2D Engine scrolling on OpenGL via hardware?
- by drudru
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