TINYGL: Fixed a bug that caused unneessary draw call creation.
TINYGL: Fixed a bug with flipped and clipped blitting
TINYGL: Fixed a bug with image clipping.
TINYGL: Separated pixel scissoring logic from pixel writing one.
TINYGL: Added pixel scissoring logic to triangle rasterization.
TINYGL: Implemented pixel scissoring in line rasterization.