The value of the RGB of transparent pixels is crucial for applications involving realtime MIPmapped textures...pretty much all 3D games for example.

MIPmapping works by creating successively reduced resolution images -
each (typically) half the resolution of the previous one.

When a MIPmapped image has alpha, this down-filtering produces semi-translucent
pixels in areas of the image that were formerly completely transparent.

At these locations, the colour you see will be a down-filtered version
of the higher resolution image.

It it therefore ESSENTIAL that the pixels in the areas outside of the
opaque parts of the image can also be painted - and have user controllable
RGB values.

What GIMP does now is just fine - what might be nicer would be some kind
of toggle to temporarily show the entire image as opaque (without actually
destroying the value of the alpha buffer).

If GIMP were to do something like (say) making all the transparent pixels
be solidly black, you'd see a dark halo.  This is a really common problem
and GIMP is the tool that saves you.

The second law of Frisbee throwing states: "Never precede any maneuver
by a comment more predictive than "Watch this!" turns out that
this also applies to writing Fragment Shaders.
Steve Baker                      (817)619-2657 (Vox/Vox-Mail)
L3Com/Link Simulation & Training (817)619-2466 (Fax)

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