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greg |
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/* Copyright (c) 1990 Regents of the University of California */
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greg |
1.1 |
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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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* mat4.c - routines dealing with 4 X 4 homogeneous transformation matrices.
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*
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* 10/19/85
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*/
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greg |
1.5 |
#include "mat4.h"
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greg |
1.1 |
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greg |
1.6 |
MAT4 m4ident = MAT4IDENT;
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greg |
1.5 |
static MAT4 m4tmp; /* for efficiency */
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greg |
1.1 |
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multmat4(m4a, m4b, m4c) /* multiply m4b X m4c and put into m4a */
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greg |
1.5 |
MAT4 m4a;
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register MAT4 m4b, m4c;
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greg |
1.1 |
{
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register int i, j;
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for (i = 4; i--; )
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for (j = 4; j--; )
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m4tmp[i][j] = m4b[i][0]*m4c[0][j] +
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m4b[i][1]*m4c[1][j] +
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m4b[i][2]*m4c[2][j] +
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m4b[i][3]*m4c[3][j];
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copymat4(m4a, m4tmp);
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}
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multv3(v3a, v3b, m4) /* transform vector v3b by m4 and put into v3a */
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greg |
1.5 |
FVECT v3a;
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register FVECT v3b;
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register MAT4 m4;
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greg |
1.1 |
{
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greg |
1.3 |
m4tmp[0][0] = v3b[0]*m4[0][0] + v3b[1]*m4[1][0] + v3b[2]*m4[2][0];
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m4tmp[0][1] = v3b[0]*m4[0][1] + v3b[1]*m4[1][1] + v3b[2]*m4[2][1];
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m4tmp[0][2] = v3b[0]*m4[0][2] + v3b[1]*m4[1][2] + v3b[2]*m4[2][2];
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greg |
1.1 |
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v3a[0] = m4tmp[0][0];
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v3a[1] = m4tmp[0][1];
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v3a[2] = m4tmp[0][2];
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}
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multp3(p3a, p3b, m4) /* transform p3b by m4 and put into p3a */
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greg |
1.5 |
register FVECT p3a;
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FVECT p3b;
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register MAT4 m4;
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greg |
1.1 |
{
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multv3(p3a, p3b, m4); /* transform as vector */
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p3a[0] += m4[3][0]; /* translate */
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p3a[1] += m4[3][1];
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p3a[2] += m4[3][2];
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}
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