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/* Copyright (c) 1995 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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* Support routines for source objects and materials |
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*/ |
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|
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#include "ray.h" |
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|
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#include "otypes.h" |
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|
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#include "source.h" |
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|
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#include "cone.h" |
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|
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#include "face.h" |
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|
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#define SRCINC 4 /* realloc increment for array */ |
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|
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SRCREC *source = NULL; /* our list of sources */ |
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int nsources = 0; /* the number of sources */ |
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|
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SRCFUNC sfun[NUMOTYPE]; /* source dispatch table */ |
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|
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|
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initstypes() /* initialize source dispatch table */ |
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{ |
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extern VSMATERIAL mirror_vs, direct1_vs, direct2_vs; |
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extern int fsetsrc(), ssetsrc(), sphsetsrc(), cylsetsrc(), rsetsrc(); |
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extern int nopart(), flatpart(), cylpart(); |
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extern double fgetplaneq(), rgetplaneq(); |
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extern double fgetmaxdisk(), rgetmaxdisk(); |
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static SOBJECT fsobj = {fsetsrc, flatpart, fgetplaneq, fgetmaxdisk}; |
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static SOBJECT ssobj = {ssetsrc, nopart}; |
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static SOBJECT sphsobj = {sphsetsrc, nopart}; |
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static SOBJECT cylsobj = {cylsetsrc, cylpart}; |
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static SOBJECT rsobj = {rsetsrc, flatpart, rgetplaneq, rgetmaxdisk}; |
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|
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sfun[MAT_MIRROR].mf = &mirror_vs; |
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sfun[MAT_DIRECT1].mf = &direct1_vs; |
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sfun[MAT_DIRECT2].mf = &direct2_vs; |
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sfun[OBJ_FACE].of = &fsobj; |
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sfun[OBJ_SOURCE].of = &ssobj; |
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sfun[OBJ_SPHERE].of = &sphsobj; |
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sfun[OBJ_CYLINDER].of = &cylsobj; |
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sfun[OBJ_RING].of = &rsobj; |
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} |
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|
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|
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int |
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newsource() /* allocate new source in our array */ |
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{ |
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if (nsources == 0) |
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source = (SRCREC *)malloc(SRCINC*sizeof(SRCREC)); |
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else if (nsources%SRCINC == 0) |
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source = (SRCREC *)realloc((char *)source, |
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(unsigned)(nsources+SRCINC)*sizeof(SRCREC)); |
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if (source == NULL) |
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return(-1); |
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source[nsources].sflags = 0; |
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source[nsources].nhits = 1; |
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source[nsources].ntests = 2; /* initial hit probability = 1/2 */ |
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return(nsources++); |
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} |
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|
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|
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setflatss(src) /* set sampling for a flat source */ |
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register SRCREC *src; |
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{ |
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double mult; |
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register int i; |
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|
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src->ss[SV][0] = src->ss[SV][1] = src->ss[SV][2] = 0.0; |
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for (i = 0; i < 3; i++) |
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if (src->snorm[i] < 0.6 && src->snorm[i] > -0.6) |
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break; |
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src->ss[SV][i] = 1.0; |
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fcross(src->ss[SU], src->ss[SV], src->snorm); |
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mult = .5 * sqrt( src->ss2 / DOT(src->ss[SU],src->ss[SU]) ); |
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for (i = 0; i < 3; i++) |
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src->ss[SU][i] *= mult; |
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fcross(src->ss[SV], src->snorm, src->ss[SU]); |
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} |
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|
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|
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fsetsrc(src, so) /* set a face as a source */ |
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register SRCREC *src; |
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OBJREC *so; |
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{ |
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register FACE *f; |
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register int i, j; |
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double d; |
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|
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src->sa.success = 2*AIMREQT-1; /* bitch on second failure */ |
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src->so = so; |
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/* get the face */ |
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f = getface(so); |
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/* find the center */ |
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for (j = 0; j < 3; j++) { |
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src->sloc[j] = 0.0; |
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for (i = 0; i < f->nv; i++) |
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src->sloc[j] += VERTEX(f,i)[j]; |
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src->sloc[j] /= (double)f->nv; |
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} |
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if (!inface(src->sloc, f)) |
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objerror(so, USER, "cannot hit center"); |
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src->sflags |= SFLAT; |
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VCOPY(src->snorm, f->norm); |
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src->ss2 = f->area; |
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/* find maximum radius */ |
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src->srad = 0.; |
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for (i = 0; i < f->nv; i++) { |
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d = dist2(VERTEX(f,i), src->sloc); |
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if (d > src->srad) |
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src->srad = d; |
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} |
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src->srad = sqrt(src->srad); |
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/* compute size vectors */ |
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if (f->nv == 4) /* parallelogram case */ |
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for (j = 0; j < 3; j++) { |
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src->ss[SU][j] = .5*(VERTEX(f,1)[j]-VERTEX(f,0)[j]); |
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src->ss[SV][j] = .5*(VERTEX(f,3)[j]-VERTEX(f,0)[j]); |
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} |
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else |
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setflatss(src); |
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} |
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|
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|
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ssetsrc(src, so) /* set a source as a source */ |
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register SRCREC *src; |
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register OBJREC *so; |
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{ |
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double theta; |
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|
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src->sa.success = 2*AIMREQT-1; /* bitch on second failure */ |
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src->so = so; |
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if (so->oargs.nfargs != 4) |
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objerror(so, USER, "bad arguments"); |
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src->sflags |= SDISTANT; |
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VCOPY(src->sloc, so->oargs.farg); |
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if (normalize(src->sloc) == 0.0) |
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objerror(so, USER, "zero direction"); |
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theta = PI/180.0/2.0 * so->oargs.farg[3]; |
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if (theta <= FTINY) |
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objerror(so, USER, "zero size"); |
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src->ss2 = 2.0*PI * (1.0 - cos(theta)); |
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/* the following is approximate */ |
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src->srad = sqrt(src->ss2/PI); |
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VCOPY(src->snorm, src->sloc); |
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setflatss(src); /* hey, whatever works */ |
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src->ss[SW][0] = src->ss[SW][1] = src->ss[SW][2] = 0.0; |
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} |
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|
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|
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sphsetsrc(src, so) /* set a sphere as a source */ |
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register SRCREC *src; |
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register OBJREC *so; |
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{ |
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register int i; |
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|
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src->sa.success = 2*AIMREQT-1; /* bitch on second failure */ |
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src->so = so; |
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if (so->oargs.nfargs != 4) |
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objerror(so, USER, "bad # arguments"); |
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if (so->oargs.farg[3] <= FTINY) |
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objerror(so, USER, "illegal radius"); |
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VCOPY(src->sloc, so->oargs.farg); |
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src->srad = so->oargs.farg[3]; |
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src->ss2 = PI * src->srad * src->srad; |
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for (i = 0; i < 3; i++) |
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src->ss[SU][i] = src->ss[SV][i] = src->ss[SW][i] = 0.0; |
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for (i = 0; i < 3; i++) |
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src->ss[i][i] = .7236 * so->oargs.farg[3]; |
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} |
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|
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|
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rsetsrc(src, so) /* set a ring (disk) as a source */ |
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register SRCREC *src; |
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OBJREC *so; |
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{ |
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register CONE *co; |
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|
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src->sa.success = 2*AIMREQT-1; /* bitch on second failure */ |
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src->so = so; |
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/* get the ring */ |
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co = getcone(so, 0); |
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VCOPY(src->sloc, CO_P0(co)); |
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if (CO_R0(co) > 0.0) |
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objerror(so, USER, "cannot hit center"); |
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src->sflags |= SFLAT; |
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VCOPY(src->snorm, co->ad); |
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src->srad = CO_R1(co); |
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src->ss2 = PI * src->srad * src->srad; |
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setflatss(src); |
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} |
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|
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|
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cylsetsrc(src, so) /* set a cylinder as a source */ |
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register SRCREC *src; |
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OBJREC *so; |
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{ |
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register CONE *co; |
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register int i; |
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|
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src->sa.success = 4*AIMREQT-1; /* bitch on fourth failure */ |
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src->so = so; |
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/* get the cylinder */ |
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co = getcone(so, 0); |
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if (CO_R0(co) > .2*co->al) /* heuristic constraint */ |
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objerror(so, WARNING, "source aspect too small"); |
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src->sflags |= SCYL; |
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for (i = 0; i < 3; i++) |
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src->sloc[i] = .5 * (CO_P1(co)[i] + CO_P0(co)[i]); |
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src->srad = .5*co->al; |
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src->ss2 = 2.*CO_R0(co)*co->al; |
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/* set sampling vectors */ |
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for (i = 0; i < 3; i++) |
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src->ss[SU][i] = .5 * co->al * co->ad[i]; |
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src->ss[SV][0] = src->ss[SV][1] = src->ss[SV][2] = 0.0; |
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for (i = 0; i < 3; i++) |
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if (co->ad[i] < 0.6 && co->ad[i] > -0.6) |
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break; |
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src->ss[SV][i] = 1.0; |
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fcross(src->ss[SW], src->ss[SV], co->ad); |
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normalize(src->ss[SW]); |
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for (i = 0; i < 3; i++) |
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src->ss[SW][i] *= .8559 * CO_R0(co); |
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fcross(src->ss[SV], src->ss[SW], co->ad); |
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} |
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|
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|
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SPOT * |
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makespot(m) /* make a spotlight */ |
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register OBJREC *m; |
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{ |
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register SPOT *ns; |
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|
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if ((ns = (SPOT *)m->os) != NULL) |
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return(ns); |
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if ((ns = (SPOT *)malloc(sizeof(SPOT))) == NULL) |
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return(NULL); |
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ns->siz = 2.0*PI * (1.0 - cos(PI/180.0/2.0 * m->oargs.farg[3])); |
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VCOPY(ns->aim, m->oargs.farg+4); |
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if ((ns->flen = normalize(ns->aim)) == 0.0) |
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objerror(m, USER, "zero focus vector"); |
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m->os = (char *)ns; |
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return(ns); |
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} |
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|
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|
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spotout(r, s) /* check if we're outside spot region */ |
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register RAY *r; |
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register SPOT *s; |
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{ |
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double d; |
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FVECT vd; |
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|
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if (s == NULL) |
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return(0); |
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if (s->flen < -FTINY) { /* distant source */ |
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vd[0] = s->aim[0] - r->rorg[0]; |
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vd[1] = s->aim[1] - r->rorg[1]; |
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vd[2] = s->aim[2] - r->rorg[2]; |
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d = DOT(r->rdir,vd); |
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/* wrong side? |
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if (d <= FTINY) |
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return(1); */ |
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d = DOT(vd,vd) - d*d; |
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if (PI*d > s->siz) |
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return(1); /* out */ |
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return(0); /* OK */ |
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} |
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/* local source */ |
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if (s->siz < 2.0*PI * (1.0 + DOT(s->aim,r->rdir))) |
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return(1); /* out */ |
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return(0); /* OK */ |
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} |
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|
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|
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double |
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fgetmaxdisk(ocent, op) /* get center and squared radius of face */ |
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FVECT ocent; |
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OBJREC *op; |
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{ |
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double maxrad2; |
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double d; |
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register int i, j; |
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register FACE *f; |
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|
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f = getface(op); |
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if (f->area == 0.) |
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return(0.); |
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for (i = 0; i < 3; i++) { |
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ocent[i] = 0.; |
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for (j = 0; j < f->nv; j++) |
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ocent[i] += VERTEX(f,j)[i]; |
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ocent[i] /= (double)f->nv; |
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} |
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d = DOT(ocent,f->norm); |
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for (i = 0; i < 3; i++) |
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ocent[i] += (f->offset - d)*f->norm[i]; |
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maxrad2 = 0.; |
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for (j = 0; j < f->nv; j++) { |
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d = dist2(VERTEX(f,j), ocent); |
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if (d > maxrad2) |
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maxrad2 = d; |
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} |
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return(maxrad2); |
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} |
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|
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|
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double |
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rgetmaxdisk(ocent, op) /* get center and squared radius of ring */ |
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FVECT ocent; |
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OBJREC *op; |
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{ |
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register CONE *co; |
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|
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co = getcone(op, 0); |
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VCOPY(ocent, CO_P0(co)); |
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return(CO_R1(co)*CO_R1(co)); |
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} |
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|
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|
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double |
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fgetplaneq(nvec, op) /* get plane equation for face */ |
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FVECT nvec; |
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OBJREC *op; |
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{ |
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register FACE *fo; |
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|
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fo = getface(op); |
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VCOPY(nvec, fo->norm); |
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return(fo->offset); |
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} |
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|
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|
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double |
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rgetplaneq(nvec, op) /* get plane equation for ring */ |
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FVECT nvec; |
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OBJREC *op; |
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{ |
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register CONE *co; |
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|
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co = getcone(op, 0); |
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VCOPY(nvec, co->ad); |
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return(DOT(nvec, CO_P0(co))); |
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} |
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|
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|
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commonspot(sp1, sp2, org) /* set sp1 to intersection of sp1 and sp2 */ |
| 355 |
register SPOT *sp1, *sp2; |
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FVECT org; |
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{ |
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FVECT cent; |
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double rad2, cos1, cos2; |
| 360 |
|
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cos1 = 1. - sp1->siz/(2.*PI); |
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cos2 = 1. - sp2->siz/(2.*PI); |
| 363 |
if (sp2->siz >= 2.*PI-FTINY) /* BIG, just check overlap */ |
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return(DOT(sp1->aim,sp2->aim) >= cos1*cos2 - |
| 365 |
sqrt((1.-cos1*cos1)*(1.-cos2*cos2))); |
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/* compute and check disks */ |
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rad2 = intercircle(cent, sp1->aim, sp2->aim, |
| 368 |
1./(cos1*cos1) - 1., 1./(cos2*cos2) - 1.); |
| 369 |
if (rad2 <= FTINY || normalize(cent) == 0.) |
| 370 |
return(0); |
| 371 |
VCOPY(sp1->aim, cent); |
| 372 |
sp1->siz = 2.*PI*(1. - 1./sqrt(1.+rad2)); |
| 373 |
return(1); |
| 374 |
} |
| 375 |
|
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|
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commonbeam(sp1, sp2, dir) /* set sp1 to intersection of sp1 and sp2 */ |
| 378 |
register SPOT *sp1, *sp2; |
| 379 |
FVECT dir; |
| 380 |
{ |
| 381 |
FVECT cent, c1, c2; |
| 382 |
double rad2, d; |
| 383 |
register int i; |
| 384 |
/* move centers to common plane */ |
| 385 |
d = DOT(sp1->aim, dir); |
| 386 |
for (i = 0; i < 3; i++) |
| 387 |
c1[i] = sp1->aim[i] - d*dir[i]; |
| 388 |
d = DOT(sp2->aim, dir); |
| 389 |
for (i = 0; i < 3; i++) |
| 390 |
c2[i] = sp2->aim[i] - d*dir[i]; |
| 391 |
/* compute overlap */ |
| 392 |
rad2 = intercircle(cent, c1, c2, sp1->siz/PI, sp2->siz/PI); |
| 393 |
if (rad2 <= FTINY) |
| 394 |
return(0); |
| 395 |
VCOPY(sp1->aim, cent); |
| 396 |
sp1->siz = PI*rad2; |
| 397 |
return(1); |
| 398 |
} |
| 399 |
|
| 400 |
|
| 401 |
checkspot(sp, nrm) /* check spotlight for behind source */ |
| 402 |
register SPOT *sp; /* spotlight */ |
| 403 |
FVECT nrm; /* source surface normal */ |
| 404 |
{ |
| 405 |
double d, d1; |
| 406 |
|
| 407 |
d = DOT(sp->aim, nrm); |
| 408 |
if (d > FTINY) /* center in front? */ |
| 409 |
return(1); |
| 410 |
/* else check horizon */ |
| 411 |
d1 = 1. - sp->siz/(2.*PI); |
| 412 |
return(1.-FTINY-d*d < d1*d1); |
| 413 |
} |
| 414 |
|
| 415 |
|
| 416 |
double |
| 417 |
spotdisk(oc, op, sp, pos) /* intersect spot with object op */ |
| 418 |
FVECT oc; |
| 419 |
OBJREC *op; |
| 420 |
register SPOT *sp; |
| 421 |
FVECT pos; |
| 422 |
{ |
| 423 |
FVECT onorm; |
| 424 |
double offs, d, dist; |
| 425 |
register int i; |
| 426 |
|
| 427 |
offs = getplaneq(onorm, op); |
| 428 |
d = -DOT(onorm, sp->aim); |
| 429 |
if (d >= -FTINY && d <= FTINY) |
| 430 |
return(0.); |
| 431 |
dist = (DOT(pos, onorm) - offs)/d; |
| 432 |
if (dist < 0.) |
| 433 |
return(0.); |
| 434 |
for (i = 0; i < 3; i++) |
| 435 |
oc[i] = pos[i] + dist*sp->aim[i]; |
| 436 |
return(sp->siz*dist*dist/PI/(d*d)); |
| 437 |
} |
| 438 |
|
| 439 |
|
| 440 |
double |
| 441 |
beamdisk(oc, op, sp, dir) /* intersect beam with object op */ |
| 442 |
FVECT oc; |
| 443 |
OBJREC *op; |
| 444 |
register SPOT *sp; |
| 445 |
FVECT dir; |
| 446 |
{ |
| 447 |
FVECT onorm; |
| 448 |
double offs, d, dist; |
| 449 |
register int i; |
| 450 |
|
| 451 |
offs = getplaneq(onorm, op); |
| 452 |
d = -DOT(onorm, dir); |
| 453 |
if (d >= -FTINY && d <= FTINY) |
| 454 |
return(0.); |
| 455 |
dist = (DOT(sp->aim, onorm) - offs)/d; |
| 456 |
for (i = 0; i < 3; i++) |
| 457 |
oc[i] = sp->aim[i] + dist*dir[i]; |
| 458 |
return(sp->siz/PI/(d*d)); |
| 459 |
} |
| 460 |
|
| 461 |
|
| 462 |
double |
| 463 |
intercircle(cc, c1, c2, r1s, r2s) /* intersect two circles */ |
| 464 |
FVECT cc; /* midpoint (return value) */ |
| 465 |
FVECT c1, c2; /* circle centers */ |
| 466 |
double r1s, r2s; /* radii squared */ |
| 467 |
{ |
| 468 |
double a2, d2, l; |
| 469 |
FVECT disp; |
| 470 |
register int i; |
| 471 |
|
| 472 |
for (i = 0; i < 3; i++) |
| 473 |
disp[i] = c2[i] - c1[i]; |
| 474 |
d2 = DOT(disp,disp); |
| 475 |
/* circle within overlap? */ |
| 476 |
if (r1s < r2s) { |
| 477 |
if (r2s >= r1s + d2) { |
| 478 |
VCOPY(cc, c1); |
| 479 |
return(r1s); |
| 480 |
} |
| 481 |
} else { |
| 482 |
if (r1s >= r2s + d2) { |
| 483 |
VCOPY(cc, c2); |
| 484 |
return(r2s); |
| 485 |
} |
| 486 |
} |
| 487 |
a2 = .25*(2.*(r1s+r2s) - d2 - (r2s-r1s)*(r2s-r1s)/d2); |
| 488 |
/* no overlap? */ |
| 489 |
if (a2 <= 0.) |
| 490 |
return(0.); |
| 491 |
/* overlap, compute center */ |
| 492 |
l = sqrt((r1s - a2)/d2); |
| 493 |
for (i = 0; i < 3; i++) |
| 494 |
cc[i] = c1[i] + l*disp[i]; |
| 495 |
return(a2); |
| 496 |
} |
