35 lines
683 B
C
35 lines
683 B
C
/*
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======================================================================
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vecmath.c
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Basic vector and matrix functions.
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Ernie Wright 17 Sep 00
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====================================================================== */
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#include <math.h>
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float dot( float a[], float b[] ){
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return a[ 0 ] * b[ 0 ] + a[ 1 ] * b[ 1 ] + a[ 2 ] * b[ 2 ];
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}
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void cross( float a[], float b[], float c[] ){
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c[ 0 ] = a[ 1 ] * b[ 2 ] - a[ 2 ] * b[ 1 ];
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c[ 1 ] = a[ 2 ] * b[ 0 ] - a[ 0 ] * b[ 2 ];
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c[ 2 ] = a[ 0 ] * b[ 1 ] - a[ 1 ] * b[ 0 ];
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}
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void normalize( float v[] ){
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float r;
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r = ( float ) sqrt( dot( v, v ) );
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if ( r > 0 ) {
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v[ 0 ] /= r;
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v[ 1 ] /= r;
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v[ 2 ] /= r;
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}
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}
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