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/* Copyright (c) 1992 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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#include "func.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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|
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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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int nv; |
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FVECT disp; |
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double dval[3], pt[MAXDIM]; |
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double d; |
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DATARRAY *dp; |
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register MFUNC *mf; |
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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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dp = getdata(m->oargs.sarg[3]); |
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i = (1 << (nv = dp->nd)) - 1; |
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mf = getfunc(m, 6, i<<7, 1); |
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setfunc(m, r); |
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errno = 0; |
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for (i = 0; i < nv; i++) |
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pt[i] = evalue(mf->ep[i]); |
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if (errno) |
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goto computerr; |
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dval[0] = datavalue(dp, pt); |
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for (i = 1; i < 3; i++) { |
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dp = getdata(m->oargs.sarg[i+3]); |
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if (dp->nd != nv) |
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objerror(m, USER, "dimension error"); |
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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(m->oargs.sarg[i], 3, dval); |
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if (errno) |
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goto computerr; |
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if (mf->f != &unitxf) |
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multv3(disp, disp, mf->f->xfm); |
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if (r->rox != NULL) { |
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multv3(disp, disp, r->rox->f.xfm); |
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d = 1.0 / (mf->f->sca * r->rox->f.sca); |
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} else |
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d = 1.0 / mf->f->sca; |
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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(0); |
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computerr: |
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objerror(m, WARNING, "compute error"); |
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return(0); |
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} |
