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 float nodes[MAXNODES][3];
46 float normals[MAXNODES][3];
49 /* given three points defining a triangle, calculate the normal */
50 void calc_normal(float p1[3], float p2[3], float 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) {
68 char line[256], winding_str[256];
69 double approx_normal[3], normal[3], scale;
72 int first, ncount, vncount, n1, n2, n3, n4;
73 static int use_vertex_norms = 1;
75 int last1, last2, odd;
77 if ( (f = fopen(path, "r")) == NULL ) {
78 fgPrintf(FG_TERRAIN, FG_ALERT, "Cannot open file: %s\n", path);
83 area = xglGenLists(1);
84 xglNewList(area, 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 %f %f %f\n",
100 &nodes[ncount][0], &nodes[ncount][1], &nodes[ncount][2]);
102 /* first node becomes the reference point */
103 ref->x = nodes[ncount][0];
104 ref->y = nodes[ncount][1];
105 ref->z = nodes[ncount][2];
106 /* scenery.center = ref; */
110 fgPrintf( FG_TERRAIN, FG_EXIT,
111 "Read too many nodes ... dying :-(\n");
113 } else if ( strncmp(line, "vn ", 3) == 0 ) {
115 if ( vncount < MAXNODES ) {
116 /* fgPrintf( FG_TERRAIN, FG_DEBUG, "vertex normal = %s", line); */
117 sscanf(line, "vn %f %f %f\n",
118 &normals[vncount][0], &normals[vncount][1],
119 &normals[vncount][2]);
122 fgPrintf( FG_TERRAIN, FG_EXIT,
123 "Read too many vertex normals ... dying :-(\n");
125 } else if ( strncmp(line, "winding ", 8) == 0 ) {
126 sscanf(line+8, "%s", winding_str);
127 fgPrintf( FG_TERRAIN, FG_DEBUG, " WINDING = %s\n", winding_str);
129 /* can't call xglFrontFace() between xglBegin() & xglEnd() */
133 if ( strcmp(winding_str, "cw") == 0 ) {
134 xglFrontFace( GL_CW );
137 glFrontFace ( GL_CCW );
140 } else if ( line[0] == 't' ) {
141 /* start a new triangle strip */
143 n1 = n2 = n3 = n4 = 0;
146 /* close out the previous structure and start the next */
152 /* fgPrintf( FG_TERRAIN, FG_DEBUG, " new tri strip = %s",
154 sscanf(line, "t %d %d %d %d\n", &n1, &n2, &n3, &n4);
156 /* fgPrintf( FG_TERRAIN, FG_DEBUG, "(t) = "); */
158 xglBegin(GL_TRIANGLE_STRIP);
168 if ( use_vertex_norms ) {
169 MAT3_SCALE_VEC(normal, normals[n1], scale);
170 xglNormal3dv(normal);
171 xglVertex3d(nodes[n1][0] - ref->x, nodes[n1][1] - ref->y,
172 nodes[n1][2] - ref->z);
174 MAT3_SCALE_VEC(normal, normals[n2], scale);
175 xglNormal3dv(normal);
176 xglVertex3d(nodes[n2][0] - ref->x, nodes[n2][1] - ref->y,
177 nodes[n2][2] - ref->z);
179 MAT3_SCALE_VEC(normal, normals[n3], scale);
180 xglNormal3dv(normal);
181 xglVertex3d(nodes[n3][0] - ref->x, nodes[n3][1] - ref->y,
182 nodes[n3][2] - ref->z);
185 calc_normal(nodes[n1], nodes[n2], nodes[n3], approx_normal);
187 calc_normal(nodes[n2], nodes[n1], nodes[n3], approx_normal);
189 MAT3_SCALE_VEC(normal, approx_normal, scale);
190 xglNormal3dv(normal);
192 xglVertex3d(nodes[n1][0] - ref->x, nodes[n1][1] - ref->y,
193 nodes[n1][2] - ref->z);
194 xglVertex3d(nodes[n2][0] - ref->x, nodes[n2][1] - ref->y,
195 nodes[n2][2] - ref->z);
196 xglVertex3d(nodes[n3][0] - ref->x, nodes[n3][1] - ref->y,
197 nodes[n3][2] - ref->z);
205 if ( use_vertex_norms ) {
206 MAT3_SCALE_VEC(normal, normals[n4], scale);
208 calc_normal(nodes[n3], nodes[n2], nodes[n4], approx_normal);
209 MAT3_SCALE_VEC(normal, approx_normal, scale);
211 xglNormal3dv(normal);
212 xglVertex3d(nodes[n4][0] - ref->x, nodes[n4][1] - ref->y,
213 nodes[n4][2] - ref->z);
219 } else if ( line[0] == 'f' ) {
220 /* unoptimized face */
223 /* close out the previous structure and start the next */
229 xglBegin(GL_TRIANGLES);
231 /* fgPrintf( FG_TERRAIN, FG_DEBUG, "new triangle = %s", line);*/
232 sscanf(line, "f %d %d %d\n", &n1, &n2, &n3);
234 xglNormal3d(normals[n1][0], normals[n1][1], normals[n1][2]);
235 xglVertex3d(nodes[n1][0] - ref->x, nodes[n1][1] - ref->y,
236 nodes[n1][2] - ref->z);
238 xglNormal3d(normals[n2][0], normals[n2][1], normals[n2][2]);
239 xglVertex3d(nodes[n2][0] - ref->x, nodes[n2][1] - ref->y,
240 nodes[n2][2] - ref->z);
242 xglNormal3d(normals[n3][0], normals[n3][1], normals[n3][2]);
243 xglVertex3d(nodes[n3][0] - ref->x, nodes[n3][1] - ref->y,
244 nodes[n3][2] - ref->z);
245 } else if ( line[0] == 'q' ) {
246 /* continue a triangle strip */
249 /* fgPrintf( FG_TERRAIN, FG_DEBUG, "continued tri strip = %s ",
251 sscanf(line, "q %d %d\n", &n1, &n2);
252 /* fgPrintf( FG_TERRAIN, FG_DEBUG, "read %d %d\n", n1, n2); */
254 if ( use_vertex_norms ) {
255 MAT3_SCALE_VEC(normal, normals[n1], scale);
256 xglNormal3dv(normal);
259 calc_normal(nodes[last1], nodes[last2], nodes[n1],
262 calc_normal(nodes[last2], nodes[last1], nodes[n1],
265 MAT3_SCALE_VEC(normal, approx_normal, scale);
266 xglNormal3dv(normal);
269 xglVertex3d(nodes[n1][0] - ref->x, nodes[n1][1] - ref->y,
270 nodes[n1][2] - ref->z);
277 /* fgPrintf( FG_TERRAIN, FG_DEBUG, " (cont)\n"); */
279 if ( use_vertex_norms ) {
280 MAT3_SCALE_VEC(normal, normals[n2], scale);
281 xglNormal3dv(normal);
284 calc_normal(nodes[last1], nodes[last2], nodes[n2],
287 calc_normal(nodes[last2], nodes[last1], nodes[n2],
290 MAT3_SCALE_VEC(normal, approx_normal, scale);
291 xglNormal3dv(normal);
294 xglVertex3d(nodes[n2][0] - ref->x, nodes[n2][1] - ref->y,
295 nodes[n2][2] - ref->z);
302 fgPrintf( FG_TERRAIN, FG_WARN, "Unknown line in %s = %s\n",
309 /* Draw normal vectors (for visually verifying normals)*/
312 xglColor3f(0.0, 0.0, 0.0);
313 for ( i = 0; i < ncount; i++ ) {
314 xglVertex3d(nodes[i][0] - ref->x,
315 nodes[i][1] - ref->y,
316 nodes[i][2] - ref->z);
317 xglVertex3d(nodes[i][0] - ref->x + 500*normals[i][0],
318 nodes[i][1] - ref->y + 500*normals[i][1],
319 nodes[i][2] - ref->z + 500*normals[i][2]);
324 xglFrontFace ( GL_CCW );
335 /* Revision 1.19 1998/01/27 03:26:42 curt
336 /* Playing with new fgPrintf command.
338 * Revision 1.18 1998/01/19 19:27:16 curt
339 * Merged in make system changes from Bob Kuehne <rpk@sgi.com>
340 * This should simplify things tremendously.
342 * Revision 1.17 1998/01/13 00:23:10 curt
343 * Initial changes to support loading and management of scenery tiles. Note,
344 * there's still a fair amount of work left to be done.
346 * Revision 1.16 1997/12/30 23:09:40 curt
347 * Worked on winding problem without luck, so back to calling glFrontFace()
348 * 3 times for each scenery area.
350 * Revision 1.15 1997/12/30 20:47:51 curt
351 * Integrated new event manager with subsystem initializations.
353 * Revision 1.14 1997/12/30 01:38:46 curt
354 * Switched back to per vertex normals and smooth shading for terrain.
356 * Revision 1.13 1997/12/18 23:32:36 curt
357 * First stab at sky dome actually starting to look reasonable. :-)
359 * Revision 1.12 1997/12/17 23:13:47 curt
360 * Began working on rendering the sky.
362 * Revision 1.11 1997/12/15 23:55:01 curt
363 * Add xgl wrappers for debugging.
364 * Generate terrain normals on the fly.
366 * Revision 1.10 1997/12/12 21:41:28 curt
367 * More light/material property tweaking ... still a ways off.
369 * Revision 1.9 1997/12/12 19:52:57 curt
370 * Working on lightling and material properties.
372 * Revision 1.8 1997/12/10 01:19:51 curt
373 * Tweaks for verion 0.15 release.
375 * Revision 1.7 1997/12/08 22:51:17 curt
376 * Enhanced to handle ccw and cw tri-stripe winding. This is a temporary
377 * admission of defeat. I will eventually go back and get all the stripes
378 * wound the same way (ccw).
380 * Revision 1.6 1997/11/25 19:25:35 curt
381 * Changes to integrate Durk's moon/sun code updates + clean up.
383 * Revision 1.5 1997/11/15 18:16:39 curt
386 * Revision 1.4 1997/11/14 00:26:49 curt
387 * Transform scenery coordinates earlier in pipeline when scenery is being
388 * created, not when it is being loaded. Precalculate normals for each node
389 * as average of the normals of each containing polygon so Garoude shading is
392 * Revision 1.3 1997/10/31 04:49:12 curt
393 * Tweaking vertex orders.
395 * Revision 1.2 1997/10/30 12:38:45 curt
396 * Working on new scenery subsystem.
398 * Revision 1.1 1997/10/28 21:14:54 curt