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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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* Routines for light-redirecting materials and |
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* their associated virtual light sources |
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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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/* |
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* The arguments for MAT_DIRECT1 are: |
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* |
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* 5+ coef1 dx1 dy1 dz1 funcfile transform.. |
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* 0 |
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* n A1 A2 .. An |
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* |
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* The arguments for MAT_DIRECT2 are: |
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* |
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* 9+ coef1 dx1 dy1 dz1 coef2 dx2 dy2 dz2 funcfile transform.. |
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* 0 |
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* n A1 A2 .. An |
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*/ |
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|
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|
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extern double varvalue(); |
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|
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int dir_proj(); |
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VSMATERIAL direct1_vs = {dir_proj, 1}; |
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VSMATERIAL direct2_vs = {dir_proj, 2}; |
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|
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|
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m_direct(m, r) /* shade redirected ray */ |
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register OBJREC *m; |
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register RAY *r; |
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{ |
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/* check if source ray */ |
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if (r->rsrc >= 0 && source[r->rsrc].so != r->ro) |
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return; /* got the wrong guy */ |
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dir_check(m); |
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/* compute first projection */ |
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if (m->otype == MAT_DIRECT1 || |
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(r->rsrc < 0 || source[r->rsrc].sa.sv.pn == 0)) |
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redirect(m, r, 0); |
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/* compute second projection */ |
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if (m->otype == MAT_DIRECT2 && |
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(r->rsrc < 0 || source[r->rsrc].sa.sv.pn == 1)) |
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redirect(m, r, 1); |
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} |
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|
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|
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redirect(m, r, n) /* compute n'th ray redirection */ |
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OBJREC *m; |
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RAY *r; |
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int n; |
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{ |
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register char **sa; |
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RAY nr; |
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double coef; |
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register int j; |
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/* set up function */ |
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setfunc(m, r); |
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sa = m->oargs.sarg + 4*n; |
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/* compute coefficient */ |
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errno = 0; |
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coef = varvalue(sa[0]); |
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if (errno) |
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goto computerr; |
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if (coef <= FTINY || rayorigin(&nr, r, TRANS, coef) < 0) |
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return(0); |
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/* compute direction */ |
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errno = 0; |
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for (j = 0; j < 3; j++) |
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nr.rdir[j] = varvalue(sa[j+1]); |
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if (errno || normalize(nr.rdir) == 0.0) |
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goto computerr; |
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/* compute value */ |
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if (r->rsrc >= 0) |
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nr.rsrc = source[r->rsrc].sa.sv.sn; |
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rayvalue(&nr); |
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scalecolor(nr.rcol, coef); |
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addcolor(r->rcol, nr.rcol); |
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return(1); |
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computerr: |
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objerror(m, WARNING, "compute error"); |
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return(-1); |
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} |
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|
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|
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dir_proj(pm, o, s, n) /* compute a director's projection */ |
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MAT4 pm; |
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OBJREC *o; |
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SRCREC *s; |
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int n; |
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{ |
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RAY tr; |
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register OBJREC *m; |
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char **sa; |
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FVECT cent, newdir, nv, h; |
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double olddot, newdot, od; |
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register int i, j; |
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/* get material arguments */ |
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m = objptr(o->omod); |
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dir_check(m); |
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sa = m->oargs.sarg + 4*n; |
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/* initialize test ray */ |
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getmaxdisk(cent, o); |
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if (s->sflags & SDISTANT) |
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for (i = 0; i < 3; i++) { |
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tr.rdir[i] = -s->sloc[i]; |
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tr.rorg[i] = cent[i] - tr.rdir[i]; |
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} |
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else { |
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for (i = 0; i < 3; i++) { |
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tr.rdir[i] = cent[i] - s->sloc[i]; |
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tr.rorg[i] = s->sloc[i]; |
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} |
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if (normalize(tr.rdir) == 0.0) |
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return(0); /* at source! */ |
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} |
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od = getplaneq(nv, o); |
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olddot = DOT(tr.rdir, nv); |
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if (olddot <= FTINY && olddot >= -FTINY) |
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return(0); /* old dir parallels plane */ |
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rayorigin(&tr, NULL, PRIMARY, 1.0); |
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if (!(*ofun[o->otype].funp)(o, &tr)) |
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return(0); /* no intersection! */ |
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/* compute redirection */ |
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setfunc(m, &tr); |
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errno = 0; |
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if (varvalue(sa[0]) <= FTINY) |
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return(0); /* insignificant */ |
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if (errno) |
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goto computerr; |
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for (i = 0; i < 3; i++) |
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newdir[i] = varvalue(sa[i+1]); |
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if (errno) |
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goto computerr; |
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newdot = DOT(newdir, nv); |
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if (newdot <= FTINY && newdot >= -FTINY) |
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return(0); /* new dir parallels plane */ |
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/* everything OK -- compute shear */ |
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for (i = 0; i < 3; i++) |
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h[i] = tr.rdir[i]/olddot + newdir[i]/newdot; |
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setident4(pm); |
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for (j = 0; j < 3; j++) { |
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for (i = 0; i < 3; i++) |
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pm[i][j] += nv[i]*h[j]; |
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pm[3][j] = -od*h[j]; |
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} |
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if (newdot > 0.0 ^ olddot > 0.0) /* add mirroring */ |
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for (j = 0; j < 3; j++) { |
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for (i = 0; i < 3; i++) |
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pm[i][j] -= 2.*nv[i]*nv[j]; |
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pm[3][j] += 2.*od*nv[j]; |
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} |
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return(1); |
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computerr: |
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objerror(m, WARNING, "projection compute error"); |
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return(0); |
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} |
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|
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|
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static |
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dir_check(m) /* check arguments and load function file */ |
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register OBJREC *m; |
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{ |
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register int ff; |
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|
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ff = m->otype == MAT_DIRECT1 ? 4 : 8; |
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if (ff >= m->oargs.nsargs) |
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objerror(m, USER, "too few arguments"); |
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if (!vardefined(m->oargs.sarg[0])) |
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loadfunc(m->oargs.sarg[ff]); |
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} |
