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authorBrian Paul <brian.paul@tungstengraphics.com>2006-05-01 16:01:17 +0000
committerBrian Paul <brian.paul@tungstengraphics.com>2006-05-01 16:01:17 +0000
commitae7f22f1ef53c79c8b27792a93a44b28271185d4 (patch)
tree6937b77076f2de77be99ee00f75521c6e3241acd /src/glu
parent0174d894ef79aa5d6f093af8c5c6f97a5edd4e86 (diff)
new, faster version of __gluInvertMatrixd(), bug 6748
Diffstat (limited to 'src/glu')
-rw-r--r--src/glu/sgi/libutil/project.c121
1 files changed, 62 insertions, 59 deletions
diff --git a/src/glu/sgi/libutil/project.c b/src/glu/sgi/libutil/project.c
index ddb3e7ec757..2b20ad4fb33 100644
--- a/src/glu/sgi/libutil/project.c
+++ b/src/glu/sgi/libutil/project.c
@@ -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;
+ 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];
+ }
}
- for (j = 0; j < 4; j++) {
- if (j != i) {
- t = temp[j][i];
+ __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[j][k] -= temp[i][k]*t;
- inverse[j*4+k] -= inverse[i*4+k]*t;
+ 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;
+ return GL_TRUE;
}
static void __gluMultMatricesd(const GLdouble a[16], const GLdouble b[16],