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greg |
1.1 |
/* Copyright (c) 1991 Regents of the University of California */
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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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* Routines for mirror material supporting virtual light sources
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*/
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#include "ray.h"
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#include "otypes.h"
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#include "source.h"
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/*
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* The real arguments for MAT_MIRROR are simply:
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*
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* 3 rrefl grefl brefl
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*
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* Additionally, the user may specify a single string argument
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* which is interpreted as the name of the material to use
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* instead of the mirror if the ray being considered is not
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* part of the direct calculation.
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*/
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int mir_proj();
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VSMATERIAL mirror_vs = {mir_proj, 1};
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m_mirror(m, r) /* shade mirrored ray */
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register OBJREC *m;
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register RAY *r;
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{
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COLOR mcolor;
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RAY nr;
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register int i;
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/* check arguments */
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if (m->oargs.nfargs != 3 || m->oargs.nsargs > 1)
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objerror(m, USER, "bad number of arguments");
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greg |
1.3 |
/* check for substitute material */
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if (m->oargs.nsargs > 0 &&
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(r->rsrc < 0 || source[r->rsrc].so != r->ro)) {
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greg |
1.1 |
rayshade(r, modifier(m->oargs.sarg[0]));
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return;
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}
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greg |
1.3 |
/* check for bad source ray */
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if (r->rsrc >= 0 && source[r->rsrc].so != r->ro)
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return;
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greg |
1.1 |
if (r->rod < 0.) /* back is black */
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return;
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/* get modifiers */
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raytexture(r, m->omod);
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/* assign material color */
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setcolor(mcolor, m->oargs.farg[0],
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m->oargs.farg[1],
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m->oargs.farg[2]);
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multcolor(mcolor, r->pcol);
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/* compute reflected ray */
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if (r->rsrc >= 0) { /* relayed light source */
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rayorigin(&nr, r, REFLECTED, 1.);
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/* ignore textures */
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for (i = 0; i < 3; i++)
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nr.rdir[i] = r->rdir[i] + 2.*r->rod*r->ron[i];
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/* source we're aiming for next */
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greg |
1.2 |
nr.rsrc = source[r->rsrc].sa.sv.sn;
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greg |
1.1 |
} else { /* ordinary reflection */
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FVECT pnorm;
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double pdot;
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if (rayorigin(&nr, r, REFLECTED, bright(mcolor)) < 0)
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return;
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pdot = raynormal(pnorm, r); /* use textures */
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for (i = 0; i < 3; i++)
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nr.rdir[i] = r->rdir[i] + 2.*pdot*pnorm[i];
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}
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rayvalue(&nr);
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multcolor(nr.rcol, mcolor);
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addcolor(r->rcol, nr.rcol);
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}
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mir_proj(pm, o, s, n) /* compute a mirror's projection */
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MAT4 pm;
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register OBJREC *o;
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greg |
1.2 |
SRCREC *s;
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greg |
1.1 |
int n;
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{
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FVECT nv;
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double od;
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/* get surface normal and offset */
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greg |
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od = getplaneq(nv, o);
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greg |
1.1 |
/* check for behind */
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if (DOT(s->sloc, nv) <= (s->sflags & SDISTANT ? FTINY : od+FTINY))
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return(0);
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/* everything OK -- compute projection */
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mirrorproj(pm, nv, od);
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return(1);
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}
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mirrorproj(m, nv, offs) /* get mirror projection for surface */
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register MAT4 m;
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FVECT nv;
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double offs;
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{
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register int i, j;
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/* assign matrix */
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setident4(m);
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greg |
1.2 |
for (j = 0; j < 3; j++) {
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for (i = 0; i < 3; i++)
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greg |
1.1 |
m[i][j] -= 2.*nv[i]*nv[j];
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m[3][j] = 2.*offs*nv[j];
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greg |
1.2 |
}
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greg |
1.1 |
}
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