930003 - Remove CoreGraphics backend for Moz2D

Status: NEW

(Core :: Graphics, defect)

Description

[Andreas Gal :gal]

We should reduce our backends to D2D and Skia/SkiaGL. There seems to be no advantage to using CG, especially since we didn't really manage to get CG Extreme to work reliably. The competition is using Skia/SkiaGL on Mac, so we will be competitive. CG is strictly more work to maintain for a fairly small audience. SkiaGL will give us already today superior performance since quartz extreme isn't working for us and its not worth fixing it.

Ideally we would just do Skia/SkiaGL, but D2D is so much more powerful than Skia/SkiaGL, that its worth making an exception there and keeping D2D around.

Comment 1

[Jeff Muizelaar [:jrmuizel]]

So one thing that needs to be investigated here is text quality. Skia doesn't use the same blending for text that CoreGraphics does and I've heard of complaints over Chrome's text quality compared to Firefox/Safari.

Out of curiosity it would also be nice to know how the performance of GPU CoreGraphics compares to SkiaGL, in case there's a similar performance advantage for GPU CoreGraphics as compared to D2D. That being said, even if there is a similar performance advantage for GPU CoreGraphics it may still not be worth keeping CoreGraphics around given the size of our Mac users base.

Comment 2

[beingalink]

That worries me a bit to hear. The assumption here seems to be that Skia/SkiaGL is/will be as efficient and fast as OpenGL accelerated Core Graphics. I think Apple optimizes its technology pretty well which can be experienced in Safari which, for example, still has the smoothest scrolling of all browsers. I'm doubtful that it is easier to make skia/GL reach the same performance levels as Safari than working on the existing Core Graphics implementation to become faster. Also an important issue is, as Jeff Muizelaar pointed out, font rendering. A non-native look would definitely be a bad thing and would turn quite some people to use Safari instead.