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authorjtg <jtg>1999-08-19 00:55:39 +0000
committerjtg <jtg>1999-08-19 00:55:39 +0000
commitafb833d4e89c312460a4ab9ed6a7a8ca4ebbfe1c (patch)
tree59d65b4da12fb5379224cf5f6b808fde91523c7f /src/glu/mesa/project.c
parentf2544d4920ce168bec9cd94d774b7ea5103a3d74 (diff)
Initial revision
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+/* $Id: project.c,v 1.1 1999/08/19 00:55:42 jtg 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 1.1 1999/08/19 00:55:42 jtg
+ * Initial revision
+ *
+ * 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 <stdio.h>
+#include <string.h>
+#include <math.h>
+#include "gluP.h"
+#endif
+
+
+/*
+ * This code was contributed by Marc Buffat ([email protected]).
+ * 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 [email protected]
+ * 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);
+ invert_matrix(A,m);
+
+ /* 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;
+}
+