progs/tests/blitfb.c

   1 /**
   2  * Test glFramebufferBlit()
   3  * Brian Paul
   4  * 27 Oct 2009
   5  */
   6
   7 #include <assert.h>
   8 #include <stdio.h>
   9 #include <stdlib.h>
  10 #include <string.h>
  11 #include <math.h>
  12 #include <GL/glew.h>
  13 #include <GL/glut.h>
  14
  15
  16 static int Win;
  17 static int WinWidth = 1100, WinHeight = 600;
  18
  19 static int SrcWidth = 512, SrcHeight = 512;
  20 static int DstWidth = 512, DstHeight = 512;
  21
  22 static GLuint SrcFB, DstFB;
  23 static GLuint SrcTex, DstTex;
  24
  25 #if 0
  26 static GLenum SrcTexTarget = GL_TEXTURE_2D, SrcTexFace = GL_TEXTURE_2D;
  27 #else
  28 static GLenum SrcTexTarget = GL_TEXTURE_CUBE_MAP, SrcTexFace = GL_TEXTURE_CUBE_MAP_POSITIVE_X;
  29 #endif
  30
  31 static GLenum DstTexTarget = GL_TEXTURE_2D, DstTexFace = GL_TEXTURE_2D;
  32
  33 static GLuint SrcTexLevel = 01, DstTexLevel = 0;
  34
  35
  36 static void
  37 Draw(void)
  38 {
  39    GLboolean rp = GL_FALSE;
  40    GLubyte *buf;
  41    GLint srcWidth = SrcWidth >> SrcTexLevel;
  42    GLint srcHeight = SrcHeight >> SrcTexLevel;
  43    GLint dstWidth = DstWidth >> DstTexLevel;
  44    GLint dstHeight = DstHeight >> DstTexLevel;
  45    GLenum status;
  46
  47    /* clear window */
  48    glBindFramebufferEXT(GL_FRAMEBUFFER, 0);
  49    glClearColor(0.5, 0.5, 0.5, 1.0);
  50    glClear(GL_COLOR_BUFFER_BIT);
  51
  52
  53    /* clear src buf */
  54    glBindFramebufferEXT(GL_FRAMEBUFFER, SrcFB);
  55    status = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);
  56    assert(status == GL_FRAMEBUFFER_COMPLETE_EXT);
  57    glClearColor(0, 1, 0, 0);
  58    glClear(GL_COLOR_BUFFER_BIT);
  59
  60    /* clear dst buf */
  61    glBindFramebufferEXT(GL_FRAMEBUFFER, DstFB);
  62    status = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);
  63    assert(status == GL_FRAMEBUFFER_COMPLETE_EXT);
  64    glClearColor(1, 0, 0, 0);
  65    glClear(GL_COLOR_BUFFER_BIT);
  66
  67    /* blit src -> dst */
  68    glBindFramebufferEXT(GL_READ_FRAMEBUFFER, SrcFB);
  69    glBindFramebufferEXT(GL_DRAW_FRAMEBUFFER, DstFB);
  70    glBlitFramebufferEXT(0, 0, srcWidth, srcHeight,
  71                         0, 0, dstWidth, dstHeight,
  72                         GL_COLOR_BUFFER_BIT, GL_NEAREST);
  73
  74 #if 01
  75    /* read src results */
  76    buf = malloc(4 * srcWidth * srcHeight);
  77    memset(buf, 0x88, 4 * srcWidth * srcHeight);
  78    glBindFramebufferEXT(GL_FRAMEBUFFER, SrcFB);
  79    if (rp)
  80       glReadPixels(0, 0, srcWidth, srcHeight, GL_RGBA, GL_UNSIGNED_BYTE, buf);
  81    else {
  82       glBindTexture(SrcTexTarget, SrcTex);
  83       glGetTexImage(SrcTexFace, SrcTexLevel, GL_RGBA, GL_UNSIGNED_BYTE, buf);
  84    }
  85
  86    /* draw dst in window */
  87    glBindFramebufferEXT(GL_FRAMEBUFFER, 0);
  88    glWindowPos2i(0, 0);
  89    glDrawPixels(srcWidth, srcHeight, GL_RGBA, GL_UNSIGNED_BYTE, buf);
  90
  91    printf("Src Pix[0] = %d %d %d %d\n", buf[0], buf[1], buf[2], buf[3]);
  92    free(buf);
  93 #endif
  94
  95    glFinish();
  96
  97    /* read dst results */
  98    buf = malloc(4 * dstWidth * dstHeight);
  99    memset(buf, 0x88, 4 * dstWidth * dstHeight);
 100    glBindFramebufferEXT(GL_FRAMEBUFFER, DstFB);
 101    if (rp)
 102       glReadPixels(0, 0, dstWidth, dstHeight, GL_RGBA, GL_UNSIGNED_BYTE, buf);
 103    else {
 104       glBindTexture(DstTexTarget, DstTex);
 105       glGetTexImage(DstTexFace, DstTexLevel, GL_RGBA, GL_UNSIGNED_BYTE, buf);
 106    }
 107
 108    /* draw dst in window */
 109    glBindFramebufferEXT(GL_FRAMEBUFFER, 0);
 110    glWindowPos2i(srcWidth + 2, 0);
 111    glDrawPixels(dstWidth, dstHeight, GL_RGBA, GL_UNSIGNED_BYTE, buf);
 112
 113    printf("Dst Pix[0] = %d %d %d %d\n", buf[0], buf[1], buf[2], buf[3]);
 114    free(buf);
 115
 116    glFinish();
 117
 118    glutSwapBuffers();
 119 }
 120
 121
 122 static void
 123 Reshape(int width, int height)
 124 {
 125    WinWidth = width;
 126    WinHeight = height;
 127    glViewport(0, 0, width, height);
 128    glMatrixMode(GL_PROJECTION);
 129    glLoadIdentity();
 130    glFrustum(-1.0, 1.0, -1.0, 1.0, 5.0, 25.0);
 131    glMatrixMode(GL_MODELVIEW);
 132    glLoadIdentity();
 133    glTranslatef(0.0, 0.0, -15.0);
 134 }
 135
 136
 137 static void
 138 Key(unsigned char key, int x, int y)
 139 {
 140    (void) x;
 141    (void) y;
 142    switch (key) {
 143    case 27:
 144       glutDestroyWindow(Win);
 145       exit(0);
 146       break;
 147    }
 148    glutPostRedisplay();
 149 }
 150
 151
 152 static void
 153 SpecialKey(int key, int x, int y)
 154 {
 155    (void) x;
 156    (void) y;
 157    switch (key) {
 158    }
 159    glutPostRedisplay();
 160 }
 161
 162
 163 static void
 164 InitFBOs(void)
 165 {
 166    GLuint w, h, lvl;
 167
 168    /* Src */
 169    glGenTextures(1, &SrcTex);
 170    glBindTexture(SrcTexTarget, SrcTex);
 171    w = SrcWidth;
 172    h = SrcHeight;
 173    lvl = 0;
 174    for (lvl = 0; ; lvl++) {
 175       if (SrcTexTarget == GL_TEXTURE_CUBE_MAP) {
 176          GLuint f;
 177          for (f = 0; f < 6; f++) {
 178             glTexImage2D(GL_TEXTURE_CUBE_MAP_POSITIVE_X + f, lvl, GL_RGBA8,
 179                          w, h, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
 180          }
 181       }
 182       else {
 183          /* single face */
 184          glTexImage2D(SrcTexFace, lvl, GL_RGBA8, w, h, 0,
 185                       GL_RGBA, GL_UNSIGNED_BYTE, NULL);
 186       }
 187       if (w == 1 && h == 1)
 188          break;
 189       if (w > 1)
 190          w /= 2;
 191       if (h > 1)
 192          h /= 2;
 193    }
 194
 195    glGenFramebuffersEXT(1, &SrcFB);
 196    glBindFramebufferEXT(GL_FRAMEBUFFER, SrcFB);
 197    glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT,
 198                              SrcTexFace, SrcTex, SrcTexLevel);
 199
 200    /* Dst */
 201    glGenTextures(1, &DstTex);
 202    glBindTexture(DstTexTarget, DstTex);
 203    w = DstWidth;
 204    h = DstHeight;
 205    lvl = 0;
 206    for (lvl = 0; ; lvl++) {
 207       glTexImage2D(DstTexFace, lvl, GL_RGBA8, w, h, 0,
 208                    GL_RGBA, GL_UNSIGNED_BYTE, NULL);
 209       if (w == 1 && h == 1)
 210          break;
 211       if (w > 1)
 212          w /= 2;
 213       if (h > 1)
 214          h /= 2;
 215    }
 216
 217    glGenFramebuffersEXT(1, &DstFB);
 218    glBindFramebufferEXT(GL_FRAMEBUFFER, DstFB);
 219    glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT,
 220                              DstTexFace, DstTex, DstTexLevel);
 221 }
 222
 223
 224 static void
 225 Init(void)
 226 {
 227    if (!glutExtensionSupported("GL_EXT_framebuffer_object")) {
 228       fprintf(stderr, "This test requires GL_EXT_framebuffer_object\n");
 229       exit(1);
 230    }
 231
 232    if (!glutExtensionSupported("GL_EXT_framebuffer_blit")) {
 233       fprintf(stderr, "This test requires GL_EXT_framebuffer_blit,\n");
 234       exit(1);
 235    }
 236
 237    InitFBOs();
 238
 239    printf("Left rect = src FBO, Right rect = dst FBO.\n");
 240    printf("Both should be green.\n");
 241 }
 242
 243
 244 int
 245 main(int argc, char *argv[])
 246 {
 247    glutInit(&argc, argv);
 248    glutInitWindowSize(WinWidth, WinHeight);
 249    glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
 250    Win = glutCreateWindow(argv[0]);
 251    glewInit();
 252    glutReshapeFunc(Reshape);
 253    glutKeyboardFunc(Key);
 254    glutSpecialFunc(SpecialKey);
 255    glutDisplayFunc(Draw);
 256    Init();
 257    glutMainLoop();
 258    return 0;
 259 }