Adds ability to change compositing operator used by CanvasPaint....

Adds ability to change compositing operator used by CanvasPaint.

BUG=none
TEST=none


Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=17744

[sky, 2009-06-05 16:09:11]

This time to the right Evan.

[Evan Martin, 2009-06-05 17:56:34]

LGTM if you disagree with my comment

http://codereview.chromium.org/119226/diff/1/2
File skia/ext/platform_canvas_linux.h (right):

http://codereview.chromium.org/119226/diff/1/2#newcode109
Line 109: // Sets the compositing operator. Default is CAIRO_OPERATOR_OVER.
I wonder if it would make more sense to just expose the concrete thing you're
trying to tweak (e.g. a boolean like "make alpha work" or something) so callers
don't need to know the details of how cairo works.

[sky, 2009-06-05 18:14:58]

On 2009/06/05 17:56:34, Evan Martin wrote:
> LGTM if you disagree with my comment
> 
> http://codereview.chromium.org/119226/diff/1/2
> File skia/ext/platform_canvas_linux.h (right):
> 
> http://codereview.chromium.org/119226/diff/1/2#newcode109
> Line 109: // Sets the compositing operator. Default is CAIRO_OPERATOR_OVER.
> I wonder if it would make more sense to just expose the concrete thing you're
> trying to tweak (e.g. a boolean like "make alpha work" or something) so
callers
> don't need to know the details of how cairo works.

That makes sense if we never want to use other compositing operators. I don't
feel strongly though, and chances are good that we won't use the other
operators. So, I've changed it to set_composite_alpha. That isn't technically
correct, but better that set_use_cairo_operator_source (or something).

New snapshot uploaded.

[Evan Martin, 2009-06-05 18:18:12]

LGTM