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/* Copyright (c) 1989 Regents of the University of California */
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#ifndef lint
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static char SCCSid[] = "$SunId$ LBL";
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#endif
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/*
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* t_data.c - routine for stored textures
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*
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* 6/4/86
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*/
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#include "ray.h"
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#include "data.h"
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/*
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* A stored texture is specified as follows:
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*
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* modifier texdata name
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* 8+ xfunc yfunc zfunc xdfname ydfname zdfname vfname v0 v1 .. xf
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* 0
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* n A1 A2 .. An
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*
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* Vfname is the name of the file where the variable definitions
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* can be found. The list of real arguments can be accessed by
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* definitions in the file. The dfnames are the data file
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* names. The dimensions of the data files and the number
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* of variables must match. The funcs take three arguments to produce
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* interpolated values from the file. The xf is a transformation
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* to get from the original coordinates to the current coordinates.
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*/
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typedef struct {
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struct {
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double sca; /* scale factor */
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double xfm[4][4]; /* transformation matrix */
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} fore, back;
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} XFORM;
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t_data(m, r) /* interpolate texture data */
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register OBJREC *m;
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RAY *r;
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{
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extern double varvalue(), funvalue(), datavalue();
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extern int errno;
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int nv;
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FVECT dval, disp;
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double pt[MAXDIM];
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double d;
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DATARRAY *dp;
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register XFORM *mxf;
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register char **sa;
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register int i;
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if (m->oargs.nsargs < 8)
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objerror(m, USER, "bad # arguments");
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sa = m->oargs.sarg;
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for (i = 7; i < m->oargs.nsargs && sa[i][0] != '-'; i++)
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;
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nv = i-7;
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if ((mxf = (XFORM *)m->os) == NULL) {
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mxf = (XFORM *)malloc(sizeof(XFORM));
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if (mxf == NULL)
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goto memerr;
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mxf->fore.sca = 1.0;
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setident4(mxf->fore.xfm);
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if (xf(mxf->fore.xfm, &mxf->fore.sca,
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m->oargs.nsargs-i, sa+i) != m->oargs.nsargs-i)
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objerror(m, USER, "bad transform");
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if (mxf->fore.sca < 0.0)
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mxf->fore.sca = -mxf->fore.sca;
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mxf->back.sca = 1.0;
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setident4(mxf->back.xfm);
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invxf(mxf->back.xfm, &mxf->back.sca,
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m->oargs.nsargs-i, sa+i);
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if (mxf->back.sca < 0.0)
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mxf->back.sca = -mxf->back.sca;
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m->os = (char *)mxf;
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}
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setmap(m, r, mxf->back.xfm, mxf->back.sca);
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if (nv > MAXDIM)
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goto dimerr;
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if (!vardefined(sa[7]))
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loadfunc(sa[6]);
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errno = 0;
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for (i = 0; i < nv; i++)
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pt[i] = varvalue(sa[i+7]);
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if (errno)
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goto computerr;
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for (i = 0; i < 3; i++) {
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dp = getdata(sa[i+3]);
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if (dp->nd != nv)
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goto dimerr;
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dval[i] = datavalue(dp, pt);
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}
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errno = 0;
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for (i = 0; i < 3; i++)
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disp[i] = funvalue(sa[i], 3, dval);
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if (errno)
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goto computerr;
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multv3(disp, disp, mxf->fore.xfm);
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multv3(disp, disp, r->rofx);
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d = 1.0 / (mxf->fore.sca * r->rofs);
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for (i = 0; i < 3; i++)
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r->pert[i] += disp[i] * d;
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return;
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dimerr:
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objerror(m, USER, "dimension error");
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memerr:
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error(SYSTEM, "out of memory in t_data");
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computerr:
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objerror(m, WARNING, "compute error");
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return;
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}
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