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root/radiance/ray/src/rt/srcsupp.c
Revision: 1.2
Committed: Thu Jun 20 16:36:46 1991 UTC (32 years, 10 months ago) by greg
Content type: text/plain
Branch: MAIN
Changes since 1.1: +3 -3 lines
Log Message:
bug fixes and enhancements

File Contents

# Content
1 /* Copyright (c) 1991 Regents of the University of California */
2
3 #ifndef lint
4 static char SCCSid[] = "$SunId$ LBL";
5 #endif
6
7 /*
8 * Support routines for source objects and materials
9 */
10
11 #include "ray.h"
12
13 #include "otypes.h"
14
15 #include "source.h"
16
17 #include "cone.h"
18
19 #include "face.h"
20
21
22 SRCREC *source = NULL; /* our list of sources */
23 int nsources = 0; /* the number of sources */
24
25 SRCFUNC sfun[NUMOTYPE]; /* source dispatch table */
26
27
28 initstypes() /* initialize source dispatch table */
29 {
30 extern VSMATERIAL mirror_vs;
31 extern int fsetsrc(), ssetsrc(), sphsetsrc(), rsetsrc();
32 extern double fgetplaneq(), rgetplaneq();
33 extern double fgetmaxdisk(), rgetmaxdisk();
34 static SOBJECT fsobj = {fsetsrc, fgetplaneq, fgetmaxdisk};
35 static SOBJECT ssobj = {ssetsrc};
36 static SOBJECT sphsobj = {sphsetsrc};
37 static SOBJECT rsobj = {rsetsrc, rgetplaneq, rgetmaxdisk};
38
39 sfun[MAT_MIRROR].mf = &mirror_vs;
40 sfun[OBJ_FACE].of = &fsobj;
41 sfun[OBJ_SOURCE].of = &ssobj;
42 sfun[OBJ_SPHERE].of = &sphsobj;
43 sfun[OBJ_RING].of = &rsobj;
44 }
45
46
47 int
48 newsource() /* allocate new source in our array */
49 {
50 if (nsources == 0)
51 source = (SRCREC *)malloc(sizeof(SRCREC));
52 else
53 source = (SRCREC *)realloc((char *)source,
54 (unsigned)(nsources+1)*sizeof(SRCREC));
55 if (source == NULL)
56 return(-1);
57 source[nsources].sflags = 0;
58 source[nsources].nhits = 1;
59 source[nsources].ntests = 2; /* initial hit probability = 1/2 */
60 return(nsources++);
61 }
62
63
64 fsetsrc(src, so) /* set a face as a source */
65 register SRCREC *src;
66 OBJREC *so;
67 {
68 register FACE *f;
69 register int i, j;
70
71 src->sa.success = 2*AIMREQT-1; /* bitch on second failure */
72 src->so = so;
73 /* get the face */
74 f = getface(so);
75 /* find the center */
76 for (j = 0; j < 3; j++) {
77 src->sloc[j] = 0.0;
78 for (i = 0; i < f->nv; i++)
79 src->sloc[j] += VERTEX(f,i)[j];
80 src->sloc[j] /= (double)f->nv;
81 }
82 if (!inface(src->sloc, f))
83 objerror(so, USER, "cannot hit center");
84 src->sflags |= SFLAT;
85 VCOPY(src->snorm, f->norm);
86 src->ss = sqrt(f->area / PI);
87 src->ss2 = f->area;
88 }
89
90
91 ssetsrc(src, so) /* set a source as a source */
92 register SRCREC *src;
93 register OBJREC *so;
94 {
95 double theta;
96
97 src->sa.success = 2*AIMREQT-1; /* bitch on second failure */
98 src->so = so;
99 if (so->oargs.nfargs != 4)
100 objerror(so, USER, "bad arguments");
101 src->sflags |= SDISTANT;
102 VCOPY(src->sloc, so->oargs.farg);
103 if (normalize(src->sloc) == 0.0)
104 objerror(so, USER, "zero direction");
105 theta = PI/180.0/2.0 * so->oargs.farg[3];
106 if (theta <= FTINY)
107 objerror(so, USER, "zero size");
108 src->ss = theta >= PI/4 ? 1.0 : tan(theta);
109 src->ss2 = 2.0*PI * (1.0 - cos(theta));
110 }
111
112
113 sphsetsrc(src, so) /* set a sphere as a source */
114 register SRCREC *src;
115 register OBJREC *so;
116 {
117 src->sa.success = 2*AIMREQT-1; /* bitch on second failure */
118 src->so = so;
119 if (so->oargs.nfargs != 4)
120 objerror(so, USER, "bad # arguments");
121 if (so->oargs.farg[3] <= FTINY)
122 objerror(so, USER, "illegal radius");
123 VCOPY(src->sloc, so->oargs.farg);
124 src->ss = so->oargs.farg[3];
125 src->ss2 = PI * src->ss * src->ss;
126 }
127
128
129 rsetsrc(src, so) /* set a ring (disk) as a source */
130 register SRCREC *src;
131 OBJREC *so;
132 {
133 register CONE *co;
134
135 src->sa.success = 2*AIMREQT-1; /* bitch on second failure */
136 src->so = so;
137 /* get the ring */
138 co = getcone(so, 0);
139 VCOPY(src->sloc, CO_P0(co));
140 if (CO_R0(co) > 0.0)
141 objerror(so, USER, "cannot hit center");
142 src->sflags |= SFLAT;
143 VCOPY(src->snorm, co->ad);
144 src->ss = CO_R1(co);
145 src->ss2 = PI * src->ss * src->ss;
146 }
147
148
149 SPOT *
150 makespot(m) /* make a spotlight */
151 register OBJREC *m;
152 {
153 extern double cos();
154 register SPOT *ns;
155
156 if ((ns = (SPOT *)malloc(sizeof(SPOT))) == NULL)
157 return(NULL);
158 ns->siz = 2.0*PI * (1.0 - cos(PI/180.0/2.0 * m->oargs.farg[3]));
159 VCOPY(ns->aim, m->oargs.farg+4);
160 if ((ns->flen = normalize(ns->aim)) == 0.0)
161 objerror(m, USER, "zero focus vector");
162 return(ns);
163 }
164
165
166 double
167 fgetmaxdisk(ocent, op) /* get center and squared radius of face */
168 FVECT ocent;
169 OBJREC *op;
170 {
171 double maxrad2;
172 double d2;
173 register int i, j;
174 register FACE *f;
175
176 f = getface(op);
177 for (i = 0; i < 3; i++) {
178 ocent[i] = 0.;
179 for (j = 0; j < f->nv; j++)
180 ocent[i] += VERTEX(f,j)[i];
181 ocent[i] /= (double)f->nv;
182 }
183 maxrad2 = 0.;
184 for (j = 0; j < f->nv; j++) {
185 d2 = dist2(VERTEX(f,j), ocent);
186 if (d2 > maxrad2)
187 maxrad2 = d2;
188 }
189 return(maxrad2);
190 }
191
192
193 double
194 rgetmaxdisk(ocent, op) /* get center and squared radius of ring */
195 FVECT ocent;
196 OBJREC *op;
197 {
198 register CONE *co;
199
200 co = getcone(op, 0);
201 VCOPY(ocent, CO_P0(co));
202 return(CO_R1(co)*CO_R1(co));
203 }
204
205
206 double
207 fgetplaneq(nvec, op) /* get plane equation for face */
208 FVECT nvec;
209 OBJREC *op;
210 {
211 register FACE *fo;
212
213 fo = getface(op);
214 VCOPY(nvec, fo->norm);
215 return(fo->offset);
216 }
217
218
219 double
220 rgetplaneq(nvec, op) /* get plane equation for ring */
221 FVECT nvec;
222 OBJREC *op;
223 {
224 register CONE *co;
225
226 co = getcone(op, 0);
227 VCOPY(nvec, co->ad);
228 return(DOT(nvec, CO_P0(co)));
229 }
230
231
232 sourcehit(r) /* check to see if ray hit distant source */
233 register RAY *r;
234 {
235 int first, last;
236 register int i;
237
238 if (r->rsrc >= 0) { /* check only one if aimed */
239 first = last = r->rsrc;
240 } else { /* otherwise check all */
241 first = 0; last = nsources-1;
242 }
243 for (i = first; i <= last; i++)
244 if (source[i].sflags & SDISTANT)
245 /*
246 * Check to see if ray is within
247 * solid angle of source.
248 */
249 if (2.0*PI * (1.0 - DOT(source[i].sloc,r->rdir))
250 <= source[i].ss2) {
251 r->ro = source[i].so;
252 if (!(source[i].sflags & SSKIP))
253 break;
254 }
255
256 if (r->ro != NULL) {
257 for (i = 0; i < 3; i++)
258 r->ron[i] = -r->rdir[i];
259 r->rod = 1.0;
260 r->rox = NULL;
261 return(1);
262 }
263 return(0);
264 }
265
266
267 #define wrongsource(m, r) (m->otype!=MAT_ILLUM && \
268 r->rsrc>=0 && \
269 source[r->rsrc].so!=r->ro)
270
271 #define badambient(m, r) ((r->crtype&(AMBIENT|SHADOW))==AMBIENT && \
272 !(m->otype==MAT_GLOW&&r->rot>m->oargs.farg[3]))
273
274 #define passillum(m, r) (m->otype==MAT_ILLUM && \
275 !(r->rsrc>=0&&source[r->rsrc].so==r->ro))
276
277
278 m_light(m, r) /* ray hit a light source */
279 register OBJREC *m;
280 register RAY *r;
281 {
282 /* check for over-counting */
283 if (wrongsource(m, r) || badambient(m, r))
284 return;
285 /* check for passed illum */
286 if (passillum(m, r)) {
287
288 if (m->oargs.nsargs < 1 || !strcmp(m->oargs.sarg[0], VOIDID))
289 raytrans(r);
290 else
291 rayshade(r, modifier(m->oargs.sarg[0]));
292
293 /* otherwise treat as source */
294 } else {
295 /* check for behind */
296 if (r->rod < 0.0)
297 return;
298 /* get distribution pattern */
299 raytexture(r, m->omod);
300 /* get source color */
301 setcolor(r->rcol, m->oargs.farg[0],
302 m->oargs.farg[1],
303 m->oargs.farg[2]);
304 /* modify value */
305 multcolor(r->rcol, r->pcol);
306 }
307 }