On Mon, Oct 24, 2011 at 11:55:53AM -0700, David Barbour wrote:
Thanks.
Diagrams package seems it could be promising for a declarative UI model - i.e. integration with functional reactive programming and similar models - so long as I'm willing to sacrifice `native` look and feel, which doesn't seem like a big problem.
Yes, I imagine it could. Not one of the use cases I personally had in mind -- but I've been hoping that people will find it useful for things I had not thought of.
A couple more questions: 1) Am I right in assuming that Diagrams does very little `occlusion` of its own - i.e. when rendering a soda-straw view of a complex diagram, or masking large areas with a rectangle or sphere? There won't be any competition or redundancy with an external index and backend (e.g. Cairo-GL layer) occlusion?
Right, diagrams currently doesn't do any sort of "culling", occlusion, etc., that's all up to the backend.
2) Is there support for Cairo-like linear and radial gradients?
Not yet, but it's on the todo list.
Also, it seems that for Cairo rendering, we cannot currently supply our own Cairo context.
renderDia Cairo (CairoOptions "foo.png" (PNG (100,100))) myDiagram
This section of your manual is incomplete, I admit, but from browsing the code it seems you provide a simplified interface that fully encapsulates the Cairo rendering. Is there any way to render a diagram within the Cairo stack? or leverage Cairo's own experimental backends (like OpenGL)?
You're right, currently there's no way do these sorts of things. However, there's no fundamental limitation here and adding this sort of functionality should not be hard, and I'd be quite open to extending the cairo backend in this direction. -Brent