I second David's invitation, widening it to the list. If you have ideas about interfaces for lighting, please chime in. Particularly, elegant, general, functional (unlike the usual steful GL & scene-graph models), and GPU-friendly. A model (denotational semantics) and interface for lights is given in the paper "Programming Graphics Processors Functionally" ( http://conal.net/papers/Vertigo/). As Ivan also suggested, a light is a function. - Conal On Wed, Jan 7, 2009 at 8:30 AM, David Sankel wrote:

On Wed, Jan 7, 2009 at 10:31 AM, Ivan Tomac wrote:

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David Sankel wrote:

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The FieldTrip.Light structure, from a semantic point of view, gives access to a lot of common light models and is independent of the underlying OpenGL operations.

If the back-end code is completely replaced with GLSL, it will just be a matter of setting "uniform variables" instead of glLight calls in renderLightIO and possibly expanding the Light structure with more funky light forms.

Yes the code behind it could be changed to use shaders and all that would do is emulate legacy OpenGL.

The shaders themselves could render using a variety of styles besides Blinn-Phong using these light structures while also allowing procedural textures and special material simulations like skin.

Of course the parameters of a light, specifically the color parameters, may be different for different shader models.

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These concepts are tied to legacy OpenGL.

I think the concept of a light (omni/directional) goes beyond OpenGL. The exposed parameters make most sense for Blinn-Phong models which are the most common. Like I mentioned, it would be easy to expand on these structures.

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The lighting models are just simple functions and with shaders they are best represented as such.

Perhaps you could post a haskell interface of the alternative light structure you have in mind. I think it'd help the discussion.

David

-- David Sankel _______________________________________________ FieldTrip mailing list FieldTrip@haskell.org http://www.haskell.org/mailman/listinfo/fieldtrip