| 1 |
#ifndef lint |
| 2 |
static const char RCSid[] = "$Id: m_mirror.c,v 2.20 2018/11/13 19:58:33 greg Exp $"; |
| 3 |
#endif |
| 4 |
/* |
| 5 |
* Routines for mirror material supporting virtual light sources |
| 6 |
*/ |
| 7 |
|
| 8 |
#include "copyright.h" |
| 9 |
|
| 10 |
#include "ray.h" |
| 11 |
#include "otypes.h" |
| 12 |
#include "rtotypes.h" |
| 13 |
#include "source.h" |
| 14 |
|
| 15 |
/* |
| 16 |
* The real arguments for MAT_MIRROR are simply: |
| 17 |
* |
| 18 |
* 3 rrefl grefl brefl |
| 19 |
* |
| 20 |
* Additionally, the user may specify a single string argument |
| 21 |
* which is interpreted as the name of the material to use |
| 22 |
* instead of the mirror if the ray being considered is not |
| 23 |
* part of the direct calculation. |
| 24 |
*/ |
| 25 |
|
| 26 |
static int mir_proj(MAT4 pm, OBJREC *o, SRCREC *s, int n); |
| 27 |
static void mirrorproj(MAT4 m, FVECT nv, double offs); |
| 28 |
|
| 29 |
VSMATERIAL mirror_vs = {mir_proj, 1}; |
| 30 |
|
| 31 |
|
| 32 |
int |
| 33 |
m_mirror( /* shade mirrored ray */ |
| 34 |
OBJREC *m, |
| 35 |
RAY *r |
| 36 |
) |
| 37 |
{ |
| 38 |
COLOR mcolor; |
| 39 |
RAY nr; |
| 40 |
int rpure = 1; |
| 41 |
int i; |
| 42 |
/* check arguments */ |
| 43 |
if (m->oargs.nfargs != 3 || m->oargs.nsargs > 1) |
| 44 |
objerror(m, USER, "bad number of arguments"); |
| 45 |
/* check for substitute material */ |
| 46 |
/* but avoid double-counting */ |
| 47 |
if ( m->oargs.nsargs > 0 && |
| 48 |
(r->rsrc < 0 || source[r->rsrc].so != r->ro) && |
| 49 |
!(r->crtype & (AMBIENT|SPECULAR) && r->rod > 0.) ) { |
| 50 |
if (!strcmp(m->oargs.sarg[0], VOIDID)) { |
| 51 |
raytrans(r); |
| 52 |
return(1); |
| 53 |
} |
| 54 |
return(rayshade(r, lastmod(objndx(m), m->oargs.sarg[0]))); |
| 55 |
} |
| 56 |
/* check for bad source ray */ |
| 57 |
if (r->rsrc >= 0 && source[r->rsrc].so != r->ro) |
| 58 |
return(1); |
| 59 |
|
| 60 |
if (r->rod < 0.) { /* back is black */ |
| 61 |
if (!backvis) |
| 62 |
raytrans(r); /* unless back visibility is off */ |
| 63 |
return(1); |
| 64 |
} |
| 65 |
/* get modifiers */ |
| 66 |
raytexture(r, m->omod); |
| 67 |
/* assign material color */ |
| 68 |
setcolor(mcolor, m->oargs.farg[0], |
| 69 |
m->oargs.farg[1], |
| 70 |
m->oargs.farg[2]); |
| 71 |
multcolor(mcolor, r->pcol); |
| 72 |
/* compute reflected ray */ |
| 73 |
if (r->rsrc >= 0) { /* relayed light source */ |
| 74 |
rayorigin(&nr, REFLECTED, r, mcolor); |
| 75 |
/* ignore textures */ |
| 76 |
for (i = 0; i < 3; i++) |
| 77 |
nr.rdir[i] = r->rdir[i] + 2.*r->rod*r->ron[i]; |
| 78 |
/* source we're aiming for next */ |
| 79 |
nr.rsrc = source[r->rsrc].sa.sv.sn; |
| 80 |
} else { /* ordinary reflection */ |
| 81 |
FVECT pnorm; |
| 82 |
double pdot; |
| 83 |
|
| 84 |
if (rayorigin(&nr, REFLECTED, r, mcolor) < 0) |
| 85 |
return(1); |
| 86 |
if (!(r->crtype & AMBIENT) && |
| 87 |
DOT(r->pert,r->pert) > FTINY*FTINY) { |
| 88 |
pdot = raynormal(pnorm, r); /* use textures */ |
| 89 |
for (i = 0; i < 3; i++) |
| 90 |
nr.rdir[i] = r->rdir[i] + 2.*pdot*pnorm[i]; |
| 91 |
rpure = 0; |
| 92 |
} |
| 93 |
/* check for penetration */ |
| 94 |
if (rpure || DOT(nr.rdir, r->ron) <= FTINY) |
| 95 |
for (i = 0; i < 3; i++) |
| 96 |
nr.rdir[i] = r->rdir[i] + 2.*r->rod*r->ron[i]; |
| 97 |
} |
| 98 |
checknorm(nr.rdir); |
| 99 |
rayvalue(&nr); |
| 100 |
multcolor(nr.rcol, nr.rcoef); |
| 101 |
copycolor(r->mcol, nr.rcol); |
| 102 |
addcolor(r->rcol, nr.rcol); |
| 103 |
r->rmt = r->rot; |
| 104 |
if (rpure && r->ro != NULL && isflat(r->ro->otype)) |
| 105 |
r->rmt += r->rot + raydistance(&nr); |
| 106 |
return(1); |
| 107 |
} |
| 108 |
|
| 109 |
|
| 110 |
static int |
| 111 |
mir_proj( /* compute a mirror's projection */ |
| 112 |
MAT4 pm, |
| 113 |
OBJREC *o, |
| 114 |
SRCREC *s, |
| 115 |
int n |
| 116 |
) |
| 117 |
{ |
| 118 |
double corr = 1.; |
| 119 |
FVECT nv, sc; |
| 120 |
double od, offs; |
| 121 |
int i; |
| 122 |
/* get surface normal and offset */ |
| 123 |
offs = od = getplaneq(nv, o); |
| 124 |
if (s->sflags & SDISTANT) |
| 125 |
offs = 0.; |
| 126 |
/* check for extreme point behind */ |
| 127 |
if (s->sflags & SCIR) { |
| 128 |
if (s->sflags & (SFLAT|SDISTANT)) |
| 129 |
corr = 1.12837917; /* correct setflatss() */ |
| 130 |
else |
| 131 |
corr = 1.0/0.7236; /* correct sphsetsrc() */ |
| 132 |
} |
| 133 |
VCOPY(sc, s->sloc); |
| 134 |
for (i = s->sflags & SFLAT ? SV : SW; i >= 0; i--) |
| 135 |
if (DOT(nv, s->ss[i]) > offs) |
| 136 |
VSUM(sc, sc, s->ss[i], corr); |
| 137 |
else |
| 138 |
VSUM(sc, sc, s->ss[i], -corr); |
| 139 |
if (DOT(sc, nv) <= offs+FTINY) |
| 140 |
return(0); |
| 141 |
/* everything OK -- compute projection */ |
| 142 |
mirrorproj(pm, nv, od); |
| 143 |
return(1); |
| 144 |
} |
| 145 |
|
| 146 |
|
| 147 |
static void |
| 148 |
mirrorproj( /* get mirror projection for surface */ |
| 149 |
MAT4 m, |
| 150 |
FVECT nv, |
| 151 |
double offs |
| 152 |
) |
| 153 |
{ |
| 154 |
int i, j; |
| 155 |
/* assign matrix */ |
| 156 |
setident4(m); |
| 157 |
for (j = 0; j < 3; j++) { |
| 158 |
for (i = 0; i < 3; i++) |
| 159 |
m[i][j] -= 2.*nv[i]*nv[j]; |
| 160 |
m[3][j] = 2.*offs*nv[j]; |
| 161 |
} |
| 162 |
} |
