24 Oct
2011
24 Oct
'11
1:41 p.m.
On Sun, Oct 23, 2011 at 11:06:19PM -0700, David Barbour wrote:
Is there any way to `query` a diagram, i.e. associate data with each pixel for mouse clicks?
Yes. Every diagram has an associated 'query function', which associates a monoidal value to every point. By default it just returns True/False indicating whether the given point is in the interior of any shape, but you can use any monoid you like. I believe John Lato has been using this in conjunction with the support for rendering directly to a gtk widget to develop some sort of interactive graphical application (I don't know many details). For more info see http://projects.haskell.org/diagrams/manual/diagrams-manual.html#using-queri... -Brent