TINYGL: Encapsulated pixel access in FrameBuffer class, provided an implementation of glBlendFunc.
TINYGL: fixed formatting.
TINYGL: Implemented alpha interpolation in triangle rasterization routine.
TINYGL: Minor cleanup of code/formatting.
TINYGL: fixed minor formatting issues.
TINYGL: fixed a few issues with alpha blending and 2D blitting.