progs/redbook/accpersp.c

   1 /*
   2  * Copyright (c) 1993-1997, Silicon Graphics, Inc.
   3  * ALL RIGHTS RESERVED
   4  * Permission to use, copy, modify, and distribute this software for
   5  * any purpose and without fee is hereby granted, provided that the above
   6  * copyright notice appear in all copies and that both the copyright notice
   7  * and this permission notice appear in supporting documentation, and that
   8  * the name of Silicon Graphics, Inc. not be used in advertising
   9  * or publicity pertaining to distribution of the software without specific,
  10  * written prior permission.
  11  *
  12  * THE MATERIAL EMBODIED ON THIS SOFTWARE IS PROVIDED TO YOU "AS-IS"
  13  * AND WITHOUT WARRANTY OF ANY KIND, EXPRESS, IMPLIED OR OTHERWISE,
  14  * INCLUDING WITHOUT LIMITATION, ANY WARRANTY OF MERCHANTABILITY OR
  15  * FITNESS FOR A PARTICULAR PURPOSE.  IN NO EVENT SHALL SILICON
  16  * GRAPHICS, INC.  BE LIABLE TO YOU OR ANYONE ELSE FOR ANY DIRECT,
  17  * SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY
  18  * KIND, OR ANY DAMAGES WHATSOEVER, INCLUDING WITHOUT LIMITATION,
  19  * LOSS OF PROFIT, LOSS OF USE, SAVINGS OR REVENUE, OR THE CLAIMS OF
  20  * THIRD PARTIES, WHETHER OR NOT SILICON GRAPHICS, INC.  HAS BEEN
  21  * ADVISED OF THE POSSIBILITY OF SUCH LOSS, HOWEVER CAUSED AND ON
  22  * ANY THEORY OF LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE
  23  * POSSESSION, USE OR PERFORMANCE OF THIS SOFTWARE.
  24  *
  25  * US Government Users Restricted Rights
  26  * Use, duplication, or disclosure by the Government is subject to
  27  * restrictions set forth in FAR 52.227.19(c)(2) or subparagraph
  28  * (c)(1)(ii) of the Rights in Technical Data and Computer Software
  29  * clause at DFARS 252.227-7013 and/or in similar or successor
  30  * clauses in the FAR or the DOD or NASA FAR Supplement.
  31  * Unpublished-- rights reserved under the copyright laws of the
  32  * United States.  Contractor/manufacturer is Silicon Graphics,
  33  * Inc., 2011 N.  Shoreline Blvd., Mountain View, CA 94039-7311.
  34  *
  35  * OpenGL(R) is a registered trademark of Silicon Graphics, Inc.
  36  */
  37
  38 /*  accpersp.c
  39  *  Use the accumulation buffer to do full-scene antialiasing
  40  *  on a scene with perspective projection, using the special
  41  *  routines accFrustum() and accPerspective().
  42  */
  43 #include <stdlib.h>
  44 #include <math.h>
  45 #include <GL/glut.h>
  46 #include "jitter.h"
  47
  48 #define PI_ 3.14159265358979323846
  49
  50 /* accFrustum()
  51  * The first 6 arguments are identical to the glFrustum() call.
  52  *
  53  * pixdx and pixdy are anti-alias jitter in pixels.
  54  * Set both equal to 0.0 for no anti-alias jitter.
  55  * eyedx and eyedy are depth-of field jitter in pixels.
  56  * Set both equal to 0.0 for no depth of field effects.
  57  *
  58  * focus is distance from eye to plane in focus.
  59  * focus must be greater than, but not equal to 0.0.
  60  *
  61  * Note that accFrustum() calls glTranslatef().  You will
  62  * probably want to insure that your ModelView matrix has been
  63  * initialized to identity before calling accFrustum().
  64  */
  65 static void accFrustum(GLdouble left, GLdouble right, GLdouble bottom,
  66    GLdouble top, GLdouble nnear, GLdouble ffar, GLdouble pixdx,
  67    GLdouble pixdy, GLdouble eyedx, GLdouble eyedy, GLdouble focus)
  68 {
  69    GLdouble xwsize, ywsize;
  70    GLdouble dx, dy;
  71    GLint viewport[4];
  72
  73    glGetIntegerv (GL_VIEWPORT, viewport);
  74
  75    xwsize = right - left;
  76    ywsize = top - bottom;
  77
  78    dx = -(pixdx*xwsize/(GLdouble) viewport[2] + eyedx*nnear/focus);
  79    dy = -(pixdy*ywsize/(GLdouble) viewport[3] + eyedy*nnear/focus);
  80
  81    glMatrixMode(GL_PROJECTION);
  82    glLoadIdentity();
  83    glFrustum (left + dx, right + dx, bottom + dy, top + dy, nnear, ffar);
  84    glMatrixMode(GL_MODELVIEW);
  85    glLoadIdentity();
  86    glTranslatef (-eyedx, -eyedy, 0.0);
  87 }
  88
  89 /* accPerspective()
  90  *
  91  * The first 4 arguments are identical to the gluPerspective() call.
  92  * pixdx and pixdy are anti-alias jitter in pixels.
  93  * Set both equal to 0.0 for no anti-alias jitter.
  94  * eyedx and eyedy are depth-of field jitter in pixels.
  95  * Set both equal to 0.0 for no depth of field effects.
  96  *
  97  * focus is distance from eye to plane in focus.
  98  * focus must be greater than, but not equal to 0.0.
  99  *
 100  * Note that accPerspective() calls accFrustum().
 101  */
 102 static void accPerspective(GLdouble fovy, GLdouble aspect,
 103    GLdouble nnear, GLdouble ffar, GLdouble pixdx, GLdouble pixdy,
 104    GLdouble eyedx, GLdouble eyedy, GLdouble focus)
 105 {
 106    GLdouble fov2,left,right,bottom,top;
 107
 108    fov2 = ((fovy*PI_) / 180.0) / 2.0;
 109
 110    top = nnear / (cos(fov2) / sin(fov2));
 111    bottom = -top;
 112
 113    right = top * aspect;
 114    left = -right;
 115
 116    accFrustum (left, right, bottom, top, nnear, ffar,
 117                pixdx, pixdy, eyedx, eyedy, focus);
 118 }
 119
 120 /*  Initialize lighting and other values.
 121  */
 122 static void init(void)
 123 {
 124    GLfloat mat_ambient[] = { 1.0, 1.0, 1.0, 1.0 };
 125    GLfloat mat_specular[] = { 1.0, 1.0, 1.0, 1.0 };
 126    GLfloat light_position[] = { 0.0, 0.0, 10.0, 1.0 };
 127    GLfloat lm_ambient[] = { 0.2, 0.2, 0.2, 1.0 };
 128
 129    glMaterialfv(GL_FRONT, GL_AMBIENT, mat_ambient);
 130    glMaterialfv(GL_FRONT, GL_SPECULAR, mat_specular);
 131    glMaterialf(GL_FRONT, GL_SHININESS, 50.0);
 132    glLightfv(GL_LIGHT0, GL_POSITION, light_position);
 133    glLightModelfv(GL_LIGHT_MODEL_AMBIENT, lm_ambient);
 134
 135    glEnable(GL_LIGHTING);
 136    glEnable(GL_LIGHT0);
 137    glEnable(GL_DEPTH_TEST);
 138    glShadeModel (GL_FLAT);
 139
 140    glClearColor(0.0, 0.0, 0.0, 0.0);
 141    glClearAccum(0.0, 0.0, 0.0, 0.0);
 142 }
 143
 144 static void displayObjects(void)
 145 {
 146    GLfloat torus_diffuse[] = { 0.7, 0.7, 0.0, 1.0 };
 147    GLfloat cube_diffuse[] = { 0.0, 0.7, 0.7, 1.0 };
 148    GLfloat sphere_diffuse[] = { 0.7, 0.0, 0.7, 1.0 };
 149    GLfloat octa_diffuse[] = { 0.7, 0.4, 0.4, 1.0 };
 150
 151    glPushMatrix ();
 152    glTranslatef (0.0, 0.0, -5.0);
 153    glRotatef (30.0, 1.0, 0.0, 0.0);
 154
 155    glPushMatrix ();
 156    glTranslatef (-0.80, 0.35, 0.0);
 157    glRotatef (100.0, 1.0, 0.0, 0.0);
 158    glMaterialfv(GL_FRONT, GL_DIFFUSE, torus_diffuse);
 159    glutSolidTorus (0.275, 0.85, 16, 16);
 160    glPopMatrix ();
 161
 162    glPushMatrix ();
 163    glTranslatef (-0.75, -0.50, 0.0);
 164    glRotatef (45.0, 0.0, 0.0, 1.0);
 165    glRotatef (45.0, 1.0, 0.0, 0.0);
 166    glMaterialfv(GL_FRONT, GL_DIFFUSE, cube_diffuse);
 167    glutSolidCube (1.5);
 168    glPopMatrix ();
 169
 170    glPushMatrix ();
 171    glTranslatef (0.75, 0.60, 0.0);
 172    glRotatef (30.0, 1.0, 0.0, 0.0);
 173    glMaterialfv(GL_FRONT, GL_DIFFUSE, sphere_diffuse);
 174    glutSolidSphere (1.0, 16, 16);
 175    glPopMatrix ();
 176
 177    glPushMatrix ();
 178    glTranslatef (0.70, -0.90, 0.25);
 179    glMaterialfv(GL_FRONT, GL_DIFFUSE, octa_diffuse);
 180    glutSolidOctahedron ();
 181    glPopMatrix ();
 182
 183    glPopMatrix ();
 184 }
 185
 186 #define ACSIZE  8
 187
 188 static void display(void)
 189 {
 190    GLint viewport[4];
 191    int jitter;
 192
 193    glGetIntegerv (GL_VIEWPORT, viewport);
 194
 195    glClear(GL_ACCUM_BUFFER_BIT);
 196    for (jitter = 0; jitter < ACSIZE; jitter++) {
 197       glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 198       accPerspective (50.0,
 199          (GLdouble) viewport[2]/(GLdouble) viewport[3],
 200          1.0, 15.0, j8[jitter].x, j8[jitter].y, 0.0, 0.0, 1.0);
 201       displayObjects ();
 202       glAccum(GL_ACCUM, 1.0/ACSIZE);
 203    }
 204    glAccum (GL_RETURN, 1.0);
 205    glFlush();
 206 }
 207
 208 static void reshape(int w, int h)
 209 {
 210    glViewport(0, 0, (GLsizei) w, (GLsizei) h);
 211 }
 212
 213 /* ARGSUSED1 */
 214 static void keyboard(unsigned char key, int x, int y)
 215 {
 216    switch (key) {
 217       case 27:
 218          exit(0);
 219          break;
 220    }
 221 }
 222
 223 /*  Main Loop
 224  *  Be certain you request an accumulation buffer.
 225  */
 226 int main(int argc, char** argv)
 227 {
 228    glutInit(&argc, argv);
 229    glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB
 230                         | GLUT_ACCUM | GLUT_DEPTH);
 231    glutInitWindowSize (250, 250);
 232    glutInitWindowPosition (100, 100);
 233    glutCreateWindow (argv[0]);
 234    init();
 235    glutReshapeFunc(reshape);
 236    glutDisplayFunc(display);
 237    glutKeyboardFunc(keyboard);
 238    glutMainLoop();
 239    return 0;
 240 }