diff options
| -rw-r--r-- | src/glu/sgi/libutil/project.c | 121 |
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], |