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new, faster version of __gluInvertMatrixd(), bug 6748

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This commit is contained in:
Brian Paul 2006-05-01 16:01:17 +00:00
parent 0174d894ef
commit ae7f22f1ef
1 changed files with 64 additions and 61 deletions
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125
src/glu/sgi/libutil/project.c
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@ -31,8 +31,8 @@
** published by SGI, but has not been independently verified as being
** compliant with the OpenGL(R) version 1.2.1 Specification.
**
** $Date: 2002/11/01 23:45:31 $ $Revision: 1.5 $
** $Header: /home/krh/git/sync/mesa-cvs-repo/Mesa/src/glu/sgi/libutil/project.c,v 1.5 2002/11/01 23:45:31 brianp Exp $
** $Date: 2006/05/01 16:01:17 $ $Revision: 1.6 $
** $Header: /home/krh/git/sync/mesa-cvs-repo/Mesa/src/glu/sgi/libutil/project.c,v 1.6 2006/05/01 16:01:17 brianp Exp $
*/
#include "gluos.h"
@ -169,70 +169,73 @@ static void __gluMultMatrixVecd(const GLdouble matrix[16], const GLdouble in[4],
/*
** inverse = invert(src)
** New, faster implementation by Shan Hao Bo, April 2006.
*/
static int __gluInvertMatrixd(const GLdouble src[16], GLdouble inverse[16])
{
int i, j, k, swap;
double t;
GLdouble temp[4][4];
for (i=0; i<4; i++) {
for (j=0; j<4; j++) {
temp[i][j] = src[i*4+j];
}
}
__gluMakeIdentityd(inverse);
for (i = 0; i < 4; i++) {
/*
** Look for largest element in column
*/
swap = i;
for (j = i + 1; j < 4; j++) {
if (fabs(temp[j][i]) > fabs(temp[i][i])) {
swap = j;
}
}
if (swap != i) {
/*
** Swap rows.
*/
for (k = 0; k < 4; k++) {
t = temp[i][k];
temp[i][k] = temp[swap][k];
temp[swap][k] = t;
t = inverse[i*4+k];
inverse[i*4+k] = inverse[swap*4+k];
inverse[swap*4+k] = t;
}
}
if (temp[i][i] == 0) {
/*
** No non-zero pivot. The matrix is singular, which shouldn't
** happen. This means the user gave us a bad matrix.
*/
return GL_FALSE;
}
t = temp[i][i];
for (k = 0; k < 4; k++) {
temp[i][k] /= t;
inverse[i*4+k] /= t;
}
for (j = 0; j < 4; j++) {
if (j != i) {
t = temp[j][i];
for (k = 0; k < 4; k++) {
temp[j][k] -= temp[i][k]*t;
inverse[j*4+k] -= inverse[i*4+k]*t;
int i, j, k;
double t;
GLdouble temp[4][4];
for (i=0; i<4; i++) {
for (j=0; j<4; j++) {
temp[i][j] = src[i*4+j];
}
}
}
}
return GL_TRUE;
__gluMakeIdentityd(inverse);
for (i = 0; i < 4; i++) {
if (temp[i][i] == 0.0f) {
/*
** Look for non-zero element in column
*/
for (j = i + 1; j < 4; j++) {
if (temp[j][i] != 0.0f) {
break;
}
}
if (j != 4) {
/*
** Swap rows.
*/
for (k = 0; k < 4; k++) {
t = temp[i][k];
temp[i][k] = temp[j][k];
temp[j][k] = t;
t = inverse[i*4+k];
inverse[i*4+k] = inverse[j*4+k];
inverse[j*4+k] = t;
}
}
else {
/*
** No non-zero pivot. The matrix is singular,
which shouldn't
** happen. This means the user gave us a bad
matrix.
*/
return GL_FALSE;
}
}
t = 1.0f / temp[i][i];
for (k = 0; k < 4; k++) {
temp[i][k] *= t;
inverse[i*4+k] *= t;
}
for (j = 0; j < 4; j++) {
if (j != i) {
t = temp[j][i];
for (k = 0; k < 4; k++) {
temp[j][k] -= temp[i][k]*t;
inverse[j*4+k] -= inverse[i*4+k]*t;
}
}
}
}
return GL_TRUE;
}
static void __gluMultMatricesd(const GLdouble a[16], const GLdouble b[16],