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1.1 |
#ifndef lint |
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greg |
2.11 |
static const char RCSid[] = "$Id: m_mirror.c,v 2.10 2004/03/30 16:13:01 schorsch Exp $"; |
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greg |
1.1 |
#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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greg |
2.9 |
#include "copyright.h" |
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2.8 |
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greg |
1.1 |
#include "ray.h" |
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#include "otypes.h" |
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schorsch |
2.10 |
#include "rtotypes.h" |
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1.1 |
#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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schorsch |
2.10 |
static int mir_proj(MAT4 pm, OBJREC *o, SRCREC *s, int n); |
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static void mirrorproj(MAT4 m, FVECT nv, double offs); |
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2.8 |
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1.1 |
VSMATERIAL mirror_vs = {mir_proj, 1}; |
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schorsch |
2.10 |
extern int |
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m_mirror( /* 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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1.1 |
{ |
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COLOR mcolor; |
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RAY nr; |
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2.6 |
int rpure = 1; |
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1.1 |
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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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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2.4 |
if (!strcmp(m->oargs.sarg[0], VOIDID)) { |
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raytrans(r); |
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return(1); |
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} |
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gwlarson |
2.7 |
return(rayshade(r, lastmod(objndx(m), m->oargs.sarg[0]))); |
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greg |
1.1 |
} |
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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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2.3 |
return(1); |
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1.3 |
|
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1.1 |
if (r->rod < 0.) /* back is black */ |
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2.3 |
return(1); |
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greg |
1.1 |
/* 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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2.11 |
rayorigin(&nr, REFLECTED, r, mcolor); |
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1.1 |
/* 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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1.2 |
nr.rsrc = source[r->rsrc].sa.sv.sn; |
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1.1 |
} else { /* ordinary reflection */ |
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FVECT pnorm; |
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double pdot; |
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2.11 |
if (rayorigin(&nr, REFLECTED, r, mcolor) < 0) |
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2.3 |
return(1); |
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2.6 |
if (DOT(r->pert,r->pert) > FTINY*FTINY) { |
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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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rpure = 0; |
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} |
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2.2 |
/* check for penetration */ |
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2.6 |
if (rpure || DOT(nr.rdir, r->ron) <= FTINY) |
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2.2 |
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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1.1 |
} |
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rayvalue(&nr); |
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2.11 |
multcolor(nr.rcol, nr.rcoef); |
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1.1 |
addcolor(r->rcol, nr.rcol); |
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greg |
2.6 |
if (rpure && r->ro != NULL && isflat(r->ro->otype)) |
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r->rt = r->rot + nr.rt; |
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2.3 |
return(1); |
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greg |
1.1 |
} |
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greg |
2.8 |
static int |
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schorsch |
2.10 |
mir_proj( /* compute a mirror's projection */ |
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MAT4 pm, |
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register OBJREC *o, |
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SRCREC *s, |
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int n |
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) |
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greg |
1.1 |
{ |
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2.5 |
FVECT nv, sc; |
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greg |
1.1 |
double od; |
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2.5 |
register int i, j; |
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1.1 |
/* get surface normal and offset */ |
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1.2 |
od = getplaneq(nv, o); |
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2.5 |
/* check for extreme point for behind */ |
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VCOPY(sc, s->sloc); |
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for (i = s->sflags & SFLAT ? SV : SW; i >= 0; i--) |
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if (DOT(nv, s->ss[i]) > 0.) |
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for (j = 0; j < 3; j++) |
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sc[j] += s->ss[i][j]; |
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else |
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for (j = 0; j < 3; j++) |
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sc[j] -= s->ss[i][j]; |
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if (DOT(sc, nv) <= (s->sflags & SDISTANT ? FTINY : od+FTINY)) |
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greg |
1.1 |
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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schorsch |
2.10 |
static void |
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mirrorproj( /* 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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greg |
1.1 |
{ |
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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 |
} |