/* * Mesa 3-D graphics library * Version: 3.3 * Copyright (C) 1995-2000 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. */ #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)); } /* * 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(r3[0]) > fabs(r2[0])) SWAP_ROWS(r3, r2); if (fabs(r2[0]) > fabs(r1[0])) SWAP_ROWS(r2, r1); if (fabs(r1[0]) > fabs(r0[0])) SWAP_ROWS(r1, r0); if (0.0 == r0[0]) return GL_FALSE; /* eliminate first variable */ m1 = r1[0] / r0[0]; m2 = r2[0] / r0[0]; m3 = r3[0] / r0[0]; s = r0[1]; r1[1] -= m1 * s; r2[1] -= m2 * s; r3[1] -= m3 * s; s = r0[2]; r1[2] -= m1 * s; r2[2] -= m2 * s; r3[2] -= m3 * s; s = r0[3]; r1[3] -= m1 * s; r2[3] -= m2 * s; r3[3] -= m3 * s; s = r0[4]; if (s != 0.0) { r1[4] -= m1 * s; r2[4] -= m2 * s; r3[4] -= m3 * s; } s = r0[5]; if (s != 0.0) { r1[5] -= m1 * s; r2[5] -= m2 * s; r3[5] -= m3 * s; } s = r0[6]; if (s != 0.0) { r1[6] -= m1 * s; r2[6] -= m2 * s; r3[6] -= m3 * s; } s = r0[7]; if (s != 0.0) { r1[7] -= m1 * s; r2[7] -= m2 * s; r3[7] -= m3 * s; } /* choose pivot - or die */ if (fabs(r3[1]) > fabs(r2[1])) SWAP_ROWS(r3, r2); if (fabs(r2[1]) > fabs(r1[1])) SWAP_ROWS(r2, r1); if (0.0 == r1[1]) return GL_FALSE; /* eliminate second variable */ m2 = r2[1] / r1[1]; m3 = r3[1] / r1[1]; r2[2] -= m2 * r1[2]; r3[2] -= m3 * r1[2]; r2[3] -= m2 * r1[3]; r3[3] -= m3 * r1[3]; s = r1[4]; if (0.0 != s) { r2[4] -= m2 * s; r3[4] -= m3 * s; } s = r1[5]; if (0.0 != s) { r2[5] -= m2 * s; r3[5] -= m3 * s; } s = r1[6]; if (0.0 != s) { r2[6] -= m2 * s; r3[6] -= m3 * s; } s = r1[7]; if (0.0 != s) { r2[7] -= m2 * s; r3[7] -= m3 * s; } /* choose pivot - or die */ if (fabs(r3[2]) > fabs(r2[2])) SWAP_ROWS(r3, r2); if (0.0 == r2[2]) return GL_FALSE; /* eliminate third variable */ m3 = r3[2] / r2[2]; r3[3] -= m3 * r2[3], r3[4] -= m3 * r2[4], r3[5] -= m3 * r2[5], r3[6] -= m3 * r2[6], r3[7] -= m3 * r2[7]; /* last check */ if (0.0 == r3[3]) return GL_FALSE; s = 1.0 / r3[3]; /* now back substitute row 3 */ r3[4] *= s; r3[5] *= s; r3[6] *= s; r3[7] *= s; m2 = r2[3]; /* now back substitute row 2 */ s = 1.0 / r2[2]; r2[4] = s * (r2[4] - r3[4] * m2), r2[5] = s * (r2[5] - r3[5] * m2), r2[6] = s * (r2[6] - r3[6] * m2), r2[7] = s * (r2[7] - r3[7] * m2); m1 = r1[3]; r1[4] -= r3[4] * m1, r1[5] -= r3[5] * m1, r1[6] -= r3[6] * m1, r1[7] -= r3[7] * m1; m0 = r0[3]; r0[4] -= r3[4] * m0, r0[5] -= r3[5] * m0, r0[6] -= r3[6] * m0, r0[7] -= r3[7] * m0; m1 = r1[2]; /* now back substitute row 1 */ s = 1.0 / r1[1]; r1[4] = s * (r1[4] - r2[4] * m1), r1[5] = s * (r1[5] - r2[5] * m1), r1[6] = s * (r1[6] - r2[6] * m1), r1[7] = s * (r1[7] - r2[7] * m1); m0 = r0[2]; r0[4] -= r2[4] * m0, r0[5] -= r2[5] * m0, r0[6] -= r2[6] * m0, r0[7] -= r2[7] * m0; m0 = r0[1]; /* now back substitute row 0 */ s = 1.0 / r0[0]; r0[4] = s * (r0[4] - r1[4] * m0), r0[5] = s * (r0[5] - r1[5] * m0), r0[6] = s * (r0[6] - r1[6] * m0), r0[7] = s * (r0[7] - r1[7] * m0); MAT(out, 0, 0) = r0[4]; MAT(out, 0, 1) = r0[5], MAT(out, 0, 2) = r0[6]; MAT(out, 0, 3) = r0[7], MAT(out, 1, 0) = r1[4]; MAT(out, 1, 1) = r1[5], MAT(out, 1, 2) = r1[6]; MAT(out, 1, 3) = r1[7], MAT(out, 2, 0) = r2[4]; MAT(out, 2, 1) = r2[5], MAT(out, 2, 2) = r2[6]; MAT(out, 2, 3) = r2[7], MAT(out, 3, 0) = r3[4]; MAT(out, 3, 1) = r3[5], MAT(out, 3, 2) = r3[6]; MAT(out, 3, 3) = r3[7]; return GL_TRUE; #undef MAT #undef SWAP_ROWS } /* projection du point (objx,objy,obz) sur l'ecran (winx,winy,winz) */ GLint GLAPIENTRY gluProject(GLdouble objx, GLdouble objy, GLdouble objz, const GLdouble model[16], const GLdouble proj[16], const GLint viewport[4], GLdouble * winx, GLdouble * winy, GLdouble * winz) { /* matrice de transformation */ GLdouble in[4], out[4]; /* initilise la matrice et le vecteur a transformer */ in[0] = objx; in[1] = objy; in[2] = objz; in[3] = 1.0; transform_point(out, model, in); transform_point(in, proj, out); /* d'ou le resultat normalise entre -1 et 1 */ if (in[3] == 0.0) return GL_FALSE; in[0] /= in[3]; in[1] /= in[3]; in[2] /= in[3]; /* en coordonnees ecran */ *winx = viewport[0] + (1 + in[0]) * viewport[2] / 2; *winy = viewport[1] + (1 + in[1]) * viewport[3] / 2; /* entre 0 et 1 suivant z */ *winz = (1 + in[2]) / 2; return GL_TRUE; } /* transformation du point ecran (winx,winy,winz) en point objet */ GLint GLAPIENTRY gluUnProject(GLdouble winx, GLdouble winy, GLdouble winz, const GLdouble model[16], const GLdouble proj[16], const GLint viewport[4], GLdouble * objx, GLdouble * objy, GLdouble * objz) { /* matrice de transformation */ GLdouble m[16], A[16]; GLdouble in[4], out[4]; /* transformation coordonnees normalisees entre -1 et 1 */ in[0] = (winx - viewport[0]) * 2 / viewport[2] - 1.0; in[1] = (winy - viewport[1]) * 2 / viewport[3] - 1.0; in[2] = 2 * winz - 1.0; in[3] = 1.0; /* calcul transformation inverse */ matmul(A, proj, model); if (!invert_matrix(A, m)) return GL_FALSE; /* d'ou les coordonnees objets */ transform_point(out, m, in); if (out[3] == 0.0) return GL_FALSE; *objx = out[0] / out[3]; *objy = out[1] / out[3]; *objz = out[2] / out[3]; return GL_TRUE; } /* * New in GLU 1.3 * This is like gluUnProject but also takes near and far DepthRange values. */ #ifdef GLU_VERSION_1_3 GLint GLAPIENTRY gluUnProject4(GLdouble winx, GLdouble winy, GLdouble winz, GLdouble clipw, const GLdouble modelMatrix[16], const GLdouble projMatrix[16], const GLint viewport[4], GLclampd nearZ, GLclampd farZ, GLdouble * objx, GLdouble * objy, GLdouble * objz, GLdouble * objw) { /* matrice de transformation */ GLdouble m[16], A[16]; GLdouble in[4], out[4]; GLdouble z = nearZ + winz * (farZ - nearZ); /* transformation coordonnees normalisees entre -1 et 1 */ in[0] = (winx - viewport[0]) * 2 / viewport[2] - 1.0; in[1] = (winy - viewport[1]) * 2 / viewport[3] - 1.0; in[2] = 2.0 * z - 1.0; in[3] = clipw; /* calcul transformation inverse */ matmul(A, projMatrix, modelMatrix); if (!invert_matrix(A, m)) return GL_FALSE; /* d'ou les coordonnees objets */ transform_point(out, m, in); if (out[3] == 0.0) return GL_FALSE; *objx = out[0] / out[3]; *objy = out[1] / out[3]; *objz = out[2] / out[3]; *objw = out[3]; return GL_TRUE; } #endif