[cairo] Questions about operators, clipping and etc
podain77 at gmail.com
Sun Jun 19 05:30:23 PDT 2011
I have several questions about cairo internals.
1. Clipping and masking equation
According to http://cairographics.org/operators, there're three kinds of
XRender, Bounded and Simple. However I couldn't find any case where XRender
Bounded equations produce different results. What's the difference between
2. Unbounded operation
Unbounded interpretation is introduced as follows:
The area where the compositing operation is performed is not bounded by
mask. Instead, any parts where the source layer is not transferred are
to be fully transparent. We call this interpretation of the source *
So does this mean that following equations??
dst = (src IN mask) OP dst (mask is allowed)
dst = 0 (mask is not allowed)
3. Limit boxes
Boxes, traps, polygon can have there limit boxes. I thought the boxes should
because I couldn't find any handling of overlapping boxes. Is this true?
In case of cairo_fill(), the member "bounded" is calculated by fill extents
So although a path is finally tessellated into a single box, it might not be
the same with
Thanks in advance
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