/* $Id: project.c,v 1.7 1999/01/03 03:23:15 brianp Exp $ */ /* * Mesa 3-D graphics library * Version: 3.1 * Copyright (C) 1995-1999 Brian Paul * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Library General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Library General Public License for more details. * * You should have received a copy of the GNU Library General Public * License along with this library; if not, write to the Free * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ /* * $Log: project.c,v $ * Revision 1.7 1999/01/03 03:23:15 brianp * now using GLAPIENTRY and GLCALLBACK keywords (Ted Jump) * * Revision 1.6 1998/07/08 01:43:43 brianp * new version of invert_matrix() (also in src/matrix.c) * * Revision 1.5 1997/07/24 01:28:44 brianp * changed precompiled header symbol from PCH to PC_HEADER * * Revision 1.4 1997/05/28 02:29:38 brianp * added support for precompiled headers (PCH), inserted APIENTRY keyword * * Revision 1.3 1997/04/11 23:22:42 brianp * added divide by zero checks to gluProject() and gluUnproject() * * Revision 1.2 1997/01/29 19:05:29 brianp * faster invert_matrix() function from Stephane Rehel * * Revision 1.1 1996/09/27 01:19:39 brianp * Initial revision * */ #ifdef PC_HEADER #include "all.h" #else #include #include #include #include "gluP.h" #endif /* * This code was contributed by Marc Buffat (buffat@mecaflu.ec-lyon.fr). * Thanks Marc!!! */ /* implementation de gluProject et gluUnproject */ /* M. Buffat 17/2/95 */ /* * Transform a point (column vector) by a 4x4 matrix. I.e. out = m * in * Input: m - the 4x4 matrix * in - the 4x1 vector * Output: out - the resulting 4x1 vector. */ static void transform_point( GLdouble out[4], const GLdouble m[16], const GLdouble in[4] ) { #define M(row,col) m[col*4+row] out[0] = M(0,0) * in[0] + M(0,1) * in[1] + M(0,2) * in[2] + M(0,3) * in[3]; out[1] = M(1,0) * in[0] + M(1,1) * in[1] + M(1,2) * in[2] + M(1,3) * in[3]; out[2] = M(2,0) * in[0] + M(2,1) * in[1] + M(2,2) * in[2] + M(2,3) * in[3]; out[3] = M(3,0) * in[0] + M(3,1) * in[1] + M(3,2) * in[2] + M(3,3) * in[3]; #undef M } /* * Perform a 4x4 matrix multiplication (product = a x b). * Input: a, b - matrices to multiply * Output: product - product of a and b */ static void matmul( GLdouble *product, const GLdouble *a, const GLdouble *b ) { /* This matmul was contributed by Thomas Malik */ GLdouble temp[16]; GLint i; #define A(row,col) a[(col<<2)+row] #define B(row,col) b[(col<<2)+row] #define T(row,col) temp[(col<<2)+row] /* i-te Zeile */ for (i = 0; i < 4; i++) { T(i, 0) = A(i, 0) * B(0, 0) + A(i, 1) * B(1, 0) + A(i, 2) * B(2, 0) + A(i, 3) * B(3, 0); T(i, 1) = A(i, 0) * B(0, 1) + A(i, 1) * B(1, 1) + A(i, 2) * B(2, 1) + A(i, 3) * B(3, 1); T(i, 2) = A(i, 0) * B(0, 2) + A(i, 1) * B(1, 2) + A(i, 2) * B(2, 2) + A(i, 3) * B(3, 2); T(i, 3) = A(i, 0) * B(0, 3) + A(i, 1) * B(1, 3) + A(i, 2) * B(2, 3) + A(i, 3) * B(3, 3); } #undef A #undef B #undef T MEMCPY( product, temp, 16*sizeof(GLdouble) ); } static GLdouble Identity[16] = { 1.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 0.0, 1.0 }; /* * Compute inverse of 4x4 transformation matrix. * Code contributed by Jacques Leroy jle@star.be * Return GL_TRUE for success, GL_FALSE for failure (singular matrix) */ static GLboolean invert_matrix( const GLdouble *m, GLdouble *out ) { /* NB. OpenGL Matrices are COLUMN major. */ #define SWAP_ROWS(a, b) { GLdouble *_tmp = a; (a)=(b); (b)=_tmp; } #define MAT(m,r,c) (m)[(c)*4+(r)] GLdouble wtmp[4][8]; GLdouble m0, m1, m2, m3, s; GLdouble *r0, *r1, *r2, *r3; r0 = wtmp[0], r1 = wtmp[1], r2 = wtmp[2], r3 = wtmp[3]; r0[0] = MAT(m,0,0), r0[1] = MAT(m,0,1), r0[2] = MAT(m,0,2), r0[3] = MAT(m,0,3), r0[4] = 1.0, r0[5] = r0[6] = r0[7] = 0.0, r1[0] = MAT(m,1,0), r1[1] = MAT(m,1,1), r1[2] = MAT(m,1,2), r1[3] = MAT(m,1,3), r1[5] = 1.0, r1[4] = r1[6] = r1[7] = 0.0, r2[0] = MAT(m,2,0), r2[1] = MAT(m,2,1), r2[2] = MAT(m,2,2), r2[3] = MAT(m,2,3), r2[6] = 1.0, r2[4] = r2[5] = r2[7] = 0.0, r3[0] = MAT(m,3,0), r3[1] = MAT(m,3,1), r3[2] = MAT(m,3,2), r3[3] = MAT(m,3,3), r3[7] = 1.0, r3[4] = r3[5] = r3[6] = 0.0; /* choose pivot - or die */ if (fabs(r