[Thuban-list] [Patch] Improved hsv ramps patch

[Daniel Calvelo Aros]

On Mon, 23 Feb 2004 21:20:29 +0100, Bernhard Herzog wrote
> I think we can check this in once we have tests.  I would especially
> like to see tests for interpolate_hsv because it has quite a few special
> cases.

Right. It's coming along.

> Another thing that we might want to fix, but this can be done after the
> hsv code has been checked in, is the way Transparent is interpolated
> with non-transparent color.
> 
> As it's currently implemented in CVS (and inherited from the that in 
> the interpolate_rgb and interpolate_hsv functions in the patch) is 
> wrong, imo.  For example. interpolate_rgb(Color(1, 1, 1),
>  Transparent, 0) yields black and not as one would expect, white.  
> However, I'm not even sure those functions should even allow 
> interpolation of Transparent with non-transparent colors.  If Thuban 
> could handle translucent shapes that might be useful but currently 
> it doesn't so that kind of interpolation cannot really be done in a 
> sensible way.
> 
> At the moment, I'd say that the interpolation functions should simply
> assume that the color parameters are normal RGB colors and raise
> exceptions when that assumption doesn't hold.  This could either be done
> implicitly when trying to access the red, green and blue attributes 
> or more explicitly by checking whether either of the color 
> parameters is Transparent and raise e.g. TypeError.  Handling of 
> Transparent for class generation would then have to be done by the 
> CustomRamp class.

How hard would be to switch the default renderer to a wxGL canvas? Maybe it's
time to begin that work...
 
>    Bernhard

Daniel.

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