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(GLboolean npot)
  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 = npot ? (p * 20) : (1 << p);
  31       GLint h = npot ? (p * 10) : (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       /* get as BGRA */
  63       glGetTexImage(GL_TEXTURE_2D, level, GL_BGRA, GL_UNSIGNED_BYTE, data2);
  64
  65       /* compare */
  66       {
  67          const GLubyte *rgba = (GLubyte *) data;
  68          const GLubyte *bgra = (GLubyte *) data2;
  69          for (i = 0; i < w * h; i += 4) {
  70             if (rgba[i+0] != bgra[i+2] ||
  71                 rgba[i+1] != bgra[i+1] ||
  72                 rgba[i+2] != bgra[i+0] ||
  73                 rgba[i+3] != bgra[i+3]) {
  74                printf("glTexImage + glGetTexImage(GL_BGRA) failure!\n");
  75                printf("Expected value %d, found %d\n", data[i], data2[i]);
  76                abort();
  77             }
  78          }
  79       }
  80
  81    }
  82
  83    printf("Passed\n");
  84    glDisable(GL_TEXTURE_2D);
  85    free(data);
  86    free(data2);
  87 }
  88
  89
  90 static GLboolean
  91 ColorsEqual(const GLubyte ref[4], const GLubyte act[4])
  92 {
  93    if (abs((int) ref[0] - (int) act[0]) > 1 ||
  94        abs((int) ref[1] - (int) act[1]) > 1 ||
  95        abs((int) ref[2] - (int) act[2]) > 1 ||
  96        abs((int) ref[3] - (int) act[3]) > 1) {
  97       printf("expected %d %d %d %d\n", ref[0], ref[1], ref[2], ref[3]);
  98       printf("found    %d %d %d %d\n", act[0], act[1], act[2], act[3]);
  99       return GL_FALSE;
 100    }
 101    return GL_TRUE;
 102 }
 103
 104
 105 static void
 106 TestGetTexImageRTT(GLboolean npot)
 107 {
 108    GLuint iter;
 109
 110    printf("Render to texture + glGetTexImage:\n");
 111
 112    for (iter = 0; iter < 8; iter++) {
 113
 114       GLuint fb, tex;
 115       GLint w, h;
 116       GLint level = 0;
 117
 118       if (npot) {
 119          w = 200 + iter * 40;
 120          h = 200 + iter * 12;
 121       }
 122       else {
 123          w = 4 << iter;
 124          h = 4 << iter;
 125       }
 126
 127       glGenTextures(1, &tex);
 128       glGenFramebuffersEXT(1, &fb);
 129
 130       glBindTexture(GL_TEXTURE_2D, tex);
 131       glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
 132       glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
 133       glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, w, h, 0,
 134                    GL_RGBA, GL_UNSIGNED_BYTE, NULL);
 135
 136       glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, fb);
 137       glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT,
 138                                 GL_TEXTURE_2D, tex, level);
 139
 140       glViewport(0, 0, w, h);
 141
 142       printf("  Testing %d x %d tex image\n", w, h);
 143       {
 144          static const GLubyte blue[4] = {0, 0, 255, 255};
 145          GLubyte color[4];
 146          GLubyte *data2 = (GLubyte *) malloc(w * h * 4);
 147          GLuint i;
 148
 149          /* random clear color */
 150          for (i = 0; i < 4; i++) {
 151             color[i] = rand() % 256;
 152          }
 153
 154          glClearColor(color[0] / 255.0,
 155                       color[1] / 255.0,
 156                       color[2] / 255.0,
 157                       color[3] / 255.0);
 158
 159          glClear(GL_COLOR_BUFFER_BIT);
 160
 161          /* draw polygon over top half, in blue */
 162          glColor4ubv(blue);
 163          glRectf(0, 0.5, 1.0, 1.0);
 164
 165          /* get */
 166          glGetTexImage(GL_TEXTURE_2D, level, GL_RGBA, GL_UNSIGNED_BYTE, data2);
 167
 168          /* compare */
 169          for (i = 0; i < w * h; i += 4) {
 170             if (i < w * h / 2) {
 171                /* lower half */
 172                if (!ColorsEqual(color, data2 + i * 4)) {
 173                   printf("Render to texture failure (expected clear color)!\n");
 174                   abort();
 175                }
 176             }
 177             else {
 178                /* upper half */
 179                if (!ColorsEqual(blue, data2 + i * 4)) {
 180                   printf("Render to texture failure (expected blue)!\n");
 181                   abort();
 182                }
 183             }
 184          }
 185
 186          free(data2);
 187       }
 188
 189       glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
 190       glDeleteFramebuffersEXT(1, &fb);
 191       glDeleteTextures(1, &tex);
 192
 193    }
 194
 195    printf("Passed\n");
 196 }
 197
 198
 199
 200
 201 static void
 202 Draw(void)
 203 {
 204    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 205
 206    TestGetTexImage(GL_FALSE);
 207    if (glutExtensionSupported("GL_ARB_texture_non_power_of_two"))
 208       TestGetTexImage(GL_TRUE);
 209
 210    if (glutExtensionSupported("GL_EXT_framebuffer_object") ||
 211        glutExtensionSupported("GL_ARB_framebuffer_object")) {
 212       TestGetTexImageRTT(GL_FALSE);
 213       if (glutExtensionSupported("GL_ARB_texture_non_power_of_two"))
 214          TestGetTexImageRTT(GL_TRUE);
 215    }
 216
 217    glutDestroyWindow(Win);
 218    exit(0);
 219
 220    glutSwapBuffers();
 221 }
 222
 223
 224 static void
 225 Reshape(int width, int height)
 226 {
 227    glViewport(0, 0, width, height);
 228    glMatrixMode(GL_PROJECTION);
 229    glLoadIdentity();
 230    glOrtho(0, 1, 0, 1, -1, 1);
 231    glMatrixMode(GL_MODELVIEW);
 232    glLoadIdentity();
 233    glTranslatef(0.0, 0.0, 0.0);
 234 }
 235
 236
 237 static void
 238 Key(unsigned char key, int x, int y)
 239 {
 240    (void) x;
 241    (void) y;
 242    switch (key) {
 243       case 27:
 244          glutDestroyWindow(Win);
 245          exit(0);
 246          break;
 247    }
 248    glutPostRedisplay();
 249 }
 250
 251
 252 static void
 253 Init(void)
 254 {
 255 }
 256
 257
 258 int
 259 main(int argc, char *argv[])
 260 {
 261    glutInit(&argc, argv);
 262    glutInitWindowPosition(0, 0);
 263    glutInitWindowSize(400, 400);
 264    glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
 265    Win = glutCreateWindow(argv[0]);
 266    glewInit();
 267    glutReshapeFunc(Reshape);
 268    glutKeyboardFunc(Key);
 269    glutDisplayFunc(Draw);
 270    Init();
 271    glutMainLoop();
 272    return 0;
 273 }