This was long overdue. From my observation dirty rects don't need much
care, usually game engines already prepare them in a good shape (no
overlapping).
Also the overhead of calling the rect version of C2P isn't as big as I
was fearing, 256 64x64 rectangles are blitted roughly as quickly
as blitting one 1 MB block.
Removal of the rects traversal significantly speeds up Eco Quest for
instance.
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