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#ifndef lint |
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static const char RCSid[] = "$Id: srcobstr.c,v 2.5 2004/06/22 13:40:54 greg Exp $"; |
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#endif |
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/* |
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* Source occlusion caching routines |
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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 "otspecial.h" |
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|
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#include "source.h" |
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|
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#define ABS(x) ((x)>0 ? (x) : -(x)) |
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|
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|
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#if SHADCACHE /* preemptive shadow checking */ |
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|
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|
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static void /* cast source ray to first blocker */ |
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castshadow(int sn, FVECT rorg, FVECT rdir) |
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{ |
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RAY rt; |
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|
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VCOPY(rt.rorg, rorg); |
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VCOPY(rt.rdir, rdir); |
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rt.rmax = 0; |
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rayorigin(&rt, NULL, PRIMARY, 1.0); |
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if (!localhit(&rt, &thescene)) |
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return; |
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/* pretend we were aimed at source */ |
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rt.crtype |= rt.rtype = SHADOW; |
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rt.rdir[0] = -rt.rdir[0]; |
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rt.rdir[1] = -rt.rdir[1]; |
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rt.rdir[2] = -rt.rdir[2]; |
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rt.rod = -rt.rod; |
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VSUB(rt.rorg, rt.rop, rt.rdir); |
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rt.rot = 1.; |
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rt.rsrc = sn; |
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/* record blocker */ |
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srcblocker(&rt); |
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} |
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|
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|
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static void /* initialize occlusion cache */ |
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initobscache(int sn) |
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{ |
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register SRCREC *srcp = &source[sn]; |
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int cachelen; |
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FVECT rorg, rdir; |
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RREAL d; |
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int i, j, k; |
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int ax, ax1, ax2; |
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|
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if (srcp->sflags & SDISTANT) |
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cachelen = 4*SHADCACHE*SHADCACHE; |
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else if (srcp->sflags & SFLAT) |
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cachelen = SHADCACHE*SHADCACHE*3 + (SHADCACHE&1)*SHADCACHE*4; |
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else /* spherical distribution */ |
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cachelen = SHADCACHE*SHADCACHE*6; |
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/* allocate cache */ |
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DCHECK(srcp->obscache != NULL, |
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CONSISTENCY, "initobscache() called twice"); |
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srcp->obscache = (OBSCACHE *)malloc(sizeof(OBSCACHE) + |
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sizeof(OBJECT)*(cachelen-1)); |
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if (srcp->obscache == NULL) |
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error(SYSTEM, "out of memory in initobscache()"); |
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/* set parameters */ |
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if (srcp->sflags & SDISTANT) { |
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RREAL amax = 0; |
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for (ax1 = 3; ax1--; ) |
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if (ABS(srcp->sloc[ax1]) > amax) { |
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amax = ABS(srcp->sloc[ax1]); |
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ax = ax1; |
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} |
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srcp->obscache->p.d.ax = ax; |
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ax1 = (ax+1)%3; |
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ax2 = (ax+2)%3; |
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VCOPY(srcp->obscache->p.d.o, thescene.cuorg); |
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if (srcp->sloc[ax] > 0) |
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srcp->obscache->p.d.o[ax] += thescene.cusize; |
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if (srcp->sloc[ax1] < 0) |
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srcp->obscache->p.d.o[ax1] += thescene.cusize * |
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srcp->sloc[ax1] / amax; |
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if (srcp->sloc[ax2] < 0) |
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srcp->obscache->p.d.o[ax2] += thescene.cusize * |
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srcp->sloc[ax2] / amax; |
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srcp->obscache->p.d.e1 = 1. / (thescene.cusize*(1. + |
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fabs(srcp->sloc[ax1])/amax)); |
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srcp->obscache->p.d.e2 = 1. / (thescene.cusize*(1. + |
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fabs(srcp->sloc[ax2])/amax)); |
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} else if (srcp->sflags & SFLAT) { |
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VCOPY(srcp->obscache->p.f.u, srcp->ss[SU]); |
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normalize(srcp->obscache->p.f.u); |
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fcross(srcp->obscache->p.f.v, |
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srcp->snorm, srcp->obscache->p.f.u); |
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} |
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/* clear cache */ |
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for (i = cachelen; i--; ) |
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srcp->obscache->obs[i] = OVOID; |
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/* cast shadow rays */ |
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if (srcp->sflags & SDISTANT) { |
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for (k = 3; k--; ) |
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rdir[k] = -srcp->sloc[k]; |
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for (i = 2*SHADCACHE; i--; ) |
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for (j = 2*SHADCACHE; j--; ) { |
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VCOPY(rorg, srcp->obscache->p.d.o); |
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rorg[ax1] += (i+.5) / |
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(2*SHADCACHE*srcp->obscache->p.d.e1); |
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rorg[ax2] += (j+.5) / |
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(2*SHADCACHE*srcp->obscache->p.d.e2); |
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castshadow(sn, rorg, rdir); |
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} |
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} else if (srcp->sflags & SFLAT) { |
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d = 0.01*srcp->srad; |
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VSUM(rorg, srcp->sloc, srcp->snorm, d); |
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for (i = SHADCACHE; i--; ) |
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for (j = SHADCACHE; j--; ) { |
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d = 2./SHADCACHE*(i+.5) - 1.; |
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VSUM(rdir, srcp->snorm, |
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srcp->obscache->p.f.u, d); |
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d = 2./SHADCACHE*(j+.5) - 1.; |
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VSUM(rdir, rdir, srcp->obscache->p.f.v, d); |
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normalize(rdir); |
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castshadow(sn, rorg, rdir); |
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} |
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for (k = 2; k--; ) |
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for (i = SHADCACHE; i--; ) |
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for (j = SHADCACHE>>1; j--; ) { |
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d = 2./SHADCACHE*(i+.5) - 1.; |
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if (k) |
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VSUM(rdir, srcp->obscache->p.f.u, |
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srcp->obscache->p.f.v, d); |
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else |
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VSUM(rdir, srcp->obscache->p.f.v, |
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srcp->obscache->p.f.u, d); |
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d = 1. - 2./SHADCACHE*(j+.5); |
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VSUM(rdir, rdir, srcp->snorm, d); |
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normalize(rdir); |
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castshadow(sn, rorg, rdir); |
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d = 2.*DOT(rdir, srcp->snorm); |
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rdir[0] = d*srcp->snorm[0] - rdir[0]; |
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rdir[1] = d*srcp->snorm[1] - rdir[1]; |
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rdir[2] = d*srcp->snorm[2] - rdir[2]; |
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castshadow(sn, rorg, rdir); |
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} |
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} else /* spherical distribution */ |
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for (k = 6; k--; ) { |
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ax = k%3; |
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ax1 = (k+1)%3; |
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ax2 = (k+2)%3; |
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for (i = SHADCACHE; i--; ) |
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for (j = SHADCACHE; j--; ) { |
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rdir[0]=rdir[1]=rdir[2] = 0.; |
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rdir[ax] = k<3 ? 1. : -1.; |
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rdir[ax1] = 2./SHADCACHE*(i+.5) - 1.; |
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rdir[ax2] = 2./SHADCACHE*(j+.5) - 1.; |
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normalize(rdir); |
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d = 1.05*srcp->srad; |
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VSUM(rorg, srcp->sloc, rdir, d); |
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castshadow(sn, rorg, rdir); |
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} |
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} |
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} |
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|
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|
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static OBJECT * /* return occluder cache entry */ |
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srcobstructp(register RAY *r) |
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{ |
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static unsigned long lastrno = ~0; |
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static OBJECT noobs; |
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static OBJECT *lastobjp; |
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SRCREC *srcp; |
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int ondx; |
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|
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noobs = OVOID; |
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if (r->rno == lastrno) |
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return lastobjp; /* just recall last pointer */ |
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DCHECK(r->rsrc < 0, CONSISTENCY, |
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"srcobstructp() called with unaimed ray"); |
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lastrno = r->rno; |
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lastobjp = &noobs; |
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srcp = &source[r->rsrc]; |
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if (srcp->sflags & (SSKIP|SPROX|SSPOT|SVIRTUAL)) |
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return(&noobs); /* don't cache these */ |
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if (srcp->obscache == NULL) /* initialize cache */ |
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initobscache(r->rsrc); |
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/* compute cache index */ |
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if (srcp->sflags & SDISTANT) { |
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int ax, ax1, ax2; |
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double t; |
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ax = srcp->obscache->p.d.ax; |
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if ((ax1 = ax+1) >= 3) ax1 -= 3; |
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if ((ax2 = ax+2) >= 3) ax2 -= 3; |
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t = (srcp->obscache->p.d.o[ax] - r->rorg[ax]) / srcp->sloc[ax]; |
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if (t <= FTINY) |
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return(&noobs); /* could happen if ray is outside */ |
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ondx = 2*SHADCACHE*(int)(2*SHADCACHE*srcp->obscache->p.d.e1 * |
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(r->rorg[ax1] + t*srcp->sloc[ax1] - |
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srcp->obscache->p.d.o[ax1])); |
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ondx += (int)(2*SHADCACHE*srcp->obscache->p.d.e2 * |
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(r->rorg[ax2] + t*srcp->sloc[ax2] - |
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srcp->obscache->p.d.o[ax2])); |
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if ((ondx < 0) | (ondx >= 4*SHADCACHE*SHADCACHE)) |
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return(&noobs); /* could happen if ray is outside */ |
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} else if (srcp->sflags & SFLAT) { |
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FVECT sd; |
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RREAL sd0m, sd1m; |
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sd[0] = -DOT(r->rdir, srcp->obscache->p.f.u); |
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sd[1] = -DOT(r->rdir, srcp->obscache->p.f.v); |
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sd[2] = -DOT(r->rdir, srcp->snorm); |
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if (sd[2] < 0) |
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return(&noobs); /* shouldn't happen */ |
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sd0m = ABS(sd[0]); |
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sd1m = ABS(sd[1]); |
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if (sd[2] >= sd0m && sd[2] >= sd1m) { |
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ondx = SHADCACHE*(int)(SHADCACHE*(.5-FTINY) * |
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(1. + sd[0]/sd[2])); |
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ondx += (int)(SHADCACHE*(.5-FTINY) * |
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(1. + sd[1]/sd[2])); |
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} else if (sd0m >= sd1m) { |
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ondx = SHADCACHE*SHADCACHE; |
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if (sd[0] < 0) |
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ondx += ((SHADCACHE+1)>>1)*SHADCACHE; |
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ondx += SHADCACHE*(int)(SHADCACHE*(.5-FTINY) * |
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(1. - sd[2]/sd0m)); |
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ondx += (int)(SHADCACHE*(.5-FTINY) * |
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(1. + sd[1]/sd0m)); |
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} else /* sd1m > sd0m */ { |
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ondx = SHADCACHE*SHADCACHE + |
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((SHADCACHE+1)>>1)*SHADCACHE*2; |
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if (sd[1] < 0) |
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ondx += ((SHADCACHE+1)>>1)*SHADCACHE; |
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ondx += SHADCACHE*(int)(SHADCACHE*(.5-FTINY) * |
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(1. - sd[2]/sd1m)); |
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ondx += (int)(SHADCACHE*(.5-FTINY) * |
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(1. + sd[0]/sd1m)); |
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} |
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DCHECK((ondx < 0) | (ondx >= SHADCACHE*SHADCACHE*3 + |
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(SHADCACHE&1)*SHADCACHE*4), CONSISTENCY, |
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"flat source cache index out of bounds"); |
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} else /* spherical distribution */ { |
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int ax, ax1, ax2; |
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RREAL amax = 0; |
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for (ax1 = 3; ax1--; ) |
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if (ABS(r->rdir[ax1]) > amax) { |
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amax = ABS(r->rdir[ax1]); |
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ax = ax1; |
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} |
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if ((ax1 = ax+1) >= 3) ax1 -= 3; |
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if ((ax2 = ax+2) >= 3) ax2 -= 3; |
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ondx = 2*SHADCACHE*SHADCACHE * ax; |
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if (r->rdir[ax] < 0) |
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ondx += SHADCACHE*SHADCACHE; |
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ondx += SHADCACHE*(int)(SHADCACHE*(.5-FTINY) * |
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(1. + r->rdir[ax1]/amax)); |
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ondx += (int)(SHADCACHE*(.5-FTINY) * |
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(1. + r->rdir[ax2]/amax)); |
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DCHECK((ondx < 0) | (ondx >= SHADCACHE*SHADCACHE*6), CONSISTENCY, |
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"radial source cache index out of bounds"); |
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} |
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/* return cache pointer */ |
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return(lastobjp = &srcp->obscache->obs[ondx]); |
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} |
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|
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|
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void /* free obstruction cache */ |
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freeobscache(SRCREC *srcp) |
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{ |
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if (srcp->obscache == NULL) |
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return; |
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free((void *)srcp->obscache); |
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srcp->obscache = NULL; |
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} |
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|
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|
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void /* record a source blocker */ |
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srcblocker(register RAY *r) |
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{ |
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OBJREC *m; |
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|
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if (r->robj == OVOID || objptr(r->robj) != r->ro || |
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isvolume(r->ro->otype)) |
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return; /* don't record complex blockers */ |
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m = findmaterial(r->ro); |
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if (m == NULL) |
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return; /* no material?! */ |
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if (!isopaque(m->otype)) |
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return; /* material not a reliable blocker */ |
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*srcobstructp(r) = r->robj; /* else record obstructor */ |
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} |
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|
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|
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int /* check ray against cached blocker */ |
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srcblocked(RAY *r) |
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{ |
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OBJECT obs = *srcobstructp(r); |
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OBJREC *op; |
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|
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if (obs == OVOID) |
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return(0); |
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op = objptr(obs); /* check for intersection */ |
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return((*ofun[op->otype].funp)(op, r)); |
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} |
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|
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|
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#endif /* SHADCACHE */ |
