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/point3d.hxx>
58 #include <Math/polar3d.hxx>
59 #include <Misc/stopwatch.hxx>
60 #include <Misc/fgstream.hxx>
61 #include <Scenery/tile.hxx>
63 #include "material.hxx"
67 static double normals[MAX_NODES][3];
70 // given three points defining a triangle, calculate the normal
71 static void calc_normal(double p1[3], double p2[3],
72 double p3[3], double normal[3])
77 v1[0] = p2[0] - p1[0]; v1[1] = p2[1] - p1[1]; v1[2] = p2[2] - p1[2];
78 v2[0] = p3[0] - p1[0]; v2[1] = p3[1] - p1[1]; v2[2] = p3[2] - p1[2];
80 MAT3cross_product(normal, v1, v2);
81 MAT3_NORMALIZE_VEC(normal,temp);
83 // fgPrintf( FG_TERRAIN, FG_DEBUG, " Normal = %.2f %.2f %.2f\n",
84 // normal[0], normal[1], normal[2]);
88 #define FG_TEX_CONSTANT 128.0
91 // Calculate texture coordinates for a given point.
92 Point3D calc_tex_coords(double *node, const Point3D& ref) {
96 cp.setvals( node[0] + ref.x(),
100 pp = fgCartToPolar3d(cp);
102 pp.setx( fmod(RAD_TO_DEG * FG_TEX_CONSTANT * pp.x(), 25.0) );
103 pp.sety( fmod(RAD_TO_DEG * FG_TEX_CONSTANT * pp.y(), 25.0) );
105 if ( pp.x() < 0.0 ) {
106 pp.setx( pp.x() + 25.0 );
109 if ( pp.y() < 0.0 ) {
110 pp.sety( pp.y() + 25.0 );
117 // Load a .obj file and build the GL fragment list
118 int fgObjLoad( const string& path, fgTILE *t) {
121 double approx_normal[3], normal[3], scale;
122 // double x, y, z, xmax, xmin, ymax, ymin, zmax, zmin;
123 // GLfloat sgenparams[] = { 1.0, 0.0, 0.0, 0.0 };
126 int in_fragment, in_faces, vncount, n1, n2, n3, n4;
127 int last1, last2, odd;
131 // printf("loading %s\n", path.c_str() );
133 // Attempt to open "path.gz" or "path"
134 fg_gzifstream in( path );
137 // Attempt to open "path.obj" or "path.obj.gz"
138 in.open( path + ".obj" );
141 fgPrintf( FG_TERRAIN, FG_ALERT,
142 "Cannot open file: %s\n", path.c_str() );
147 shading = current_options.get_shading();
152 t->bounding_radius = 0.0;
159 // ignore initial comments and blank lines. (priming the pump)
166 in.stream() >> token;
168 // printf("token = %s\n", token.c_str() );
170 if ( token == "gbs" )
172 // reference point (center offset)
173 in.stream() >> t->center >> t->bounding_radius;
175 else if ( token == "bs" )
177 // reference point (center offset)
179 in.stream() >> fragment.center.x
183 in.stream() >> fragment.center;
184 in.stream() >> fragment.bounding_radius;
186 else if ( token == "vn" )
189 if ( vncount < MAX_NODES ) {
190 in.stream() >> normals[vncount][0]
191 >> normals[vncount][1]
192 >> normals[vncount][2];
195 fgPrintf( FG_TERRAIN, FG_EXIT,
196 "Read too many vertex normals ... dying :-(\n");
199 else if ( token[0] == 'v' )
202 if ( t->ncount < MAX_NODES ) {
203 in.stream() >> t->nodes[t->ncount][0]
204 >> t->nodes[t->ncount][1]
205 >> t->nodes[t->ncount][2];
208 fgPrintf( FG_TERRAIN, FG_EXIT,
209 "Read too many nodes ... dying :-(\n");
212 else if ( token == "usemtl" )
214 // material property specification
216 // this also signals the start of a new fragment
218 // close out the previous structure and start the next
221 // printf("xglEnd(); xglEndList();\n");
224 fragment.display_list = display_list;
226 // push this fragment onto the tile's object list
227 t->fragment_list.push_back(fragment);
232 // printf("start of fragment (usemtl)\n");
234 display_list = xglGenLists(1);
235 xglNewList(display_list, GL_COMPILE);
236 // printf("xglGenLists(); xglNewList();\n");
239 // reset the existing face list
240 // printf("cleaning a fragment with %d faces\n",
241 // fragment.faces.size());
244 // scan the material line
246 in.stream() >> material;
247 fragment.tile_ptr = t;
249 // find this material in the properties list
250 if ( ! material_mgr.find( material, fragment.material_ptr )) {
251 fgPrintf( FG_TERRAIN, FG_ALERT,
252 "Ack! unknown usemtl name = %s in %s\n",
253 material.c_str(), path.c_str() );
256 // initialize the fragment transformation matrix
258 for ( i = 0; i < 16; i++ ) {
259 fragment.matrix[i] = 0.0;
261 fragment.matrix[0] = fragment.matrix[5] =
262 fragment.matrix[10] = fragment.matrix[15] = 1.0;
264 } else if ( token[0] == 't' ) {
265 // start a new triangle strip
267 n1 = n2 = n3 = n4 = 0;
269 // fgPrintf( FG_TERRAIN, FG_DEBUG, " new tri strip = %s", line);
270 in.stream() >> n1 >> n2 >> n3;
271 fragment.add_face(n1, n2, n3);
273 // fgPrintf( FG_TERRAIN, FG_DEBUG, "(t) = ");
275 xglBegin(GL_TRIANGLE_STRIP);
276 // printf("xglBegin(tristrip) %d %d %d\n", n1, n2, n3);
282 // Shading model is "GL_SMOOTH" so use precalculated
283 // (averaged) normals
284 MAT3_SCALE_VEC(normal, normals[n1], scale);
285 xglNormal3dv(normal);
286 pp = calc_tex_coords(nodes[n1], center);
287 xglTexCoord2f(pp.lon(), pp.lat());
288 // xglVertex3d(t->nodes[n1][0],t->nodes[n1][1],t->nodes[n1][2]);
289 xglVertex3dv(nodes[n1]);
291 MAT3_SCALE_VEC(normal, normals[n2], scale);
292 xglNormal3dv(normal);
293 pp = calc_tex_coords(nodes[n2], center);
294 xglTexCoord2f(pp.lon(), pp.lat());
295 //xglVertex3d(t->nodes[n2][0],t->nodes[n2][1],t->nodes[n2][2]);
296 xglVertex3dv(nodes[n2]);
298 MAT3_SCALE_VEC(normal, normals[n3], scale);
299 xglNormal3dv(normal);
300 pp = calc_tex_coords(nodes[n3], center);
301 xglTexCoord2f(pp.lon(), pp.lat());
302 // xglVertex3d(t->nodes[n3][0],t->nodes[n3][1],t->nodes[n3][2]);
303 xglVertex3dv(nodes[n3]);
305 // Shading model is "GL_FLAT" so calculate per face
306 // normals on the fly.
308 calc_normal(nodes[n1], nodes[n2],
309 nodes[n3], approx_normal);
311 calc_normal(nodes[n2], nodes[n1],
312 nodes[n3], approx_normal);
314 MAT3_SCALE_VEC(normal, approx_normal, scale);
315 xglNormal3dv(normal);
317 pp = calc_tex_coords(nodes[n1], center);
318 xglTexCoord2f(pp.lon(), pp.lat());
319 // xglVertex3d(t->nodes[n1][0],t->nodes[n1][1],t->nodes[n1][2]);
320 xglVertex3dv(nodes[n1]);
322 pp = calc_tex_coords(nodes[n2], center);
323 xglTexCoord2f(pp.lon(), pp.lat());
324 // xglVertex3d(t->nodes[n2][0],t->nodes[n2][1],t->nodes[n2][2]);
325 xglVertex3dv(nodes[n2]);
327 pp = calc_tex_coords(nodes[n3], center);
328 xglTexCoord2f(pp.lon(), pp.lat());
329 // xglVertex3d(t->nodes[n3][0],t->nodes[n3][1],t->nodes[n3][2]);
330 xglVertex3dv(nodes[n3]);
332 // printf("some normals, texcoords, and vertices\n");
338 // There can be three or four values
343 break; // only the one
354 fragment.add_face(n3, n2, n4);
357 // Shading model is "GL_SMOOTH"
358 MAT3_SCALE_VEC(normal, normals[n4], scale);
360 // Shading model is "GL_FLAT"
361 calc_normal(nodes[n3], nodes[n2], nodes[n4],
363 MAT3_SCALE_VEC(normal, approx_normal, scale);
365 xglNormal3dv(normal);
366 pp = calc_tex_coords(nodes[n4], center);
367 xglTexCoord2f(pp.lon(), pp.lat());
368 // xglVertex3d(t->nodes[n4][0],t->nodes[n4][1],t->nodes[n4][2]);
369 xglVertex3dv(nodes[n4]);
374 // printf("a normal, texcoord, and vertex (4th)\n");
376 } else if ( token[0] == 'f' ) {
380 xglBegin(GL_TRIANGLES);
381 // printf("xglBegin(triangles)\n");
385 // fgPrintf( FG_TERRAIN, FG_DEBUG, "new triangle = %s", line);*/
386 in.stream() >> n1 >> n2 >> n3;
387 fragment.add_face(n1, n2, n3);
389 // xglNormal3d(normals[n1][0], normals[n1][1], normals[n1][2]);
390 xglNormal3dv(normals[n1]);
391 pp = calc_tex_coords(nodes[n1], center);
392 xglTexCoord2f(pp.lon(), pp.lat());
393 // xglVertex3d(t->nodes[n1][0], t->nodes[n1][1], t->nodes[n1][2]);
394 xglVertex3dv(nodes[n1]);
396 // xglNormal3d(normals[n2][0], normals[n2][1], normals[n2][2]);
397 xglNormal3dv(normals[n2]);
398 pp = calc_tex_coords(nodes[n2], center);
399 xglTexCoord2f(pp.lon(), pp.lat());
400 // xglVertex3d(t->nodes[n2][0], t->nodes[n2][1], t->nodes[n2][2]);
401 xglVertex3dv(nodes[n2]);
403 // xglNormal3d(normals[n3][0], normals[n3][1], normals[n3][2]);
404 xglNormal3dv(normals[n3]);
405 pp = calc_tex_coords(nodes[n3], center);
406 xglTexCoord2f(pp.lon(), pp.lat());
407 // xglVertex3d(t->nodes[n3][0], t->nodes[n3][1], t->nodes[n3][2]);
408 xglVertex3dv(nodes[n3]);
409 // printf("some normals, texcoords, and vertices (tris)\n");
410 } else if ( token[0] == 'q' ) {
411 // continue a triangle strip
414 // fgPrintf( FG_TERRAIN, FG_DEBUG, "continued tri strip = %s ",
418 // There can be one or two values
423 break; // only the one
432 // fgPrintf( FG_TERRAIN, FG_DEBUG, "read %d %d\n", n1, n2);
435 fragment.add_face(last1, last2, n1);
437 fragment.add_face(last2, last1, n1);
441 // Shading model is "GL_SMOOTH"
442 MAT3_SCALE_VEC(normal, normals[n1], scale);
444 // Shading model is "GL_FLAT"
446 calc_normal(nodes[last1], nodes[last2], nodes[n1],
449 calc_normal(nodes[last2], nodes[last1], nodes[n1],
452 MAT3_SCALE_VEC(normal, approx_normal, scale);
454 xglNormal3dv(normal);
456 pp = calc_tex_coords(nodes[n1], center);
457 xglTexCoord2f(pp.lon(), pp.lat());
458 // xglVertex3d(t->nodes[n1][0], t->nodes[n1][1], t->nodes[n1][2]);
459 xglVertex3dv(nodes[n1]);
460 // printf("a normal, texcoord, and vertex (4th)\n");
467 // fgPrintf( FG_TERRAIN, FG_DEBUG, " (cont)\n");
470 fragment.add_face(last1, last2, n2);
472 fragment.add_face(last2, last1, n2);
476 // Shading model is "GL_SMOOTH"
477 MAT3_SCALE_VEC(normal, normals[n2], scale);
479 // Shading model is "GL_FLAT"
481 calc_normal(nodes[last1], nodes[last2],
482 nodes[n2], approx_normal);
484 calc_normal(nodes[last2], nodes[last1],
485 nodes[n2], approx_normal);
487 MAT3_SCALE_VEC(normal, approx_normal, scale);
489 xglNormal3dv(normal);
491 pp = calc_tex_coords(nodes[n2], center);
492 xglTexCoord2f(pp.lon(), pp.lat());
493 // xglVertex3d(t->nodes[n2][0],t->nodes[n2][1],t->nodes[n2][2]);
494 xglVertex3dv(nodes[n2]);
495 // printf("a normal, texcoord, and vertex (4th)\n");
502 fgPrintf( FG_TERRAIN, FG_WARN, "Unknown token in %s = %s\n",
503 path.c_str(), token.c_str() );
506 // eat comments and blank lines before start of while loop so
507 // if we are done with useful input it is noticed before hand.
512 // close out the previous structure and start the next
515 // printf("xglEnd(); xglEndList();\n");
518 fragment.display_list = display_list;
520 // push this fragment onto the tile's object list
521 t->fragment_list.push_back(fragment);
524 // Draw normal vectors (for visually verifying normals)
527 xglColor3f(0.0, 0.0, 0.0);
528 for ( i = 0; i < t->ncount; i++ ) {
529 xglVertex3d(t->nodes[i][0],
532 xglVertex3d(t->nodes[i][0] + 500*normals[i][0],
533 t->nodes[i][1] + 500*normals[i][1],
534 t->nodes[i][2] + 500*normals[i][2]);
540 fgPrintf( FG_TERRAIN, FG_INFO, "Loaded %s in %f seconds\n",
541 path.c_str(), stopwatch.elapsedSeconds() );
543 // printf("end of tile\n");
550 // Revision 1.5 1998/10/16 00:54:39 curt
551 // Converted to Point3D class.
553 // Revision 1.4 1998/09/15 01:35:07 curt
554 // cleaned up my fragment.num_faces hack :-) to use the STL (no need in
555 // duplicating work.)
556 // Tweaked fgTileMgrRender() do not calc tile matrix unless necessary.
557 // removed some unneeded stuff from fgTileMgrCurElev()
559 // Revision 1.3 1998/09/03 21:27:03 curt
560 // Fixed a serious bug caused by not-quite-correct comment/white space eating
561 // which resulted in mismatched glBegin() glEnd() pairs, incorrect display lists,
562 // and ugly display artifacts.
564 // Revision 1.2 1998/09/01 19:03:09 curt
565 // Changes contributed by Bernie Bright <bbright@c031.aone.net.au>
566 // - The new classes in libmisc.tgz define a stream interface into zlib.
567 // I've put these in a new directory, Lib/Misc. Feel free to rename it
568 // to something more appropriate. However you'll have to change the
569 // include directives in all the other files. Additionally you'll have
570 // add the library to Lib/Makefile.am and Simulator/Main/Makefile.am.
572 // The StopWatch class in Lib/Misc requires a HAVE_GETRUSAGE autoconf
573 // test so I've included the required changes in config.tgz.
575 // There are a fair few changes to Simulator/Objects as I've moved
576 // things around. Loading tiles is quicker but thats not where the delay
577 // is. Tile loading takes a few tenths of a second per file on a P200
578 // but it seems to be the post-processing that leads to a noticeable
579 // blip in framerate. I suppose its time to start profiling to see where
582 // I've included a brief description of each archives contents.
587 // C++ stream interface into zlib.
588 // Taken from zlib-1.1.3/contrib/iostream/.
589 // Minor mods for STL compatibility.
590 // There's no copyright associated with these so I assume they're
591 // covered by zlib's.
595 // FlightGear input stream using gz_ifstream. Tries to open the
596 // given filename. If that fails then filename is examined and a
597 // ".gz" suffix is removed or appended and that file is opened.
600 // A simple timer for benchmarking. Not used in production code.
601 // Taken from the Blitz++ project. Covered by GPL.
605 // Some simple string manipulation routines.
607 // Simulator/Airports/
608 // Load airports database using fgstream.
609 // Changed fgAIRPORTS to use set<> instead of map<>.
610 // Added bool fgAIRPORTS::search() as a neater way doing the lookup.
611 // Returns true if found.
614 // Modified fgStarsInit() to load stars database using fgstream.
616 // Simulator/Objects/
617 // Modified fgObjLoad() to use fgstream.
618 // Modified fgMATERIAL_MGR::load_lib() to use fgstream.
619 // Many changes to fgMATERIAL.
620 // Some changes to fgFRAGMENT but I forget what!
622 // Revision 1.1 1998/08/25 16:51:25 curt
623 // Moved from ../Scenery
625 // Revision 1.23 1998/08/20 15:16:43 curt
626 // obj.cxx: use more explicit parenthases.
627 // texload.[ch]: use const in function definitions where appropriate.
629 // Revision 1.22 1998/08/20 15:12:03 curt
630 // Used a forward declaration of classes fgTILE and fgMATERIAL to eliminate
631 // the need for "void" pointers and casts.
632 // Quick hack to count the number of scenery polygons that are being drawn.
634 // Revision 1.21 1998/08/12 21:13:04 curt
635 // material.cxx: don't load textures if they are disabled
636 // obj.cxx: optimizations from Norman Vine
637 // tile.cxx: minor tweaks
638 // tile.hxx: addition of num_faces
639 // tilemgr.cxx: minor tweaks
641 // Revision 1.20 1998/07/24 21:42:07 curt
642 // material.cxx: whups, double method declaration with no definition.
643 // obj.cxx: tweaks to avoid errors in SGI's CC.
644 // tile.cxx: optimizations by Norman Vine.
645 // tilemgr.cxx: optimizations by Norman Vine.
647 // Revision 1.19 1998/07/13 21:01:58 curt
648 // Wrote access functions for current fgOPTIONS.
650 // Revision 1.18 1998/07/12 03:18:27 curt
651 // Added ground collision detection. This involved:
652 // - saving the entire vertex list for each tile with the tile records.
653 // - saving the face list for each fragment with the fragment records.
654 // - code to intersect the current vertical line with the proper face in
655 // an efficient manner as possible.
656 // Fixed a bug where the tiles weren't being shifted to "near" (0,0,0)
658 // Revision 1.17 1998/07/08 14:47:21 curt
659 // Fix GL_MODULATE vs. GL_DECAL problem introduced by splash screen.
660 // polare3d.h renamed to polar3d.hxx
661 // fg{Cartesian,Polar}Point3d consolodated.
662 // Added some initial support for calculating local current ground elevation.
664 // Revision 1.16 1998/07/06 21:34:33 curt
665 // Added using namespace std for compilers that support this.
667 // Revision 1.15 1998/07/04 00:54:28 curt
668 // Added automatic mipmap generation.
670 // When rendering fragments, use saved model view matrix from associated tile
671 // rather than recalculating it with push() translate() pop().
673 // Revision 1.14 1998/06/17 21:36:40 curt
674 // Load and manage multiple textures defined in the Materials library.
675 // Boost max material fagments for each material property to 800.
676 // Multiple texture support when rendering.
678 // Revision 1.13 1998/06/12 00:58:05 curt
679 // Build only static libraries.
680 // Declare memmove/memset for Sloaris.
682 // Revision 1.12 1998/06/08 17:57:54 curt
683 // Working first pass at material proporty sorting.
685 // Revision 1.11 1998/06/06 01:09:31 curt
686 // I goofed on the log message in the last commit ... now fixed.
688 // Revision 1.10 1998/06/06 01:07:17 curt
689 // Increased per material fragment list size from 100 to 400.
690 // Now correctly draw viewable fragments in per material order.
692 // Revision 1.9 1998/06/05 22:39:54 curt
693 // Working on sorting by, and rendering by material properties.
695 // Revision 1.8 1998/06/05 18:19:18 curt
696 // Recognize file, file.gz, and file.obj as scenery object files.
698 // Revision 1.7 1998/05/24 02:49:09 curt
699 // Implimented fragment level view frustum culling.
701 // Revision 1.6 1998/05/23 14:09:20 curt
702 // Added tile.cxx and tile.hxx.
703 // Working on rewriting the tile management system so a tile is just a list
704 // fragments, and the fragment record contains the display list for that
707 // Revision 1.5 1998/05/20 20:53:53 curt
708 // Moved global ref point and radius (bounding sphere info, and offset) to
709 // data file rather than calculating it on the fly.
710 // Fixed polygon winding problem in scenery generation stage rather than
711 // compensating for it on the fly.
712 // Made a fgTILECACHE class.
714 // Revision 1.4 1998/05/16 13:09:57 curt
715 // Beginning to add support for view frustum culling.
716 // Added some temporary code to calculate bouding radius, until the
717 // scenery generation tools and scenery can be updated.
719 // Revision 1.3 1998/05/03 00:48:01 curt
720 // Updated texture coordinate fmod() parameter.
722 // Revision 1.2 1998/05/02 01:52:14 curt
723 // Playing around with texture coordinates.
725 // Revision 1.1 1998/04/30 12:35:28 curt
726 // Added a command line rendering option specify smooth/flat shading.
728 // Revision 1.35 1998/04/28 21:43:26 curt
729 // Wrapped zlib calls up so we can conditionally comment out zlib support.
731 // Revision 1.34 1998/04/28 01:21:42 curt
732 // Tweaked texture parameter calculations to keep the number smaller. This
733 // avoids the "swimming" problem.
734 // Type-ified fgTIME and fgVIEW.
736 // Revision 1.33 1998/04/27 15:58:15 curt
737 // Screwing around with texture coordinate generation ... still needs work.
739 // Revision 1.32 1998/04/27 03:30:13 curt
740 // Minor transformation adjustments to try to keep scenery tiles closer to
741 // (0, 0, 0) GLfloats run out of precision at the distances we need to model
742 // the earth, but we can do a bunch of pre-transformations using double math
743 // and then cast to GLfloat once everything is close in where we have less
744 // precision problems.
746 // Revision 1.31 1998/04/25 15:09:57 curt
747 // Changed "r" to "rb" in gzopen() options. This fixes bad behavior in win32.
749 // Revision 1.30 1998/04/24 14:21:08 curt
750 // Added "file.obj.gz" support.
752 // Revision 1.29 1998/04/24 00:51:07 curt
753 // Wrapped "#include <config.h>" in "#ifdef HAVE_CONFIG_H"
754 // Tweaked the scenery file extentions to be "file.obj" (uncompressed)
755 // or "file.obz" (compressed.)
757 // Revision 1.28 1998/04/22 13:22:44 curt
758 // C++ - ifing the code a bit.
760 // Revision 1.27 1998/04/18 04:13:17 curt
761 // Added zlib on the fly decompression support for loading scenery objects.
763 // Revision 1.26 1998/04/03 22:11:36 curt
764 // Converting to Gnu autoconf system.
766 // Revision 1.25 1998/03/14 00:30:50 curt
767 // Beginning initial terrain texturing experiments.
769 // Revision 1.24 1998/02/09 21:30:18 curt
770 // Fixed a nagging problem with terrain tiles not "quite" matching up perfectly.
772 // Revision 1.23 1998/02/09 15:07:52 curt
775 // Revision 1.22 1998/02/01 03:39:54 curt
778 // Revision 1.21 1998/01/31 00:43:25 curt
779 // Added MetroWorks patches from Carmen Volpe.
781 // Revision 1.20 1998/01/29 00:51:39 curt
782 // First pass at tile cache, dynamic tile loading and tile unloading now works.
784 // Revision 1.19 1998/01/27 03:26:42 curt
785 // Playing with new fgPrintf command.
787 // Revision 1.18 1998/01/19 19:27:16 curt
788 // Merged in make system changes from Bob Kuehne <rpk@sgi.com>
789 // This should simplify things tremendously.
791 // Revision 1.17 1998/01/13 00:23:10 curt
792 // Initial changes to support loading and management of scenery tiles. Note,
793 // there's still a fair amount of work left to be done.
795 // Revision 1.16 1997/12/30 23:09:40 curt
796 // Worked on winding problem without luck, so back to calling glFrontFace()
797 // 3 times for each scenery area.
799 // Revision 1.15 1997/12/30 20:47:51 curt
800 // Integrated new event manager with subsystem initializations.
802 // Revision 1.14 1997/12/30 01:38:46 curt
803 // Switched back to per vertex normals and smooth shading for terrain.
805 // Revision 1.13 1997/12/18 23:32:36 curt
806 // First stab at sky dome actually starting to look reasonable. :-)
808 // Revision 1.12 1997/12/17 23:13:47 curt
809 // Began working on rendering the sky.
811 // Revision 1.11 1997/12/15 23:55:01 curt
812 // Add xgl wrappers for debugging.
813 // Generate terrain normals on the fly.
815 // Revision 1.10 1997/12/12 21:41:28 curt
816 // More light/material property tweaking ... still a ways off.
818 // Revision 1.9 1997/12/12 19:52:57 curt
819 // Working on lightling and material properties.
821 // Revision 1.8 1997/12/10 01:19:51 curt
822 // Tweaks for verion 0.15 release.
824 // Revision 1.7 1997/12/08 22:51:17 curt
825 // Enhanced to handle ccw and cw tri-stripe winding. This is a temporary
826 // admission of defeat. I will eventually go back and get all the stripes
827 // wound the same way (ccw).
829 // Revision 1.6 1997/11/25 19:25:35 curt
830 // Changes to integrate Durk's moon/sun code updates + clean up.
832 // Revision 1.5 1997/11/15 18:16:39 curt
835 // Revision 1.4 1997/11/14 00:26:49 curt
836 // Transform scenery coordinates earlier in pipeline when scenery is being
837 // created, not when it is being loaded. Precalculate normals for each node
838 // as average of the normals of each containing polygon so Garoude shading is
841 // Revision 1.3 1997/10/31 04:49:12 curt
842 // Tweaking vertex orders.
844 // Revision 1.2 1997/10/30 12:38:45 curt
845 // Working on new scenery subsystem.
847 // Revision 1.1 1997/10/28 21:14:54 curt