1 /**************************************************************************
2 * obj.c -- routines to handle WaveFront .obj format files.
4 * Written by Curtis Olson, started October 1997.
6 * Copyright (C) 1997 Curtis L. Olson - curt@infoplane.com
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License as
10 * published by the Free Software Foundation; either version 2 of the
11 * License, or (at your option) any later version.
13 * This program is distributed in the hope that it will be useful, but
14 * WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
23 * (Log is kept at end of this file)
24 **************************************************************************/
36 #include <Main/fg_debug.h>
37 #include <Math/mat3.h>
38 #include <Scenery/obj.h>
39 #include <Scenery/scenery.h>
43 #define MAXNODES 100000
45 double nodes[MAXNODES][3];
46 double normals[MAXNODES][3];
49 /* given three points defining a triangle, calculate the normal */
50 void calc_normal(double p1[3], double p2[3], double p3[3], double normal[3])
55 v1[0] = p2[0] - p1[0]; v1[1] = p2[1] - p1[1]; v1[2] = p2[2] - p1[2];
56 v2[0] = p3[0] - p1[0]; v2[1] = p3[1] - p1[1]; v2[2] = p3[2] - p1[2];
58 MAT3cross_product(normal, v1, v2);
59 MAT3_NORMALIZE_VEC(normal,temp);
61 /* fgPrintf( FG_TERRAIN, FG_DEBUG, " Normal = %.2f %.2f %.2f\n",
62 normal[0], normal[1], normal[2]);*/
66 /* Load a .obj file and generate the GL call list */
67 GLint fgObjLoad(char *path, struct fgCartesianPoint *ref, double *radius) {
68 char line[256], winding_str[256];
69 double approx_normal[3], normal[3], scale;
70 double x, y, z, xmax, xmin, ymax, ymin, zmax, zmin;
73 int first, ncount, vncount, n1, n2, n3, n4;
74 static int use_vertex_norms = 1;
76 int last1, last2, odd;
78 if ( (f = fopen(path, "r")) == NULL ) {
79 fgPrintf(FG_TERRAIN, FG_ALERT, "Cannot open file: %s\n", path);
83 tile = xglGenLists(1);
84 xglNewList(tile, GL_COMPILE);
90 while ( fgets(line, 250, f) != NULL ) {
91 if ( line[0] == '#' ) {
92 /* comment -- ignore */
93 } else if ( line[0] == '\n' ) {
94 /* empty line -- ignore */
95 } else if ( strncmp(line, "v ", 2) == 0 ) {
97 if ( ncount < MAXNODES ) {
98 /* fgPrintf( FG_TERRAIN, FG_DEBUG, "vertex = %s", line); */
99 sscanf(line, "v %lf %lf %lf\n", &x, &y, &z);
100 nodes[ncount][0] = x;
101 nodes[ncount][1] = y;
102 nodes[ncount][2] = z;
104 /* first time through set min's and max'es */
114 /* keep track of min/max vertex values */
115 if ( x < xmin ) xmin = x;
116 if ( x > xmax ) xmax = x;
117 if ( y < ymin ) ymin = y;
118 if ( y > ymax ) ymax = y;
119 if ( z < zmin ) zmin = z;
120 if ( z > zmax ) zmax = z;
122 /* reference point is the "center" */
123 /* this is overkill to calculate it everytime we get a
124 * new node, but it's hard to know with the .obj
125 * format when we are done with vertices */
126 ref->x = (xmin + xmax) / 2;
127 ref->y = (ymin + ymax) / 2;
128 ref->z = (zmin + zmax) / 2;
132 fgPrintf( FG_TERRAIN, FG_EXIT,
133 "Read too many nodes ... dying :-(\n");
135 } else if ( strncmp(line, "vn ", 3) == 0 ) {
137 if ( vncount < MAXNODES ) {
138 /* fgPrintf( FG_TERRAIN, FG_DEBUG, "vertex normal = %s", line); */
139 sscanf(line, "vn %lf %lf %lf\n",
140 &normals[vncount][0], &normals[vncount][1],
141 &normals[vncount][2]);
144 fgPrintf( FG_TERRAIN, FG_EXIT,
145 "Read too many vertex normals ... dying :-(\n");
147 } else if ( strncmp(line, "winding ", 8) == 0 ) {
148 sscanf(line+8, "%s", winding_str);
149 fgPrintf( FG_TERRAIN, FG_DEBUG, " WINDING = %s\n", winding_str);
151 /* can't call xglFrontFace() between xglBegin() & xglEnd() */
155 if ( strcmp(winding_str, "cw") == 0 ) {
156 xglFrontFace( GL_CW );
159 glFrontFace ( GL_CCW );
162 } else if ( line[0] == 't' ) {
163 /* start a new triangle strip */
165 n1 = n2 = n3 = n4 = 0;
168 /* close out the previous structure and start the next */
174 /* fgPrintf( FG_TERRAIN, FG_DEBUG, " new tri strip = %s",
176 sscanf(line, "t %d %d %d %d\n", &n1, &n2, &n3, &n4);
178 /* fgPrintf( FG_TERRAIN, FG_DEBUG, "(t) = "); */
180 xglBegin(GL_TRIANGLE_STRIP);
190 if ( use_vertex_norms ) {
191 MAT3_SCALE_VEC(normal, normals[n1], scale);
192 xglNormal3dv(normal);
193 xglVertex3d(nodes[n1][0] - ref->x, nodes[n1][1] - ref->y,
194 nodes[n1][2] - ref->z);
196 MAT3_SCALE_VEC(normal, normals[n2], scale);
197 xglNormal3dv(normal);
198 xglVertex3d(nodes[n2][0] - ref->x, nodes[n2][1] - ref->y,
199 nodes[n2][2] - ref->z);
201 MAT3_SCALE_VEC(normal, normals[n3], scale);
202 xglNormal3dv(normal);
203 xglVertex3d(nodes[n3][0] - ref->x, nodes[n3][1] - ref->y,
204 nodes[n3][2] - ref->z);
207 calc_normal(nodes[n1], nodes[n2], nodes[n3], approx_normal);
209 calc_normal(nodes[n2], nodes[n1], nodes[n3], approx_normal);
211 MAT3_SCALE_VEC(normal, approx_normal, scale);
212 xglNormal3dv(normal);
214 xglVertex3d(nodes[n1][0] - ref->x, nodes[n1][1] - ref->y,
215 nodes[n1][2] - ref->z);
216 xglVertex3d(nodes[n2][0] - ref->x, nodes[n2][1] - ref->y,
217 nodes[n2][2] - ref->z);
218 xglVertex3d(nodes[n3][0] - ref->x, nodes[n3][1] - ref->y,
219 nodes[n3][2] - ref->z);
227 if ( use_vertex_norms ) {
228 MAT3_SCALE_VEC(normal, normals[n4], scale);
230 calc_normal(nodes[n3], nodes[n2], nodes[n4], approx_normal);
231 MAT3_SCALE_VEC(normal, approx_normal, scale);
233 xglNormal3dv(normal);
234 xglVertex3d(nodes[n4][0] - ref->x, nodes[n4][1] - ref->y,
235 nodes[n4][2] - ref->z);
241 } else if ( line[0] == 'f' ) {
242 /* unoptimized face */
245 /* close out the previous structure and start the next */
251 xglBegin(GL_TRIANGLES);
253 /* fgPrintf( FG_TERRAIN, FG_DEBUG, "new triangle = %s", line);*/
254 sscanf(line, "f %d %d %d\n", &n1, &n2, &n3);
256 xglNormal3d(normals[n1][0], normals[n1][1], normals[n1][2]);
257 xglVertex3d(nodes[n1][0] - ref->x, nodes[n1][1] - ref->y,
258 nodes[n1][2] - ref->z);
260 xglNormal3d(normals[n2][0], normals[n2][1], normals[n2][2]);
261 xglVertex3d(nodes[n2][0] - ref->x, nodes[n2][1] - ref->y,
262 nodes[n2][2] - ref->z);
264 xglNormal3d(normals[n3][0], normals[n3][1], normals[n3][2]);
265 xglVertex3d(nodes[n3][0] - ref->x, nodes[n3][1] - ref->y,
266 nodes[n3][2] - ref->z);
267 } else if ( line[0] == 'q' ) {
268 /* continue a triangle strip */
271 /* fgPrintf( FG_TERRAIN, FG_DEBUG, "continued tri strip = %s ",
273 sscanf(line, "q %d %d\n", &n1, &n2);
274 /* fgPrintf( FG_TERRAIN, FG_DEBUG, "read %d %d\n", n1, n2); */
276 if ( use_vertex_norms ) {
277 MAT3_SCALE_VEC(normal, normals[n1], scale);
278 xglNormal3dv(normal);
281 calc_normal(nodes[last1], nodes[last2], nodes[n1],
284 calc_normal(nodes[last2], nodes[last1], nodes[n1],
287 MAT3_SCALE_VEC(normal, approx_normal, scale);
288 xglNormal3dv(normal);
291 xglVertex3d(nodes[n1][0] - ref->x, nodes[n1][1] - ref->y,
292 nodes[n1][2] - ref->z);
299 /* fgPrintf( FG_TERRAIN, FG_DEBUG, " (cont)\n"); */
301 if ( use_vertex_norms ) {
302 MAT3_SCALE_VEC(normal, normals[n2], scale);
303 xglNormal3dv(normal);
306 calc_normal(nodes[last1], nodes[last2], nodes[n2],
309 calc_normal(nodes[last2], nodes[last1], nodes[n2],
312 MAT3_SCALE_VEC(normal, approx_normal, scale);
313 xglNormal3dv(normal);
316 xglVertex3d(nodes[n2][0] - ref->x, nodes[n2][1] - ref->y,
317 nodes[n2][2] - ref->z);
324 fgPrintf( FG_TERRAIN, FG_WARN, "Unknown line in %s = %s\n",
331 /* Draw normal vectors (for visually verifying normals)*/
334 xglColor3f(0.0, 0.0, 0.0);
335 for ( i = 0; i < ncount; i++ ) {
336 xglVertex3d(nodes[i][0] - ref->x,
337 nodes[i][1] - ref->y,
338 nodes[i][2] - ref->z);
339 xglVertex3d(nodes[i][0] - ref->x + 500*normals[i][0],
340 nodes[i][1] - ref->y + 500*normals[i][1],
341 nodes[i][2] - ref->z + 500*normals[i][2]);
346 xglFrontFace ( GL_CCW );
357 /* Revision 1.22 1998/02/01 03:39:54 curt
360 * Revision 1.21 1998/01/31 00:43:25 curt
361 * Added MetroWorks patches from Carmen Volpe.
363 * Revision 1.20 1998/01/29 00:51:39 curt
364 * First pass at tile cache, dynamic tile loading and tile unloading now works.
366 * Revision 1.19 1998/01/27 03:26:42 curt
367 * Playing with new fgPrintf command.
369 * Revision 1.18 1998/01/19 19:27:16 curt
370 * Merged in make system changes from Bob Kuehne <rpk@sgi.com>
371 * This should simplify things tremendously.
373 * Revision 1.17 1998/01/13 00:23:10 curt
374 * Initial changes to support loading and management of scenery tiles. Note,
375 * there's still a fair amount of work left to be done.
377 * Revision 1.16 1997/12/30 23:09:40 curt
378 * Worked on winding problem without luck, so back to calling glFrontFace()
379 * 3 times for each scenery area.
381 * Revision 1.15 1997/12/30 20:47:51 curt
382 * Integrated new event manager with subsystem initializations.
384 * Revision 1.14 1997/12/30 01:38:46 curt
385 * Switched back to per vertex normals and smooth shading for terrain.
387 * Revision 1.13 1997/12/18 23:32:36 curt
388 * First stab at sky dome actually starting to look reasonable. :-)
390 * Revision 1.12 1997/12/17 23:13:47 curt
391 * Began working on rendering the sky.
393 * Revision 1.11 1997/12/15 23:55:01 curt
394 * Add xgl wrappers for debugging.
395 * Generate terrain normals on the fly.
397 * Revision 1.10 1997/12/12 21:41:28 curt
398 * More light/material property tweaking ... still a ways off.
400 * Revision 1.9 1997/12/12 19:52:57 curt
401 * Working on lightling and material properties.
403 * Revision 1.8 1997/12/10 01:19:51 curt
404 * Tweaks for verion 0.15 release.
406 * Revision 1.7 1997/12/08 22:51:17 curt
407 * Enhanced to handle ccw and cw tri-stripe winding. This is a temporary
408 * admission of defeat. I will eventually go back and get all the stripes
409 * wound the same way (ccw).
411 * Revision 1.6 1997/11/25 19:25:35 curt
412 * Changes to integrate Durk's moon/sun code updates + clean up.
414 * Revision 1.5 1997/11/15 18:16:39 curt
417 * Revision 1.4 1997/11/14 00:26:49 curt
418 * Transform scenery coordinates earlier in pipeline when scenery is being
419 * created, not when it is being loaded. Precalculate normals for each node
420 * as average of the normals of each containing polygon so Garoude shading is
423 * Revision 1.3 1997/10/31 04:49:12 curt
424 * Tweaking vertex orders.
426 * Revision 1.2 1997/10/30 12:38:45 curt
427 * Working on new scenery subsystem.
429 * Revision 1.1 1997/10/28 21:14:54 curt