src/rt/t_func.c

/* Copyright (c) 1990 Regents of the University of California */

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

/*
 *  t_func.c - routine for procedural textures.
 *
 *     4/8/86
 */

#include  "ray.h"

/*
 *      A procedural texture perturbs the surface normal
 *  at the point of intersection with an object.  It has
 *  the form:
 *
 *      modifier texfunc name
 *      4+ xvarname yvarname zvarname filename xf
 *      0
 *      n A1 A2 ..
 *
 *  Filename is the name of the file where the variable definitions
 *  can be found.  The list of real arguments can be accessed by
 *  definitions in the file.  The xf is a transformation to get
 *  from the original coordinates to the current coordinates.
 */


t_func(m, r)                    /* compute texture for ray */
register OBJREC  *m;
register RAY  *r;
{
        extern double  varvalue();
        extern int  errno;
        FVECT  disp;
        double  d;
        register FULLXF  *mxf;
        register int  i;
        register char  **sa;

        if (m->oargs.nsargs < 4)
                objerror(m, USER, "bad # arguments");
        sa = m->oargs.sarg;

        if ((mxf = (FULLXF *)m->os) == NULL) {
                mxf = (FULLXF *)malloc(sizeof(FULLXF));
                if (mxf == NULL)
                        goto memerr;
                if (fullxf(mxf, m->oargs.nsargs-4, sa+4) != m->oargs.nsargs-4)
                        objerror(m, USER, "bad transform");
                if (mxf->f.sca < 0.0)
                        mxf->f.sca = -mxf->f.sca;
                if (mxf->b.sca < 0.0)
                        mxf->b.sca = -mxf->b.sca;
                m->os = (char *)mxf;
        }

        setmap(m, r, &mxf->b);

        if (!vardefined(sa[0]))
                loadfunc(sa[3]);
        errno = 0;
        for (i = 0; i < 3; i++)
                disp[i] = varvalue(sa[i]);
        if (errno) {
                objerror(m, WARNING, "compute error");
                return;
        }
        multv3(disp, disp, mxf->f.xfm);
        if (r->rox != NULL) {
                multv3(disp, disp, r->rox->f.xfm);
                d = 1.0 / (mxf->f.sca * r->rox->f.sca);
        } else
                d = 1.0 / mxf->f.sca;
        for (i = 0; i < 3; i++)
                r->pert[i] += disp[i] * d;
        return;
memerr:
        error(SYSTEM, "out of memory in t_func");
}
Revision:	1.8
Committed:	Sat Dec 15 15:03:38 1990 UTC (33 years, 4 months ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 1.7:	+16 -23 lines
Log Message:	changed handling of matrix transformations with new MAT4 & XF types dynamic allocation of ray transformations with newrayxf() added missing light source vector transformation to m_brdf.c
#	User	Rev	Content
1	greg	1.8	/* Copyright (c) 1990 Regents of the University of California */
2	greg	1.1
3			#ifndef lint
4			static char SCCSid[] = "$SunId$ LBL";
5			#endif
6
7			/*
8			* t_func.c - routine for procedural textures.
9			*
10			* 4/8/86
11			*/
12
13			#include "ray.h"
14
15			/*
16			* A procedural texture perturbs the surface normal
17			* at the point of intersection with an object. It has
18			* the form:
19			*
20			* modifier texfunc name
21			* 4+ xvarname yvarname zvarname filename xf
22			* 0
23			* n A1 A2 ..
24			*
25			* Filename is the name of the file where the variable definitions
26			* can be found. The list of real arguments can be accessed by
27			* definitions in the file. The xf is a transformation to get
28			* from the original coordinates to the current coordinates.
29			*/
30
31
32			t_func(m, r) /* compute texture for ray */
33			register OBJREC *m;
34			register RAY *r;
35			{
36			extern double varvalue();
37			extern int errno;
38			FVECT disp;
39	greg	1.6	double d;
40	greg	1.8	register FULLXF *mxf;
41	greg	1.1	register int i;
42			register char **sa;
43
44			if (m->oargs.nsargs < 4)
45			objerror(m, USER, "bad # arguments");
46			sa = m->oargs.sarg;
47
48	greg	1.8	if ((mxf = (FULLXF *)m->os) == NULL) {
49			mxf = (FULLXF *)malloc(sizeof(FULLXF));
50	greg	1.1	if (mxf == NULL)
51			goto memerr;
52	greg	1.8	if (fullxf(mxf, m->oargs.nsargs-4, sa+4) != m->oargs.nsargs-4)
53	greg	1.1	objerror(m, USER, "bad transform");
54	greg	1.8	if (mxf->f.sca < 0.0)
55			mxf->f.sca = -mxf->f.sca;
56			if (mxf->b.sca < 0.0)
57			mxf->b.sca = -mxf->b.sca;
58	greg	1.2	m->os = (char *)mxf;
59	greg	1.1	}
60
61	greg	1.8	setmap(m, r, &mxf->b);
62	greg	1.1
63			if (!vardefined(sa[0]))
64			loadfunc(sa[3]);
65			errno = 0;
66			for (i = 0; i < 3; i++)
67			disp[i] = varvalue(sa[i]);
68			if (errno) {
69			objerror(m, WARNING, "compute error");
70			return;
71			}
72	greg	1.8	multv3(disp, disp, mxf->f.xfm);
73			if (r->rox != NULL) {
74			multv3(disp, disp, r->rox->f.xfm);
75			d = 1.0 / (mxf->f.sca * r->rox->f.sca);
76			} else
77			d = 1.0 / mxf->f.sca;
78	greg	1.4	for (i = 0; i < 3; i++)
79	greg	1.6	r->pert[i] += disp[i] * d;
80	greg	1.1	return;
81			memerr:
82			error(SYSTEM, "out of memory in t_func");
83			}