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Use floor when converting float coordinates to ints in draw_lines and draw_polygon, and make ROUND_UP/ROUND_DOWN translation-invariant across the origin. Geometry that extends past the left or top edge of an image now matches a shifted-and-cropped render of the same shapes. Fixes python-pillow#10228
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Summary
ImageDrawconverted float coordinates with a C cast (truncate toward zero) and used sign-symmetricROUND_UP/ROUND_DOWN. Geometry that extends past the left or top edge of an image therefore rendered differently than the same shapes drawn after a positive pixel shift and crop.This change uses floor for coordinate conversion in
draw_lines/draw_polygon, and definesROUND_UP/ROUND_DOWNasfloor(f+0.5)/ceil(f-0.5)so edge rounding is translation-invariant across the origin.Fixes #10228
Test plan
test_draw_translation_invariant_negative_coordscovering the four shapes from the issue