Apart from putting the cached bitmaps in a better place, this about
finishes up the texture caching optimization and IT IS FAST!
When I spam drag a lot of pixels around the FPS may drop to the 40's but
once the caches are warmed up the FPS returns to 60 and stays there,
even if the screen is very busy with pixels.
An undocumented debug feature: set the environment variable
DEBUG_CHUNK_COLOR='#00FFFF' to set a bitmap background color besides
white to be used when caching the chunks. It helps to visualize where on
the screen the bitmaps are being used. May go away in the future.
Changes:
- Found that the old default chunk size of 1000 was slow to generate
bitmap images to cache. The 100px test size was fast and 128 sounds
like a good middle ground number to pick for now.
- Fixed all the problems with scroll behavior and offset by inverting
the sign of the scroll behavior. Scrolling to the Right and Down
actually subtracts X,Y values instead of adds them.
Noah Petherbridge
97394f6cdb