Karl Tomlinson (:karlt) Reporter
	Description • 12 years ago

Detected by content/canvas/test/reftest/webgl-color-alpha-test.html?colorVal=0.5&alphaVal=0.5&alpha from bug 782860.

The readback case could be easily fixed by using gfxUtils::PremultiplyImageSurface as BasicCanvasLayer does.

The BindTex2DOffscreen path wants a different ShaderProgramOGL, which may also be a better solution for the readback path.

Or if non-premultiplied WebGL buffers are not something we need to optimize, then the readback path could be used.

	Kelsey Gilbert [:jgilbert]
	Comment 1 • 11 years ago

Yep, this is a problem.

	Nicolas Silva [:nical]
	Comment 3 • 9 years ago

This bug is a bit old (pre-layers refactoring era) and we have code in CompositorOGL to handle non-premultiplied surfaces now. Can we close?

	Kelsey Gilbert [:jgilbert]
	Comment 4 • 9 years ago

Should be able to. We have reftests for this now, too.

	Karl Tomlinson (:karlt) Reporter
	Comment 5 • 9 years ago

We had reftests before too, but I don't know whether these are the same bug or not
https://hg.mozilla.org/mozilla-central/annotate/70e1d04f9487/dom/canvas/test/reftest/reftest.list#l53

	Kelsey Gilbert [:jgilbert]
	Comment 6 • 9 years ago

The reftests are newish as of Wed, 14 Jan 2015. What you see there looks like failure for Linux+e10s and D3D9 for non-premult alpha.