src/rt/srcsupp.c

/* Copyright (c) 1991 Regents of the University of California */

#ifndef lint
static char SCCSid[] = "$SunId$ LBL";
#endif

/*
 *  Support routines for source objects and materials
 */

#include  "ray.h"

#include  "otypes.h"

#include  "source.h"

#include  "cone.h"

#include  "face.h"


SRCREC  *source = NULL;                 /* our list of sources */
int  nsources = 0;                      /* the number of sources */

SRCFUNC  sfun[NUMOTYPE];                /* source dispatch table */


initstypes()                    /* initialize source dispatch table */
{
        extern VSMATERIAL  mirror_vs;
        extern int  fsetsrc(), ssetsrc(), sphsetsrc(), rsetsrc();
        extern double  fgetplaneq(), rgetplaneq();
        extern double  fgetmaxdisk(), rgetmaxdisk();
        static SOBJECT  fsobj = {fsetsrc, fgetplaneq, fgetmaxdisk};
        static SOBJECT  ssobj = {ssetsrc};
        static SOBJECT  sphsobj = {sphsetsrc};
        static SOBJECT  rsobj = {rsetsrc, rgetplaneq, rgetmaxdisk};

        sfun[MAT_MIRROR].mf = &mirror_vs;
        sfun[OBJ_FACE].of = &fsobj;
        sfun[OBJ_SOURCE].of = &ssobj;
        sfun[OBJ_SPHERE].of = &sphsobj;
        sfun[OBJ_RING].of = &rsobj;
}


int
newsource()                     /* allocate new source in our array */
{
        if (nsources == 0)
                source = (SRCREC *)malloc(sizeof(SRCREC));
        else
                source = (SRCREC *)realloc((char *)source,
                                (unsigned)(nsources+1)*sizeof(SRCREC));
        if (source == NULL)
                return(-1);
        source[nsources].sflags = 0;
        source[nsources].nhits = 1;
        source[nsources].ntests = 2;    /* initial hit probability = 1/2 */
        return(nsources++);
}


fsetsrc(src, so)                        /* set a face as a source */
register SRCREC  *src;
OBJREC  *so;
{
        register FACE  *f;
        register int  i, j;
        
        src->sa.success = 2*AIMREQT-1;          /* bitch on second failure */
        src->so = so;
                                                /* get the face */
        f = getface(so);
                                                /* find the center */
        for (j = 0; j < 3; j++) {
                src->sloc[j] = 0.0;
                for (i = 0; i < f->nv; i++)
                        src->sloc[j] += VERTEX(f,i)[j];
                src->sloc[j] /= (double)f->nv;
        }
        if (!inface(src->sloc, f))
                objerror(so, USER, "cannot hit center");
        src->sflags |= SFLAT;
        VCOPY(src->snorm, f->norm);
        src->ss = sqrt(f->area / PI);
        src->ss2 = f->area;
}


ssetsrc(src, so)                        /* set a source as a source */
register SRCREC  *src;
register OBJREC  *so;
{
        double  theta;
        
        src->sa.success = 2*AIMREQT-1;          /* bitch on second failure */
        src->so = so;
        if (so->oargs.nfargs != 4)
                objerror(so, USER, "bad arguments");
        src->sflags |= SDISTANT;
        VCOPY(src->sloc, so->oargs.farg);
        if (normalize(src->sloc) == 0.0)
                objerror(so, USER, "zero direction");
        theta = PI/180.0/2.0 * so->oargs.farg[3];
        if (theta <= FTINY)
                objerror(so, USER, "zero size");
        src->ss = theta >= PI/4 ? 1.0 : tan(theta);
        src->ss2 = 2.0*PI * (1.0 - cos(theta));
}


sphsetsrc(src, so)                      /* set a sphere as a source */
register SRCREC  *src;
register OBJREC  *so;
{
        src->sa.success = 2*AIMREQT-1;          /* bitch on second failure */
        src->so = so;
        if (so->oargs.nfargs != 4)
                objerror(so, USER, "bad # arguments");
        if (so->oargs.farg[3] <= FTINY)
                objerror(so, USER, "illegal radius");
        VCOPY(src->sloc, so->oargs.farg);
        src->ss = so->oargs.farg[3];
        src->ss2 = PI * src->ss * src->ss;
}


rsetsrc(src, so)                        /* set a ring (disk) as a source */
register SRCREC  *src;
OBJREC  *so;
{
        register CONE  *co;
        
        src->sa.success = 2*AIMREQT-1;          /* bitch on second failure */
        src->so = so;
                                                /* get the ring */
        co = getcone(so, 0);
        VCOPY(src->sloc, CO_P0(co));
        if (CO_R0(co) > 0.0)
                objerror(so, USER, "cannot hit center");
        src->sflags |= SFLAT;
        VCOPY(src->snorm, co->ad);
        src->ss = CO_R1(co);
        src->ss2 = PI * src->ss * src->ss;
}


SPOT *
makespot(m)                     /* make a spotlight */
register OBJREC  *m;
{
        extern double  cos();
        register SPOT  *ns;

        if ((ns = (SPOT *)malloc(sizeof(SPOT))) == NULL)
                return(NULL);
        ns->siz = 2.0*PI * (1.0 - cos(PI/180.0/2.0 * m->oargs.farg[3]));
        VCOPY(ns->aim, m->oargs.farg+4);
        if ((ns->flen = normalize(ns->aim)) == 0.0)
                objerror(m, USER, "zero focus vector");
        return(ns);
}


double
fgetmaxdisk(ocent, op)          /* get center and squared radius of face */
FVECT  ocent;
OBJREC  *op;
{
        double  maxrad2;
        double  d2;
        register int  i, j;
        register FACE  *f;
        
        f = getface(op);
        for (i = 0; i < 3; i++) {
                ocent[i] = 0.;
                for (j = 0; j < f->nv; j++)
                        ocent[i] += VERTEX(f,j)[i];
                ocent[i] /= (double)f->nv;
        }
        if (f->area == 0.)
                return(0.);
        maxrad2 = 0.;
        for (j = 0; j < f->nv; j++) {
                d2 = dist2(VERTEX(f,j), ocent);
                if (d2 > maxrad2)
                        maxrad2 = d2;
        }
        return(maxrad2);
}


double
rgetmaxdisk(ocent, op)          /* get center and squared radius of ring */
FVECT  ocent;
OBJREC  *op;
{
        register CONE  *co;
        
        co = getcone(op, 0);
        VCOPY(ocent, CO_P0(co));
        return(CO_R1(co)*CO_R1(co));
}


double
fgetplaneq(nvec, op)                    /* get plane equation for face */
FVECT  nvec;
OBJREC  *op;
{
        register FACE  *fo;

        fo = getface(op);
        VCOPY(nvec, fo->norm);
        return(fo->offset);
}


double
rgetplaneq(nvec, op)                    /* get plane equation for ring */
FVECT  nvec;
OBJREC  *op;
{
        register CONE  *co;

        co = getcone(op, 0);
        VCOPY(nvec, co->ad);
        return(DOT(nvec, CO_P0(co)));
}


sourcehit(r)                    /* check to see if ray hit distant source */
register RAY  *r;
{
        int  first, last;
        register int  i;

        if (r->rsrc >= 0) {             /* check only one if aimed */
                first = last = r->rsrc;
        } else {                        /* otherwise check all */
                first = 0; last = nsources-1;
        }
        for (i = first; i <= last; i++)
                if (source[i].sflags & SDISTANT)
                        /*
                         * Check to see if ray is within
                         * solid angle of source.
                         */
                        if (2.0*PI * (1.0 - DOT(source[i].sloc,r->rdir))
                                        <= source[i].ss2) {
                                r->ro = source[i].so;
                                if (!(source[i].sflags & SSKIP))
                                        break;
                        }

        if (r->ro != NULL) {
                for (i = 0; i < 3; i++)
                        r->ron[i] = -r->rdir[i];
                r->rod = 1.0;
                r->rox = NULL;
                return(1);
        }
        return(0);
}


#define  wrongsource(m, r)      (m->otype!=MAT_ILLUM && \
                                r->rsrc>=0 && \
                                source[r->rsrc].so!=r->ro)

#define  badambient(m, r)       ((r->crtype&(AMBIENT|SHADOW))==AMBIENT && \
                                !(m->otype==MAT_GLOW&&r->rot>m->oargs.farg[3]))

#define  passillum(m, r)        (m->otype==MAT_ILLUM && \
                                !(r->rsrc>=0&&source[r->rsrc].so==r->ro))


m_light(m, r)                   /* ray hit a light source */
register OBJREC  *m;
register RAY  *r;
{
                                                /* check for over-counting */
        if (wrongsource(m, r) || badambient(m, r))
                return;
                                                /* check for passed illum */
        if (passillum(m, r)) {

                if (m->oargs.nsargs < 1 || !strcmp(m->oargs.sarg[0], VOIDID))
                        raytrans(r);
                else
                        rayshade(r, modifier(m->oargs.sarg[0]));

                                                /* otherwise treat as source */
        } else {
                                                /* check for behind */
                if (r->rod < 0.0)
                        return;
                                                /* get distribution pattern */
                raytexture(r, m->omod);
                                                /* get source color */
                setcolor(r->rcol, m->oargs.farg[0],
                                  m->oargs.farg[1],
                                  m->oargs.farg[2]);
                                                /* modify value */
                multcolor(r->rcol, r->pcol);
        }
}
Revision:	1.3
Committed:	Fri Jun 21 13:23:05 1991 UTC (32 years, 10 months ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 1.2:	+2 -0 lines
Log Message:	added test for zero area face in fgetdisk()
#	User	Rev	Content
1	greg	1.1	/* 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	greg	1.2	int
48	greg	1.1	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	greg	1.2	return(-1);
57	greg	1.1	source[nsources].sflags = 0;
58			source[nsources].nhits = 1;
59			source[nsources].ntests = 2; /* initial hit probability = 1/2 */
60	greg	1.2	return(nsources++);
61	greg	1.1	}
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 = 2AIMREQT-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 = 2AIMREQT-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 = 2.0PI (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 = 2AIMREQT-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 = 2AIMREQT-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 = 2.0PI (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	greg	1.3	if (f->area == 0.)
184			return(0.);
185	greg	1.1	maxrad2 = 0.;
186			for (j = 0; j < f->nv; j++) {
187			d2 = dist2(VERTEX(f,j), ocent);
188			if (d2 > maxrad2)
189			maxrad2 = d2;
190			}
191			return(maxrad2);
192			}
193
194
195			double
196			rgetmaxdisk(ocent, op) /* get center and squared radius of ring */
197			FVECT ocent;
198			OBJREC *op;
199			{
200			register CONE *co;
201
202			co = getcone(op, 0);
203			VCOPY(ocent, CO_P0(co));
204			return(CO_R1(co)*CO_R1(co));
205			}
206
207
208			double
209			fgetplaneq(nvec, op) /* get plane equation for face */
210			FVECT nvec;
211			OBJREC *op;
212			{
213			register FACE *fo;
214
215			fo = getface(op);
216			VCOPY(nvec, fo->norm);
217			return(fo->offset);
218			}
219
220
221			double
222			rgetplaneq(nvec, op) /* get plane equation for ring */
223			FVECT nvec;
224			OBJREC *op;
225			{
226			register CONE *co;
227
228			co = getcone(op, 0);
229			VCOPY(nvec, co->ad);
230			return(DOT(nvec, CO_P0(co)));
231			}
232
233
234			sourcehit(r) /* check to see if ray hit distant source */
235			register RAY *r;
236			{
237			int first, last;
238			register int i;
239
240			if (r->rsrc >= 0) { /* check only one if aimed */
241			first = last = r->rsrc;
242			} else { /* otherwise check all */
243			first = 0; last = nsources-1;
244			}
245			for (i = first; i <= last; i++)
246			if (source[i].sflags & SDISTANT)
247			/*
248			* Check to see if ray is within
249			* solid angle of source.
250			*/
251			if (2.0PI (1.0 - DOT(source[i].sloc,r->rdir))
252			<= source[i].ss2) {
253			r->ro = source[i].so;
254			if (!(source[i].sflags & SSKIP))
255			break;
256			}
257
258			if (r->ro != NULL) {
259			for (i = 0; i < 3; i++)
260			r->ron[i] = -r->rdir[i];
261			r->rod = 1.0;
262			r->rox = NULL;
263			return(1);
264			}
265			return(0);
266			}
267
268
269			#define wrongsource(m, r) (m->otype!=MAT_ILLUM && \
270			r->rsrc>=0 && \
271			source[r->rsrc].so!=r->ro)
272
273			#define badambient(m, r) ((r->crtype&(AMBIENT\|SHADOW))==AMBIENT && \
274			!(m->otype==MAT_GLOW&&r->rot>m->oargs.farg[3]))
275
276			#define passillum(m, r) (m->otype==MAT_ILLUM && \
277			!(r->rsrc>=0&&source[r->rsrc].so==r->ro))
278
279
280			m_light(m, r) /* ray hit a light source */
281			register OBJREC *m;
282			register RAY *r;
283			{
284			/* check for over-counting */
285			if (wrongsource(m, r) \|\| badambient(m, r))
286			return;
287			/* check for passed illum */
288			if (passillum(m, r)) {
289
290			if (m->oargs.nsargs < 1 \|\| !strcmp(m->oargs.sarg[0], VOIDID))
291			raytrans(r);
292			else
293			rayshade(r, modifier(m->oargs.sarg[0]));
294
295			/* otherwise treat as source */
296			} else {
297			/* check for behind */
298			if (r->rod < 0.0)
299			return;
300			/* get distribution pattern */
301			raytexture(r, m->omod);
302			/* get source color */
303			setcolor(r->rcol, m->oargs.farg[0],
304			m->oargs.farg[1],
305			m->oargs.farg[2]);
306			/* modify value */
307			multcolor(r->rcol, r->pcol);
308			}
309			}