[Cairo] mouse pointer and cairo
info at teh-web.de
Mon Oct 13 16:43:01 PDT 2003
> 1. Make the "number" reliably hold a void* pointer, not just an integer.
Would this need a new backend?
> 2. Return how opaque the object is. Programs can use this to decide if the
> user was clicking through an almost-transparent window on the foreground
> object. More importantly, transparent areas of images and letters can return
> but the program can skip them if it wants.
I did not think about it before, but exact text-selection seems important to
me. The only way to do it geometrically correct would be decomposition?
> 3. Somehow return a distance value. This should be the distance between the
> center of the pixel from the nearest line or vertex (squared to avoid the
> need for sqrt). Make it negative if the pixel is inside the a filled shape.
Why is the distance important? Either one selects a shape, or one does not. A
certain unexactness could be introduced by a larger "hit area".
The most important use-case for intersections I can think of is a
user-interface for some vector operations, maybe some collision detection in
a game. CAD and stuff probably calculates intersections between lines and
shapes itself. But my fantasy is quite limited.
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