Re: NSBezierPath
Re: NSBezierPath
- Subject: Re: NSBezierPath
- From: Scott Thompson <email@hidden>
- Date: Mon, 27 Jun 2005 09:02:39 -0500
On Jun 27, 2005, at 8:47 AM, Eric Brunstad wrote:
Hi everyone,
Looking through the NSBezierPath docs, I see it is possible to find
if a path contains a point. However, I need to find if a
NSBezierPath contains a rect.
How should I do this?
Note: I'm looking to see if the actual path contains a rect, not
just the path's bounds.
That is, in general, a "hard problem". There are several ways you
could create trivial rejects:
If the paths's bounds and the rectangle' don't intersect then reject
If the path's control polygon and the rectangle don't intersect then
reject.
If the four corners of the rectangle do not lie within the path, then
reject.
At that point you'd be pretty confident that the rectangle intersects
the path (though you still can't say for sure). At that point you'd
either have to use numerical methods to determine if the path crosses
the edge of the rectangle at any point, or not.
The above assumes you want to find out if a rectangle is in a path in
the resolution independent space they are defined in. If you are
working at a fixed resolution... it's probably easiest to either
flatten the path, and see if the rectangle lies inside of the
resulting polygon, or intersect the two shapes as bitmaps and see if
all of the pixels in the rectangle intersect pixels of the path.
Scott
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| | >NSBezierPath (From: Eric Brunstad <email@hidden>) |