hi, I'm using OpenGL as the bottom end for a 2D tiling engine. When everything is 2D, it is simple to optimize certain issues. For example, scrolling. If I know a certain section of the screen needs to scroll off the bottom, then I can just blit over that portion. I'm evening moving more than 1 pixel at a time. Without explicit hardware support (think old nintendo hw), this requires a lot of pixel writes. An on chip bitblt would be the next best thing. Essentially, I'm looking at how I can optimize my GL calls to use VRAM texture renders as efficient hardware blits. Is it possible to have GL scroll the framebuffer, or should I just resign myself to double-buffering and re-rendering an entire scene for each frame? Thx