src/rt/m_mirror.c

/* Copyright (c) 1991 Regents of the University of California */

#ifndef lint
static char SCCSid[] = "$SunId$ LBL";
#endif

/*
 * Routines for mirror material supporting virtual light sources
 */

#include  "ray.h"

#include  "otypes.h"

#include  "source.h"

/*
 * The real arguments for MAT_MIRROR are simply:
 *
 *      3 rrefl grefl brefl
 *
 * Additionally, the user may specify a single string argument
 * which is interpreted as the name of the material to use
 * instead of the mirror if the ray being considered is not
 * part of the direct calculation.
 */


int  mir_proj();
VSMATERIAL  mirror_vs = {mir_proj, 1};


m_mirror(m, r)                  /* shade mirrored ray */
register OBJREC  *m;
register RAY  *r;
{
        COLOR  mcolor;
        RAY  nr;
        register int  i;
                                        /* check arguments */
        if (m->oargs.nfargs != 3 || m->oargs.nsargs > 1)
                objerror(m, USER, "bad number of arguments");
                                        /* check for substitute material */
        if (m->oargs.nsargs > 0 &&
                        (r->rsrc < 0 || source[r->rsrc].so != r->ro)) {
                rayshade(r, modifier(m->oargs.sarg[0]));
                return;
        }
                                        /* check for bad source ray */
        if (r->rsrc >= 0 && source[r->rsrc].so != r->ro)
                return;

        if (r->rod < 0.)                /* back is black */
                return;
                                        /* get modifiers */
        raytexture(r, m->omod);
                                        /* assign material color */
        setcolor(mcolor, m->oargs.farg[0],
                        m->oargs.farg[1],
                        m->oargs.farg[2]);
        multcolor(mcolor, r->pcol);
                                        /* compute reflected ray */
        if (r->rsrc >= 0) {                     /* relayed light source */
                rayorigin(&nr, r, REFLECTED, 1.);
                                        /* ignore textures */
                for (i = 0; i < 3; i++)
                        nr.rdir[i] = r->rdir[i] + 2.*r->rod*r->ron[i];
                                        /* source we're aiming for next */
                nr.rsrc = source[r->rsrc].sa.sv.sn;
        } else {                                /* ordinary reflection */
                FVECT  pnorm;
                double  pdot;

                if (rayorigin(&nr, r, REFLECTED, bright(mcolor)) < 0)
                        return;
                pdot = raynormal(pnorm, r);     /* use textures */
                for (i = 0; i < 3; i++)
                        nr.rdir[i] = r->rdir[i] + 2.*pdot*pnorm[i];
        }
        rayvalue(&nr);
        multcolor(nr.rcol, mcolor);
        addcolor(r->rcol, nr.rcol);
}


mir_proj(pm, o, s, n)           /* compute a mirror's projection */
MAT4  pm;
register OBJREC  *o;
SRCREC  *s;
int  n;
{
        FVECT  nv;
        double  od;
                                /* get surface normal and offset */
        od = getplaneq(nv, o);
                                /* check for behind */
        if (DOT(s->sloc, nv) <= (s->sflags & SDISTANT ? FTINY : od+FTINY))
                return(0);
                                /* everything OK -- compute projection */
        mirrorproj(pm, nv, od);
        return(1);
}


mirrorproj(m, nv, offs)         /* get mirror projection for surface */
register MAT4  m;
FVECT  nv;
double  offs;
{
        register int  i, j;
                                        /* assign matrix */
        setident4(m);
        for (j = 0; j < 3; j++) {
                for (i = 0; i < 3; i++)
                        m[i][j] -= 2.*nv[i]*nv[j];
                m[3][j] = 2.*offs*nv[j];
        }
}
Revision:	2.1
Committed:	Tue Nov 12 17:10:20 1991 UTC (32 years, 5 months ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 1.3:	+0 -0 lines
Log Message:	updated revision number for release 2.0
#	User	Rev	Content
1	greg	1.1	/* Copyright (c) 1991 Regents of the University of California */
2
3			#ifndef lint
4			static char SCCSid[] = "$SunId$ LBL";
5			#endif
6
7			/*
8			* Routines for mirror material supporting virtual light sources
9			*/
10
11			#include "ray.h"
12
13			#include "otypes.h"
14
15			#include "source.h"
16
17			/*
18			* The real arguments for MAT_MIRROR are simply:
19			*
20			* 3 rrefl grefl brefl
21			*
22			* Additionally, the user may specify a single string argument
23			* which is interpreted as the name of the material to use
24			* instead of the mirror if the ray being considered is not
25			* part of the direct calculation.
26			*/
27
28
29			int mir_proj();
30			VSMATERIAL mirror_vs = {mir_proj, 1};
31
32
33			m_mirror(m, r) /* shade mirrored ray */
34			register OBJREC *m;
35			register RAY *r;
36			{
37			COLOR mcolor;
38			RAY nr;
39			register int i;
40			/* check arguments */
41			if (m->oargs.nfargs != 3 \|\| m->oargs.nsargs > 1)
42			objerror(m, USER, "bad number of arguments");
43	greg	1.3	/* check for substitute material */
44			if (m->oargs.nsargs > 0 &&
45			(r->rsrc < 0 \|\| source[r->rsrc].so != r->ro)) {
46	greg	1.1	rayshade(r, modifier(m->oargs.sarg[0]));
47			return;
48			}
49	greg	1.3	/* check for bad source ray */
50			if (r->rsrc >= 0 && source[r->rsrc].so != r->ro)
51			return;
52
53	greg	1.1	if (r->rod < 0.) /* back is black */
54			return;
55			/* get modifiers */
56			raytexture(r, m->omod);
57			/* assign material color */
58			setcolor(mcolor, m->oargs.farg[0],
59			m->oargs.farg[1],
60			m->oargs.farg[2]);
61			multcolor(mcolor, r->pcol);
62			/* compute reflected ray */
63			if (r->rsrc >= 0) { /* relayed light source */
64			rayorigin(&nr, r, REFLECTED, 1.);
65			/* ignore textures */
66			for (i = 0; i < 3; i++)
67			nr.rdir[i] = r->rdir[i] + 2.r->rodr->ron[i];
68			/* source we're aiming for next */
69	greg	1.2	nr.rsrc = source[r->rsrc].sa.sv.sn;
70	greg	1.1	} else { /* ordinary reflection */
71			FVECT pnorm;
72			double pdot;
73
74			if (rayorigin(&nr, r, REFLECTED, bright(mcolor)) < 0)
75			return;
76			pdot = raynormal(pnorm, r); /* use textures */
77			for (i = 0; i < 3; i++)
78			nr.rdir[i] = r->rdir[i] + 2.pdotpnorm[i];
79			}
80			rayvalue(&nr);
81			multcolor(nr.rcol, mcolor);
82			addcolor(r->rcol, nr.rcol);
83			}
84
85
86			mir_proj(pm, o, s, n) /* compute a mirror's projection */
87			MAT4 pm;
88			register OBJREC *o;
89	greg	1.2	SRCREC *s;
90	greg	1.1	int n;
91			{
92			FVECT nv;
93			double od;
94			/* get surface normal and offset */
95	greg	1.2	od = getplaneq(nv, o);
96	greg	1.1	/* check for behind */
97			if (DOT(s->sloc, nv) <= (s->sflags & SDISTANT ? FTINY : od+FTINY))
98			return(0);
99			/* everything OK -- compute projection */
100			mirrorproj(pm, nv, od);
101			return(1);
102			}
103
104
105			mirrorproj(m, nv, offs) /* get mirror projection for surface */
106			register MAT4 m;
107			FVECT nv;
108			double offs;
109			{
110			register int i, j;
111			/* assign matrix */
112			setident4(m);
113	greg	1.2	for (j = 0; j < 3; j++) {
114			for (i = 0; i < 3; i++)
115	greg	1.1	m[i][j] -= 2.nv[i]nv[j];
116			m[3][j] = 2.offsnv[j];
117	greg	1.2	}
118	greg	1.1	}