src/redbook/dof.c

   1
   2 /* Copyright (c) Mark J. Kilgard, 1994. */
   3
   4 /*
   5  * (c) Copyright 1993, Silicon Graphics, Inc.
   6  * ALL RIGHTS RESERVED
   7  * Permission to use, copy, modify, and distribute this software for
   8  * any purpose and without fee is hereby granted, provided that the above
   9  * copyright notice appear in all copies and that both the copyright notice
  10  * and this permission notice appear in supporting documentation, and that
  11  * the name of Silicon Graphics, Inc. not be used in advertising
  12  * or publicity pertaining to distribution of the software without specific,
  13  * written prior permission.
  14  *
  15  * THE MATERIAL EMBODIED ON THIS SOFTWARE IS PROVIDED TO YOU "AS-IS"
  16  * AND WITHOUT WARRANTY OF ANY KIND, EXPRESS, IMPLIED OR OTHERWISE,
  17  * INCLUDING WITHOUT LIMITATION, ANY WARRANTY OF MERCHANTABILITY OR
  18  * FITNESS FOR A PARTICULAR PURPOSE.  IN NO EVENT SHALL SILICON
  19  * GRAPHICS, INC.  BE LIABLE TO YOU OR ANYONE ELSE FOR ANY DIRECT,
  20  * SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY
  21  * KIND, OR ANY DAMAGES WHATSOEVER, INCLUDING WITHOUT LIMITATION,
  22  * LOSS OF PROFIT, LOSS OF USE, SAVINGS OR REVENUE, OR THE CLAIMS OF
  23  * THIRD PARTIES, WHETHER OR NOT SILICON GRAPHICS, INC.  HAS BEEN
  24  * ADVISED OF THE POSSIBILITY OF SUCH LOSS, HOWEVER CAUSED AND ON
  25  * ANY THEORY OF LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE
  26  * POSSESSION, USE OR PERFORMANCE OF THIS SOFTWARE.
  27  *
  28  * US Government Users Restricted Rights
  29  * Use, duplication, or disclosure by the Government is subject to
  30  * restrictions set forth in FAR 52.227.19(c)(2) or subparagraph
  31  * (c)(1)(ii) of the Rights in Technical Data and Computer Software
  32  * clause at DFARS 252.227-7013 and/or in similar or successor
  33  * clauses in the FAR or the DOD or NASA FAR Supplement.
  34  * Unpublished-- rights reserved under the copyright laws of the
  35  * United States.  Contractor/manufacturer is Silicon Graphics,
  36  * Inc., 2011 N.  Shoreline Blvd., Mountain View, CA 94039-7311.
  37  *
  38  * OpenGL(TM) is a trademark of Silicon Graphics, Inc.
  39  */
  40 /*
  41  *  dof.c
  42  *  This program demonstrates use of the accumulation buffer to
  43  *  create an out-of-focus depth-of-field effect.  The teapots
  44  *  are drawn several times into the accumulation buffer.  The
  45  *  viewing volume is jittered, except at the focal point, where
  46  *  the viewing volume is at the same position, each time.  In
  47  *  this case, the gold teapot remains in focus.
  48  */
  49 #include <stdlib.h>
  50 #include <math.h>
  51 #include <GL/glut.h>
  52 #include "jitter.h"
  53
  54 #define PI_ 3.14159265358979323846
  55
  56 /*      accFrustum()
  57  *  The first 6 arguments are identical to the glFrustum() call.
  58  *
  59  *  pixdx and pixdy are anti-alias jitter in pixels.
  60  *  Set both equal to 0.0 for no anti-alias jitter.
  61  *  eyedx and eyedy are depth-of field jitter in pixels.
  62  *  Set both equal to 0.0 for no depth of field effects.
  63  *
  64  *  focus is distance from eye to plane in focus.
  65  *  focus must be greater than, but not equal to 0.0.
  66  *
  67  *  Note that accFrustum() calls glTranslatef().  You will
  68  *  probably want to insure that your ModelView matrix has been
  69  *  initialized to identity before calling accFrustum().
  70  */
  71 void accFrustum(GLdouble left, GLdouble right, GLdouble bottom,
  72     GLdouble top, GLdouble nnear, GLdouble ffar, GLdouble pixdx,
  73     GLdouble pixdy, GLdouble eyedx, GLdouble eyedy, GLdouble focus)
  74 {
  75     GLdouble xwsize, ywsize;
  76     GLdouble dx, dy;
  77     GLint viewport[4];
  78
  79     glGetIntegerv (GL_VIEWPORT, viewport);
  80
  81     xwsize = right - left;
  82     ywsize = top - bottom;
  83
  84     dx = -(pixdx*xwsize/(GLdouble) viewport[2] + eyedx*nnear/focus);
  85     dy = -(pixdy*ywsize/(GLdouble) viewport[3] + eyedy*nnear/focus);
  86
  87     glMatrixMode(GL_PROJECTION);
  88     glLoadIdentity();
  89     glFrustum (left + dx, right + dx, bottom + dy, top + dy, nnear, ffar);
  90     glMatrixMode(GL_MODELVIEW);
  91     glLoadIdentity();
  92     glTranslatef (-eyedx, -eyedy, 0.0);
  93 }
  94
  95 /*  accPerspective()
  96  *
  97  *  The first 4 arguments are identical to the gluPerspective() call.
  98  *  pixdx and pixdy are anti-alias jitter in pixels.
  99  *  Set both equal to 0.0 for no anti-alias jitter.
 100  *  eyedx and eyedy are depth-of field jitter in pixels.
 101  *  Set both equal to 0.0 for no depth of field effects.
 102  *
 103  *  focus is distance from eye to plane in focus.
 104  *  focus must be greater than, but not equal to 0.0.
 105  *
 106  *  Note that accPerspective() calls accFrustum().
 107  */
 108 void accPerspective(GLdouble fovy, GLdouble aspect,
 109     GLdouble nnear, GLdouble ffar, GLdouble pixdx, GLdouble pixdy,
 110     GLdouble eyedx, GLdouble eyedy, GLdouble focus)
 111 {
 112     GLdouble fov2,left,right,bottom,top;
 113
 114     fov2 = ((fovy*PI_) / 180.0) / 2.0;
 115
 116     top = nnear / (cos(fov2) / sin(fov2));
 117     bottom = -top;
 118
 119     right = top * aspect;
 120     left = -right;
 121
 122     accFrustum (left, right, bottom, top, nnear, ffar,
 123         pixdx, pixdy, eyedx, eyedy, focus);
 124 }
 125
 126 void myinit(void)
 127 {
 128     GLfloat ambient[] = { 0.0, 0.0, 0.0, 1.0 };
 129     GLfloat diffuse[] = { 1.0, 1.0, 1.0, 1.0 };
 130     GLfloat position[] = { 0.0, 3.0, 3.0, 0.0 };
 131
 132     GLfloat lmodel_ambient[] = { 0.2, 0.2, 0.2, 1.0 };
 133     GLfloat local_view[] = { 0.0 };
 134
 135     glEnable(GL_DEPTH_TEST);
 136     glDepthFunc(GL_LESS);
 137
 138     glLightfv(GL_LIGHT0, GL_AMBIENT, ambient);
 139     glLightfv(GL_LIGHT0, GL_DIFFUSE, diffuse);
 140     glLightfv(GL_LIGHT0, GL_POSITION, position);
 141
 142     glLightModelfv(GL_LIGHT_MODEL_AMBIENT, lmodel_ambient);
 143     glLightModelfv(GL_LIGHT_MODEL_LOCAL_VIEWER, local_view);
 144
 145     glFrontFace (GL_CW);
 146     glEnable(GL_LIGHTING);
 147     glEnable(GL_LIGHT0);
 148     glEnable(GL_AUTO_NORMAL);
 149     glEnable(GL_NORMALIZE);
 150
 151     glMatrixMode (GL_MODELVIEW);
 152     glLoadIdentity ();
 153
 154     glClearColor(0.0, 0.0, 0.0, 0.0);
 155     glClearAccum(0.0, 0.0, 0.0, 0.0);
 156 }
 157
 158 void renderTeapot (GLfloat x, GLfloat y, GLfloat z,
 159     GLfloat ambr, GLfloat ambg, GLfloat ambb,
 160     GLfloat difr, GLfloat difg, GLfloat difb,
 161     GLfloat specr, GLfloat specg, GLfloat specb, GLfloat shine)
 162 {
 163     float mat[4];
 164
 165     glPushMatrix();
 166     glTranslatef (x, y, z);
 167     mat[0] = ambr; mat[1] = ambg; mat[2] = ambb; mat[3] = 1.0;
 168     glMaterialfv (GL_FRONT, GL_AMBIENT, mat);
 169     mat[0] = difr; mat[1] = difg; mat[2] = difb;
 170     glMaterialfv (GL_FRONT, GL_DIFFUSE, mat);
 171     mat[0] = specr; mat[1] = specg; mat[2] = specb;
 172     glMaterialfv (GL_FRONT, GL_SPECULAR, mat);
 173     glMaterialf (GL_FRONT, GL_SHININESS, shine*128.0);
 174     glutSolidTeapot(0.5);
 175     glPopMatrix();
 176 }
 177
 178 /*  display() draws 5 teapots into the accumulation buffer
 179  *  several times; each time with a jittered perspective.
 180  *  The focal point is at z = 5.0, so the gold teapot will
 181  *  stay in focus.  The amount of jitter is adjusted by the
 182  *  magnitude of the accPerspective() jitter; in this example, 0.33.
 183  *  In this example, the teapots are drawn 8 times.  See jitter.h
 184  */
 185 void display(void)
 186 {
 187     int jitter;
 188     GLint viewport[4];
 189
 190     glGetIntegerv (GL_VIEWPORT, viewport);
 191     glClear(GL_ACCUM_BUFFER_BIT);
 192
 193     for (jitter = 0; jitter < 8; jitter++) {
 194         glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 195         accPerspective (45.0,
 196                 (GLdouble) viewport[2]/(GLdouble) viewport[3],
 197                 1.0, 15.0, 0.0, 0.0,
 198                 0.33*j8[jitter].x, 0.33*j8[jitter].y, 5.0);
 199 /*      ruby, gold, silver, emerald, and cyan teapots   */
 200         renderTeapot (-1.1, -0.5, -4.5, 0.1745, 0.01175, 0.01175,
 201             0.61424, 0.04136, 0.04136, 0.727811, 0.626959, 0.626959, 0.6);
 202         renderTeapot (-0.5, -0.5, -5.0, 0.24725, 0.1995, 0.0745,
 203             0.75164, 0.60648, 0.22648, 0.628281, 0.555802, 0.366065, 0.4);
 204         renderTeapot (0.2, -0.5, -5.5, 0.19225, 0.19225, 0.19225,
 205             0.50754, 0.50754, 0.50754, 0.508273, 0.508273, 0.508273, 0.4);
 206         renderTeapot (1.0, -0.5, -6.0, 0.0215, 0.1745, 0.0215,
 207             0.07568, 0.61424, 0.07568, 0.633, 0.727811, 0.633, 0.6);
 208         renderTeapot (1.8, -0.5, -6.5, 0.0, 0.1, 0.06, 0.0, 0.50980392,
 209             0.50980392, 0.50196078, 0.50196078, 0.50196078, .25);
 210         glAccum (GL_ACCUM, 0.125);
 211     }
 212
 213     glAccum (GL_RETURN, 1.0);
 214     glFlush();
 215 }
 216
 217 void myReshape(int w, int h)
 218 {
 219     glViewport(0, 0, w, h);
 220 }
 221
 222 static void
 223 key(unsigned char k, int x, int y)
 224 {
 225   switch (k) {
 226   case 27:  /* Escape */
 227     exit(0);
 228     break;
 229   default:
 230     return;
 231   }
 232   glutPostRedisplay();
 233 }
 234
 235 /*  Main Loop
 236  *  Open window with initial window size, title bar,
 237  *  RGBA display mode, depth buffer, and handle input events.
 238  */
 239 int main(int argc, char** argv)
 240 {
 241     glutInit(&argc, argv);
 242     glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB
 243                         | GLUT_ACCUM | GLUT_DEPTH);
 244     glutCreateWindow (argv[0]);
 245     myinit();
 246     glutReshapeFunc(myReshape);
 247     glutDisplayFunc(display);
 248     glutKeyboardFunc(key);
 249     glutMainLoop();
 250     return 0;             /* ANSI C requires main to return int. */
 251 }