src/glu/sgi/libutil/project.c

   1 /*
   2 ** License Applicability. Except to the extent portions of this file are
   3 ** made subject to an alternative license as permitted in the SGI Free
   4 ** Software License B, Version 1.1 (the "License"), the contents of this
   5 ** file are subject only to the provisions of the License. You may not use
   6 ** this file except in compliance with the License. You may obtain a copy
   7 ** of the License at Silicon Graphics, Inc., attn: Legal Services, 1600
   8 ** Amphitheatre Parkway, Mountain View, CA 94043-1351, or at:
   9 **
  10 ** http://oss.sgi.com/projects/FreeB
  11 **
  12 ** Note that, as provided in the License, the Software is distributed on an
  13 ** "AS IS" basis, with ALL EXPRESS AND IMPLIED WARRANTIES AND CONDITIONS
  14 ** DISCLAIMED, INCLUDING, WITHOUT LIMITATION, ANY IMPLIED WARRANTIES AND
  15 ** CONDITIONS OF MERCHANTABILITY, SATISFACTORY QUALITY, FITNESS FOR A
  16 ** PARTICULAR PURPOSE, AND NON-INFRINGEMENT.
  17 **
  18 ** Original Code. The Original Code is: OpenGL Sample Implementation,
  19 ** Version 1.2.1, released January 26, 2000, developed by Silicon Graphics,
  20 ** Inc. The Original Code is Copyright (c) 1991-2000 Silicon Graphics, Inc.
  21 ** Copyright in any portions created by third parties is as indicated
  22 ** elsewhere herein. All Rights Reserved.
  23 **
  24 ** Additional Notice Provisions: The application programming interfaces
  25 ** established by SGI in conjunction with the Original Code are The
  26 ** OpenGL(R) Graphics System: A Specification (Version 1.2.1), released
  27 ** April 1, 1999; The OpenGL(R) Graphics System Utility Library (Version
  28 ** 1.3), released November 4, 1998; and OpenGL(R) Graphics with the X
  29 ** Window System(R) (Version 1.3), released October 19, 1998. This software
  30 ** was created using the OpenGL(R) version 1.2.1 Sample Implementation
  31 ** published by SGI, but has not been independently verified as being
  32 ** compliant with the OpenGL(R) version 1.2.1 Specification.
  33 **
  34 ** $Date: 2001/03/17 00:25:41 $ $Revision: 1.1 $
  35 ** $Header: /home/krh/git/sync/mesa-cvs-repo/Mesa/src/glu/sgi/libutil/project.c,v 1.1 2001/03/17 00:25:41 brianp Exp $
  36 */
  37
  38 #include "gluos.h"
  39 #include <math.h>
  40 #include <GL/gl.h>
  41 #include <GL/glu.h>
  42 #include "gluint.h"
  43
  44 /*
  45 ** Make m an identity matrix
  46 */
  47 static void __gluMakeIdentityd(GLdouble m[16])
  48 {
  49     m[0+4*0] = 1; m[0+4*1] = 0; m[0+4*2] = 0; m[0+4*3] = 0;
  50     m[1+4*0] = 0; m[1+4*1] = 1; m[1+4*2] = 0; m[1+4*3] = 0;
  51     m[2+4*0] = 0; m[2+4*1] = 0; m[2+4*2] = 1; m[2+4*3] = 0;
  52     m[3+4*0] = 0; m[3+4*1] = 0; m[3+4*2] = 0; m[3+4*3] = 1;
  53 }
  54
  55 static void __gluMakeIdentityf(GLfloat m[16])
  56 {
  57     m[0+4*0] = 1; m[0+4*1] = 0; m[0+4*2] = 0; m[0+4*3] = 0;
  58     m[1+4*0] = 0; m[1+4*1] = 1; m[1+4*2] = 0; m[1+4*3] = 0;
  59     m[2+4*0] = 0; m[2+4*1] = 0; m[2+4*2] = 1; m[2+4*3] = 0;
  60     m[3+4*0] = 0; m[3+4*1] = 0; m[3+4*2] = 0; m[3+4*3] = 1;
  61 }
  62
  63 void GLAPIENTRY
  64 gluOrtho2D(GLdouble left, GLdouble right, GLdouble bottom, GLdouble top)
  65 {
  66     glOrtho(left, right, bottom, top, -1, 1);
  67 }
  68
  69 #define __glPi 3.14159265358979323846
  70
  71 void GLAPIENTRY
  72 gluPerspective(GLdouble fovy, GLdouble aspect, GLdouble zNear, GLdouble zFar)
  73 {
  74     GLdouble m[4][4];
  75     double sine, cotangent, deltaZ;
  76     double radians = fovy / 2 * __glPi / 180;
  77
  78     deltaZ = zFar - zNear;
  79     sine = sin(radians);
  80     if ((deltaZ == 0) || (sine == 0) || (aspect == 0)) {
  81         return;
  82     }
  83     cotangent = COS(radians) / sine;
  84
  85     __gluMakeIdentityd(&m[0][0]);
  86     m[0][0] = cotangent / aspect;
  87     m[1][1] = cotangent;
  88     m[2][2] = -(zFar + zNear) / deltaZ;
  89     m[2][3] = -1;
  90     m[3][2] = -2 * zNear * zFar / deltaZ;
  91     m[3][3] = 0;
  92     glMultMatrixd(&m[0][0]);
  93 }
  94
  95 static void normalize(float v[3])
  96 {
  97     float r;
  98
  99     r = sqrt( v[0]*v[0] + v[1]*v[1] + v[2]*v[2] );
 100     if (r == 0.0) return;
 101
 102     v[0] /= r;
 103     v[1] /= r;
 104     v[2] /= r;
 105 }
 106
 107 static void cross(float v1[3], float v2[3], float result[3])
 108 {
 109     result[0] = v1[1]*v2[2] - v1[2]*v2[1];
 110     result[1] = v1[2]*v2[0] - v1[0]*v2[2];
 111     result[2] = v1[0]*v2[1] - v1[1]*v2[0];
 112 }
 113
 114 void GLAPIENTRY
 115 gluLookAt(GLdouble eyex, GLdouble eyey, GLdouble eyez, GLdouble centerx,
 116           GLdouble centery, GLdouble centerz, GLdouble upx, GLdouble upy,
 117           GLdouble upz)
 118 {
 119     int i;
 120     float forward[3], side[3], up[3];
 121     GLfloat m[4][4];
 122
 123     forward[0] = centerx - eyex;
 124     forward[1] = centery - eyey;
 125     forward[2] = centerz - eyez;
 126
 127     up[0] = upx;
 128     up[1] = upy;
 129     up[2] = upz;
 130
 131     normalize(forward);
 132
 133     /* Side = forward x up */
 134     cross(forward, up, side);
 135     normalize(side);
 136
 137     /* Recompute up as: up = side x forward */
 138     cross(side, forward, up);
 139
 140     __gluMakeIdentityf(&m[0][0]);
 141     m[0][0] = side[0];
 142     m[1][0] = side[1];
 143     m[2][0] = side[2];
 144
 145     m[0][1] = up[0];
 146     m[1][1] = up[1];
 147     m[2][1] = up[2];
 148
 149     m[0][2] = -forward[0];
 150     m[1][2] = -forward[1];
 151     m[2][2] = -forward[2];
 152
 153     glMultMatrixf(&m[0][0]);
 154     glTranslated(-eyex, -eyey, -eyez);
 155 }
 156
 157 static void __gluMultMatrixVecd(const GLdouble matrix[16], const GLdouble in[4],
 158                       GLdouble out[4])
 159 {
 160     int i;
 161
 162     for (i=0; i<4; i++) {
 163         out[i] =
 164             in[0] * matrix[0*4+i] +
 165             in[1] * matrix[1*4+i] +
 166             in[2] * matrix[2*4+i] +
 167             in[3] * matrix[3*4+i];
 168     }
 169 }
 170
 171 /*
 172 ** inverse = invert(src)
 173 */
 174 static int __gluInvertMatrixd(const GLdouble src[16], GLdouble inverse[16])
 175 {
 176     int i, j, k, swap;
 177     double t;
 178     GLdouble temp[4][4];
 179
 180     for (i=0; i<4; i++) {
 181         for (j=0; j<4; j++) {
 182             temp[i][j] = src[i*4+j];
 183         }
 184     }
 185     __gluMakeIdentityd(inverse);
 186
 187     for (i = 0; i < 4; i++) {
 188         /*
 189         ** Look for largest element in column
 190         */
 191         swap = i;
 192         for (j = i + 1; j < 4; j++) {
 193             if (fabs(temp[j][i]) > fabs(temp[i][i])) {
 194                 swap = j;
 195             }
 196         }
 197
 198         if (swap != i) {
 199             /*
 200             ** Swap rows.
 201             */
 202             for (k = 0; k < 4; k++) {
 203                 t = temp[i][k];
 204                 temp[i][k] = temp[swap][k];
 205                 temp[swap][k] = t;
 206
 207                 t = inverse[i*4+k];
 208                 inverse[i*4+k] = inverse[swap*4+k];
 209                 inverse[swap*4+k] = t;
 210             }
 211         }
 212
 213         if (temp[i][i] == 0) {
 214             /*
 215             ** No non-zero pivot.  The matrix is singular, which shouldn't
 216             ** happen.  This means the user gave us a bad matrix.
 217             */
 218             return GL_FALSE;
 219         }
 220
 221         t = temp[i][i];
 222         for (k = 0; k < 4; k++) {
 223             temp[i][k] /= t;
 224             inverse[i*4+k] /= t;
 225         }
 226         for (j = 0; j < 4; j++) {
 227             if (j != i) {
 228                 t = temp[j][i];
 229                 for (k = 0; k < 4; k++) {
 230                     temp[j][k] -= temp[i][k]*t;
 231                     inverse[j*4+k] -= inverse[i*4+k]*t;
 232                 }
 233             }
 234         }
 235     }
 236     return GL_TRUE;
 237 }
 238
 239 static void __gluMultMatricesd(const GLdouble a[16], const GLdouble b[16],
 240                                 GLdouble r[16])
 241 {
 242     int i, j;
 243
 244     for (i = 0; i < 4; i++) {
 245         for (j = 0; j < 4; j++) {
 246             r[i*4+j] =
 247                 a[i*4+0]*b[0*4+j] +
 248                 a[i*4+1]*b[1*4+j] +
 249                 a[i*4+2]*b[2*4+j] +
 250                 a[i*4+3]*b[3*4+j];
 251         }
 252     }
 253 }
 254
 255 GLint GLAPIENTRY
 256 gluProject(GLdouble objx, GLdouble objy, GLdouble objz,
 257               const GLdouble modelMatrix[16],
 258               const GLdouble projMatrix[16],
 259               const GLint viewport[4],
 260               GLdouble *winx, GLdouble *winy, GLdouble *winz)
 261 {
 262     double in[4];
 263     double out[4];
 264
 265     in[0]=objx;
 266     in[1]=objy;
 267     in[2]=objz;
 268     in[3]=1.0;
 269     __gluMultMatrixVecd(modelMatrix, in, out);
 270     __gluMultMatrixVecd(projMatrix, out, in);
 271     if (in[3] == 0.0) return(GL_FALSE);
 272     in[0] /= in[3];
 273     in[1] /= in[3];
 274     in[2] /= in[3];
 275     /* Map x, y and z to range 0-1 */
 276     in[0] = in[0] * 0.5 + 0.5;
 277     in[1] = in[1] * 0.5 + 0.5;
 278     in[2] = in[2] * 0.5 + 0.5;
 279
 280     /* Map x,y to viewport */
 281     in[0] = in[0] * viewport[2] + viewport[0];
 282     in[1] = in[1] * viewport[3] + viewport[1];
 283
 284     *winx=in[0];
 285     *winy=in[1];
 286     *winz=in[2];
 287     return(GL_TRUE);
 288 }
 289
 290 GLint GLAPIENTRY
 291 gluUnProject(GLdouble winx, GLdouble winy, GLdouble winz,
 292                 const GLdouble modelMatrix[16],
 293                 const GLdouble projMatrix[16],
 294                 const GLint viewport[4],
 295                 GLdouble *objx, GLdouble *objy, GLdouble *objz)
 296 {
 297     double finalMatrix[16];
 298     double in[4];
 299     double out[4];
 300
 301     __gluMultMatricesd(modelMatrix, projMatrix, finalMatrix);
 302     if (!__gluInvertMatrixd(finalMatrix, finalMatrix)) return(GL_FALSE);
 303
 304     in[0]=winx;
 305     in[1]=winy;
 306     in[2]=winz;
 307     in[3]=1.0;
 308
 309     /* Map x and y from window coordinates */
 310     in[0] = (in[0] - viewport[0]) / viewport[2];
 311     in[1] = (in[1] - viewport[1]) / viewport[3];
 312
 313     /* Map to range -1 to 1 */
 314     in[0] = in[0] * 2 - 1;
 315     in[1] = in[1] * 2 - 1;
 316     in[2] = in[2] * 2 - 1;
 317
 318     __gluMultMatrixVecd(finalMatrix, in, out);
 319     if (out[3] == 0.0) return(GL_FALSE);
 320     out[0] /= out[3];
 321     out[1] /= out[3];
 322     out[2] /= out[3];
 323     *objx = out[0];
 324     *objy = out[1];
 325     *objz = out[2];
 326     return(GL_TRUE);
 327 }
 328
 329 GLint GLAPIENTRY
 330 gluUnProject4(GLdouble winx, GLdouble winy, GLdouble winz, GLdouble clipw,
 331               const GLdouble modelMatrix[16],
 332               const GLdouble projMatrix[16],
 333               const GLint viewport[4],
 334               GLclampd near, GLclampd far,
 335               GLdouble *objx, GLdouble *objy, GLdouble *objz,
 336               GLdouble *objw)
 337 {
 338     double finalMatrix[16];
 339     double in[4];
 340     double out[4];
 341
 342     __gluMultMatricesd(modelMatrix, projMatrix, finalMatrix);
 343     if (!__gluInvertMatrixd(finalMatrix, finalMatrix)) return(GL_FALSE);
 344
 345     in[0]=winx;
 346     in[1]=winy;
 347     in[2]=winz;
 348     in[3]=clipw;
 349
 350     /* Map x and y from window coordinates */
 351     in[0] = (in[0] - viewport[0]) / viewport[2];
 352     in[1] = (in[1] - viewport[1]) / viewport[3];
 353     in[2] = (in[2] - near) / (far - near);
 354
 355     /* Map to range -1 to 1 */
 356     in[0] = in[0] * 2 - 1;
 357     in[1] = in[1] * 2 - 1;
 358     in[2] = in[2] * 2 - 1;
 359
 360     __gluMultMatrixVecd(finalMatrix, in, out);
 361     if (out[3] == 0.0) return(GL_FALSE);
 362     *objx = out[0];
 363     *objy = out[1];
 364     *objz = out[2];
 365     *objw = out[3];
 366     return(GL_TRUE);
 367 }
 368
 369 void GLAPIENTRY
 370 gluPickMatrix(GLdouble x, GLdouble y, GLdouble deltax, GLdouble deltay,
 371                   GLint viewport[4])
 372 {
 373     if (deltax <= 0 || deltay <= 0) {
 374         return;
 375     }
 376
 377     /* Translate and scale the picked region to the entire window */
 378     glTranslatef((viewport[2] - 2 * (x - viewport[0])) / deltax,
 379             (viewport[3] - 2 * (y - viewport[1])) / deltay, 0);
 380     glScalef(viewport[2] / deltax, viewport[3] / deltay, 1.0);
 381 }