Graphics Reference
In-Depth Information
Example 11-1
Setting up Multiple Render Targets
(continued)
// Set up fbo
glGenFramebuffers ( 1, &userData−>fbo );
glBindFramebuffer ( GL_FRAMEBUFFER, userData−>fbo );
// Set up four output buffers and attach to fbo
userData−>textureHeight = userData−>textureWidth = 400;
glGenTextures ( 4, &userData−>colorTexId[0] );
for (i = 0; i < 4; ++i)
{
glBindTexture ( GL_TEXTURE_2D, userData−>colorTexId[i] );
glTexImage2D ( GL_TEXTURE_2D, 0, GL_RGBA,
userData−>textureWidth,
userData−>textureHeight,
0, GL_RGBA, GL_UNSIGNED_BYTE, NULL );
// Set the filtering mode
glTexParameteri ( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,
GL_NEAREST );
glTexParameteri ( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER,
GL_NEAREST );
glFramebufferTexture2D ( GL_DRAW_FRAMEBUFFER,
attachments[i],
GL_TEXTURE_2D,
userData−>colorTexId[i], 0 );
}
glDrawBuffers ( 4, attachments );
if ( GL_FRAMEBUFFER_COMPLETE !=
glCheckFramebufferStatus ( GL_FRAMEBUFFER ) )
{
return FALSE;
}
// Restore the original framebuffer
glBindFramebuffer ( GL_FRAMEBUFFER, defaultFramebuffer );
return TRUE;
}
Example 11-2 (as part of the
Chapter_11/MRTs
example) illustrates how
to output four colors per fragment in a fragment shader.
