[webkit-reviews] review canceled: [Bug 74982] [chromium] Estimate pixel count for frame rate control : [Attachment 121929] Patch

[bugzilla-daemon at webkit.org]

W. James MacLean <wjmaclean at chromium.org> has canceled W. James MacLean
<wjmaclean at chromium.org>'s request for review:
Bug 74982: [chromium] Estimate pixel count for frame rate control
https://bugs.webkit.org/show_bug.cgi?id=74982

Attachment 121929: Patch
https://bugs.webkit.org/attachment.cgi?id=121929&action=review

------- Additional Comments from W. James MacLean <wjmaclean at chromium.org>
Again, just ideas for discussion.

This patch places the "pixels drawn" measure into LRC's drawTexturedQuad (which
pretty much all drawing seems to go through), and compensates for the draw
transform. It can be extended to include scissoring by intersecting the
transformed quad with the scissor rect, and taking the area of that (the
quadArea function can be trivially extended to compute the area of any planar
polygon - computing the intersection polygon is harder but not unreasonable).

Output is in fraction of viewport drawn (1.0 = every pixel drawn once). To see
results * 1000, enter "about:histograms" in the location bar, and search for
"pixelOverDraw".

Does not estimate how much overdraw is "unavoidable overdraw", e.g. a fully
transparent layer over a fully opaque one.