1 |
#ifndef lint |
2 |
static const char RCSid[] = "$Id: m_mirror.c,v 2.9 2003/02/25 02:47:22 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 |
extern int |
33 |
m_mirror( /* shade mirrored ray */ |
34 |
register OBJREC *m, |
35 |
register RAY *r |
36 |
) |
37 |
{ |
38 |
COLOR mcolor; |
39 |
RAY nr; |
40 |
int rpure = 1; |
41 |
register 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 |
if (m->oargs.nsargs > 0 && |
47 |
(r->rsrc < 0 || source[r->rsrc].so != r->ro)) { |
48 |
if (!strcmp(m->oargs.sarg[0], VOIDID)) { |
49 |
raytrans(r); |
50 |
return(1); |
51 |
} |
52 |
return(rayshade(r, lastmod(objndx(m), m->oargs.sarg[0]))); |
53 |
} |
54 |
/* check for bad source ray */ |
55 |
if (r->rsrc >= 0 && source[r->rsrc].so != r->ro) |
56 |
return(1); |
57 |
|
58 |
if (r->rod < 0.) /* back is black */ |
59 |
return(1); |
60 |
/* get modifiers */ |
61 |
raytexture(r, m->omod); |
62 |
/* assign material color */ |
63 |
setcolor(mcolor, m->oargs.farg[0], |
64 |
m->oargs.farg[1], |
65 |
m->oargs.farg[2]); |
66 |
multcolor(mcolor, r->pcol); |
67 |
/* compute reflected ray */ |
68 |
if (r->rsrc >= 0) { /* relayed light source */ |
69 |
rayorigin(&nr, r, REFLECTED, 1.); |
70 |
/* ignore textures */ |
71 |
for (i = 0; i < 3; i++) |
72 |
nr.rdir[i] = r->rdir[i] + 2.*r->rod*r->ron[i]; |
73 |
/* source we're aiming for next */ |
74 |
nr.rsrc = source[r->rsrc].sa.sv.sn; |
75 |
} else { /* ordinary reflection */ |
76 |
FVECT pnorm; |
77 |
double pdot; |
78 |
|
79 |
if (rayorigin(&nr, r, REFLECTED, bright(mcolor)) < 0) |
80 |
return(1); |
81 |
if (DOT(r->pert,r->pert) > FTINY*FTINY) { |
82 |
pdot = raynormal(pnorm, r); /* use textures */ |
83 |
for (i = 0; i < 3; i++) |
84 |
nr.rdir[i] = r->rdir[i] + 2.*pdot*pnorm[i]; |
85 |
rpure = 0; |
86 |
} |
87 |
/* check for penetration */ |
88 |
if (rpure || DOT(nr.rdir, r->ron) <= FTINY) |
89 |
for (i = 0; i < 3; i++) |
90 |
nr.rdir[i] = r->rdir[i] + 2.*r->rod*r->ron[i]; |
91 |
} |
92 |
rayvalue(&nr); |
93 |
multcolor(nr.rcol, mcolor); |
94 |
addcolor(r->rcol, nr.rcol); |
95 |
if (rpure && r->ro != NULL && isflat(r->ro->otype)) |
96 |
r->rt = r->rot + nr.rt; |
97 |
return(1); |
98 |
} |
99 |
|
100 |
|
101 |
static int |
102 |
mir_proj( /* compute a mirror's projection */ |
103 |
MAT4 pm, |
104 |
register OBJREC *o, |
105 |
SRCREC *s, |
106 |
int n |
107 |
) |
108 |
{ |
109 |
FVECT nv, sc; |
110 |
double od; |
111 |
register int i, j; |
112 |
/* get surface normal and offset */ |
113 |
od = getplaneq(nv, o); |
114 |
/* check for extreme point for behind */ |
115 |
VCOPY(sc, s->sloc); |
116 |
for (i = s->sflags & SFLAT ? SV : SW; i >= 0; i--) |
117 |
if (DOT(nv, s->ss[i]) > 0.) |
118 |
for (j = 0; j < 3; j++) |
119 |
sc[j] += s->ss[i][j]; |
120 |
else |
121 |
for (j = 0; j < 3; j++) |
122 |
sc[j] -= s->ss[i][j]; |
123 |
if (DOT(sc, nv) <= (s->sflags & SDISTANT ? FTINY : od+FTINY)) |
124 |
return(0); |
125 |
/* everything OK -- compute projection */ |
126 |
mirrorproj(pm, nv, od); |
127 |
return(1); |
128 |
} |
129 |
|
130 |
|
131 |
static void |
132 |
mirrorproj( /* get mirror projection for surface */ |
133 |
register MAT4 m, |
134 |
FVECT nv, |
135 |
double offs |
136 |
) |
137 |
{ |
138 |
register int i, j; |
139 |
/* assign matrix */ |
140 |
setident4(m); |
141 |
for (j = 0; j < 3; j++) { |
142 |
for (i = 0; i < 3; i++) |
143 |
m[i][j] -= 2.*nv[i]*nv[j]; |
144 |
m[3][j] = 2.*offs*nv[j]; |
145 |
} |
146 |
} |