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root/radiance/ray/src/ot/wfconv.c
Revision: 2.7
Committed: Thu Jan 29 22:21:34 2004 UTC (20 years, 9 months ago) by greg
Content type: text/plain
Branch: MAIN
Changes since 2.6: +4 -3 lines
Log Message:
Improved behavior to remove normals from flat triangles and reverse vertices

File Contents

# Content
1 #ifndef lint
2 static const char RCSid[] = "$Id: wfconv.c,v 2.6 2003/07/27 22:12:03 schorsch Exp $";
3 #endif
4 /*
5 * Load Wavefront .OBJ file and convert to triangles with mesh info.
6 * Code borrowed largely from obj2rad.c
7 */
8
9 #include "copyright.h"
10 #include "standard.h"
11 #include "cvmesh.h"
12 #include <ctype.h>
13
14 typedef int VNDX[3]; /* vertex index (point,map,normal) */
15
16 #define CHUNKSIZ 1024 /* vertex allocation chunk size */
17
18 #define MAXARG 64 /* maximum # arguments in a statement */
19
20 static FVECT *vlist; /* our vertex list */
21 static int nvs; /* number of vertices in our list */
22 static FVECT *vnlist; /* vertex normal list */
23 static int nvns;
24 static RREAL (*vtlist)[2]; /* map vertex list */
25 static int nvts;
26
27 static char *inpfile; /* input file name */
28 static int havemats; /* materials available? */
29 static char material[64]; /* current material name */
30 static char group[64]; /* current group name */
31 static int lineno; /* current line number */
32 static int faceno; /* current face number */
33
34 static int getstmt();
35 static int cvtndx();
36 static OBJECT getmod();
37 static int putface();
38 static int puttri();
39 static void freeverts();
40 static int newv();
41 static int newvn();
42 static int newvt();
43 static void syntax();
44
45
46 void
47 wfreadobj(objfn) /* read in .OBJ file and convert */
48 char *objfn;
49 {
50 FILE *fp;
51 char *argv[MAXARG];
52 int argc;
53 int nstats, nunknown;
54 int i;
55
56 if (objfn == NULL) {
57 inpfile = "<stdin>";
58 fp = stdin;
59 } else if ((fp = fopen(inpfile=objfn, "r")) == NULL) {
60 sprintf(errmsg, "cannot open \"%s\"", inpfile);
61 error(USER, errmsg);
62 }
63 havemats = (nobjects > 0);
64 nstats = nunknown = 0;
65 material[0] = '\0';
66 group[0] = '\0';
67 lineno = 0; faceno = 0;
68 /* scan until EOF */
69 while ( (argc = getstmt(argv, fp)) ) {
70 switch (argv[0][0]) {
71 case 'v': /* vertex */
72 switch (argv[0][1]) {
73 case '\0': /* point */
74 if (badarg(argc-1,argv+1,"fff"))
75 syntax("bad vertex");
76 newv(atof(argv[1]), atof(argv[2]),
77 atof(argv[3]));
78 break;
79 case 'n': /* normal */
80 if (argv[0][2])
81 goto unknown;
82 if (badarg(argc-1,argv+1,"fff"))
83 syntax("bad normal");
84 if (!newvn(atof(argv[1]), atof(argv[2]),
85 atof(argv[3])))
86 syntax("zero normal");
87 break;
88 case 't': /* coordinate */
89 if (argv[0][2])
90 goto unknown;
91 if (badarg(argc-1,argv+1,"ff"))
92 goto unknown;
93 newvt(atof(argv[1]), atof(argv[2]));
94 break;
95 default:
96 goto unknown;
97 }
98 break;
99 case 'f': /* face */
100 if (argv[0][1])
101 goto unknown;
102 faceno++;
103 switch (argc-1) {
104 case 0: case 1: case 2:
105 syntax("too few vertices");
106 break;
107 case 3:
108 if (!puttri(argv[1], argv[2], argv[3]))
109 syntax("bad triangle");
110 break;
111 default:
112 if (!putface(argc-1, argv+1))
113 syntax("bad face");
114 break;
115 }
116 break;
117 case 'u': /* usemtl/usemap */
118 if (!strcmp(argv[0], "usemap"))
119 break;
120 if (strcmp(argv[0], "usemtl"))
121 goto unknown;
122 if (argc > 1)
123 strcpy(material, argv[1]);
124 else
125 material[0] = '\0';
126 break;
127 case 'o': /* object name */
128 if (argv[0][1])
129 goto unknown;
130 break;
131 case 'g': /* group name */
132 if (argv[0][1])
133 goto unknown;
134 if (argc > 1)
135 strcpy(group, argv[1]);
136 else
137 group[0] = '\0';
138 break;
139 case '#': /* comment */
140 break;
141 default:; /* something we don't deal with */
142 unknown:
143 nunknown++;
144 break;
145 }
146 nstats++;
147 }
148 /* clean up */
149 freeverts();
150 fclose(fp);
151 if (nunknown > 0) {
152 sprintf(errmsg, "%d of %d statements unrecognized",
153 nunknown, nstats);
154 error(WARNING, errmsg);
155 }
156 }
157
158
159 static int
160 getstmt(av, fp) /* read the next statement from fp */
161 register char *av[MAXARG];
162 FILE *fp;
163 {
164 static char sbuf[MAXARG*16];
165 register char *cp;
166 register int i;
167
168 do {
169 if (fgetline(cp=sbuf, sizeof(sbuf), fp) == NULL)
170 return(0);
171 i = 0;
172 for ( ; ; ) {
173 while (isspace(*cp) || *cp == '\\') {
174 if (*cp == '\n')
175 lineno++;
176 *cp++ = '\0';
177 }
178 if (!*cp || i >= MAXARG-1)
179 break;
180 av[i++] = cp;
181 while (*++cp && !isspace(*cp))
182 ;
183 }
184 av[i] = NULL;
185 lineno++;
186 } while (!i);
187
188 return(i);
189 }
190
191
192 static int
193 cvtndx(vi, vs) /* convert vertex string to index */
194 register VNDX vi;
195 register char *vs;
196 {
197 /* get point */
198 vi[0] = atoi(vs);
199 if (vi[0] > 0) {
200 if (vi[0]-- > nvs)
201 return(0);
202 } else if (vi[0] < 0) {
203 vi[0] += nvs;
204 if (vi[0] < 0)
205 return(0);
206 } else
207 return(0);
208 /* get map coord. */
209 while (*vs)
210 if (*vs++ == '/')
211 break;
212 vi[1] = atoi(vs);
213 if (vi[1] > 0) {
214 if (vi[1]-- > nvts)
215 return(0);
216 } else if (vi[1] < 0) {
217 vi[1] += nvts;
218 if (vi[1] < 0)
219 return(0);
220 } else
221 vi[1] = -1;
222 /* get normal */
223 while (*vs)
224 if (*vs++ == '/')
225 break;
226 vi[2] = atoi(vs);
227 if (vi[2] > 0) {
228 if (vi[2]-- > nvns)
229 return(0);
230 } else if (vi[2] < 0) {
231 vi[2] += nvns;
232 if (vi[2] < 0)
233 return(0);
234 } else
235 vi[2] = -1;
236 return(1);
237 }
238
239
240 static int
241 putface(ac, av) /* put out an N-sided polygon */
242 int ac;
243 register char **av;
244 {
245 char *cp;
246 register int i;
247
248 while (ac > 3) { /* break into triangles */
249 if (!puttri(av[0], av[1], av[2]))
250 return(0);
251 ac--; /* remove vertex & rotate */
252 cp = av[0];
253 for (i = 0; i < ac-1; i++)
254 av[i] = av[i+2];
255 av[i] = cp;
256 }
257 return(puttri(av[0], av[1], av[2]));
258 }
259
260
261 static OBJECT
262 getmod() /* get current modifier ID */
263 {
264 char *mnam;
265 OBJECT mod;
266
267 if (!havemats)
268 return(OVOID);
269 if (!strcmp(material, VOIDID))
270 return(OVOID);
271 if (material[0]) /* prefer usemtl statements */
272 mnam = material;
273 else if (group[0]) /* else use group name */
274 mnam = group;
275 else
276 return(OVOID);
277 mod = modifier(mnam);
278 if (mod == OVOID) {
279 sprintf(errmsg, "%s: undefined modifier \"%s\"",
280 inpfile, mnam);
281 error(USER, errmsg);
282 }
283 return(mod);
284 }
285
286
287 static int
288 puttri(v1, v2, v3) /* convert a triangle */
289 char *v1, *v2, *v3;
290 {
291 VNDX v1i, v2i, v3i;
292 RREAL *v1c, *v2c, *v3c;
293 RREAL *v1n, *v2n, *v3n;
294
295 if (!cvtndx(v1i, v1) || !cvtndx(v2i, v2) || !cvtndx(v3i, v3)) {
296 error(WARNING, "bad vertex reference");
297 return(0);
298 }
299 if (v1i[1]>=0 && v2i[1]>=0 && v3i[1]>=0) {
300 v1c = vtlist[v1i[1]];
301 v2c = vtlist[v2i[1]];
302 v3c = vtlist[v3i[1]];
303 } else
304 v1c = v2c = v3c = NULL;
305
306 if (v1i[2]>=0 && v2i[2]>=0 && v3i[2]>=0) {
307 v1n = vnlist[v1i[2]];
308 v2n = vnlist[v2i[2]];
309 v3n = vnlist[v3i[2]];
310 } else
311 v1n = v2n = v3n = NULL;
312
313 return(cvtri(getmod(), vlist[v1i[0]], vlist[v2i[0]], vlist[v3i[0]],
314 v1n, v2n, v3n, v1c, v2c, v3c) >= 0);
315 }
316
317
318 static void
319 freeverts() /* free all vertices */
320 {
321 if (nvs) {
322 free((void *)vlist);
323 nvs = 0;
324 }
325 if (nvts) {
326 free((void *)vtlist);
327 nvts = 0;
328 }
329 if (nvns) {
330 free((void *)vnlist);
331 nvns = 0;
332 }
333 }
334
335
336 static int
337 newv(x, y, z) /* create a new vertex */
338 double x, y, z;
339 {
340 if (!(nvs%CHUNKSIZ)) { /* allocate next block */
341 if (nvs == 0)
342 vlist = (FVECT *)malloc(CHUNKSIZ*sizeof(FVECT));
343 else
344 vlist = (FVECT *)realloc((void *)vlist,
345 (nvs+CHUNKSIZ)*sizeof(FVECT));
346 if (vlist == NULL)
347 error(SYSTEM, "out of memory in newv");
348 }
349 /* assign new vertex */
350 vlist[nvs][0] = x;
351 vlist[nvs][1] = y;
352 vlist[nvs][2] = z;
353 return(++nvs);
354 }
355
356
357 static int
358 newvn(x, y, z) /* create a new vertex normal */
359 double x, y, z;
360 {
361 if (!(nvns%CHUNKSIZ)) { /* allocate next block */
362 if (nvns == 0)
363 vnlist = (FVECT *)malloc(CHUNKSIZ*sizeof(FVECT));
364 else
365 vnlist = (FVECT *)realloc((void *)vnlist,
366 (nvns+CHUNKSIZ)*sizeof(FVECT));
367 if (vnlist == NULL)
368 error(SYSTEM, "out of memory in newvn");
369 }
370 /* assign new normal */
371 vnlist[nvns][0] = x;
372 vnlist[nvns][1] = y;
373 vnlist[nvns][2] = z;
374 if (normalize(vnlist[nvns]) == 0.0)
375 return(0);
376 return(++nvns);
377 }
378
379
380 static int
381 newvt(x, y) /* create a new texture map vertex */
382 double x, y;
383 {
384 if (!(nvts%CHUNKSIZ)) { /* allocate next block */
385 if (nvts == 0)
386 vtlist = (RREAL (*)[2])malloc(CHUNKSIZ*2*sizeof(RREAL));
387 else
388 vtlist = (RREAL (*)[2])realloc((void *)vtlist,
389 (nvts+CHUNKSIZ)*2*sizeof(RREAL));
390 if (vtlist == NULL)
391 error(SYSTEM, "out of memory in newvt");
392 }
393 /* assign new vertex */
394 vtlist[nvts][0] = x;
395 vtlist[nvts][1] = y;
396 return(++nvts);
397 }
398
399
400 static void
401 syntax(er) /* report syntax error and exit */
402 char *er;
403 {
404 sprintf(errmsg, "%s: Wavefront syntax error near line %d: %s\n",
405 inpfile, lineno, er);
406 error(USER, errmsg);
407 }