progs/trivial/quad-tex-3d.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
  25 #include <stdio.h>
  26 #include <string.h>
  27 #include <stdlib.h>
  28 #include <GL/glut.h>
  29
  30
  31 #define CI_OFFSET_1 16
  32 #define CI_OFFSET_2 32
  33
  34 GLfloat z= 0;
  35 GLenum doubleBuffer;
  36
  37 static void Init(void)
  38 {
  39    fprintf(stderr, "GL_RENDERER   = %s\n", (char *) glGetString(GL_RENDERER));
  40    fprintf(stderr, "GL_VERSION    = %s\n", (char *) glGetString(GL_VERSION));
  41    fprintf(stderr, "GL_VENDOR     = %s\n", (char *) glGetString(GL_VENDOR));
  42
  43    glClearColor(0.0, 0.0, 1.0, 0.0);
  44
  45 #define SIZE 16
  46    {
  47       GLubyte tex3d[SIZE][SIZE][SIZE][3];
  48       GLint r, s, t;
  49
  50       for (s = 0; s < SIZE; s++) {
  51          for (t = 0; t < SIZE; t++) {
  52             for (r = 0; r < SIZE; r++) {
  53 #if 0
  54                tex3d[r][t][s][0] = (s < SIZE/2) ? 0 : 255;
  55                tex3d[r][t][s][1] = (t < SIZE/2) ? 0 : 255;
  56                tex3d[r][t][s][2] = (r < SIZE/2) ? 0 : 255;
  57 #else
  58                tex3d[r][t][s][0] = s*255/(SIZE-1);
  59                tex3d[r][t][s][1] = t*255/(SIZE-1);
  60                tex3d[r][t][s][2] = r*255/(SIZE-1);
  61 #endif
  62             }
  63          }
  64       }
  65
  66       glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
  67       glTexParameterf(GL_TEXTURE_3D, GL_TEXTURE_WRAP_R, GL_REPEAT);
  68       glTexParameterf(GL_TEXTURE_3D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
  69       glTexParameterf(GL_TEXTURE_3D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
  70
  71       glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
  72       glTexImage3D(GL_TEXTURE_3D, 0, 3, SIZE, SIZE, SIZE, 0,
  73                    GL_RGB, GL_UNSIGNED_BYTE, tex3d);
  74       glPixelStorei(GL_UNPACK_ALIGNMENT, 4);
  75       glEnable(GL_TEXTURE_3D);
  76    }
  77
  78 }
  79
  80 static void Reshape(int width, int height)
  81 {
  82
  83     glViewport(0, 0, (GLint)width, (GLint)height);
  84
  85     glMatrixMode(GL_PROJECTION);
  86     glLoadIdentity();
  87     glOrtho(-1.0, 1.0, -1.0, 1.0, -0.5, 1000.0);
  88     glMatrixMode(GL_MODELVIEW);
  89 }
  90
  91 static void Key(unsigned char key, int x, int y)
  92 {
  93
  94     switch (key) {
  95     case ' ':
  96        z += 1.0/SIZE;
  97        break;
  98       case 27:
  99         exit(1);
 100       default:
 101         return;
 102     }
 103
 104     glutPostRedisplay();
 105 }
 106
 107 static void Draw(void)
 108 {
 109    glClear(GL_COLOR_BUFFER_BIT);
 110
 111    fprintf(stderr, "z: %f\n", z);
 112
 113    glBegin(GL_QUADS);
 114    glTexCoord3f(1,0,z);
 115    glVertex3f( 0.9, -0.9, -30.0);
 116    glTexCoord3f(1,1,z);
 117    glVertex3f( 0.9,  0.9, -30.0);
 118    glTexCoord3f(0,1,z);
 119    glVertex3f(-0.9,  0.9, -30.0);
 120    glTexCoord3f(0,0,z);
 121    glVertex3f(-0.9,  -0.9, -30.0);
 122    glEnd();
 123
 124    glFlush();
 125
 126    if (doubleBuffer) {
 127       glutSwapBuffers();
 128    }
 129 }
 130
 131 static GLenum Args(int argc, char **argv)
 132 {
 133     GLint i;
 134
 135     doubleBuffer = GL_FALSE;
 136
 137     for (i = 1; i < argc; i++) {
 138         if (strcmp(argv[i], "-sb") == 0) {
 139             doubleBuffer = GL_FALSE;
 140         } else if (strcmp(argv[i], "-db") == 0) {
 141             doubleBuffer = GL_TRUE;
 142         } else {
 143             fprintf(stderr, "%s (Bad option).\n", argv[i]);
 144             return GL_FALSE;
 145         }
 146     }
 147     return GL_TRUE;
 148 }
 149
 150 int main(int argc, char **argv)
 151 {
 152     GLenum type;
 153
 154     glutInit(&argc, argv);
 155
 156     if (Args(argc, argv) == GL_FALSE) {
 157         exit(1);
 158     }
 159
 160     glutInitWindowPosition(0, 0); glutInitWindowSize( 250, 250);
 161
 162     type = GLUT_RGB | GLUT_ALPHA;
 163     type |= (doubleBuffer) ? GLUT_DOUBLE : GLUT_SINGLE;
 164     glutInitDisplayMode(type);
 165
 166     if (glutCreateWindow("First Tri") == GL_FALSE) {
 167         exit(1);
 168     }
 169
 170     Init();
 171
 172     glutReshapeFunc(Reshape);
 173     glutKeyboardFunc(Key);
 174     glutDisplayFunc(Draw);
 175     glutMainLoop();
 176         return 0;
 177 }