1 |
#ifndef lint |
2 |
static const char RCSid[] = "$Id: wfconv.c,v 2.10 2013/11/08 16:49:04 greg Exp $"; |
3 |
#endif |
4 |
/* |
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* Load Wavefront .OBJ file and convert to triangles with mesh info. |
6 |
* Code borrowed largely from obj2rad.c |
7 |
*/ |
8 |
|
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#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 */ |
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static int nvs; /* number of vertices in our list */ |
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static FVECT *vnlist; /* vertex normal list */ |
24 |
static int nvns; |
25 |
static RREAL (*vtlist)[2]; /* map vertex list */ |
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static int nvts; |
27 |
|
28 |
static char *inpfile; /* input file name */ |
29 |
static int havemats; /* materials available? */ |
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static char material[256]; /* current material name */ |
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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); |
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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); |
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static void syntax(char *er); |
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|
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|
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void |
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wfreadobj( /* read in .OBJ file and convert */ |
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char *objfn |
50 |
) |
51 |
{ |
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FILE *fp; |
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char *argv[MAXARG]; |
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int argc; |
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int nstats, nunknown; |
56 |
|
57 |
if (objfn == NULL) { |
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inpfile = "<stdin>"; |
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fp = stdin; |
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} else if ((fp = fopen(inpfile=objfn, "r")) == NULL) { |
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sprintf(errmsg, "cannot open \"%s\"", inpfile); |
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error(USER, errmsg); |
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} |
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havemats = (nobjects > 0); |
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nstats = nunknown = 0; |
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material[0] = '\0'; |
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group[0] = '\0'; |
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lineno = 0; faceno = 0; |
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/* scan until EOF */ |
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while ( (argc = getstmt(argv, fp)) ) { |
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switch (argv[0][0]) { |
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case 'v': /* vertex */ |
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switch (argv[0][1]) { |
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case '\0': /* point */ |
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if (badarg(argc-1,argv+1,"fff")) |
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syntax("bad vertex"); |
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newv(atof(argv[1]), atof(argv[2]), |
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atof(argv[3])); |
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break; |
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case 'n': /* normal */ |
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if (argv[0][2]) |
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goto unknown; |
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if (badarg(argc-1,argv+1,"fff")) |
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syntax("bad normal"); |
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if (!newvn(atof(argv[1]), atof(argv[2]), |
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atof(argv[3]))) |
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syntax("zero normal"); |
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break; |
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case 't': /* coordinate */ |
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if (argv[0][2]) |
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goto unknown; |
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if (badarg(argc-1,argv+1,"ff")) |
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goto unknown; |
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newvt(atof(argv[1]), atof(argv[2])); |
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break; |
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default: |
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goto unknown; |
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} |
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break; |
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case 'f': /* face */ |
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if (argv[0][1]) |
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goto unknown; |
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faceno++; |
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switch (argc-1) { |
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case 0: case 1: case 2: |
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syntax("too few vertices"); |
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break; |
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case 3: |
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if (!puttri(argv[1], argv[2], argv[3])) |
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syntax("bad triangle"); |
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break; |
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default: |
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if (!putface(argc-1, argv+1)) |
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syntax("bad face"); |
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break; |
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} |
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break; |
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case 'u': /* usemtl/usemap */ |
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if (!strcmp(argv[0], "usemap")) |
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break; |
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if (strcmp(argv[0], "usemtl")) |
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goto unknown; |
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if (argc > 1) |
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strcpy(material, argv[1]); |
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else |
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material[0] = '\0'; |
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break; |
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case 'o': /* object name */ |
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if (argv[0][1]) |
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goto unknown; |
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break; |
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case 'g': /* group name */ |
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if (argv[0][1]) |
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goto unknown; |
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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; |
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default:; /* something we don't deal with */ |
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unknown: |
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nunknown++; |
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break; |
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} |
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nstats++; |
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} |
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/* clean up */ |
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freeverts(); |
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fclose(fp); |
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if (nunknown > 0) { |
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sprintf(errmsg, "%d of %d statements unrecognized", |
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nunknown, nstats); |
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error(WARNING, errmsg); |
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} |
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} |
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|
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|
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static int |
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getstmt( /* read the next statement from fp */ |
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char *av[MAXARG], |
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FILE *fp |
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) |
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{ |
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static char sbuf[MAXARG*16]; |
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char *cp; |
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int i; |
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|
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do { |
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if (fgetline(cp=sbuf, sizeof(sbuf), fp) == NULL) |
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return(0); |
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i = 0; |
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for ( ; ; ) { |
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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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} |
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if (!*cp) |
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break; |
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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); |
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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; |
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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. */ |
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while (*vs) |
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if (*vs++ == '/') |
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break; |
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vi[1] = atoi(vs); |
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if (vi[1] > 0) { |
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if (vi[1]-- > nvts) |
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return(0); |
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} else if (vi[1] < 0) { |
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vi[1] += nvts; |
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if (vi[1] < 0) |
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return(0); |
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} else |
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vi[1] = -1; |
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/* get normal */ |
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while (*vs) |
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if (*vs++ == '/') |
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break; |
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vi[2] = atoi(vs); |
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if (vi[2] > 0) { |
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if (vi[2]-- > nvns) |
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return(0); |
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} else if (vi[2] < 0) { |
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vi[2] += nvns; |
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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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} |
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|
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/* determine dominant axis for triangle */ |
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static int |
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dominant_axis(char *v1, char *v2, char *v3) |
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{ |
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int v1i = atoi(v1), v2i = atoi(v2), v3i = atoi(v3); |
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FVECT e1, e2, vn; |
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int i, imax; |
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|
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VSUB(e1, vlist[v2i], vlist[v1i]); |
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VSUB(e2, vlist[v3i], vlist[v2i]); |
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VCROSS(vn, e1, e2); |
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for (i = imax = 2; i--; ) |
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if (vn[i]*vn[i] > vn[imax]*vn[imax]) |
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imax = i; |
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return(vn[imax]*vn[imax] > FTINY ? imax : -1); |
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} |
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|
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/* callback for triangle output from polygon */ |
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static int |
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tri_out(const Vert2_list *tp, int a, int b, int c) |
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{ |
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return( puttri( ((char **)tp->p)[a], |
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((char **)tp->p)[b], |
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((char **)tp->p)[c] ) ); |
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} |
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|
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static int |
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putface( /* put out an N-sided polygon */ |
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int ac, |
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char **av |
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) |
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{ |
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Vert2_list *poly = polyAlloc(ac); |
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int i, ax, ay; |
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|
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if (poly == NULL) |
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return(0); |
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poly->p = (void *)av; |
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for (i = ac-3; i >= 0; i--) /* identify dominant axis */ |
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if ((ax = dominant_axis(av[i], av[i+1], av[i+2])) >= 0) |
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break; |
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if (ax < 0) |
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return(0); |
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if (++ax >= 3) ax = 0; |
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ay = ax; |
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if (++ay >= 3) ay = 0; |
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for (i = 0; i < ac; i++) { /* convert to 2-D polygon */ |
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VNDX vi; |
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if (!cvtndx(vi, av[i])) { |
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error(WARNING, "bad vertex reference"); |
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polyFree(poly); |
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return(0); |
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} |
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poly->v[i].mX = vlist[vi[0]][ax]; |
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poly->v[i].mY = vlist[vi[0]][ay]; |
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} |
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/* break into triangles & output */ |
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if (!polyTriangulate(poly, &tri_out)) |
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return(0); |
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polyFree(poly); |
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return(1); |
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} |
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|
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|
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static OBJECT |
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getmod(void) /* get current modifier ID */ |
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{ |
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char *mnam; |
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OBJECT mod; |
317 |
|
318 |
if (!havemats) |
319 |
return(OVOID); |
320 |
if (!strcmp(material, VOIDID)) |
321 |
return(OVOID); |
322 |
if (material[0]) /* prefer usemtl statements */ |
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mnam = material; |
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else if (group[0]) /* else use group name */ |
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mnam = group; |
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else |
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return(OVOID); |
328 |
mod = modifier(mnam); |
329 |
if (mod == OVOID) { |
330 |
sprintf(errmsg, "%s: undefined modifier \"%s\"", |
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inpfile, mnam); |
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error(USER, errmsg); |
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} |
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return(mod); |
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} |
336 |
|
337 |
|
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static int |
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puttri( /* convert a triangle */ |
340 |
char *v1, |
341 |
char *v2, |
342 |
char *v3 |
343 |
) |
344 |
{ |
345 |
VNDX v1i, v2i, v3i; |
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RREAL *v1c, *v2c, *v3c; |
347 |
RREAL *v1n, *v2n, *v3n; |
348 |
|
349 |
if (!cvtndx(v1i, v1) || !cvtndx(v2i, v2) || !cvtndx(v3i, v3)) { |
350 |
error(WARNING, "bad vertex reference"); |
351 |
return(0); |
352 |
} |
353 |
if (v1i[1]>=0 && v2i[1]>=0 && v3i[1]>=0) { |
354 |
v1c = vtlist[v1i[1]]; |
355 |
v2c = vtlist[v2i[1]]; |
356 |
v3c = vtlist[v3i[1]]; |
357 |
} else |
358 |
v1c = v2c = v3c = NULL; |
359 |
|
360 |
if (v1i[2]>=0 && v2i[2]>=0 && v3i[2]>=0) { |
361 |
v1n = vnlist[v1i[2]]; |
362 |
v2n = vnlist[v2i[2]]; |
363 |
v3n = vnlist[v3i[2]]; |
364 |
} else |
365 |
v1n = v2n = v3n = NULL; |
366 |
|
367 |
return(cvtri(getmod(), vlist[v1i[0]], vlist[v2i[0]], vlist[v3i[0]], |
368 |
v1n, v2n, v3n, v1c, v2c, v3c) >= 0); |
369 |
} |
370 |
|
371 |
|
372 |
static void |
373 |
freeverts(void) /* free all vertices */ |
374 |
{ |
375 |
if (nvs) { |
376 |
free((void *)vlist); |
377 |
nvs = 0; |
378 |
} |
379 |
if (nvts) { |
380 |
free((void *)vtlist); |
381 |
nvts = 0; |
382 |
} |
383 |
if (nvns) { |
384 |
free((void *)vnlist); |
385 |
nvns = 0; |
386 |
} |
387 |
} |
388 |
|
389 |
|
390 |
static int |
391 |
newv( /* create a new vertex */ |
392 |
double x, |
393 |
double y, |
394 |
double z |
395 |
) |
396 |
{ |
397 |
if (!(nvs%CHUNKSIZ)) { /* allocate next block */ |
398 |
if (nvs == 0) |
399 |
vlist = (FVECT *)malloc(CHUNKSIZ*sizeof(FVECT)); |
400 |
else |
401 |
vlist = (FVECT *)realloc((void *)vlist, |
402 |
(nvs+CHUNKSIZ)*sizeof(FVECT)); |
403 |
if (vlist == NULL) |
404 |
error(SYSTEM, "out of memory in newv"); |
405 |
} |
406 |
/* assign new vertex */ |
407 |
vlist[nvs][0] = x; |
408 |
vlist[nvs][1] = y; |
409 |
vlist[nvs][2] = z; |
410 |
return(++nvs); |
411 |
} |
412 |
|
413 |
|
414 |
static int |
415 |
newvn( /* create a new vertex normal */ |
416 |
double x, |
417 |
double y, |
418 |
double z |
419 |
) |
420 |
{ |
421 |
if (!(nvns%CHUNKSIZ)) { /* allocate next block */ |
422 |
if (nvns == 0) |
423 |
vnlist = (FVECT *)malloc(CHUNKSIZ*sizeof(FVECT)); |
424 |
else |
425 |
vnlist = (FVECT *)realloc((void *)vnlist, |
426 |
(nvns+CHUNKSIZ)*sizeof(FVECT)); |
427 |
if (vnlist == NULL) |
428 |
error(SYSTEM, "out of memory in newvn"); |
429 |
} |
430 |
/* assign new normal */ |
431 |
vnlist[nvns][0] = x; |
432 |
vnlist[nvns][1] = y; |
433 |
vnlist[nvns][2] = z; |
434 |
if (normalize(vnlist[nvns]) == 0.0) |
435 |
return(0); |
436 |
return(++nvns); |
437 |
} |
438 |
|
439 |
|
440 |
static int |
441 |
newvt( /* create a new texture map vertex */ |
442 |
double x, |
443 |
double y |
444 |
) |
445 |
{ |
446 |
if (!(nvts%CHUNKSIZ)) { /* allocate next block */ |
447 |
if (nvts == 0) |
448 |
vtlist = (RREAL (*)[2])malloc(CHUNKSIZ*2*sizeof(RREAL)); |
449 |
else |
450 |
vtlist = (RREAL (*)[2])realloc((void *)vtlist, |
451 |
(nvts+CHUNKSIZ)*2*sizeof(RREAL)); |
452 |
if (vtlist == NULL) |
453 |
error(SYSTEM, "out of memory in newvt"); |
454 |
} |
455 |
/* assign new vertex */ |
456 |
vtlist[nvts][0] = x; |
457 |
vtlist[nvts][1] = y; |
458 |
return(++nvts); |
459 |
} |
460 |
|
461 |
|
462 |
static void |
463 |
syntax( /* report syntax error and exit */ |
464 |
char *er |
465 |
) |
466 |
{ |
467 |
sprintf(errmsg, "%s: Wavefront syntax error near line %d: %s\n", |
468 |
inpfile, lineno, er); |
469 |
error(USER, errmsg); |
470 |
} |