[cairo] antialiasing pixel alignment for applications

[Robert O'Callahan]

Sorry if this is off-topic or has come up before or is just my own ignorance...

Suppose I have two adjacent rectangles with pixel coordinates
(0,0,10,10.5) and (0,10.5,10,20). If I fill them on a non-antialiased
device and I do my rounding correctly it's easy to ensure I get a
solid (0,0,10,20) rectangle. If I do antialiased fills based on
coverage I'm going to get one row of pixels that's not solid. What do
you recommend applications do to deal with this sort of thing?

Rob
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