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/glew.h>
  12 #include <GL/glut.h>
  13
  14 static int Win;
  15
  16
  17 static void
  18 TestGetTexImage(void)
  19 {
  20    GLuint iter;
  21    GLubyte *data = (GLubyte *) malloc(1024 * 1024 * 4);
  22    GLubyte *data2 = (GLubyte *) malloc(1024 * 1024 * 4);
  23
  24    glEnable(GL_TEXTURE_2D);
  25
  26    printf("glTexImage2D + glGetTexImage:\n");
  27
  28    for (iter = 0; iter < 8; iter++) {
  29       GLint p = (iter % 8) + 3;
  30       GLint w = (1 << p);
  31       GLint h = (1 << p);
  32       GLuint i;
  33       GLint level = 0;
  34
  35       printf("  Testing %d x %d tex image\n", w, h);
  36
  37       /* fill data */
  38       for (i = 0; i < w * h * 4; i++) {
  39          data[i] = i & 0xff;
  40          data2[i] = 0;
  41       }
  42
  43       glTexImage2D(GL_TEXTURE_2D, level, GL_RGBA, w, h, 0,
  44                    GL_RGBA, GL_UNSIGNED_BYTE, data);
  45
  46       glBegin(GL_POINTS);
  47       glVertex2f(0, 0);
  48       glEnd();
  49
  50       /* get */
  51       glGetTexImage(GL_TEXTURE_2D, level, GL_RGBA, GL_UNSIGNED_BYTE, data2);
  52
  53       /* compare */
  54       for (i = 0; i < w * h * 4; i++) {
  55          if (data2[i] != data[i]) {
  56             printf("glTexImage + glGetTexImage failure!\n");
  57             printf("Expected value %d, found %d\n", data[i], data2[i]);
  58             abort();
  59          }
  60       }
  61    }
  62
  63    printf("Passed\n");
  64    glDisable(GL_TEXTURE_2D);
  65    free(data);
  66    free(data2);
  67 }
  68
  69
  70 static GLboolean
  71 ColorsEqual(const GLubyte ref[4], const GLubyte act[4])
  72 {
  73    if (abs((int) ref[0] - (int) act[0]) > 1 ||
  74        abs((int) ref[1] - (int) act[1]) > 1 ||
  75        abs((int) ref[2] - (int) act[2]) > 1 ||
  76        abs((int) ref[3] - (int) act[3]) > 1) {
  77       printf("expected %d %d %d %d\n", ref[0], ref[1], ref[2], ref[3]);
  78       printf("found    %d %d %d %d\n", act[0], act[1], act[2], act[3]);
  79       return GL_FALSE;
  80    }
  81    return GL_TRUE;
  82 }
  83
  84
  85 static void
  86 TestGetTexImageRTT(void)
  87 {
  88    GLuint iter;
  89    GLuint fb, tex;
  90    GLint w = 512;
  91    GLint h = 256;
  92    GLint level = 0;
  93
  94    glGenTextures(1, &tex);
  95    glGenFramebuffersEXT(1, &fb);
  96
  97    glBindTexture(GL_TEXTURE_2D, tex);
  98    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
  99    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
 100    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, w, h, 0,
 101                 GL_RGBA, GL_UNSIGNED_BYTE, NULL);
 102
 103    glBindFramebuffer(GL_FRAMEBUFFER_EXT, fb);
 104    glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT,
 105                              GL_TEXTURE_2D, tex, level);
 106
 107    printf("Render to texture + glGetTexImage:\n");
 108    printf("  Testing %d x %d tex image\n", w, h);
 109    for (iter = 0; iter < 8; iter++) {
 110       GLubyte color[4];
 111       GLubyte *data2 = (GLubyte *) malloc(w * h * 4);
 112       GLuint i;
 113
 114       /* random clear color */
 115       for (i = 0; i < 4; i++) {
 116          color[i] = rand() % 256;
 117       }
 118
 119       glClearColor(color[0] / 255.0,
 120                    color[1] / 255.0,
 121                    color[2] / 255.0,
 122                    color[3] / 255.0);
 123
 124       glClear(GL_COLOR_BUFFER_BIT);
 125
 126       /* get */
 127       glGetTexImage(GL_TEXTURE_2D, level, GL_RGBA, GL_UNSIGNED_BYTE, data2);
 128
 129       /* compare */
 130       for (i = 0; i < w * h; i += 4) {
 131          if (!ColorsEqual(color, data2 + i * 4)) {
 132             printf("Render to texture failure!\n");
 133             abort();
 134          }
 135       }
 136
 137       free(data2);
 138    }
 139
 140    glBindFramebuffer(GL_FRAMEBUFFER_EXT, 0);
 141    glDeleteFramebuffersEXT(1, &fb);
 142    glDeleteTextures(1, &tex);
 143
 144    printf("Passed\n");
 145 }
 146
 147
 148
 149
 150 static void
 151 Draw(void)
 152 {
 153    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 154
 155    TestGetTexImage();
 156
 157    if (glutExtensionSupported("GL_EXT_framebuffer_object") ||
 158        glutExtensionSupported("GL_ARB_framebuffer_object"))
 159       TestGetTexImageRTT();
 160
 161    glutDestroyWindow(Win);
 162    exit(0);
 163
 164    glutSwapBuffers();
 165 }
 166
 167
 168 static void
 169 Reshape(int width, int height)
 170 {
 171    glViewport(0, 0, width, height);
 172    glMatrixMode(GL_PROJECTION);
 173    glLoadIdentity();
 174    glFrustum(-1.0, 1.0, -1.0, 1.0, 5.0, 25.0);
 175    glMatrixMode(GL_MODELVIEW);
 176    glLoadIdentity();
 177    glTranslatef(0.0, 0.0, -15.0);
 178 }
 179
 180
 181 static void
 182 Key(unsigned char key, int x, int y)
 183 {
 184    (void) x;
 185    (void) y;
 186    switch (key) {
 187       case 27:
 188          glutDestroyWindow(Win);
 189          exit(0);
 190          break;
 191    }
 192    glutPostRedisplay();
 193 }
 194
 195
 196 static void
 197 Init(void)
 198 {
 199 }
 200
 201
 202 int
 203 main(int argc, char *argv[])
 204 {
 205    glutInit(&argc, argv);
 206    glutInitWindowPosition(0, 0);
 207    glutInitWindowSize(400, 400);
 208    glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
 209    Win = glutCreateWindow(argv[0]);
 210    glewInit();
 211    glutReshapeFunc(Reshape);
 212    glutKeyboardFunc(Key);
 213    glutDisplayFunc(Draw);
 214    Init();
 215    glutMainLoop();
 216    return 0;
 217 }