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/* Copyright (c) 1989 Regents of the University of California */ |
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|
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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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/* |
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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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|
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#include "ray.h" |
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|
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#include "data.h" |
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|
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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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|
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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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|
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|
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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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|
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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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|
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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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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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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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|
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setmap(m, r, mxf->back.xfm, mxf->back.sca); |
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|
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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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|
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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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} |
