src/rt/m_direct.c

/* Copyright (c) 1994 Regents of the University of California */

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

/*
 * Routines for light-redirecting materials and
 *   their associated virtual light sources
 */

#include  "ray.h"

#include  "otypes.h"

#include  "source.h"

#include  "func.h"

/*
 * The arguments for MAT_DIRECT1 are:
 *
 *      5+ coef1 dx1 dy1 dz1 funcfile transform..
 *      0
 *      n A1 A2 .. An
 *
 * The arguments for MAT_DIRECT2 are:
 *
 *      9+ coef1 dx1 dy1 dz1 coef2 dx2 dy2 dz2 funcfile transform..
 *      0
 *      n A1 A2 .. An
 */


int  dir_proj();
VSMATERIAL  direct1_vs = {dir_proj, 1};
VSMATERIAL  direct2_vs = {dir_proj, 2};

#define getdfunc(m)     ( (m)->otype == MAT_DIRECT1 ? \
                                getfunc(m, 4, 0xf, 1) : \
                                getfunc(m, 8, 0xff, 1) )


m_direct(m, r)                  /* shade redirected ray */
register OBJREC  *m;
register RAY  *r;
{
                                        /* check if source ray */
        if (r->rsrc >= 0 && source[r->rsrc].so != r->ro)
                return(1);                      /* got the wrong guy */
                                        /* compute first projection */
        if (m->otype == MAT_DIRECT1 ||
                        (r->rsrc < 0 || source[r->rsrc].sa.sv.pn == 0))
                redirect(m, r, 0);
                                        /* compute second projection */
        if (m->otype == MAT_DIRECT2 &&
                        (r->rsrc < 0 || source[r->rsrc].sa.sv.pn == 1))
                redirect(m, r, 1);
        return(1);
}


redirect(m, r, n)               /* compute n'th ray redirection */
OBJREC  *m;
RAY  *r;
int  n;
{
        MFUNC  *mf;
        register EPNODE  **va;
        FVECT  nsdir;
        RAY  nr;
        double  coef;
        register int  j;
                                        /* set up function */
        mf = getdfunc(m);
        setfunc(m, r);
                                        /* assign direction variable */
        if (r->rsrc >= 0) {
                register SRCREC  *sp = source + source[r->rsrc].sa.sv.sn;

                if (sp->sflags & SDISTANT)
                        VCOPY(nsdir, sp->sloc);
                else {
                        for (j = 0; j < 3; j++)
                                nsdir[j] = sp->sloc[j] - r->rop[j];
                        normalize(nsdir);
                }
                multv3(nsdir, nsdir, funcxf.xfm);
                varset("DxA", '=', nsdir[0]/funcxf.sca);
                varset("DyA", '=', nsdir[1]/funcxf.sca);
                varset("DzA", '=', nsdir[2]/funcxf.sca);
        } else {
                varset("DxA", '=', 0.0);
                varset("DyA", '=', 0.0);
                varset("DzA", '=', 0.0);
        }
                                        /* compute coefficient */
        errno = 0;
        va = mf->ep + 4*n;
        coef = evalue(va[0]);
        if (errno)
                goto computerr;
        if (coef <= FTINY || rayorigin(&nr, r, TRANS, coef) < 0)
                return(0);
        va++;                           /* compute direction */
        for (j = 0; j < 3; j++) {
                nr.rdir[j] = evalue(va[j]);
                if (errno)
                        goto computerr;
        }
        if (mf->f != &unitxf)
                multv3(nr.rdir, nr.rdir, mf->f->xfm);
        if (r->rox != NULL)
                multv3(nr.rdir, nr.rdir, r->rox->f.xfm);
        if (normalize(nr.rdir) == 0.0)
                goto computerr;
                                        /* compute value */
        if (r->rsrc >= 0)
                nr.rsrc = source[r->rsrc].sa.sv.sn;
        rayvalue(&nr);
        scalecolor(nr.rcol, coef);
        addcolor(r->rcol, nr.rcol);
        return(1);
computerr:
        objerror(m, WARNING, "compute error");
        return(-1);
}


dir_proj(pm, o, s, n)           /* compute a director's projection */
MAT4  pm;
OBJREC  *o;
SRCREC  *s;
int  n;
{
        RAY  tr;
        OBJREC  *m;
        MFUNC  *mf;
        EPNODE  **va;
        FVECT  cent, newdir, nv, h;
        double  coef, olddot, newdot, od;
        register int  i, j;
                                /* initialize test ray */
        getmaxdisk(cent, o);
        if (s->sflags & SDISTANT)
                for (i = 0; i < 3; i++) {
                        tr.rdir[i] = -s->sloc[i];
                        tr.rorg[i] = cent[i] - tr.rdir[i];
                }
        else {
                for (i = 0; i < 3; i++) {
                        tr.rdir[i] = cent[i] - s->sloc[i];
                        tr.rorg[i] = s->sloc[i];
                }
                if (normalize(tr.rdir) == 0.0)
                        return(0);              /* at source! */
        }
        od = getplaneq(nv, o);
        olddot = DOT(tr.rdir, nv);
        if (olddot <= FTINY && olddot >= -FTINY)
                return(0);              /* old dir parallels plane */
        tr.rmax = 0.0;
        rayorigin(&tr, NULL, PRIMARY, 1.0);
        if (!(*ofun[o->otype].funp)(o, &tr))
                return(0);              /* no intersection! */
                                /* compute redirection */
        m = vsmaterial(o);
        mf = getdfunc(m);
        setfunc(m, &tr);
        varset("DxA", '=', 0.0);
        varset("DyA", '=', 0.0);
        varset("DzA", '=', 0.0);
        errno = 0;
        va = mf->ep + 4*n;
        coef = evalue(va[0]);
        if (errno)
                goto computerr;
        if (coef <= FTINY)
                return(0);              /* insignificant */
        va++;
        for (i = 0; i < 3; i++) {
                newdir[i] = evalue(va[i]);
                if (errno)
                        goto computerr;
        }
        if (mf->f != &unitxf)
                multv3(newdir, newdir, mf->f->xfm);
                                        /* normalization unnecessary */
        newdot = DOT(newdir, nv);
        if (newdot <= FTINY && newdot >= -FTINY)
                return(0);              /* new dir parallels plane */
                                /* everything OK -- compute shear */
        for (i = 0; i < 3; i++)
                h[i] = newdir[i]/newdot - tr.rdir[i]/olddot;
        setident4(pm);
        for (j = 0; j < 3; j++) {
                for (i = 0; i < 3; i++)
                        pm[i][j] += nv[i]*h[j];
                pm[3][j] = -od*h[j];
        }
        if (newdot > 0.0 ^ olddot > 0.0)        /* add mirroring */
                for (j = 0; j < 3; j++) {
                        for (i = 0; i < 3; i++)
                                pm[i][j] -= 2.*nv[i]*nv[j];
                        pm[3][j] += 2.*od*nv[j];
                }
        return(1);
computerr:
        objerror(m, WARNING, "projection compute error");
        return(0);
}
Revision:	2.6
Committed:	Thu Sep 7 12:35:21 1995 UTC (28 years, 7 months ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 2.5:	+9 -9 lines
Log Message:	made assignment of DxA, DyA, DzA a little more robust
#	User	Rev	Content
1	greg	2.5	/* Copyright (c) 1994 Regents of the University of California */
2	greg	1.1
3			#ifndef lint
4			static char SCCSid[] = "$SunId$ LBL";
5			#endif
6
7			/*
8			* Routines for light-redirecting materials and
9			* their associated virtual light sources
10			*/
11
12			#include "ray.h"
13
14			#include "otypes.h"
15
16			#include "source.h"
17
18	greg	2.2	#include "func.h"
19
20	greg	1.1	/*
21			* The arguments for MAT_DIRECT1 are:
22			*
23	greg	1.3	* 5+ coef1 dx1 dy1 dz1 funcfile transform..
24	greg	1.1	* 0
25			* n A1 A2 .. An
26			*
27			* The arguments for MAT_DIRECT2 are:
28			*
29	greg	1.3	* 9+ coef1 dx1 dy1 dz1 coef2 dx2 dy2 dz2 funcfile transform..
30	greg	1.1	* 0
31			* n A1 A2 .. An
32			*/
33
34
35			int dir_proj();
36			VSMATERIAL direct1_vs = {dir_proj, 1};
37			VSMATERIAL direct2_vs = {dir_proj, 2};
38
39	greg	2.2	#define getdfunc(m) ( (m)->otype == MAT_DIRECT1 ? \
40			getfunc(m, 4, 0xf, 1) : \
41			getfunc(m, 8, 0xff, 1) )
42	greg	1.1
43	greg	1.6
44	greg	1.1	m_direct(m, r) /* shade redirected ray */
45			register OBJREC *m;
46			register RAY *r;
47			{
48			/* check if source ray */
49			if (r->rsrc >= 0 && source[r->rsrc].so != r->ro)
50	greg	2.4	return(1); /* got the wrong guy */
51	greg	1.1	/* compute first projection */
52			if (m->otype == MAT_DIRECT1 \|\|
53			(r->rsrc < 0 \|\| source[r->rsrc].sa.sv.pn == 0))
54			redirect(m, r, 0);
55			/* compute second projection */
56			if (m->otype == MAT_DIRECT2 &&
57			(r->rsrc < 0 \|\| source[r->rsrc].sa.sv.pn == 1))
58			redirect(m, r, 1);
59	greg	2.4	return(1);
60	greg	1.1	}
61
62
63			redirect(m, r, n) /* compute n'th ray redirection */
64			OBJREC *m;
65			RAY *r;
66			int n;
67			{
68	greg	2.2	MFUNC *mf;
69			register EPNODE **va;
70	greg	2.3	FVECT nsdir;
71	greg	1.1	RAY nr;
72			double coef;
73			register int j;
74			/* set up function */
75	greg	2.2	mf = getdfunc(m);
76			setfunc(m, r);
77	greg	2.3	/* assign direction variable */
78			if (r->rsrc >= 0) {
79			register SRCREC *sp = source + source[r->rsrc].sa.sv.sn;
80
81			if (sp->sflags & SDISTANT)
82			VCOPY(nsdir, sp->sloc);
83			else {
84			for (j = 0; j < 3; j++)
85			nsdir[j] = sp->sloc[j] - r->rop[j];
86			normalize(nsdir);
87			}
88	greg	2.6	multv3(nsdir, nsdir, funcxf.xfm);
89			varset("DxA", '=', nsdir[0]/funcxf.sca);
90			varset("DyA", '=', nsdir[1]/funcxf.sca);
91			varset("DzA", '=', nsdir[2]/funcxf.sca);
92			} else {
93			varset("DxA", '=', 0.0);
94			varset("DyA", '=', 0.0);
95			varset("DzA", '=', 0.0);
96			}
97	greg	1.1	/* compute coefficient */
98			errno = 0;
99	greg	2.2	va = mf->ep + 4*n;
100			coef = evalue(va[0]);
101	greg	1.1	if (errno)
102			goto computerr;
103			if (coef <= FTINY \|\| rayorigin(&nr, r, TRANS, coef) < 0)
104			return(0);
105	greg	2.2	va++; /* compute direction */
106			for (j = 0; j < 3; j++) {
107			nr.rdir[j] = evalue(va[j]);
108			if (errno)
109			goto computerr;
110			}
111			if (mf->f != &unitxf)
112			multv3(nr.rdir, nr.rdir, mf->f->xfm);
113	greg	1.4	if (r->rox != NULL)
114			multv3(nr.rdir, nr.rdir, r->rox->f.xfm);
115			if (normalize(nr.rdir) == 0.0)
116			goto computerr;
117	greg	1.1	/* compute value */
118			if (r->rsrc >= 0)
119			nr.rsrc = source[r->rsrc].sa.sv.sn;
120			rayvalue(&nr);
121			scalecolor(nr.rcol, coef);
122			addcolor(r->rcol, nr.rcol);
123			return(1);
124			computerr:
125			objerror(m, WARNING, "compute error");
126			return(-1);
127			}
128
129
130			dir_proj(pm, o, s, n) /* compute a director's projection */
131			MAT4 pm;
132			OBJREC *o;
133			SRCREC *s;
134			int n;
135			{
136			RAY tr;
137	greg	2.2	OBJREC *m;
138			MFUNC *mf;
139			EPNODE **va;
140	greg	1.1	FVECT cent, newdir, nv, h;
141	greg	2.2	double coef, olddot, newdot, od;
142	greg	1.1	register int i, j;
143			/* initialize test ray */
144			getmaxdisk(cent, o);
145			if (s->sflags & SDISTANT)
146			for (i = 0; i < 3; i++) {
147			tr.rdir[i] = -s->sloc[i];
148			tr.rorg[i] = cent[i] - tr.rdir[i];
149			}
150			else {
151			for (i = 0; i < 3; i++) {
152			tr.rdir[i] = cent[i] - s->sloc[i];
153	greg	1.2	tr.rorg[i] = s->sloc[i];
154	greg	1.1	}
155			if (normalize(tr.rdir) == 0.0)
156			return(0); /* at source! */
157			}
158			od = getplaneq(nv, o);
159			olddot = DOT(tr.rdir, nv);
160			if (olddot <= FTINY && olddot >= -FTINY)
161			return(0); /* old dir parallels plane */
162	greg	2.5	tr.rmax = 0.0;
163	greg	1.1	rayorigin(&tr, NULL, PRIMARY, 1.0);
164			if (!(*ofun[o->otype].funp)(o, &tr))
165			return(0); /* no intersection! */
166			/* compute redirection */
167	greg	2.2	m = vsmaterial(o);
168			mf = getdfunc(m);
169			setfunc(m, &tr);
170	greg	2.3	varset("DxA", '=', 0.0);
171			varset("DyA", '=', 0.0);
172			varset("DzA", '=', 0.0);
173	greg	1.1	errno = 0;
174	greg	2.2	va = mf->ep + 4*n;
175			coef = evalue(va[0]);
176	greg	1.1	if (errno)
177			goto computerr;
178	greg	2.2	if (coef <= FTINY)
179			return(0); /* insignificant */
180			va++;
181			for (i = 0; i < 3; i++) {
182			newdir[i] = evalue(va[i]);
183			if (errno)
184			goto computerr;
185			}
186			if (mf->f != &unitxf)
187			multv3(newdir, newdir, mf->f->xfm);
188	greg	1.4	/* normalization unnecessary */
189	greg	1.1	newdot = DOT(newdir, nv);
190			if (newdot <= FTINY && newdot >= -FTINY)
191			return(0); /* new dir parallels plane */
192			/* everything OK -- compute shear */
193			for (i = 0; i < 3; i++)
194	greg	1.4	h[i] = newdir[i]/newdot - tr.rdir[i]/olddot;
195	greg	1.1	setident4(pm);
196			for (j = 0; j < 3; j++) {
197			for (i = 0; i < 3; i++)
198			pm[i][j] += nv[i]*h[j];
199			pm[3][j] = -od*h[j];
200			}
201			if (newdot > 0.0 ^ olddot > 0.0) /* add mirroring */
202			for (j = 0; j < 3; j++) {
203			for (i = 0; i < 3; i++)
204			pm[i][j] -= 2.nv[i]nv[j];
205			pm[3][j] += 2.odnv[j];
206			}
207			return(1);
208			computerr:
209			objerror(m, WARNING, "projection compute error");
210			return(0);
211			}