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
#	Content
1	/* Copyright (c) 1990 Regents of the University of California */
2
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	double d;
40	register FULLXF *mxf;
41	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	if ((mxf = (FULLXF *)m->os) == NULL) {
49	mxf = (FULLXF *)malloc(sizeof(FULLXF));
50	if (mxf == NULL)
51	goto memerr;
52	if (fullxf(mxf, m->oargs.nsargs-4, sa+4) != m->oargs.nsargs-4)
53	objerror(m, USER, "bad transform");
54	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	m->os = (char *)mxf;
59	}
60
61	setmap(m, r, &mxf->b);
62
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	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	for (i = 0; i < 3; i++)
79	r->pert[i] += disp[i] * d;
80	return;
81	memerr:
82	error(SYSTEM, "out of memory in t_func");
83	}