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/* Copyright (c) 1998 Silicon Graphics, Inc. */ |
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|
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#ifndef lint |
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static char SCCSid[] = "$SunId$ SGI"; |
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#endif |
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|
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/* |
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* mx_func.c - routine for mixture functions. |
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* |
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* 11/2/88 |
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*/ |
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|
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#include "ray.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 mixture function is specified: |
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* |
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* modifier mixfunc name |
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* 4+ foremod backmod varname vfname xf |
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* 0 |
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* n A1 A2 .. |
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* |
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* Vfname is the name of the file where the variable definition |
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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 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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mx_func(m, r) /* compute mixture function */ |
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register OBJREC *m; |
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RAY *r; |
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{ |
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OBJECT obj; |
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register int i; |
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double coef; |
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OBJECT mod[2]; |
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register MFUNC *mf; |
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|
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if (m->oargs.nsargs < 4) |
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objerror(m, USER, "bad # arguments"); |
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obj = objndx(m); |
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for (i = 0; i < 2; i++) |
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if (!strcmp(m->oargs.sarg[i], VOIDID)) |
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mod[i] = OVOID; |
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else if ((mod[i] = lastmod(obj, m->oargs.sarg[i])) == OVOID) { |
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sprintf(errmsg, "undefined modifier \"%s\"", |
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m->oargs.sarg[i]); |
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objerror(m, USER, errmsg); |
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} |
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mf = getfunc(m, 3, 0x4, 0); |
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setfunc(m, r); |
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errno = 0; |
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coef = evalue(mf->ep[0]); |
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if (errno) { |
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objerror(m, WARNING, "compute error"); |
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return(0); |
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} |
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if (raymixture(r, mod[0], mod[1], coef)) { |
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if (m->omod != OVOID) |
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objerror(m, USER, "inappropriate modifier"); |
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return(1); |
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} |
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return(0); |
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} |
