| 1 |
#ifndef lint |
| 2 |
static const char RCSid[] = "$Id: wfconv.c,v 2.17 2021/03/11 17:00:58 greg 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 "triangulate.h" |
| 13 |
#include <ctype.h> |
| 14 |
|
| 15 |
typedef int VNDX[3]; /* vertex index (point,map,normal) */ |
| 16 |
|
| 17 |
#define CHUNKSIZ 1024 /* vertex allocation chunk size */ |
| 18 |
|
| 19 |
#define MAXARG 512 /* maximum # arguments in a statement */ |
| 20 |
|
| 21 |
static FVECT *vlist; /* our vertex list */ |
| 22 |
static int nvs; /* number of vertices in our list */ |
| 23 |
static FVECT *vnlist; /* vertex normal list */ |
| 24 |
static int nvns; |
| 25 |
static RREAL (*vtlist)[2]; /* map vertex list */ |
| 26 |
static int nvts; |
| 27 |
|
| 28 |
static char *inpfile; /* input file name */ |
| 29 |
static int havemats; /* materials available? */ |
| 30 |
static char material[256]; /* current material name */ |
| 31 |
static char group[256]; /* current group name */ |
| 32 |
static int lineno; /* current line number */ |
| 33 |
static int faceno; /* current face number */ |
| 34 |
|
| 35 |
static int getstmt(char *av[MAXARG], FILE *fp); |
| 36 |
static int cvtndx(VNDX vi, char *vs); |
| 37 |
static int putface(int ac, char **av); |
| 38 |
static OBJECT getmod(void); |
| 39 |
static int puttri(char *v1, char *v2, char *v3); |
| 40 |
static void freeverts(void); |
| 41 |
static int newv(double x, double y, double z); |
| 42 |
static int newvn(double x, double y, double z); |
| 43 |
static int newvt(double x, double y); |
| 44 |
static void syntax(char *er); |
| 45 |
|
| 46 |
|
| 47 |
void |
| 48 |
wfreadobj( /* read in .OBJ file and convert */ |
| 49 |
char *objfn |
| 50 |
) |
| 51 |
{ |
| 52 |
FILE *fp; |
| 53 |
char *argv[MAXARG]; |
| 54 |
int argc; |
| 55 |
int nstats, nunknown; |
| 56 |
|
| 57 |
if (objfn == NULL) { |
| 58 |
inpfile = "<stdin>"; |
| 59 |
fp = stdin; |
| 60 |
} else if ((fp = fopen(inpfile=objfn, "r")) == NULL) { |
| 61 |
sprintf(errmsg, "cannot open \"%s\"", inpfile); |
| 62 |
error(USER, errmsg); |
| 63 |
} |
| 64 |
havemats = (nobjects > 0); |
| 65 |
nstats = nunknown = 0; |
| 66 |
material[0] = '\0'; |
| 67 |
group[0] = '\0'; |
| 68 |
lineno = 0; faceno = 0; |
| 69 |
/* scan until EOF */ |
| 70 |
while ( (argc = getstmt(argv, fp)) ) { |
| 71 |
switch (argv[0][0]) { |
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case 'v': /* vertex */ |
| 73 |
switch (argv[0][1]) { |
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case '\0': /* point */ |
| 75 |
if (badarg(argc-1,argv+1,"fff")) |
| 76 |
syntax("bad vertex"); |
| 77 |
newv(atof(argv[1]), atof(argv[2]), |
| 78 |
atof(argv[3])); |
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break; |
| 80 |
case 'n': /* normal */ |
| 81 |
if (argv[0][2]) |
| 82 |
goto unknown; |
| 83 |
if (badarg(argc-1,argv+1,"fff")) |
| 84 |
syntax("bad normal"); |
| 85 |
if (!newvn(atof(argv[1]), atof(argv[2]), |
| 86 |
atof(argv[3]))) |
| 87 |
syntax("zero normal"); |
| 88 |
break; |
| 89 |
case 't': /* coordinate */ |
| 90 |
if (argv[0][2]) |
| 91 |
goto unknown; |
| 92 |
if (badarg(argc-1,argv+1,"ff")) |
| 93 |
goto unknown; |
| 94 |
newvt(atof(argv[1]), atof(argv[2])); |
| 95 |
break; |
| 96 |
default: |
| 97 |
goto unknown; |
| 98 |
} |
| 99 |
break; |
| 100 |
case 'f': /* face */ |
| 101 |
if (argv[0][1]) |
| 102 |
goto unknown; |
| 103 |
faceno++; |
| 104 |
switch (argc-1) { |
| 105 |
case 0: case 1: case 2: |
| 106 |
syntax("too few vertices"); |
| 107 |
break; |
| 108 |
case 3: |
| 109 |
if (!puttri(argv[1], argv[2], argv[3])) |
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syntax("bad triangle"); |
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break; |
| 112 |
default: |
| 113 |
if (!putface(argc-1, argv+1)) |
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syntax("bad face"); |
| 115 |
break; |
| 116 |
} |
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break; |
| 118 |
case 'u': /* usemtl/usemap */ |
| 119 |
if (!strcmp(argv[0], "usemap")) |
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break; |
| 121 |
if (strcmp(argv[0], "usemtl")) |
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goto unknown; |
| 123 |
if (argc > 1) |
| 124 |
strcpy(material, argv[1]); |
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else |
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material[0] = '\0'; |
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break; |
| 128 |
case 'o': /* object name */ |
| 129 |
if (argv[0][1]) |
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goto unknown; |
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break; |
| 132 |
case 'g': /* group name */ |
| 133 |
if (argv[0][1]) |
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goto unknown; |
| 135 |
if (argc > 1) |
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strcpy(group, argv[1]); |
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else |
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group[0] = '\0'; |
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break; |
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case '#': /* comment */ |
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break; |
| 142 |
default:; /* something we don't deal with */ |
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unknown: |
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nunknown++; |
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break; |
| 146 |
} |
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nstats++; |
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} |
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/* clean up */ |
| 150 |
freeverts(); |
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fclose(fp); |
| 152 |
if (nunknown > 0) { |
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sprintf(errmsg, "%d of %d statements unrecognized", |
| 154 |
nunknown, nstats); |
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error(WARNING, errmsg); |
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} |
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} |
| 158 |
|
| 159 |
|
| 160 |
static int |
| 161 |
getstmt( /* read the next statement from fp */ |
| 162 |
char *av[MAXARG], |
| 163 |
FILE *fp |
| 164 |
) |
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{ |
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static char sbuf[MAXARG*16]; |
| 167 |
char *cp; |
| 168 |
int i; |
| 169 |
|
| 170 |
do { |
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if (fgetline(cp=sbuf, sizeof(sbuf), fp) == NULL) |
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return(0); |
| 173 |
i = 0; |
| 174 |
for ( ; ; ) { |
| 175 |
while (isspace(*cp) || *cp == '\\') { |
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if (*cp == '\n') |
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lineno++; |
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*cp++ = '\0'; |
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} |
| 180 |
if (!*cp) |
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break; |
| 182 |
if (i >= MAXARG-1) { |
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sprintf(errmsg, |
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"%s: too many arguments near line %d (limit %d)\n", |
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inpfile, lineno+1, MAXARG-1); |
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break; |
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} |
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av[i++] = cp; |
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while (*++cp && !isspace(*cp)) |
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; |
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} |
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av[i] = NULL; |
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lineno++; |
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} while (!i); |
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|
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return(i); |
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} |
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|
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|
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static int |
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cvtndx( /* convert vertex string to index */ |
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VNDX vi, |
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char *vs |
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) |
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{ |
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/* get point */ |
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vi[0] = atoi(vs); |
| 208 |
if (vi[0] > 0) { |
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if (vi[0]-- > nvs) |
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return(0); |
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} else if (vi[0] < 0) { |
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vi[0] += nvs; |
| 213 |
if (vi[0] < 0) |
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return(0); |
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} else |
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return(0); |
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/* get map coord. */ |
| 218 |
while (*vs) |
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if (*vs++ == '/') |
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break; |
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vi[1] = atoi(vs); |
| 222 |
if (vi[1] > 0) { |
| 223 |
if (vi[1]-- > nvts) |
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return(0); |
| 225 |
} else if (vi[1] < 0) { |
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vi[1] += nvts; |
| 227 |
if (vi[1] < 0) |
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return(0); |
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} else |
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vi[1] = -1; |
| 231 |
/* get normal */ |
| 232 |
while (*vs) |
| 233 |
if (*vs++ == '/') |
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break; |
| 235 |
vi[2] = atoi(vs); |
| 236 |
if (vi[2] > 0) { |
| 237 |
if (vi[2]-- > nvns) |
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return(0); |
| 239 |
} else if (vi[2] < 0) { |
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vi[2] += nvns; |
| 241 |
if (vi[2] < 0) |
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return(0); |
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} else |
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vi[2] = -1; |
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return(1); |
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} |
| 247 |
|
| 248 |
/* determine dominant axis for triangle */ |
| 249 |
static int |
| 250 |
dominant_axis(char *v1, char *v2, char *v3) |
| 251 |
{ |
| 252 |
VNDX v1i, v2i, v3i; |
| 253 |
FVECT e1, e2, vn; |
| 254 |
int i, imax; |
| 255 |
|
| 256 |
if (!cvtndx(v1i, v1) || !cvtndx(v2i, v2) || !cvtndx(v3i, v3)) |
| 257 |
return(-1); |
| 258 |
VSUB(e1, vlist[v2i[0]], vlist[v1i[0]]); |
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VSUB(e2, vlist[v3i[0]], vlist[v2i[0]]); |
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VCROSS(vn, e1, e2); |
| 261 |
for (i = imax = 2; i--; ) |
| 262 |
if (vn[i]*vn[i] > vn[imax]*vn[imax]) |
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imax = i; |
| 264 |
return(vn[imax]*vn[imax] > FTINY*FTINY*FTINY*FTINY ? imax : -1); |
| 265 |
} |
| 266 |
|
| 267 |
/* struct needed for triangulation callback */ |
| 268 |
typedef struct { |
| 269 |
char **avl; |
| 270 |
int rev; |
| 271 |
} WFpoly; |
| 272 |
|
| 273 |
/* callback for triangle output from polygon */ |
| 274 |
static int |
| 275 |
tri_out(const Vert2_list *tp, int a, int b, int c) |
| 276 |
{ |
| 277 |
WFpoly * wp = (WFpoly *)tp->p; |
| 278 |
|
| 279 |
if (wp->rev) |
| 280 |
return( puttri(wp->avl[c], wp->avl[b], wp->avl[a]) ); |
| 281 |
|
| 282 |
return( puttri(wp->avl[a], wp->avl[b], wp->avl[c]) ); |
| 283 |
} |
| 284 |
|
| 285 |
static int |
| 286 |
putface( /* put out an N-sided polygon */ |
| 287 |
int ac, |
| 288 |
char **av |
| 289 |
) |
| 290 |
{ |
| 291 |
Vert2_list *poly; |
| 292 |
WFpoly myps; |
| 293 |
int i, ax, ay; |
| 294 |
|
| 295 |
for (i = ac-3; i >= 0; i--) /* identify dominant axis */ |
| 296 |
if ((ax = dominant_axis(av[i], av[i+1], av[i+2])) >= 0) |
| 297 |
break; |
| 298 |
if (ax < 0) |
| 299 |
return(1); /* ignore degenerate face */ |
| 300 |
poly = polyAlloc(ac); |
| 301 |
if (poly == NULL) |
| 302 |
return(0); |
| 303 |
myps.avl = av; |
| 304 |
poly->p = &myps; |
| 305 |
if (++ax >= 3) ax = 0; |
| 306 |
ay = ax; |
| 307 |
if (++ay >= 3) ay = 0; |
| 308 |
for (i = 0; i < ac; i++) { /* convert to 2-D polygon */ |
| 309 |
VNDX vi; |
| 310 |
if (!cvtndx(vi, av[i])) { |
| 311 |
error(WARNING, "bad vertex reference"); |
| 312 |
polyFree(poly); |
| 313 |
return(0); |
| 314 |
} |
| 315 |
poly->v[i].mX = vlist[vi[0]][ax]; |
| 316 |
poly->v[i].mY = vlist[vi[0]][ay]; |
| 317 |
} |
| 318 |
/* flag for order reversal */ |
| 319 |
myps.rev = (polyArea(poly) < .0); |
| 320 |
/* break into triangles & output */ |
| 321 |
if (!polyTriangulate(poly, &tri_out)) { |
| 322 |
sprintf(errmsg, "self-intersecting face with %d vertices", ac); |
| 323 |
error(WARNING, errmsg); |
| 324 |
} |
| 325 |
polyFree(poly); |
| 326 |
return(1); |
| 327 |
} |
| 328 |
|
| 329 |
|
| 330 |
static OBJECT |
| 331 |
getmod(void) /* get current modifier ID */ |
| 332 |
{ |
| 333 |
char *mnam; |
| 334 |
OBJECT mod; |
| 335 |
|
| 336 |
if (!havemats) |
| 337 |
return(OVOID); |
| 338 |
if (!strcmp(material, VOIDID)) |
| 339 |
return(OVOID); |
| 340 |
if (material[0]) /* prefer usemtl statements */ |
| 341 |
mnam = material; |
| 342 |
else if (group[0]) /* else use group name */ |
| 343 |
mnam = group; |
| 344 |
else |
| 345 |
return(OVOID); |
| 346 |
mod = modifier(mnam); |
| 347 |
if (mod == OVOID) { |
| 348 |
sprintf(errmsg, "%s: undefined modifier \"%s\"", |
| 349 |
inpfile, mnam); |
| 350 |
error(USER, errmsg); |
| 351 |
} |
| 352 |
return(mod); |
| 353 |
} |
| 354 |
|
| 355 |
|
| 356 |
static int |
| 357 |
puttri( /* convert a triangle */ |
| 358 |
char *v1, |
| 359 |
char *v2, |
| 360 |
char *v3 |
| 361 |
) |
| 362 |
{ |
| 363 |
VNDX v1i, v2i, v3i; |
| 364 |
RREAL *v1c, *v2c, *v3c; |
| 365 |
RREAL *v1n, *v2n, *v3n; |
| 366 |
|
| 367 |
if (!cvtndx(v1i, v1) || !cvtndx(v2i, v2) || !cvtndx(v3i, v3)) { |
| 368 |
error(WARNING, "bad vertex reference"); |
| 369 |
return(0); |
| 370 |
} |
| 371 |
if (v1i[1]>=0 && v2i[1]>=0 && v3i[1]>=0) { |
| 372 |
v1c = vtlist[v1i[1]]; |
| 373 |
v2c = vtlist[v2i[1]]; |
| 374 |
v3c = vtlist[v3i[1]]; |
| 375 |
} else |
| 376 |
v1c = v2c = v3c = NULL; |
| 377 |
|
| 378 |
if (v1i[2]>=0 && v2i[2]>=0 && v3i[2]>=0) { |
| 379 |
v1n = vnlist[v1i[2]]; |
| 380 |
v2n = vnlist[v2i[2]]; |
| 381 |
v3n = vnlist[v3i[2]]; |
| 382 |
} else |
| 383 |
v1n = v2n = v3n = NULL; |
| 384 |
|
| 385 |
return(cvtri(getmod(), vlist[v1i[0]], vlist[v2i[0]], vlist[v3i[0]], |
| 386 |
v1n, v2n, v3n, v1c, v2c, v3c) >= 0); |
| 387 |
} |
| 388 |
|
| 389 |
|
| 390 |
static void |
| 391 |
freeverts(void) /* free all vertices */ |
| 392 |
{ |
| 393 |
if (nvs) { |
| 394 |
free((void *)vlist); |
| 395 |
nvs = 0; |
| 396 |
} |
| 397 |
if (nvts) { |
| 398 |
free((void *)vtlist); |
| 399 |
nvts = 0; |
| 400 |
} |
| 401 |
if (nvns) { |
| 402 |
free((void *)vnlist); |
| 403 |
nvns = 0; |
| 404 |
} |
| 405 |
} |
| 406 |
|
| 407 |
|
| 408 |
static int |
| 409 |
newv( /* create a new vertex */ |
| 410 |
double x, |
| 411 |
double y, |
| 412 |
double z |
| 413 |
) |
| 414 |
{ |
| 415 |
if (!(nvs%CHUNKSIZ)) { /* allocate next block */ |
| 416 |
if (nvs == 0) |
| 417 |
vlist = (FVECT *)malloc(CHUNKSIZ*sizeof(FVECT)); |
| 418 |
else |
| 419 |
vlist = (FVECT *)realloc((void *)vlist, |
| 420 |
(nvs+CHUNKSIZ)*sizeof(FVECT)); |
| 421 |
if (vlist == NULL) |
| 422 |
error(SYSTEM, "out of memory in newv"); |
| 423 |
} |
| 424 |
/* assign new vertex */ |
| 425 |
vlist[nvs][0] = x; |
| 426 |
vlist[nvs][1] = y; |
| 427 |
vlist[nvs][2] = z; |
| 428 |
return(++nvs); |
| 429 |
} |
| 430 |
|
| 431 |
|
| 432 |
static int |
| 433 |
newvn( /* create a new vertex normal */ |
| 434 |
double x, |
| 435 |
double y, |
| 436 |
double z |
| 437 |
) |
| 438 |
{ |
| 439 |
if (!(nvns%CHUNKSIZ)) { /* allocate next block */ |
| 440 |
if (nvns == 0) |
| 441 |
vnlist = (FVECT *)malloc(CHUNKSIZ*sizeof(FVECT)); |
| 442 |
else |
| 443 |
vnlist = (FVECT *)realloc((void *)vnlist, |
| 444 |
(nvns+CHUNKSIZ)*sizeof(FVECT)); |
| 445 |
if (vnlist == NULL) |
| 446 |
error(SYSTEM, "out of memory in newvn"); |
| 447 |
} |
| 448 |
/* assign new normal */ |
| 449 |
vnlist[nvns][0] = x; |
| 450 |
vnlist[nvns][1] = y; |
| 451 |
vnlist[nvns][2] = z; |
| 452 |
if (normalize(vnlist[nvns]) == 0.0) |
| 453 |
return(0); |
| 454 |
return(++nvns); |
| 455 |
} |
| 456 |
|
| 457 |
|
| 458 |
static int |
| 459 |
newvt( /* create a new texture map vertex */ |
| 460 |
double x, |
| 461 |
double y |
| 462 |
) |
| 463 |
{ |
| 464 |
if (!(nvts%CHUNKSIZ)) { /* allocate next block */ |
| 465 |
if (nvts == 0) |
| 466 |
vtlist = (RREAL (*)[2])malloc(CHUNKSIZ*2*sizeof(RREAL)); |
| 467 |
else |
| 468 |
vtlist = (RREAL (*)[2])realloc((void *)vtlist, |
| 469 |
(nvts+CHUNKSIZ)*2*sizeof(RREAL)); |
| 470 |
if (vtlist == NULL) |
| 471 |
error(SYSTEM, "out of memory in newvt"); |
| 472 |
} |
| 473 |
/* assign new vertex */ |
| 474 |
vtlist[nvts][0] = x; |
| 475 |
vtlist[nvts][1] = y; |
| 476 |
return(++nvts); |
| 477 |
} |
| 478 |
|
| 479 |
|
| 480 |
static void |
| 481 |
syntax( /* report syntax error and exit */ |
| 482 |
char *er |
| 483 |
) |
| 484 |
{ |
| 485 |
sprintf(errmsg, "%s: Wavefront syntax error near line %d: %s", |
| 486 |
inpfile, lineno, er); |
| 487 |
error(USER, errmsg); |
| 488 |
} |
