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root/radiance/ray/src/cv/mgflib/parser.c
Revision: 1.2
Committed: Wed Jun 22 15:33:47 1994 UTC (29 years, 10 months ago) by greg
Content type: text/plain
Branch: MAIN
Changes since 1.1: +9 -3 lines
Log Message:
various enhancements and fixes

File Contents

# User Rev Content
1 greg 1.1 /* Copyright (c) 1994 Regents of the University of California */
2    
3     #ifndef lint
4     static char SCCSid[] = "$SunId$ LBL";
5     #endif
6    
7     /*
8     * Parse an MGF file, converting or discarding unsupported entities
9     */
10    
11     #include <stdio.h>
12     #include <math.h>
13     #include <ctype.h>
14     #include <string.h>
15     #include "parser.h"
16     #include "lookup.h"
17     #include "messages.h"
18    
19     /*
20     * Global definitions of variables declared in parser.h
21     */
22     /* entity names */
23    
24     char mg_ename[MG_NENTITIES][MG_MAXELEN] = MG_NAMELIST;
25    
26     /* Handler routines for each entity */
27    
28     int (*mg_ehand[MG_NENTITIES])();
29    
30     /* error messages */
31    
32     char *mg_err[MG_NERRS] = MG_ERRLIST;
33    
34     MG_FCTXT *mg_file; /* current file context pointer */
35    
36     int mg_nqcdivs = MG_NQCD; /* number of divisions per quarter circle */
37    
38     /*
39     * The idea with this parser is to compensate for any missing entries in
40     * mg_ehand with alternate handlers that express these entities in terms
41     * of others that the calling program can handle.
42     *
43     * In some cases, no alternate handler is possible because the entity
44     * has no approximate equivalent. These entities are simply discarded.
45     *
46     * Certain entities are dependent on others, and mg_init() will fail
47     * if the supported entities are not consistent.
48     *
49     * Some alternate entity handlers require that earlier entities be
50     * noted in some fashion, and we therefore keep another array of
51     * parallel support handlers to assist in this effort.
52     */
53    
54     /* temporary settings for testing */
55     #define e_ies e_any_toss
56     /* alternate handler routines */
57    
58     static int e_any_toss(), /* discard unneeded entity */
59 greg 1.2 e_ies(), /* IES luminaire file */
60 greg 1.1 e_include(), /* include file */
61     e_sph(), /* sphere */
62     e_cyl(), /* cylinder */
63     e_cone(), /* cone */
64     e_ring(), /* ring */
65     e_torus(); /* torus */
66    
67     /* alternate handler support functions */
68    
69     static int (*e_supp[MG_NENTITIES])();
70    
71     static char FLTFMT[] = "%.12g";
72    
73     static int warpconends; /* hack for generating good normals */
74    
75    
76     void
77     mg_init() /* initialize alternate entity handlers */
78     {
79     unsigned long ineed = 0, uneed = 0;
80     register int i;
81     /* pick up slack */
82     if (mg_ehand[MG_E_IES] == NULL)
83     mg_ehand[MG_E_IES] = e_ies;
84     if (mg_ehand[MG_E_INCLUDE] == NULL)
85     mg_ehand[MG_E_INCLUDE] = e_include;
86     if (mg_ehand[MG_E_SPH] == NULL) {
87     mg_ehand[MG_E_SPH] = e_sph;
88     ineed |= 1<<MG_E_POINT|1<<MG_E_VERTEX;
89     } else
90     uneed |= 1<<MG_E_POINT|1<<MG_E_VERTEX|1<<MG_E_XF;
91     if (mg_ehand[MG_E_CYL] == NULL) {
92     mg_ehand[MG_E_CYL] = e_cyl;
93     ineed |= 1<<MG_E_POINT|1<<MG_E_VERTEX;
94     } else
95     uneed |= 1<<MG_E_POINT|1<<MG_E_VERTEX|1<<MG_E_XF;
96     if (mg_ehand[MG_E_CONE] == NULL) {
97     mg_ehand[MG_E_CONE] = e_cone;
98     ineed |= 1<<MG_E_POINT|1<<MG_E_VERTEX;
99     } else
100     uneed |= 1<<MG_E_POINT|1<<MG_E_VERTEX|1<<MG_E_XF;
101     if (mg_ehand[MG_E_RING] == NULL) {
102     mg_ehand[MG_E_RING] = e_ring;
103     ineed |= 1<<MG_E_POINT|1<<MG_E_NORMAL|1<<MG_E_VERTEX;
104     } else
105     uneed |= 1<<MG_E_POINT|1<<MG_E_NORMAL|1<<MG_E_VERTEX|1<<MG_E_XF;
106     if (mg_ehand[MG_E_TORUS] == NULL) {
107     mg_ehand[MG_E_TORUS] = e_torus;
108     ineed |= 1<<MG_E_POINT|1<<MG_E_NORMAL|1<<MG_E_VERTEX;
109     } else
110     uneed |= 1<<MG_E_POINT|1<<MG_E_NORMAL|1<<MG_E_VERTEX|1<<MG_E_XF;
111     /* check for consistency */
112     if (mg_ehand[MG_E_FACE] != NULL)
113     uneed |= 1<<MG_E_POINT|1<<MG_E_VERTEX|1<<MG_E_XF;
114     if (mg_ehand[MG_E_CXY] != NULL)
115     uneed |= 1<<MG_E_COLOR;
116     if (mg_ehand[MG_E_RD] != NULL || mg_ehand[MG_E_TD] != NULL ||
117     mg_ehand[MG_E_ED] != NULL ||
118     mg_ehand[MG_E_RS] != NULL ||
119     mg_ehand[MG_E_TS] != NULL)
120     uneed |= 1<<MG_E_MATERIAL;
121     for (i = 0; i < MG_NENTITIES; i++)
122     if (uneed & 1<<i && mg_ehand[i] == NULL) {
123     fprintf(stderr, "Missing support for \"%s\" entity\n",
124     mg_ename[i]);
125     exit(1);
126     }
127     /* add support as needed */
128     if (ineed & 1<<MG_E_VERTEX && mg_ehand[MG_E_VERTEX] != c_hvertex)
129     e_supp[MG_E_VERTEX] = c_hvertex;
130     if (ineed & 1<<MG_E_POINT && mg_ehand[MG_E_POINT] != c_hvertex)
131     e_supp[MG_E_POINT] = c_hvertex;
132     if (ineed & 1<<MG_E_NORMAL && mg_ehand[MG_E_NORMAL] != c_hvertex)
133     e_supp[MG_E_NORMAL] = c_hvertex;
134     /* discard remaining entities */
135     for (i = 0; i < MG_NENTITIES; i++)
136     if (mg_ehand[i] == NULL)
137     mg_ehand[i] = e_any_toss;
138     }
139    
140    
141    
142     int
143     mg_entity(name) /* get entity number from its name */
144     char *name;
145     {
146     static LUTAB ent_tab; /* entity lookup table */
147     register char *cp;
148    
149     if (!ent_tab.tsiz) { /* initialize hash table */
150     if (!lu_init(&ent_tab, MG_NENTITIES))
151     return(-1); /* what to do? */
152     for (cp = mg_ename[MG_NENTITIES-1]; cp >= mg_ename[0];
153     cp -= sizeof(mg_ename[0]))
154     lu_find(&ent_tab, cp)->key = cp;
155     }
156     cp = lu_find(&ent_tab, name)->key;
157     if (cp == NULL)
158     return(-1);
159     return((cp - mg_ename[0])/sizeof(mg_ename[0]));
160     }
161    
162    
163     static int
164     handle_it(en, ac, av) /* pass entity to appropriate handler */
165     register int en;
166     int ac;
167     char **av;
168     {
169     int rv;
170    
171     if (en < 0 && (en = mg_entity(av[0])) < 0)
172     return(MG_EUNK);
173     if (e_supp[en] != NULL) {
174     if ((rv = (*e_supp[en])(ac, av)) != MG_OK)
175     return(rv);
176     }
177     return((*mg_ehand[en])(ac, av));
178     }
179    
180    
181     int
182     mg_open(ctx, fn) /* open new input file */
183     register MG_FCTXT *ctx;
184     char *fn;
185     {
186     int olen;
187     register char *cp;
188    
189     ctx->lineno = 0;
190     if (fn == NULL) {
191     ctx->fname = "<stdin>";
192     ctx->fp = stdin;
193     ctx->prev = mg_file;
194     mg_file = ctx;
195     return(MG_OK);
196     }
197     /* get name relative to this context */
198     if (mg_file != NULL &&
199     (cp = strrchr(mg_file->fname, '/')) != NULL)
200     olen = cp - mg_file->fname + 1;
201     else
202     olen = 0;
203     ctx->fname = (char *)malloc(olen+strlen(fn)+1);
204     if (ctx->fname == NULL)
205     return(MG_EMEM);
206     if (olen)
207     strcpy(ctx->fname, mg_file->fname);
208     strcpy(ctx->fname+olen, fn);
209     ctx->fp = fopen(ctx->fname, "r");
210     if (ctx->fp == NULL) {
211     free((MEM_PTR)ctx->fname);
212     return(MG_ENOFILE);
213     }
214     ctx->prev = mg_file; /* establish new context */
215     mg_file = ctx;
216     return(MG_OK);
217     }
218    
219    
220     void
221     mg_close() /* close input file */
222     {
223     register MG_FCTXT *ctx = mg_file;
224    
225     mg_file = ctx->prev; /* restore enclosing context */
226     if (ctx->fp == stdin)
227     return; /* don't close standard input */
228     fclose(ctx->fp);
229     free((MEM_PTR)ctx->fname);
230     }
231    
232    
233     int
234     mg_rewind() /* rewind input file */
235     {
236     if (mg_file->lineno == 0)
237     return(MG_OK);
238     if (mg_file->fp == stdin)
239     return(MG_ESEEK); /* cannot seek on standard input */
240     if (fseek(mg_file->fp, 0L, 0) == EOF)
241     return(MG_ESEEK);
242     mg_file->lineno = 0;
243     return(MG_OK);
244     }
245    
246    
247     int
248     mg_read() /* read next line from file */
249     {
250     register int len = 0;
251    
252     do {
253     if (fgets(mg_file->inpline+len,
254     MG_MAXLINE-len, mg_file->fp) == NULL)
255     return(len);
256     mg_file->lineno++;
257     len += strlen(mg_file->inpline+len);
258     if (len > 1 && mg_file->inpline[len-2] == '\\')
259     mg_file->inpline[--len-1] = ' ';
260     } while (mg_file->inpline[len]);
261    
262     return(len);
263     }
264    
265    
266     int
267     mg_parse() /* parse current input line */
268     {
269     char abuf[MG_MAXLINE];
270     char *argv[MG_MAXARGC];
271     int en;
272     register char *cp, **ap;
273    
274     strcpy(cp=abuf, mg_file->inpline);
275     ap = argv; /* break into words */
276     for ( ; ; ) {
277     while (isspace(*cp))
278     *cp++ = '\0';
279     if (!*cp)
280     break;
281     if (ap - argv >= MG_MAXARGC-1)
282     return(MG_EARGC);
283     *ap++ = cp;
284     while (*++cp && !isspace(*cp))
285     ;
286     }
287     if (ap == argv)
288     return(MG_OK); /* no words in line */
289     *ap = NULL;
290     /* else handle it */
291     return(handle_it(-1, ap-argv, argv));
292     }
293    
294    
295     int
296     mg_load(fn) /* load an MGF file */
297     char *fn;
298     {
299     MG_FCTXT cntxt;
300     int rval;
301    
302     if ((rval = mg_open(&cntxt, fn)) != MG_OK) {
303 greg 1.2 fprintf(stderr, "%s: %s\n", fn, mg_err[rval]);
304 greg 1.1 return(rval);
305     }
306     while (mg_read()) /* parse each line */
307     if ((rval = mg_parse()) != MG_OK) {
308     fprintf(stderr, "%s: %d: %s:\n%s", cntxt.fname,
309     cntxt.lineno, mg_err[rval],
310     cntxt.inpline);
311     break;
312     }
313     mg_close();
314     return(rval);
315     }
316    
317    
318     void
319     mg_clear() /* clear parser history */
320     {
321     c_clearall(); /* clear context tables */
322     mg_file = NULL; /* reset our context */
323     }
324    
325    
326     int
327     mg_iterate(ac, av, f) /* iterate on statement */
328     int ac;
329     register char **av;
330     int (*f)();
331     {
332     int niter, rval;
333     register int i, j;
334     char *argv[MG_MAXARGC];
335     char cntbuf[10];
336     /* build partial transformation */
337     for (i = 0; i < ac; i++) {
338     if (av[i][0] == '-' && av[i][1] == 'a' && av[i][2] == '\0')
339     break;
340     argv[i+1] = av[i];
341     }
342     argv[i+1] = NULL;
343     if (i) { /* handle transformation */
344     argv[0] = mg_ename[MG_E_XF];
345     if ((rval = handle_it(MG_E_XF, i+1, argv)) != MG_OK)
346     return(rval);
347     }
348     if (i < ac) { /* run array */
349     if (i+1 >= ac || !isint(av[i+1]))
350     return(MG_ETYPE);
351     niter = atoi(av[i+1]);
352 greg 1.2 argv[0] = mg_ename[MG_E_OBJECT];
353 greg 1.1 argv[1] = cntbuf;
354     for (j = 2; j+i < ac; j++)
355     argv[j] = av[j+i];
356     argv[j] = NULL;
357     for (j = 0; j < niter; j++) {
358     sprintf(cntbuf, "%d", j);
359 greg 1.2 if ((rval = handle_it(MG_E_OBJECT, 2, argv)) != MG_OK)
360     return(rval);
361     argv[0] = "-i";
362 greg 1.1 if ((rval = mg_iterate(ac-i, argv, f)) != MG_OK)
363 greg 1.2 return(rval);
364     argv[0] = mg_ename[MG_E_OBJECT];
365     if ((rval = handle_it(MG_E_OBJECT, 1, argv)) != MG_OK)
366 greg 1.1 return(rval);
367     }
368     } else if ((rval = (*f)()) != MG_OK) /* else do this instance */
369     return(rval);
370     if (i) { /* reset the transform */
371     argv[0] = mg_ename[MG_E_XF];
372     argv[1] = NULL;
373     (void)handle_it(MG_E_XF, 1, argv);
374     }
375     return(MG_OK);
376     }
377    
378    
379     /****************************************************************************
380     * The following routines handle unsupported entities
381     */
382    
383    
384     static int
385     e_any_toss(ac, av) /* discard an unwanted entity */
386     int ac;
387     char **av;
388     {
389     return(MG_OK);
390     }
391    
392    
393     static int
394     reload_file() /* reload current MGF file */
395     {
396     register int rval;
397    
398     if ((rval = mg_rewind()) != MG_OK)
399     return(rval);
400     while (mg_read())
401     if ((rval = mg_parse()) != MG_OK)
402     return(rval);
403     return(MG_OK);
404     }
405    
406    
407     static int
408     e_include(ac, av) /* include file */
409     int ac;
410     char **av;
411     {
412     MG_FCTXT ictx;
413     int rv;
414    
415     if (ac < 2)
416     return(MG_EARGC);
417     if ((rv = mg_open(&ictx, av[1])) != MG_OK)
418     return(rv);
419     if ((rv = mg_iterate(ac-2, av+2, reload_file)) != MG_OK) {
420     fprintf(stderr, "%s: %d: %s:\n%s", ictx.fname,
421     ictx.lineno, mg_err[rv], ictx.inpline);
422     mg_close();
423     return(MG_EINCL);
424     }
425     mg_close();
426     return(MG_OK);
427     }
428    
429    
430     static void
431     make_axes(u, v, w) /* compute u and v given w (normalized) */
432     FVECT u, v, w;
433     {
434     register int i;
435    
436     v[0] = v[1] = v[2] = 0.;
437     for (i = 0; i < 3; i++)
438     if (w[i] < .6 && w[i] > -.6)
439     break;
440     v[i] = 1.;
441     fcross(u, v, w);
442     normalize(u);
443     fcross(v, w, u);
444     }
445    
446    
447     static int
448     e_sph(ac, av) /* expand a sphere into cones */
449     int ac;
450     char **av;
451     {
452     static char p2x[24], p2y[24], p2z[24], r1[24], r2[24];
453     static char *v1ent[5] = {mg_ename[MG_E_VERTEX],"_sv1","=","_sv2"};
454     static char *v2ent[4] = {mg_ename[MG_E_VERTEX],"_sv2","="};
455     static char *p2ent[5] = {mg_ename[MG_E_POINT],p2x,p2y,p2z};
456     static char *conent[6] = {mg_ename[MG_E_CONE],"_sv1",r1,"_sv2",r2};
457     register C_VERTEX *cv;
458     register int i;
459     int rval;
460     double rad;
461     double theta;
462    
463     if (ac != 3)
464     return(MG_EARGC);
465     if ((cv = c_getvert(av[1])) == NULL)
466     return(MG_EUNDEF);
467     if (!isflt(av[2]))
468     return(MG_ETYPE);
469     rad = atof(av[2]);
470     /* initialize */
471     warpconends = 1;
472     if ((rval = handle_it(MG_E_VERTEX, 3, v2ent)) != MG_OK)
473     return(rval);
474     sprintf(p2x, FLTFMT, cv->p[0]);
475     sprintf(p2y, FLTFMT, cv->p[1]);
476     sprintf(p2z, FLTFMT, cv->p[2]+rad);
477     if ((rval = handle_it(MG_E_POINT, 4, p2ent)) != MG_OK)
478     return(rval);
479     r2[0] = '0'; r2[1] = '\0';
480     for (i = 1; i <= 2*mg_nqcdivs; i++) {
481     theta = i*(PI/2)/mg_nqcdivs;
482     if ((rval = handle_it(MG_E_VERTEX, 4, v1ent)) != MG_OK)
483     return(rval);
484     sprintf(p2z, FLTFMT, cv->p[2]+rad*cos(theta));
485     if ((rval = handle_it(MG_E_VERTEX, 2, v2ent)) != MG_OK)
486     return(rval);
487     if ((rval = handle_it(MG_E_POINT, 4, p2ent)) != MG_OK)
488     return(rval);
489     strcpy(r1, r2);
490     sprintf(r2, FLTFMT, rad*sin(theta));
491     if ((rval = handle_it(MG_E_CONE, 5, conent)) != MG_OK)
492     return(rval);
493     }
494     warpconends = 0;
495     return(MG_OK);
496     }
497    
498    
499     static int
500     e_torus(ac, av) /* expand a torus into cones */
501     int ac;
502     char **av;
503     {
504     static char p2[3][24], r1[24], r2[24];
505     static char *v1ent[5] = {mg_ename[MG_E_VERTEX],"_tv1","=","_tv2"};
506     static char *v2ent[5] = {mg_ename[MG_E_VERTEX],"_tv2","="};
507     static char *p2ent[5] = {mg_ename[MG_E_POINT],p2[0],p2[1],p2[2]};
508     static char *conent[6] = {mg_ename[MG_E_CONE],"_tv1",r1,"_tv2",r2};
509     register C_VERTEX *cv;
510     register int i, j;
511     int rval;
512     int sgn;
513     double minrad, maxrad, avgrad;
514     double theta;
515    
516     if (ac != 4)
517     return(MG_EARGC);
518     if ((cv = c_getvert(av[1])) == NULL)
519     return(MG_EUNDEF);
520     if (cv->n[0]==0. && cv->n[1]==0. && cv->n[2]==0.)
521     return(MG_EILL);
522     if (!isflt(av[2]) || !isflt(av[3]))
523     return(MG_ETYPE);
524     minrad = atof(av[2]);
525     maxrad = atof(av[3]);
526     /* check orientation */
527     if (minrad > 0.)
528     sgn = 1;
529     else if (minrad < 0.)
530     sgn = -1;
531     else if (maxrad > 0.)
532     sgn = 1;
533     else if (maxrad < 0.)
534     sgn = -1;
535     else
536     return(MG_EILL);
537     if (sgn*(maxrad-minrad) <= 0.)
538     return(MG_EILL);
539     /* initialize */
540     warpconends = 1;
541     v2ent[3] = av[1];
542     for (j = 0; j < 3; j++)
543     sprintf(p2[j], FLTFMT, cv->p[j] +
544     .5*sgn*(maxrad-minrad)*cv->n[j]);
545     if ((rval = handle_it(MG_E_VERTEX, 4, v2ent)) != MG_OK)
546     return(rval);
547     if ((rval = handle_it(MG_E_POINT, 4, p2ent)) != MG_OK)
548     return(rval);
549     sprintf(r2, FLTFMT, avgrad=.5*(minrad+maxrad));
550     /* run outer section */
551     for (i = 1; i <= 2*mg_nqcdivs; i++) {
552     theta = i*(PI/2)/mg_nqcdivs;
553     if ((rval = handle_it(MG_E_VERTEX, 4, v1ent)) != MG_OK)
554     return(rval);
555     for (j = 0; j < 3; j++)
556     sprintf(p2[j], FLTFMT, cv->p[j] +
557     .5*sgn*(maxrad-minrad)*cos(theta)*cv->n[j]);
558     if ((rval = handle_it(MG_E_VERTEX, 2, v2ent)) != MG_OK)
559     return(rval);
560     if ((rval = handle_it(MG_E_POINT, 4, p2ent)) != MG_OK)
561     return(rval);
562     strcpy(r1, r2);
563     sprintf(r2, FLTFMT, avgrad + .5*(maxrad-minrad)*sin(theta));
564     if ((rval = handle_it(MG_E_CONE, 5, conent)) != MG_OK)
565     return(rval);
566     }
567     /* run inner section */
568     sprintf(r2, FLTFMT, -.5*(minrad+maxrad));
569     for ( ; i <= 4*mg_nqcdivs; i++) {
570     theta = i*(PI/2)/mg_nqcdivs;
571     for (j = 0; j < 3; j++)
572     sprintf(p2[j], FLTFMT, cv->p[j] +
573     .5*sgn*(maxrad-minrad)*cos(theta)*cv->n[j]);
574     if ((rval = handle_it(MG_E_VERTEX, 4, v1ent)) != MG_OK)
575     return(rval);
576     if ((rval = handle_it(MG_E_VERTEX, 2, v2ent)) != MG_OK)
577     return(rval);
578     if ((rval = handle_it(MG_E_POINT, 4, p2ent)) != MG_OK)
579     return(rval);
580     strcpy(r1, r2);
581     sprintf(r2, FLTFMT, -avgrad - .5*(maxrad-minrad)*sin(theta));
582     if ((rval = handle_it(MG_E_CONE, 5, conent)) != MG_OK)
583     return(rval);
584     }
585     warpconends = 0;
586     return(MG_OK);
587     }
588    
589    
590     static int
591     e_cyl(ac, av) /* replace a cylinder with equivalent cone */
592     int ac;
593     char **av;
594     {
595     static char *avnew[6] = {mg_ename[MG_E_CONE]};
596    
597     if (ac != 4)
598     return(MG_EARGC);
599     avnew[1] = av[1];
600     avnew[2] = av[2];
601     avnew[3] = av[3];
602     avnew[4] = av[2];
603     return(handle_it(MG_E_CONE, 5, avnew));
604     }
605    
606    
607     static int
608     e_ring(ac, av) /* turn a ring into polygons */
609     int ac;
610     char **av;
611     {
612     static char p3[3][24], p4[3][24];
613     static char *nzent[5] = {mg_ename[MG_E_NORMAL],"0","0","0"};
614     static char *v1ent[5] = {mg_ename[MG_E_VERTEX],"_rv1","="};
615     static char *v2ent[5] = {mg_ename[MG_E_VERTEX],"_rv2","=","_rv3"};
616     static char *v3ent[4] = {mg_ename[MG_E_VERTEX],"_rv3","="};
617     static char *p3ent[5] = {mg_ename[MG_E_POINT],p3[0],p3[1],p3[2]};
618     static char *v4ent[4] = {mg_ename[MG_E_VERTEX],"_rv4","="};
619     static char *p4ent[5] = {mg_ename[MG_E_POINT],p4[0],p4[1],p4[2]};
620     static char *fent[6] = {mg_ename[MG_E_FACE],"_rv1","_rv2","_rv3","_rv4"};
621     register C_VERTEX *cv;
622     register int i, j;
623     FVECT u, v;
624     double minrad, maxrad;
625     int rv;
626     double theta, d;
627    
628     if (ac != 4)
629     return(MG_EARGC);
630     if ((cv = c_getvert(av[1])) == NULL)
631     return(MG_EUNDEF);
632     if (cv->n[0]==0. && cv->n[1]==0. && cv->n[2]==0.)
633     return(MG_EILL);
634     if (!isflt(av[2]) || !isflt(av[3]))
635     return(MG_ETYPE);
636     minrad = atof(av[2]);
637     maxrad = atof(av[3]);
638     if (minrad < 0. || maxrad <= minrad)
639     return(MG_EILL);
640     /* initialize */
641     make_axes(u, v, cv->n);
642     for (j = 0; j < 3; j++)
643     sprintf(p3[j], FLTFMT, cv->p[j] + maxrad*u[j]);
644     if ((rv = handle_it(MG_E_VERTEX, 3, v3ent)) != MG_OK)
645     return(rv);
646     if ((rv = handle_it(MG_E_POINT, 4, p3ent)) != MG_OK)
647     return(rv);
648     if (minrad == 0.) { /* closed */
649     v1ent[3] = av[1];
650     if ((rv = handle_it(MG_E_VERTEX, 4, v1ent)) != MG_OK)
651     return(rv);
652     if ((rv = handle_it(MG_E_NORMAL, 4, nzent)) != MG_OK)
653     return(rv);
654     for (i = 1; i <= 4*mg_nqcdivs; i++) {
655     theta = i*(PI/2)/mg_nqcdivs;
656     if ((rv = handle_it(MG_E_VERTEX, 4, v2ent)) != MG_OK)
657     return(rv);
658     for (j = 0; j < 3; j++)
659     sprintf(p3[j], FLTFMT, cv->p[j] +
660     maxrad*u[j]*cos(theta) +
661     maxrad*v[j]*sin(theta));
662     if ((rv = handle_it(MG_E_VERTEX, 3, v3ent)) != MG_OK)
663     return(rv);
664     if ((rv = handle_it(MG_E_POINT, 4, p3ent)) != MG_OK)
665     return(rv);
666     if ((rv = handle_it(MG_E_FACE, 4, fent)) != MG_OK)
667     return(rv);
668     }
669     } else { /* open */
670     if ((rv = handle_it(MG_E_VERTEX, 3, v4ent)) != MG_OK)
671     return(rv);
672     for (j = 0; j < 3; j++)
673     sprintf(p4[j], FLTFMT, cv->p[j] + minrad*u[j]);
674     if ((rv = handle_it(MG_E_POINT, 4, p4ent)) != MG_OK)
675     return(rv);
676     v1ent[3] = "_rv4";
677     for (i = 1; i <= 4*mg_nqcdivs; i++) {
678     theta = i*(PI/2)/mg_nqcdivs;
679     if ((rv = handle_it(MG_E_VERTEX, 4, v1ent)) != MG_OK)
680     return(rv);
681     if ((rv = handle_it(MG_E_VERTEX, 4, v2ent)) != MG_OK)
682     return(rv);
683     for (j = 0; j < 3; j++) {
684     d = u[j]*cos(theta) + v[j]*sin(theta);
685     sprintf(p3[j], FLTFMT, cv->p[j] + maxrad*d);
686     sprintf(p4[j], FLTFMT, cv->p[j] + minrad*d);
687     }
688     if ((rv = handle_it(MG_E_VERTEX, 3, v3ent)) != MG_OK)
689     return(rv);
690     if ((rv = handle_it(MG_E_POINT, 4, p3ent)) != MG_OK)
691     return(rv);
692     if ((rv = handle_it(MG_E_VERTEX, 3, v4ent)) != MG_OK)
693     return(rv);
694     if ((rv = handle_it(MG_E_POINT, 4, p4ent)) != MG_OK)
695     return(rv);
696     if ((rv = handle_it(MG_E_FACE, 5, fent)) != MG_OK)
697     return(rv);
698     }
699     }
700     return(MG_OK);
701     }
702    
703    
704     static int
705     e_cone(ac, av) /* turn a cone into polygons */
706     int ac;
707     char **av;
708     {
709     static char p3[3][24], p4[3][24], n3[3][24], n4[3][24];
710     static char *v1ent[5] = {mg_ename[MG_E_VERTEX],"_cv1","="};
711     static char *v2ent[5] = {mg_ename[MG_E_VERTEX],"_cv2","=","_cv3"};
712     static char *v3ent[4] = {mg_ename[MG_E_VERTEX],"_cv3","="};
713     static char *p3ent[5] = {mg_ename[MG_E_POINT],p3[0],p3[1],p3[2]};
714     static char *n3ent[5] = {mg_ename[MG_E_NORMAL],n3[0],n3[1],n3[2]};
715     static char *v4ent[4] = {mg_ename[MG_E_VERTEX],"_cv4","="};
716     static char *p4ent[5] = {mg_ename[MG_E_POINT],p4[0],p4[1],p4[2]};
717     static char *n4ent[5] = {mg_ename[MG_E_NORMAL],n4[0],n4[1],n4[2]};
718     static char *fent[6] = {mg_ename[MG_E_FACE],"_cv1","_cv2","_cv3","_cv4"};
719     register C_VERTEX *cv1, *cv2;
720     register int i, j;
721     FVECT u, v, w;
722     double rad1, rad2;
723     int sgn;
724     double n1off, n2off;
725     double d;
726     int rv;
727     double theta;
728    
729     if (ac != 5)
730     return(MG_EARGC);
731     if ((cv1 = c_getvert(av[1])) == NULL ||
732     (cv2 = c_getvert(av[3])) == NULL)
733     return(MG_EUNDEF);
734     if (!isflt(av[2]) || !isflt(av[4]))
735     return(MG_ETYPE);
736     rad1 = atof(av[2]);
737     rad2 = atof(av[4]);
738     if (rad1 == 0.) {
739     if (rad2 == 0.)
740     return(MG_EILL);
741     } else if (rad2 != 0.) {
742     if (rad1 < 0. ^ rad2 < 0.)
743     return(MG_EILL);
744     } else { /* swap */
745     C_VERTEX *cv;
746    
747     cv = cv1;
748     cv1 = cv2;
749     cv2 = cv;
750     d = rad1;
751     rad1 = rad2;
752     rad2 = d;
753     }
754     sgn = rad2 < 0. ? -1 : 1;
755     /* initialize */
756     for (j = 0; j < 3; j++)
757     w[j] = cv1->p[j] - cv2->p[j];
758     if ((d = normalize(w)) == 0.)
759     return(MG_EILL);
760     n1off = n2off = (rad2 - rad1)/d;
761     if (warpconends) /* hack for e_sph and e_torus */
762     n2off = tan(atan(n2off)-(PI/4)/mg_nqcdivs);
763     n2off = sgn*n2off;
764     make_axes(u, v, w);
765     for (j = 0; j < 3; j++) {
766     sprintf(p3[j], FLTFMT, cv2->p[j] + rad2*u[j]);
767     sprintf(n3[j], FLTFMT, u[j] + w[j]*n2off);
768     }
769     if ((rv = handle_it(MG_E_VERTEX, 3, v3ent)) != MG_OK)
770     return(rv);
771     if ((rv = handle_it(MG_E_POINT, 4, p3ent)) != MG_OK)
772     return(rv);
773     if ((rv = handle_it(MG_E_NORMAL, 4, n3ent)) != MG_OK)
774     return(rv);
775     if (rad1 == 0.) { /* triangles */
776     v1ent[3] = av[1];
777     if ((rv = handle_it(MG_E_VERTEX, 4, v1ent)) != MG_OK)
778     return(rv);
779     for (j = 0; j < 3; j++)
780     sprintf(n4[j], FLTFMT, w[j]);
781     if ((rv = handle_it(MG_E_NORMAL, 4, n4ent)) != MG_OK)
782     return(rv);
783     for (i = 1; i <= 4*mg_nqcdivs; i++) {
784     theta = sgn*i*(PI/2)/mg_nqcdivs;
785     if ((rv = handle_it(MG_E_VERTEX, 4, v2ent)) != MG_OK)
786     return(rv);
787     for (j = 0; j < 3; j++) {
788     d = u[j]*cos(theta) + v[j]*sin(theta);
789     sprintf(p3[j], FLTFMT, cv2->p[j] + rad2*d);
790     sprintf(n3[j], FLTFMT, d + w[j]*n2off);
791     }
792     if ((rv = handle_it(MG_E_VERTEX, 3, v3ent)) != MG_OK)
793     return(rv);
794     if ((rv = handle_it(MG_E_POINT, 4, p3ent)) != MG_OK)
795     return(rv);
796     if ((rv = handle_it(MG_E_NORMAL, 4, n3ent)) != MG_OK)
797     return(rv);
798     if ((rv = handle_it(MG_E_FACE, 4, fent)) != MG_OK)
799     return(rv);
800     }
801     } else { /* quads */
802     v1ent[3] = "_cv4";
803     if (warpconends) /* hack for e_sph and e_torus */
804     n1off = tan(atan(n1off)+(PI/4)/mg_nqcdivs);
805     n1off = sgn*n1off;
806     for (j = 0; j < 3; j++) {
807     sprintf(p4[j], FLTFMT, cv1->p[j] + rad1*u[j]);
808     sprintf(n4[j], FLTFMT, u[j] + w[j]*n1off);
809     }
810     if ((rv = handle_it(MG_E_VERTEX, 3, v4ent)) != MG_OK)
811     return(rv);
812     if ((rv = handle_it(MG_E_POINT, 4, p4ent)) != MG_OK)
813     return(rv);
814     if ((rv = handle_it(MG_E_NORMAL, 4, n4ent)) != MG_OK)
815     return(rv);
816     for (i = 1; i <= 4*mg_nqcdivs; i++) {
817     theta = sgn*i*(PI/2)/mg_nqcdivs;
818     if ((rv = handle_it(MG_E_VERTEX, 4, v1ent)) != MG_OK)
819     return(rv);
820     if ((rv = handle_it(MG_E_VERTEX, 4, v2ent)) != MG_OK)
821     return(rv);
822     for (j = 0; j < 3; j++) {
823     d = u[j]*cos(theta) + v[j]*sin(theta);
824     sprintf(p3[j], FLTFMT, cv2->p[j] + rad2*d);
825     sprintf(n3[j], FLTFMT, d + w[j]*n2off);
826     sprintf(p4[j], FLTFMT, cv1->p[j] + rad1*d);
827     sprintf(n4[j], FLTFMT, d + w[j]*n1off);
828     }
829     if ((rv = handle_it(MG_E_VERTEX, 3, v3ent)) != MG_OK)
830     return(rv);
831     if ((rv = handle_it(MG_E_POINT, 4, p3ent)) != MG_OK)
832     return(rv);
833     if ((rv = handle_it(MG_E_NORMAL, 4, n3ent)) != MG_OK)
834     return(rv);
835     if ((rv = handle_it(MG_E_VERTEX, 3, v4ent)) != MG_OK)
836     return(rv);
837     if ((rv = handle_it(MG_E_POINT, 4, p4ent)) != MG_OK)
838     return(rv);
839     if ((rv = handle_it(MG_E_NORMAL, 4, n4ent)) != MG_OK)
840     return(rv);
841     if ((rv = handle_it(MG_E_FACE, 5, fent)) != MG_OK)
842     return(rv);
843     }
844     }
845     return(MG_OK);
846     }