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/* Copyright (c) 1991 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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|
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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; |
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extern int fsetsrc(), ssetsrc(), sphsetsrc(), rsetsrc(); |
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extern double fgetplaneq(), rgetplaneq(); |
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extern double fgetmaxdisk(), rgetmaxdisk(); |
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static SOBJECT fsobj = {fsetsrc, fgetplaneq, fgetmaxdisk}; |
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static SOBJECT ssobj = {ssetsrc}; |
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static SOBJECT sphsobj = {sphsetsrc}; |
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static SOBJECT rsobj = {rsetsrc, rgetplaneq, rgetmaxdisk}; |
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|
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sfun[MAT_MIRROR].mf = &mirror_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_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(sizeof(SRCREC)); |
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else |
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source = (SRCREC *)realloc((char *)source, |
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(unsigned)(nsources+1)*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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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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|
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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->ss = sqrt(f->area / PI); |
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src->ss2 = f->area; |
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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->ss = theta >= PI/4 ? 1.0 : tan(theta); |
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src->ss2 = 2.0*PI * (1.0 - cos(theta)); |
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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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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->ss = so->oargs.farg[3]; |
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src->ss2 = PI * src->ss * src->ss; |
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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->ss = CO_R1(co); |
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src->ss2 = PI * src->ss * src->ss; |
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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 *)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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return(ns); |
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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 d2; |
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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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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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if (f->area == 0.) |
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return(0.); |
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maxrad2 = 0.; |
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for (j = 0; j < f->nv; j++) { |
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d2 = dist2(VERTEX(f,j), ocent); |
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if (d2 > maxrad2) |
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maxrad2 = d2; |
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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 */ |
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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; |
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|
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cos1 = 1. - sp1->siz/(2.*PI); |
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cos2 = 1. - sp2->siz/(2.*PI); |
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if (sp2->siz >= 2.*PI-FTINY) /* BIG, just check overlap */ |
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return(DOT(sp1->aim,sp2->aim) >= cos1*cos2 - |
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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, |
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1./(cos1*cos1) - 1., 1./(cos2*cos2) - 1.); |
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if (rad2 <= FTINY || normalize(cent) == 0.) |
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return(0); |
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VCOPY(sp1->aim, cent); |
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sp1->siz = 2.*PI*(1. - 1./sqrt(1.+rad2)); |
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return(1); |
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} |
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|
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|
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commonbeam(sp1, sp2, dir) /* set sp1 to intersection of sp1 and sp2 */ |
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register SPOT *sp1, *sp2; |
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FVECT dir; |
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{ |
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FVECT cent, c1, c2; |
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double rad2, d; |
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register int i; |
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/* move centers to common plane */ |
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d = DOT(sp1->aim, dir); |
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for (i = 0; i < 3; i++) |
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c1[i] = sp1->aim[i] - d*dir[i]; |
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d = DOT(sp2->aim, dir); |
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for (i = 0; i < 3; i++) |
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c2[i] = sp2->aim[i] - d*dir[i]; |
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/* compute overlap */ |
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rad2 = intercircle(cent, c1, c2, sp1->siz/PI, sp2->siz/PI); |
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if (rad2 <= FTINY) |
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return(0); |
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VCOPY(sp1->aim, cent); |
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sp1->siz = PI*rad2; |
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return(1); |
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} |
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|
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|
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checkspot(sp, nrm) /* check spotlight for behind source */ |
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register SPOT *sp; /* spotlight */ |
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FVECT nrm; /* source surface normal */ |
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{ |
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double d, d1; |
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|
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d = DOT(sp->aim, nrm); |
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if (d > FTINY) /* center in front? */ |
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return(0); |
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/* else check horizon */ |
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d1 = 1. - sp->siz/(2.*PI); |
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return(1.-FTINY-d*d > d1*d1); |
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} |
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|
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|
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double |
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intercircle(cc, c1, c2, r1s, r2s) /* intersect two circles */ |
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FVECT cc; /* midpoint (return value) */ |
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FVECT c1, c2; /* circle centers */ |
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double r1s, r2s; /* radii squared */ |
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{ |
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double a2, d2, l; |
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FVECT disp; |
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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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disp[i] = c2[i] - c1[i]; |
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d2 = DOT(disp,disp); |
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/* circle within overlap? */ |
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if (r1s < r2s) { |
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if (r2s >= r1s + d2) { |
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VCOPY(cc, c1); |
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return(r1s); |
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} |
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} else { |
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if (r1s >= r2s + d2) { |
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VCOPY(cc, c2); |
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return(r2s); |
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} |
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} |
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a2 = .25*(2.*(r1s+r2s) - d2 - (r2s-r1s)*(r2s-r1s)/d2); |
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/* no overlap? */ |
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if (a2 <= 0.) |
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return(0.); |
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/* overlap, compute center */ |
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l = sqrt((r1s - a2)/d2); |
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for (i = 0; i < 3; i++) |
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cc[i] = c1[i] + l*disp[i]; |
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return(a2); |
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} |
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|
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|
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sourcehit(r) /* check to see if ray hit distant source */ |
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register RAY *r; |
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{ |
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int first, last; |
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register int i; |
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|
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if (r->rsrc >= 0) { /* check only one if aimed */ |
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first = last = r->rsrc; |
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} else { /* otherwise check all */ |
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first = 0; last = nsources-1; |
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} |
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for (i = first; i <= last; i++) |
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if (source[i].sflags & SDISTANT) |
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/* |
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* Check to see if ray is within |
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* solid angle of source. |
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*/ |
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if (2.0*PI * (1.0 - DOT(source[i].sloc,r->rdir)) |
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<= source[i].ss2) { |
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r->ro = source[i].so; |
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if (!(source[i].sflags & SSKIP)) |
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break; |
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} |
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|
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if (r->ro != NULL) { |
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for (i = 0; i < 3; i++) |
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r->ron[i] = -r->rdir[i]; |
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r->rod = 1.0; |
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r->rox = NULL; |
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return(1); |
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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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#define wrongsource(m, r) (m->otype!=MAT_ILLUM && \ |
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r->rsrc>=0 && \ |
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source[r->rsrc].so!=r->ro) |
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|
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#define badambient(m, r) ((r->crtype&(AMBIENT|SHADOW))==AMBIENT && \ |
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!(m->otype==MAT_GLOW&&r->rot>m->oargs.farg[3])) |
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|
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#define passillum(m, r) (m->otype==MAT_ILLUM && \ |
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!(r->rsrc>=0&&source[r->rsrc].so==r->ro)) |
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|
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|
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m_light(m, r) /* ray hit a light source */ |
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register OBJREC *m; |
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register RAY *r; |
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{ |
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/* check for over-counting */ |
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if (wrongsource(m, r) || badambient(m, r)) |
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return; |
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/* check for passed illum */ |
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if (passillum(m, r)) { |
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|
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if (m->oargs.nsargs < 1 || !strcmp(m->oargs.sarg[0], VOIDID)) |
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raytrans(r); |
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else |
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rayshade(r, modifier(m->oargs.sarg[0])); |
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|
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/* otherwise treat as source */ |
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} else { |
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/* check for behind */ |
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if (r->rod < 0.0) |
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return; |
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/* get distribution pattern */ |
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raytexture(r, m->omod); |
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/* get source color */ |
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setcolor(r->rcol, m->oargs.farg[0], |
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m->oargs.farg[1], |
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m->oargs.farg[2]); |
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/* modify value */ |
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multcolor(r->rcol, r->pcol); |
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} |
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} |
