[webkit-dev] RGBA8 and BGRA8 formats in WebKit

Allan Sandfeld Jensen kde at carewolf.com
Tue Jan 22 07:47:56 PST 2013

On Monday 21 January 2013, Benjamin Poulain wrote:
> On Mon, Jan 21, 2013 at 7:00 AM, Zoltan Herczeg <zherczeg at webkit.org> wrote:
> > In WebKit both RGBA and BGRA formats are used for different purposes and
> > different platforms in WebKit. Do we have a policy which one we prefer?
> > It would be nice to reduce conversions between them in the future as it
> > seems costly on embedded systems.
> The Web APIs use RGBA (E.g.
> http://www.w3.org/html/wg/drafts/2dcontext/html5_canvas/#canvas-pixel-array
> buffer )
> Using that internally will prevent conversion at the boundaries
> JS<->WebCore.
> Internally, each port should be able to use any format. On some embedded
> systems, it can be advantageous to use 24 bits colors (or even 16 bits
> sometimes).
> Where in WebKit do you experience problems with color conversion?
Well, for one thing. The Color class and RGBA32 type are encoded as ARGB, not 
as RGBA which is needed for JavaScript.


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