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59 lines
1001 B
59 lines
1001 B
/*
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* EffecTV - Realtime Digital Video Effector
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* Copyright (C) 2001-2006 FUKUCHI Kentaro
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*
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* utils.c: utilities
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*
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*/
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#include <math.h>
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#include "utils.h"
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/*
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* HSI color system utilities
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*/
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static int itrunc(double f)
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{
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int i;
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i=(int)f;
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if(i<0)i=0;
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if(i>255)i=255;
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return i;
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}
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void HSItoRGB(double H, double S, double I, int *r, int *g, int *b)
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{
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double T,Rv,Gv,Bv;
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Rv=1+S*sin(H-2*M_PI/3);
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Gv=1+S*sin(H);
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Bv=1+S*sin(H+2*M_PI/3);
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T=255.999*I/2;
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*r=itrunc(Rv*T);
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*g=itrunc(Gv*T);
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*b=itrunc(Bv*T);
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}
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/*
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* fastrand - fast fake random number generator
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* Warning: The low-order bits of numbers generated by fastrand()
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* are bad as random numbers. For example, fastrand()%4
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* generates 1,2,3,0,1,2,3,0...
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* You should use high-order bits.
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*/
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#ifdef __DARWIN__
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static
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#endif
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unsigned int fastrand_val;
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unsigned int fastrand(void)
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{
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return (fastrand_val=fastrand_val*1103515245+12345);
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}
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void fastsrand(unsigned int seed)
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{
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fastrand_val = seed;
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}
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