src/rt/t_func.c

/* Copyright (c) 1991 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"

#include  "func.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;
{
        FVECT  disp;
        double  d;
        register MFUNC  *mf;
        register int  i;

        if (m->oargs.nsargs < 4)
                objerror(m, USER, "bad # arguments");
        mf = getfunc(m, 3, 0x7, 1);
        setfunc(m, r);
        errno = 0;
        for (i = 0; i < 3; i++) {
                disp[i] = evalue(mf->ep[i]);
                if (errno) {
                        objerror(m, WARNING, "compute error");
                        return;
                }
        }
        if (mf->f != &unitxf)
                multv3(disp, disp, mf->f->xfm);
        if (r->rox != NULL) {
                multv3(disp, disp, r->rox->f.xfm);
                d = 1.0 / (mf->f->sca * r->rox->f.sca);
        } else
                d = 1.0 / mf->f->sca;
        for (i = 0; i < 3; i++)
                r->pert[i] += disp[i] * d;
}
Revision:	2.2
Committed:	Mon Nov 25 09:50:59 1991 UTC (32 years, 5 months ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 2.1:	+16 -34 lines
Log Message:	changed function file calls to allow expressions instead of just vars
#	User	Rev	Content
1	greg	2.2	/* Copyright (c) 1991 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	greg	2.2	#include "func.h"
16
17	greg	1.1	/*
18			* A procedural texture perturbs the surface normal
19			* at the point of intersection with an object. It has
20			* the form:
21			*
22			* modifier texfunc name
23			* 4+ xvarname yvarname zvarname filename xf
24			* 0
25			* n A1 A2 ..
26			*
27			* Filename is the name of the file where the variable definitions
28			* can be found. The list of real arguments can be accessed by
29			* definitions in the file. The xf is a transformation to get
30			* from the original coordinates to the current coordinates.
31			*/
32
33
34			t_func(m, r) /* compute texture for ray */
35			register OBJREC *m;
36			register RAY *r;
37			{
38			FVECT disp;
39	greg	1.6	double d;
40	greg	2.2	register MFUNC *mf;
41	greg	1.1	register int i;
42
43			if (m->oargs.nsargs < 4)
44			objerror(m, USER, "bad # arguments");
45	greg	2.2	mf = getfunc(m, 3, 0x7, 1);
46			setfunc(m, r);
47	greg	1.1	errno = 0;
48	greg	2.2	for (i = 0; i < 3; i++) {
49			disp[i] = evalue(mf->ep[i]);
50			if (errno) {
51			objerror(m, WARNING, "compute error");
52			return;
53			}
54	greg	1.1	}
55	greg	2.2	if (mf->f != &unitxf)
56			multv3(disp, disp, mf->f->xfm);
57	greg	1.8	if (r->rox != NULL) {
58			multv3(disp, disp, r->rox->f.xfm);
59	greg	2.2	d = 1.0 / (mf->f->sca * r->rox->f.sca);
60	greg	1.8	} else
61	greg	2.2	d = 1.0 / mf->f->sca;
62	greg	1.4	for (i = 0; i < 3; i++)
63	greg	1.6	r->pert[i] += disp[i] * d;
64	greg	1.1	}