progs/tests/getteximage.c

   1 /**
   2  * Test glGetTexImage()
   3  * Brian Paul
   4  * 9 June 2009
   5  */
   6
   7
   8 #include <stdio.h>
   9 #include <stdlib.h>
  10 #include <math.h>
  11 #include <GL/glut.h>
  12
  13 static int Win;
  14
  15
  16 static void
  17 TestGetTexImage(void)
  18 {
  19    GLuint iter;
  20
  21    for (iter = 0; iter < 20; iter++) {
  22       GLint p = (iter % 6) + 4;
  23       GLint w = (1 << p);
  24       GLint h = (1 << p);
  25       GLubyte data[512*512*4];
  26       GLubyte data2[512*512*4];
  27       GLuint i;
  28       GLint level = 0;
  29
  30       printf("Testing %d x %d tex image\n", w, h);
  31       /* fill data */
  32       for (i = 0; i < w * h * 4; i++) {
  33          data[i] = i & 0xff;
  34          data2[i] = 0;
  35       }
  36
  37       glTexImage2D(GL_TEXTURE_2D, level, GL_RGBA, w, h, 0,
  38                    GL_RGBA, GL_UNSIGNED_BYTE, data);
  39
  40       glBegin(GL_POINTS);
  41       glVertex2f(0, 0);
  42       glEnd();
  43
  44       /* get */
  45       glGetTexImage(GL_TEXTURE_2D, level, GL_RGBA, GL_UNSIGNED_BYTE, data2);
  46
  47       /* compare */
  48       for (i = 0; i < w * h * 4; i++) {
  49          if (data2[i] != data[i]) {
  50             printf("Failure!\n");
  51             abort();
  52          }
  53       }
  54    }
  55    printf("Passed\n");
  56    glutDestroyWindow(Win);
  57    exit(0);
  58 }
  59
  60
  61 static void
  62 Draw(void)
  63 {
  64    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
  65
  66    TestGetTexImage();
  67
  68    glutSwapBuffers();
  69 }
  70
  71
  72 static void
  73 Reshape(int width, int height)
  74 {
  75    glViewport(0, 0, width, height);
  76    glMatrixMode(GL_PROJECTION);
  77    glLoadIdentity();
  78    glFrustum(-1.0, 1.0, -1.0, 1.0, 5.0, 25.0);
  79    glMatrixMode(GL_MODELVIEW);
  80    glLoadIdentity();
  81    glTranslatef(0.0, 0.0, -15.0);
  82 }
  83
  84
  85 static void
  86 Key(unsigned char key, int x, int y)
  87 {
  88    (void) x;
  89    (void) y;
  90    switch (key) {
  91       case 27:
  92          glutDestroyWindow(Win);
  93          exit(0);
  94          break;
  95    }
  96    glutPostRedisplay();
  97 }
  98
  99
 100 static void
 101 Init(void)
 102 {
 103    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
 104    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
 105    glEnable(GL_TEXTURE_2D);
 106 }
 107
 108
 109 int
 110 main(int argc, char *argv[])
 111 {
 112    glutInit(&argc, argv);
 113    glutInitWindowPosition(0, 0);
 114    glutInitWindowSize(400, 400);
 115    glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
 116    Win = glutCreateWindow(argv[0]);
 117    glutReshapeFunc(Reshape);
 118    glutKeyboardFunc(Key);
 119    glutDisplayFunc(Draw);
 120    Init();
 121    glutMainLoop();
 122    return 0;
 123 }