t->ncount][0]
195 >> t->nodes[t->ncount][1]
196 >> t->nodes[t->ncount][2];
199 fgPrintf( FG_TERRAIN, FG_EXIT,
200 "Read too many nodes ... dying :-(\n");
203 else if ( token == "usemtl" )
205 // material property specification
207 // this also signals the start of a new fragment
209 // close out the previous structure and start the next
212 // printf("xglEnd(); xglEndList();\n");
215 fragment.display_list = display_list;
217 // push this fragment onto the tile's object list
218 t->fragment_list.push_back(fragment);
223 // printf("start of fragment (usemtl)\n");
225 display_list = xglGenLists(1);
226 xglNewList(display_list, GL_COMPILE);
227 // printf("xglGenLists(); xglNewList();\n");
230 // reset the existing face list
231 // printf("cleaning a fragment with %d faces\n",
232 // fragment.faces.size());
235 // scan the material line
237 in.stream() >> material;
238 fragment.tile_ptr = t;
240 // find this material in the properties list
241 if ( ! material_mgr.find( material, fragment.material_ptr )) {
242 fgPrintf( FG_TERRAIN, FG_ALERT,
243 "Ack! unknown usemtl name = %s in %s\n",
244 material.c_str(), path.c_str() );
247 // initialize the fragment transformation matrix
249 for ( i = 0; i < 16; i++ ) {
250 fragment.matrix[i] = 0.0;
252 fragment.matrix[0] = fragment.matrix[5] =
253 fragment.matrix[10] = fragment.matrix[15] = 1.0;
255 } else if ( token[0] == 't' ) {
256 // start a new triangle strip
258 n1 = n2 = n3 = n4 = 0;
260 // fgPrintf( FG_TERRAIN, FG_DEBUG, " new tri strip = %s", line);
261 in.stream() >> n1 >> n2 >> n3;
262 fragment.add_face(n1, n2, n3);
264 // fgPrintf( FG_TERRAIN, FG_DEBUG, "(t) = ");
266 xglBegin(GL_TRIANGLE_STRIP);
267 // printf("xglBegin(tristrip) %d %d %d\n", n1, n2, n3);
273 // Shading model is "GL_SMOOTH" so use precalculated
274 // (averaged) normals
275 MAT3_SCALE_VEC(normal, normals[n1], scale);
276 xglNormal3dv(normal);
277 pp = calc_tex_coords(nodes[n1], center);
278 xglTexCoord2f(pp.lon, pp.lat);
279 // xglVertex3d(t->nodes[n1][0],t->nodes[n1][1],t->nodes[n1][2]);
280 xglVertex3dv(nodes[n1]);
282 MAT3_SCALE_VEC(normal, normals[n2], scale);
283 xglNormal3dv(normal);
284 pp = calc_tex_coords(nodes[n2], center);
285 xglTexCoord2f(pp.lon, pp.lat);
286 //xglVertex3d(t->nodes[n2][0],t->nodes[n2][1],t->nodes[n2][2]);
287 xglVertex3dv(nodes[n2]);
289 MAT3_SCALE_VEC(normal, normals[n3], scale);
290 xglNormal3dv(normal);
291 pp = calc_tex_coords(nodes[n3], center);
292 xglTexCoord2f(pp.lon, pp.lat);
293 // xglVertex3d(t->nodes[n3][0],t->nodes[n3][1],t->nodes[n3][2]);
294 xglVertex3dv(nodes[n3]);
296 // Shading model is "GL_FLAT" so calculate per face
297 // normals on the fly.
299 calc_normal(nodes[n1], nodes[n2],
300 nodes[n3], approx_normal);
302 calc_normal(nodes[n2], nodes[n1],
303 nodes[n3], approx_normal);
305 MAT3_SCALE_VEC(normal, approx_normal, scale);
306 xglNormal3dv(normal);
308 pp = calc_tex_coords(nodes[n1], center);
309 xglTexCoord2f(pp.lon, pp.lat);
310 // xglVertex3d(t->nodes[n1][0],t->nodes[n1][1],t->nodes[n1][2]);
311 xglVertex3dv(nodes[n1]);
313 pp = calc_tex_coords(nodes[n2], center);
314 xglTexCoord2f(pp.lon, pp.lat);
315 // xglVertex3d(t->nodes[n2][0],t->nodes[n2][1],t->nodes[n2][2]);
316 xglVertex3dv(nodes[n2]);
318 pp = calc_tex_coords(nodes[n3], center);
319 xglTexCoord2f(pp.lon, pp.lat);
320 // xglVertex3d(t->nodes[n3][0],t->nodes[n3][1],t->nodes[n3][2]);
321 xglVertex3dv(nodes[n3]);
323 // printf("some normals, texcoords, and vertices\n");
329 // There can be three or four values
334 break; // only the one
345 fragment.add_face(n3, n2, n4);
348 // Shading model is "GL_SMOOTH"
349 MAT3_SCALE_VEC(normal, normals[n4], scale);
351 // Shading model is "GL_FLAT"
352 calc_normal(nodes[n3], nodes[n2], nodes[n4],
354 MAT3_SCALE_VEC(normal, approx_normal, scale);
356 xglNormal3dv(normal);
357 pp = calc_tex_coords(nodes[n4], center);
358 xglTexCoord2f(pp.lon, pp.lat);
359 // xglVertex3d(t->nodes[n4][0],t->nodes[n4][1],t->nodes[n4][2]);
360 xglVertex3dv(nodes[n4]);
365 // printf("a normal, texcoord, and vertex (4th)\n");
367 } else if ( token[0] == 'f' ) {
371 xglBegin(GL_TRIANGLES);
372 // printf("xglBegin(triangles)\n");
376 // fgPrintf( FG_TERRAIN, FG_DEBUG, "new triangle = %s", line);*/
377 in.stream() >> n1 >> n2 >> n3;
378 fragment.add_face(n1, n2, n3);
380 // xglNormal3d(normals[n1][0], normals[n1][1], normals[n1][2]);
381 xglNormal3dv(normals[n1]);
382 pp = calc_tex_coords(nodes[n1], center);
383 xglTexCoord2f(pp.lon, pp.lat);
384 // xglVertex3d(t->nodes[n1][0], t->nodes[n1][1], t->nodes[n1][2]);
385 xglVertex3dv(nodes[n1]);
387 // xglNormal3d(normals[n2][0], normals[n2][1], normals[n2][2]);
388 xglNormal3dv(normals[n2]);
389 pp = calc_tex_coords(nodes[n2], center);
390 xglTexCoord2f(pp.lon, pp.lat);
391 // xglVertex3d(t->nodes[n2][0], t->nodes[n2][1], t->nodes[n2][2]);
392 xglVertex3dv(nodes[n2]);
394 // xglNormal3d(normals[n3][0], normals[n3][1], normals[n3][2]);
395 xglNormal3dv(normals[n3]);
396 pp = calc_tex_coords(nodes[n3], center);
397 xglTexCoord2f(pp.lon, pp.lat);
398 // xglVertex3d(t->nodes[n3][0], t->nodes[n3][1], t->nodes[n3][2]);
399 xglVertex3dv(nodes[n3]);
400 // printf("some normals, texcoords, and vertices (tris)\n");
401 } else if ( token[0] == 'q' ) {
402 // continue a triangle strip
405 // fgPrintf( FG_TERRAIN, FG_DEBUG, "continued tri strip = %s ",
409 // There can be one or two values
414 break; // only the one
423 // fgPrintf( FG_TERRAIN, FG_DEBUG, "read %d %d\n", n1, n2);
426 fragment.add_face(last1, last2, n1);
428 fragment.add_face(last2, last1, n1);
432 // Shading model is "GL_SMOOTH"
433 MAT3_SCALE_VEC(normal, normals[n1], scale);
435 // Shading model is "GL_FLAT"
437 calc_normal(nodes[last1], nodes[last2], nodes[n1],
440 calc_normal(nodes[last2], nodes[last1], nodes[n1],
443 MAT3_SCALE_VEC(normal, approx_normal, scale);
445 xglNormal3dv(normal);
447 pp = calc_tex_coords(nodes[n1], center);
448 xglTexCoord2f(pp.lon, pp.lat);
449 // xglVertex3d(t->nodes[n1][0], t->nodes[n1][1], t->nodes[n1][2]);
450 xglVertex3dv(nodes[n1]);
451 // printf("a normal, texcoord, and vertex (4th)\n");
458 // fgPrintf( FG_TERRAIN, FG_DEBUG, " (cont)\n");
461 fragment.add_face(last1, last2, n2);
463 fragment.add_face(last2, last1, n2);
467 // Shading model is "GL_SMOOTH"
468 MAT3_SCALE_VEC(normal, normals[n2], scale);
470 // Shading model is "GL_FLAT"
472 calc_normal(nodes[last1], nodes[last2],
473 nodes[n2], approx_normal);
475 calc_normal(nodes[last2], nodes[last1],
476 nodes[n2], approx_normal);
478 MAT3_SCALE_VEC(normal, approx_normal, scale);
480 xglNormal3dv(normal);
482 pp = calc_tex_coords(nodes[n2], center);
483 xglTexCoord2f(pp.lon, pp.lat);
484 // xglVertex3d(t->nodes[n2][0],t->nodes[n2][1],t->nodes[n2][2]);
485 xglVertex3dv(nodes[n2]);
486 // printf("a normal, texcoord, and vertex (4th)\n");
493 fgPrintf( FG_TERRAIN, FG_WARN, "Unknown token in %s = %s\n",
494 path.c_str(), token.c_str() );
497 // eat comments and blank lines before start of while loop so
498 // if we are done with useful input it is noticed before hand.
503 // close out the previous structure and start the next
506 // printf("xglEnd(); xglEndList();\n");
509 fragment.display_list = display_list;
511 // push this fragment onto the tile's object list
512 t->fragment_list.push_back(fragment);
515 // Draw normal vectors (for visually verifying normals)
518 xglColor3f(0.0, 0.0, 0.0);
519 for ( i = 0; i < t->ncount; i++ ) {
520 xglVertex3d(t->nodes[i][0],
523 xglVertex3d(t->nodes[i][0] + 500*normals[i][0],
524 t->nodes[i][1] + 500*normals[i][1],
525 t->nodes[i][2] + 500*normals[i][2]);
531 fgPrintf( FG_TERRAIN, FG_INFO, "Loaded %s in %f seconds\n",
532 path.c_str(), stopwatch.elapsedSeconds() );
534 // printf("end of tile\n");
541 // Revision 1.3 1998/09/03 21:27:03 curt
542 // Fixed a serious bug caused by not-quite-correct comment/white space eating
543 // which resulted in mismatched glBegin() glEnd() pairs, incorrect display lists,
544 // and ugly display artifacts.
546 // Revision 1.2 1998/09/01 19:03:09 curt
547 // Changes contributed by Bernie Bright <bbright@c031.aone.net.au>
548 // - The new classes in libmisc.tgz define a stream interface into zlib.
549 // I've put these in a new directory, Lib/Misc. Feel free to rename it
550 // to something more appropriate. However you'll have to change the
551 // include directives in all the other files. Additionally you'll have
552 // add the library to Lib/Makefile.am and Simulator/Main/Makefile.am.
554 // The StopWatch class in Lib/Misc requires a HAVE_GETRUSAGE autoconf
555 // test so I've included the required changes in config.tgz.
557 // There are a fair few changes to Simulator/Objects as I've moved
558 // things around. Loading tiles is quicker but thats not where the delay
559 // is. Tile loading takes a few tenths of a second per file on a P200
560 // but it seems to be the post-processing that leads to a noticeable
561 // blip in framerate. I suppose its time to start profiling to see where
564 // I've included a brief description of each archives contents.
569 // C++ stream interface into zlib.
570 // Taken from zlib-1.1.3/contrib/iostream/.
571 // Minor mods for STL compatibility.
572 // There's no copyright associated with these so I assume they're
573 // covered by zlib's.
577 // FlightGear input stream using gz_ifstream. Tries to open the
578 // given filename. If that fails then filename is examined and a
579 // ".gz" suffix is removed or appended and that file is opened.
582 // A simple timer for benchmarking. Not used in production code.
583 // Taken from the Blitz++ project. Covered by GPL.
587 // Some simple string manipulation routines.
589 // Simulator/Airports/
590 // Load airports database using fgstream.
591 // Changed fgAIRPORTS to use set<> instead of map<>.
592 // Added bool fgAIRPORTS::search() as a neater way doing the lookup.
593 // Returns true if found.
596 // Modified fgStarsInit() to load stars database using fgstream.
598 // Simulator/Objects/
599 // Modified fgObjLoad() to use fgstream.
600 // Modified fgMATERIAL_MGR::load_lib() to use fgstream.
601 // Many changes to fgMATERIAL.
602 // Some changes to fgFRAGMENT but I forget what!
604 // Revision 1.1 1998/08/25 16:51:25 curt
605 // Moved from ../Scenery
607 // Revision 1.23 1998/08/20 15:16:43 curt
608 // obj.cxx: use more explicit parenthases.
609 // texload.[ch]: use const in function definitions where appropriate.
611 // Revision 1.22 1998/08/20 15:12:03 curt
612 // Used a forward declaration of classes fgTILE and fgMATERIAL to eliminate
613 // the need for "void" pointers and casts.
614 // Quick hack to count the number of scenery polygons that are being drawn.
616 // Revision 1.21 1998/08/12 21:13:04 curt
617 // material.cxx: don't load textures if they are disabled
618 // obj.cxx: optimizations from Norman Vine
619 // tile.cxx: minor tweaks
620 // tile.hxx: addition of num_faces
621 // tilemgr.cxx: minor tweaks
623 // Revision 1.20 1998/07/24 21:42:07 curt
624 // material.cxx: whups, double method declaration with no definition.
625 // obj.cxx: tweaks to avoid errors in SGI's CC.
626 // tile.cxx: optimizations by Norman Vine.
627 // tilemgr.cxx: optimizations by Norman Vine.
629 // Revision 1.19 1998/07/13 21:01:58 curt
630 // Wrote access functions for current fgOPTIONS.
632 // Revision 1.18 1998/07/12 03:18:27 curt
633 // Added ground collision detection. This involved:
634 // - saving the entire vertex list for each tile with the tile records.
635 // - saving the face list for each fragment with the fragment records.
636 // - code to intersect the current vertical line with the proper face in
637 // an efficient manner as possible.
638 // Fixed a bug where the tiles weren't being shifted to "near" (0,0,0)
640 // Revision 1.17 1998/07/08 14:47:21 curt
641 // Fix GL_MODULATE vs. GL_DECAL problem introduced by splash screen.
642 // polare3d.h renamed to polar3d.hxx
643 // fg{Cartesian,Polar}Point3d consolodated.
644 // Added some initial support for calculating local current ground elevation.
646 // Revision 1.16 1998/07/06 21:34:33 curt
647 // Added using namespace std for compilers that support this.
649 // Revision 1.15 1998/07/04 00:54:28 curt
650 // Added automatic mipmap generation.
652 // When rendering fragments, use saved model view matrix from associated tile
653 // rather than recalculating it with push() translate() pop().
655 // Revision 1.14 1998/06/17 21:36:40 curt
656 // Load and manage multiple textures defined in the Materials library.
657 // Boost max material fagments for each material property to 800.
658 // Multiple texture support when rendering.
660 // Revision 1.13 1998/06/12 00:58:05 curt
661 // Build only static libraries.
662 // Declare memmove/memset for Sloaris.
664 // Revision 1.12 1998/06/08 17:57:54 curt
665 // Working first pass at material proporty sorting.
667 // Revision 1.11 1998/06/06 01:09:31 curt
668 // I goofed on the log message in the last commit ... now fixed.
670 // Revision 1.10 1998/06/06 01:07:17 curt
671 // Increased per material fragment list size from 100 to 400.
672 // Now correctly draw viewable fragments in per material order.
674 // Revision 1.9 1998/06/05 22:39:54 curt
675 // Working on sorting by, and rendering by material properties.
677 // Revision 1.8 1998/06/05 18:19:18 curt
678 // Recognize file, file.gz, and file.obj as scenery object files.
680 // Revision 1.7 1998/05/24 02:49:09 curt
681 // Implimented fragment level view frustum culling.
683 // Revision 1.6 1998/05/23 14:09:20 curt
684 // Added tile.cxx and tile.hxx.
685 // Working on rewriting the tile management system so a tile is just a list
686 // fragments, and the fragment record contains the display list for that
689 // Revision 1.5 1998/05/20 20:53:53 curt
690 // Moved global ref point and radius (bounding sphere info, and offset) to
691 // data file rather than calculating it on the fly.
692 // Fixed polygon winding problem in scenery generation stage rather than
693 // compensating for it on the fly.
694 // Made a fgTILECACHE class.
696 // Revision 1.4 1998/05/16 13:09:57 curt
697 // Beginning to add support for view frustum culling.
698 // Added some temporary code to calculate bouding radius, until the
699 // scenery generation tools and scenery can be updated.
701 // Revision 1.3 1998/05/03 00:48:01 curt
702 // Updated texture coordinate fmod() parameter.
704 // Revision 1.2 1998/05/02 01:52:14 curt
705 // Playing around with texture coordinates.
707 // Revision 1.1 1998/04/30 12:35:28 curt
708 // Added a command line rendering option specify smooth/flat shading.
710 // Revision 1.35 1998/04/28 21:43:26 curt
711 // Wrapped zlib calls up so we can conditionally comment out zlib support.
713 // Revision 1.34 1998/04/28 01:21:42 curt
714 // Tweaked texture parameter calculations to keep the number smaller. This
715 // avoids the "swimming" problem.
716 // Type-ified fgTIME and fgVIEW.
718 // Revision 1.33 1998/04/27 15:58:15 curt
719 // Screwing around with texture coordinate generation ... still needs work.
721 // Revision 1.32 1998/04/27 03:30:13 curt
722 // Minor transformation adjustments to try to keep scenery tiles closer to
723 // (0, 0, 0) GLfloats run out of precision at the distances we need to model
724 // the earth, but we can do a bunch of pre-transformations using double math
725 // and then cast to GLfloat once everything is close in where we have less
726 // precision problems.
728 // Revision 1.31 1998/04/25 15:09:57 curt
729 // Changed "r" to "rb" in gzopen() options. This fixes bad behavior in win32.
731 // Revision 1.30 1998/04/24 14:21:08 curt
732 // Added "file.obj.gz" support.
734 // Revision 1.29 1998/04/24 00:51:07 curt
735 // Wrapped "#include <config.h>" in "#ifdef HAVE_CONFIG_H"
736 // Tweaked the scenery file extentions to be "file.obj" (uncompressed)
737 // or "file.obz" (compressed.)
739 // Revision 1.28 1998/04/22 13:22:44 curt
740 // C++ - ifing the code a bit.
742 // Revision 1.27 1998/04/18 04:13:17 curt
743 // Added zlib on the fly decompression support for loading scenery objects.
745 // Revision 1.26 1998/04/03 22:11:36 curt
746 // Converting to Gnu autoconf system.
748 // Revision 1.25 1998/03/14 00:30:50 curt
749 // Beginning initial terrain texturing experiments.
751 // Revision 1.24 1998/02/09 21:30:18 curt
752 // Fixed a nagging problem with terrain tiles not "quite" matching up perfectly.
754 // Revision 1.23 1998/02/09 15:07:52 curt
757 // Revision 1.22 1998/02/01 03:39:54 curt
760 // Revision 1.21 1998/01/31 00:43:25 curt
761 // Added MetroWorks patches from Carmen Volpe.
763 // Revision 1.20 1998/01/29 00:51:39 curt
764 // First pass at tile cache, dynamic tile loading and tile unloading now works.
766 // Revision 1.19 1998/01/27 03:26:42 curt
767 // Playing with new fgPrintf command.
769 // Revision 1.18 1998/01/19 19:27:16 curt
770 // Merged in make system changes from Bob Kuehne <rpk@sgi.com>
771 // This should simplify things tremendously.
773 // Revision 1.17 1998/01/13 00:23:10 curt
774 // Initial changes to support loading and management of scenery tiles. Note,
775 // there's still a fair amount of work left to be done.
777 // Revision 1.16 1997/12/30 23:09:40 curt
778 // Worked on winding problem without luck, so back to calling glFrontFace()
779 // 3 times for each scenery area.
781 // Revision 1.15 1997/12/30 20:47:51 curt
782 // Integrated new event manager with subsystem initializations.
784 // Revision 1.14 1997/12/30 01:38:46 curt
785 // Switched back to per vertex normals and smooth shading for terrain.
787 // Revision 1.13 1997/12/18 23:32:36 curt
788 // First stab at sky dome actually starting to look reasonable. :-)
790 // Revision 1.12 1997/12/17 23:13:47 curt
791 // Began working on rendering the sky.
793 // Revision 1.11 1997/12/15 23:55:01 curt
794 // Add xgl wrappers for debugging.
795 // Generate terrain normals on the fly.
797 // Revision 1.10 1997/12/12 21:41:28 curt
798 // More light/material property tweaking ... still a ways off.
800 // Revision 1.9 1997/12/12 19:52:57 curt
801 // Working on lightling and material properties.
803 // Revision 1.8 1997/12/10 01:19:51 curt
804 // Tweaks for verion 0.15 release.
806 // Revision 1.7 1997/12/08 22:51:17 curt
807 // Enhanced to handle ccw and cw tri-stripe winding. This is a temporary
808 // admission of defeat. I will eventually go back and get all the stripes
809 // wound the same way (ccw).
811 // Revision 1.6 1997/11/25 19:25:35 curt
812 // Changes to integrate Durk's moon/sun code updates + clean up.
814 // Revision 1.5 1997/11/15 18:16:39 curt
817 // Revision 1.4 1997/11/14 00:26:49 curt
818 // Transform scenery coordinates earlier in pipeline when scenery is being
819 // created, not when it is being loaded. Precalculate normals for each node
820 // as average of the normals of each containing polygon so Garoude shading is
823 // Revision 1.3 1997/10/31 04:49:12 curt
824 // Tweaking vertex orders.
826 // Revision 1.2 1997/10/30 12:38:45 curt
827 // Working on new scenery subsystem.
829 // Revision 1.1 1997/10/28 21:14:54 curt