[Cairo] mouse pointer and cairo

Jamey Sharp jamey at minilop.net
Sun Oct 12 20:09:27 PDT 2003

In X, with shaped and input-only windows available, perhaps all that's
needed is to enable applications to produce a shape bitmap while
drawing. It seems to me that the question of what to do with pixels
colored due to anti-aliasing can only be answered by thresholding the
alpha produced during drawing, because the mouse event coordinates are
no more precise than the device coordinate space anyway.

If that's true, I would think (without actually understanding
compositing yet) that rendering the component to an IcImage and
thresholding the resulting alpha channel would allow a client to easily
produce a shape bitmap, with which the client could create a shaped
window to capture events intended for that component.

I don't know what Windows and other platforms offer here, so I don't
know if this is more broadly applicable. Though obviously for the
PostScript and image backends, mouse events are irrelevant.

If it's relevant to Cairo, could somebody explain to me why PostScript
has the instroke and infill operators and why Cairo might want to also?
Jamey Sharp <jamey at minilop.net> - http://minilop.net/
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