src/rt/t_func.c

#ifndef lint
static const char       RCSid[] = "$Id: t_func.c,v 2.6 2003/03/05 16:16:53 greg Exp $";
#endif
/*
 *  t_func.c - routine for procedural textures.
 */

#include "copyright.h"

#include  "ray.h"
#include  "func.h"
#include  "rtotypes.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.
 */


extern int
t_func(                 /* 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 == EDOM || errno == ERANGE) {
                        objerror(m, WARNING, "compute error");
                        return(0);
                }
        }
        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;
        return(0);
}
Revision:	2.7
Committed:	Tue Mar 30 16:13:01 2004 UTC (20 years, 1 month ago) by schorsch
Content type:	text/plain
Branch:	MAIN
CVS Tags:	rad3R7P2, rad3R7P1, rad4R0, rad3R6, rad3R6P1, rad3R8, rad3R9
Changes since 2.6:	+7 -5 lines
Log Message:	Continued ANSIfication. There are only bits and pieces left now.
#	User	Rev	Content
1	greg	1.1	#ifndef lint
2	schorsch	2.7	static const char RCSid[] = "$Id: t_func.c,v 2.6 2003/03/05 16:16:53 greg Exp $";
3	greg	1.1	#endif
4			/*
5			* t_func.c - routine for procedural textures.
6	greg	2.4	*/
7
8	greg	2.5	#include "copyright.h"
9	greg	1.1
10			#include "ray.h"
11	greg	2.2	#include "func.h"
12	schorsch	2.7	#include "rtotypes.h"
13	greg	2.2
14	greg	1.1	/*
15			* A procedural texture perturbs the surface normal
16			* at the point of intersection with an object. It has
17			* the form:
18			*
19			* modifier texfunc name
20			* 4+ xvarname yvarname zvarname filename xf
21			* 0
22			* n A1 A2 ..
23			*
24			* Filename is the name of the file where the variable definitions
25			* can be found. The list of real arguments can be accessed by
26			* definitions in the file. The xf is a transformation to get
27			* from the original coordinates to the current coordinates.
28			*/
29
30
31	schorsch	2.7	extern int
32			t_func( /* compute texture for ray */
33			register OBJREC *m,
34			register RAY *r
35			)
36	greg	1.1	{
37			FVECT disp;
38	greg	1.6	double d;
39	greg	2.2	register MFUNC *mf;
40	greg	1.1	register int i;
41
42			if (m->oargs.nsargs < 4)
43			objerror(m, USER, "bad # arguments");
44	greg	2.2	mf = getfunc(m, 3, 0x7, 1);
45			setfunc(m, r);
46	greg	1.1	errno = 0;
47	greg	2.2	for (i = 0; i < 3; i++) {
48			disp[i] = evalue(mf->ep[i]);
49	greg	2.6	if (errno == EDOM \|\| errno == ERANGE) {
50	greg	2.2	objerror(m, WARNING, "compute error");
51	greg	2.3	return(0);
52	greg	2.2	}
53	greg	1.1	}
54	greg	2.2	if (mf->f != &unitxf)
55			multv3(disp, disp, mf->f->xfm);
56	greg	1.8	if (r->rox != NULL) {
57			multv3(disp, disp, r->rox->f.xfm);
58	greg	2.2	d = 1.0 / (mf->f->sca * r->rox->f.sca);
59	greg	1.8	} else
60	greg	2.2	d = 1.0 / mf->f->sca;
61	greg	1.4	for (i = 0; i < 3; i++)
62	greg	1.6	r->pert[i] += disp[i] * d;
63	greg	2.3	return(0);
64	greg	1.1	}