   Copying pixels from one region of the buffer to another.
  I am trying to copy the whole buffer, and then draw it a little misplaced with transparency for special effects on top of the solid buffer. I thought i could achieve this by simply doing this with glCopyPixels():[source langg = "cpp"]glLoadIdentity(); glColor4f(1.0f, 1.0f, 1.0f, 0.3f);glCopyPixels(0,0,screen->w,screen->h,GL_COLOR);   glDisable(GL_BLEND); glDisable(GL_TEXTURE_2D);   glColor4f(1.0f, 1.0f, 1.0f, 1.0f);   //swap the buffer    SDL_GL_SwapBuffers();But obviously it is not working, as it does not seem to play any role wether i leave the glCopyPixels() there or not.I am doing this in glOrtho projection using SDL with OpenGL.Thanks in advice!   
  I think you need to set glRasterPos to set the location pixels are copied to.AFAIK blending and glColour will have no effect on CopyPixels. If I understand what you're trying to do, it sounds like you'd be better rendering to a texture, enabling blending, then rendering a quad with that texture mapped onto it.   ;  "I am trying to copy the whole buffer, and then draw it a little misplaced with transparency for special effects on top of the solid buffer"Sounds like a job for the accumulation buffer!   ;  "I am trying to copy the whole buffer, and then draw it a little misplaced with transparency for special effects on top of the solid buffer"Sounds like a job for the accumulation buffer!   ;  mrbastard: how would i read from the buffer, and then draw it to a texture (read into GLuint?)?Dolf:I have not yet come to the chapter discussing OpenGL buffers in my book, so i suspect it being a little over my head just yet :).   ;  mrbastard:how would i read from the buffer, and then draw it to a texture (read into GLuint?)?Dolf:I have not yet come to the chapter discussing OpenGL buffers in my book, so i suspect it being a little over my head just yet :).;  bump   