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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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/* Copyright (c) 1989 Regents of the University of California */ |
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/* |
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* gensurf.c - program to generate functional surfaces |
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* |
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char *modname, *surfname; |
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< |
double funvalue(), l_hermite(), argument(); |
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> |
double funvalue(), l_hermite(), l_bezier(), l_bspline(), argument(); |
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typedef struct { |
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FVECT p; /* vertex position */ |
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varset("PI", PI); |
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funset("hermite", 5, l_hermite); |
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funset("bezier", 5, l_bezier); |
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funset("bspline", 5, l_bspline); |
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if (argc < 8) |
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goto userror; |
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argument(2)*(-2.0*t+3.0)*t*t + |
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argument(3)*((t-2.0)*t+1.0)*t + |
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argument(4)*(t-1.0)*t*t ); |
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} |
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double |
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l_bezier() |
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{ |
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double t; |
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t = argument(5); |
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return( argument(1) * (1.+t*(-3.+t*(3.-t))) + |
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argument(2) * 3.*t*(1.+t*(-2.+t)) + |
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argument(3) * 3.*t*t*(1.-t) + |
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argument(4) * t*t*t ); |
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} |
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|
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double |
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l_bspline() |
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{ |
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double t; |
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t = argument(5); |
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return( argument(1) * (1./6.+t*(-1./2.+t*(1./2.-1./6.*t))) + |
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argument(2) * (2./3.+t*t*(-1.+1./2.*t)) + |
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argument(3) * (1./6.+t*(1./2.+t*(1./2.-1./2.*t))) + |
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argument(4) * (1./6.*t*t*t) ); |
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} |
