progs/samples/accum.c

   1 /*
   2  * Copyright (c) 1991, 1992, 1993 Silicon Graphics, Inc.
   3  *
   4  * Permission to use, copy, modify, distribute, and sell this software and
   5  * its documentation for any purpose is hereby granted without fee, provided
   6  * that (i) the above copyright notices and this permission notice appear in
   7  * all copies of the software and related documentation, and (ii) the name of
   8  * Silicon Graphics may not be used in any advertising or
   9  * publicity relating to the software without the specific, prior written
  10  * permission of Silicon Graphics.
  11  *
  12  * THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF
  13  * ANY KIND,
  14  * EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY
  15  * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
  16  *
  17  * IN NO EVENT SHALL SILICON GRAPHICS BE LIABLE FOR
  18  * ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,
  19  * OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
  20  * WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF
  21  * LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
  22  * OF THIS SOFTWARE.
  23  */
  24 #include <stdio.h>
  25 #include <string.h>
  26 #include <stdlib.h>
  27 #include <GL/glut.h>
  28
  29
  30 GLenum doubleBuffer;
  31 GLint thing1, thing2;
  32
  33
  34 static void Init(void)
  35 {
  36
  37     glClearColor(0.0, 0.0, 0.0, 0.0);
  38     glClearAccum(0.0, 0.0, 0.0, 0.0);
  39
  40     thing1 = glGenLists(1);
  41     glNewList(thing1, GL_COMPILE);
  42         glColor3f(1.0, 0.0, 0.0);
  43         glRectf(-1.0, -1.0, 1.0, 0.0);
  44     glEndList();
  45
  46     thing2 = glGenLists(1);
  47     glNewList(thing2, GL_COMPILE);
  48         glColor3f(0.0, 1.0, 0.0);
  49         glRectf(0.0, -1.0, 1.0, 1.0);
  50     glEndList();
  51 }
  52
  53 static void Reshape(int width, int height)
  54 {
  55
  56     glViewport(0, 0, (GLint)width, (GLint)height);
  57
  58     glMatrixMode(GL_PROJECTION);
  59     glLoadIdentity();
  60     glMatrixMode(GL_MODELVIEW);
  61     glLoadIdentity();
  62 }
  63
  64 static void Key(unsigned char key, int x, int y)
  65 {
  66     (void) x;
  67     (void) y;
  68     switch (key) {
  69       case 27:
  70         exit(1);
  71       case '1':
  72         glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
  73         break;
  74       case '2':
  75         glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
  76         break;
  77       default:
  78         return;
  79     }
  80
  81     glutPostRedisplay();
  82 }
  83
  84 static void Draw(void)
  85 {
  86
  87     glPushMatrix();
  88
  89     glScalef(0.8, 0.8, 1.0);
  90
  91     glClear(GL_COLOR_BUFFER_BIT);
  92     glCallList(thing1);
  93     glAccum(GL_LOAD, 0.5);
  94
  95     glClear(GL_COLOR_BUFFER_BIT);
  96     glCallList(thing2);
  97     glAccum(GL_ACCUM, 0.5);
  98
  99     glAccum(GL_RETURN, 1.0);
 100
 101     glPopMatrix();
 102
 103     glFlush();
 104
 105     if (doubleBuffer) {
 106         glutSwapBuffers();
 107     }
 108 }
 109
 110 static GLenum Args(int argc, char **argv)
 111 {
 112     GLint i;
 113
 114     doubleBuffer = GL_FALSE;
 115
 116     for (i = 1; i < argc; i++) {
 117         if (strcmp(argv[i], "-sb") == 0) {
 118             doubleBuffer = GL_FALSE;
 119         } else if (strcmp(argv[i], "-db") == 0) {
 120             doubleBuffer = GL_TRUE;
 121         } else {
 122             printf("%s (Bad option).\n", argv[i]);
 123             return GL_FALSE;
 124         }
 125     }
 126     return GL_TRUE;
 127 }
 128
 129 int main(int argc, char **argv)
 130 {
 131     GLenum type;
 132
 133     glutInit(&argc, argv);
 134
 135     if (Args(argc, argv) == GL_FALSE) {
 136         exit(1);
 137     }
 138
 139     glutInitWindowPosition(0, 0);
 140     glutInitWindowSize( 300, 300);
 141
 142     type = GLUT_RGB | GLUT_ACCUM;
 143     type |= (doubleBuffer) ? GLUT_DOUBLE : GLUT_SINGLE;
 144     glutInitDisplayMode(type);
 145
 146     if (glutCreateWindow("Accum Test") == GL_FALSE) {
 147         exit(1);
 148     }
 149
 150     Init();
 151
 152     glutReshapeFunc(Reshape);
 153     glutKeyboardFunc(Key);
 154     glutDisplayFunc(Draw);
 155     glutMainLoop();
 156         return 0;
 157 }