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/* Copyright (c) 1994 Regents of the University of California */ |
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|
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#ifndef lint |
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static char SCCSid[] = "$SunId$ LBL"; |
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#endif |
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|
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/* |
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* Convert a triangle mesh into a Radiance description. |
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* |
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* Unlike most other converters, we have defined a file |
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* format for the mesh ourselves. It contains eight types, |
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* each of which is identified by a single letter. These are: |
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* |
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* # comment = a comment. Continues until end of line. |
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* v id Px Py Pz = a vertex. The id must be an integer. |
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* n Nx Ny Nz = a normal. Corresponds to most recent vertex. |
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* i Iu Iv = an index. Corresponds to most recent vertex. |
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* p picture = a picture. Used as a pattern what follows. |
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* m material = a material name. Used for what follows. |
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* t id1 id2 id3 = a triangle. |
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* |
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* Only the 't' type results in any output. The others merely set values |
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* to be used in generating triangles. If no picture or "p -" is given, |
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* there will be no pattern associated with the geometry. If no material |
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* or "m -" is given, no material will be associated. (Note that this |
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* only makes sense for a mesh which is to be put into an octree for |
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* instancing.) Using a pattern requires that each vertex have an |
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* associated index value for generating the colorpict primitive. |
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*/ |
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|
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#include "standard.h" |
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|
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#define CALNAME "tmesh.cal" /* the name of our auxiliary file */ |
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#define PATNAME "tpat" /* triangle pattern name (reused) */ |
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#define TEXNAME "tnor" /* triangle texture name (reused) */ |
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|
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#define V_DEFINED 01 /* this vertex is defined */ |
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#define V_HASNORM 02 /* vertex has surface normal */ |
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#define V_HASINDX 04 /* vertex has index */ |
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|
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typedef struct { |
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short flags; /* vertex flags, from above */ |
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FVECT pos; /* location */ |
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FVECT nor; /* normal */ |
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float ndx[2]; /* picture index */ |
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} VERTEX; |
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|
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VERTEX *vlist = NULL; /* our vertex list */ |
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int nverts = 0; /* number of vertices in our list */ |
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|
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typedef FLOAT BARYCCM[3][4]; |
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|
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#define novert(i) ((i)<0|(i)>=nverts||!(vlist[i].flags&V_DEFINED)) |
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|
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#define CHUNKSIZ 128 /* vertex allocation chunk size */ |
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|
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extern VERTEX *vnew(); /* allocate a vertex (never freed) */ |
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|
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|
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main(argc, argv) /* read in T-mesh files and convert */ |
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int argc; |
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char *argv[]; |
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{ |
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FILE *fp; |
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int i; |
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|
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if (argc == 1) |
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convert("<stdin>", stdin); |
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else |
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for (i = 1; i < argc; i++) { |
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if ((fp = fopen(argv[i], "r")) == NULL) { |
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perror(argv[i]); |
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exit(1); |
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} |
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convert(argv[i], fp); |
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fclose(fp); |
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} |
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exit(0); |
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} |
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|
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|
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convert(fname, fp) /* convert a T-mesh */ |
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char *fname; |
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FILE *fp; |
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{ |
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char typ[2]; |
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int id[3]; |
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double vec[3]; |
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char picfile[128]; |
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char matname[64]; |
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char *err; |
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register int c; |
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register VERTEX *lastv = NULL; |
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|
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printf("# T-mesh from: %s\n", fname); |
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|
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picfile[0] = '\0'; |
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strcpy(matname, "void"); |
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|
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while (fscanf(fp, "%1s", typ) == 1) |
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switch (typ[0]) { |
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case 'v': /* vertex */ |
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if (fscanf(fp, "%d %lf %lf %lf", &id[0], |
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&vec[0], &vec[1], &vec[2]) != 4) |
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syntax(fname, fp, "Bad vertex"); |
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lastv = vnew(id[0], vec[0], vec[1], vec[2]); |
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break; |
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case 't': /* triangle */ |
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if (fscanf(fp, "%d %d %d", &id[0], &id[1], &id[2]) != 3) |
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syntax(fname, fp, "Bad triangle"); |
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if (novert(id[0]) | novert(id[1]) | novert(id[2])) |
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syntax(fname, fp, "Undefined triangle vertex"); |
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triangle(picfile, matname, &vlist[id[0]], |
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&vlist[id[1]], &vlist[id[2]]); |
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break; |
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case 'n': /* surface normal */ |
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if (lastv == NULL) |
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syntax(fname, fp, "No vertex for normal"); |
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if (fscanf(fp, "%lf %lf %lf", |
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&vec[0], &vec[1], &vec[2]) != 3) |
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syntax(fname, fp, "Bad vertex normal"); |
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lastv->nor[0] = vec[0]; |
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lastv->nor[1] = vec[1]; |
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lastv->nor[2] = vec[2]; |
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if (normalize(lastv->nor) == 0.0) |
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syntax(fname, fp, "Zero vertex normal"); |
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lastv->flags |= V_HASNORM; |
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break; |
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case 'i': /* index position */ |
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if (lastv == NULL) |
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syntax(fname, fp, "No vertex for index"); |
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if (fscanf(fp, "%lf %lf", &vec[0], &vec[1]) != 2) |
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syntax(fname, fp, "Bad index"); |
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lastv->ndx[0] = vec[0]; |
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lastv->ndx[1] = vec[1]; |
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lastv->flags |= V_HASINDX; |
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break; |
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case 'm': /* material */ |
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if (fscanf(fp, "%s", matname) != 1) |
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syntax(fname, fp, "Bad material"); |
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if (matname[0] == '-' && !matname[1]) |
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strcpy(matname, "void"); |
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break; |
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case 'p': /* picture */ |
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if (fscanf(fp, "%s", picfile) != 1) |
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syntax(fname, fp, "Bad pattern"); |
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if (picfile[0] == '-' && !picfile[1]) |
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picfile[0] = '\0'; |
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break; |
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case '#': /* comment */ |
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while ((c = getc(fp)) != EOF && c != '\n') |
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; |
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break; |
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default: |
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syntax(fname, fp, "Unknown type"); |
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break; |
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} |
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} |
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|
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|
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triangle(pn, mn, v1, v2, v3) /* put out a triangle */ |
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char *pn, *mn; |
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register VERTEX *v1, *v2, *v3; |
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{ |
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static int ntri = 0; |
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char *mod = mn; |
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BARYCCM bvecs; |
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/* compute barycentric coordinates */ |
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if (v1->flags & v2->flags & v3->flags & (V_HASINDX|V_HASNORM)) |
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if (comp_baryc(bvecs, v1->pos, v2->pos, v3->pos) < 0) |
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return; |
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/* put out texture (if any) */ |
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if (v1->flags & v2->flags & v3->flags & V_HASNORM) { |
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printf("\n%s texfunc %s\n", mod, TEXNAME); |
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mod = TEXNAME; |
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printf("4 dx dy dz %s\n", CALNAME); |
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printf("0\n21\n"); |
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put_baryc(bvecs); |
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printf("\t%14.12g %14.12g %14.12g\n", |
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v1->nor[0], v2->nor[0], v3->nor[0]); |
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printf("\t%14.12g %14.12g %14.12g\n", |
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v1->nor[1], v2->nor[1], v3->nor[1]); |
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printf("\t%14.12g %14.12g %14.12g\n", |
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v1->nor[2], v2->nor[2], v3->nor[2]); |
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} |
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/* put out pattern (if any) */ |
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if (*pn && (v1->flags & v2->flags & v3->flags & V_HASINDX)) { |
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printf("\n%s colorpict %s\n", mod, PATNAME); |
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mod = PATNAME; |
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printf("7 noneg noneg noneg %s %s u v\n", pn, CALNAME); |
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printf("0\n18\n"); |
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put_baryc(bvecs); |
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printf("\t%f %f %f\n", v1->ndx[0], v2->ndx[0], v3->ndx[0]); |
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printf("\t%f %f %f\n", v1->ndx[1], v2->ndx[1], v3->ndx[1]); |
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} |
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/* put out triangle */ |
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printf("\n%s polygon t%d\n", mod, ++ntri); |
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printf("0\n0\n9\n"); |
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printf("%18.12g %18.12g %18.12g\n", v1->pos[0],v1->pos[1],v1->pos[2]); |
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printf("%18.12g %18.12g %18.12g\n", v2->pos[0],v2->pos[1],v2->pos[2]); |
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printf("%18.12g %18.12g %18.12g\n", v3->pos[0],v3->pos[1],v3->pos[2]); |
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} |
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|
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|
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int |
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comp_baryc(bcm, v1, v2, v3) /* compute barycentric vectors */ |
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register BARYCCM bcm; |
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FVECT v1, v2, v3; |
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{ |
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FLOAT *vt; |
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FVECT va, vab, vcb; |
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double d; |
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register int i, j; |
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|
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for (j = 0; j < 3; j++) { |
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for (i = 0; i < 3; i++) { |
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vab[i] = v1[i] - v2[i]; |
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vcb[i] = v3[i] - v2[i]; |
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} |
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d = DOT(vcb,vcb); |
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if (d <= FTINY) |
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return(-1); |
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d = DOT(vcb,vab)/d; |
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for (i = 0; i < 3; i++) |
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va[i] = vab[i] - vcb[i]*d; |
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d = DOT(va,va); |
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if (d <= FTINY) |
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return(-1); |
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for (i = 0; i < 3; i++) { |
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va[i] /= d; |
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bcm[j][i] = va[i]; |
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} |
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bcm[j][3] = -DOT(v2,va); |
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/* rotate vertices */ |
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vt = v1; |
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v1 = v2; |
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v2 = v3; |
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v3 = vt; |
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} |
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return(0); |
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} |
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|
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|
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put_baryc(bcm) /* put barycentric coord. vectors */ |
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register BARYCCM bcm; |
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{ |
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register int i; |
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|
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for (i = 0; i < 3; i++) |
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printf("%14.8f %14.8f %14.8f %14.8f\n", |
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bcm[i][0], bcm[i][1], bcm[i][2], bcm[i][3]); |
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} |
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|
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|
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VERTEX * |
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vnew(id, x, y, z) /* create a new vertex */ |
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register int id; |
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double x, y, z; |
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{ |
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register int i; |
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|
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if (id > nverts) { /* get some more */ |
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i = nverts; |
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nverts = CHUNKSIZ*((id%CHUNKSIZ)+1); |
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if (vlist == NULL) |
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vlist = (VERTEX *)malloc(nverts*sizeof(VERTEX)); |
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else |
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vlist = (VERTEX *)realloc((char *)vlist, |
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nverts*sizeof(VERTEX)); |
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if (vlist == NULL) { |
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fprintf(stderr, |
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"Out of memory while allocating vertex %d\n", id); |
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exit(1); |
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} |
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while (i < nverts) /* clear them */ |
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vlist[i++].flags = 0; |
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} |
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/* assign it */ |
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vlist[id].pos[0] = x; |
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vlist[id].pos[1] = y; |
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vlist[id].pos[2] = z; |
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vlist[id].flags = V_DEFINED; |
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/* return it */ |
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return(&vlist[id]); |
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} |
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|
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|
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syntax(fn, fp, er) /* report syntax error and exit */ |
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char *fn; |
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register FILE *fp; |
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char *er; |
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{ |
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extern long ftell(); |
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register long cpos; |
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register int c; |
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int lineno; |
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|
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if (fp == stdin) |
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fprintf(stderr, "%s: syntax error: %s\n", fn, er); |
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else { |
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cpos = ftell(fp); |
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fseek(fp, 0L, 0); |
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lineno = 1; |
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while (cpos-- > 0) { |
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if ((c = getc(fp)) == EOF) |
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break; |
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if (c == '\n') |
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lineno++; |
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} |
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fprintf(stderr, "%s: syntax error at line %d: %s\n", |
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fn, lineno, er); |
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} |
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exit(1); |
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} |
