In bug 1248044 we discussed adding a RegionBuilder. Splitting this off here.

Review commit: https://reviewboard.mozilla.org/r/41529/diff/#index_header See other reviews: https://reviewboard.mozilla.org/r/41529/

Review commit: https://reviewboard.mozilla.org/r/41523/diff/#index_header See other reviews: https://reviewboard.mozilla.org/r/41523/

Comment on attachment 8733040 [details] MozReview Request: Bug 1258481 - Add a RegionBuilder for accumulating rects. r=jrmuizel https://reviewboard.mozilla.org/r/41529/#review37955

Comment on attachment 8733041 [details] MozReview Request: Bug 1258481 - Use RegionBuilder for nsRegion IPC. r=jrmuizel https://reviewboard.mozilla.org/r/41523/#review37957 ::: gfx/ipc/GfxMessageUtils.h:27 (Diff revision 1) > -#include "FilterSupport.h" > #include "mozilla/layers/GeckoContentController.h" > +#include "mozilla/layers/LayersTypes.h" > +#include "nsRect.h" > +#include "nsRegion.h" > + I assume all of the include changes make sense.

I just did vim ':sort' on them since they were a mess.

Comment on attachment 8733041 [details] MozReview Request: Bug 1258481 - Use RegionBuilder for nsRegion IPC. r=jrmuizel Review request updated; see interdiff: https://reviewboard.mozilla.org/r/41523/diff/1-2/

Had a simple logic error in the IPC code. ni? for landing after try.

Comment on attachment 8733041 [details] MozReview Request: Bug 1258481 - Use RegionBuilder for nsRegion IPC. r=jrmuizel Review request updated; see interdiff: https://reviewboard.mozilla.org/r/41523/diff/2-3/

https://hg.mozilla.org/integration/mozilla-inbound/rev/5e60a574fcec https://hg.mozilla.org/integration/mozilla-inbound/rev/8e7a8791854f

backed out for bustage like https://treeherder.mozilla.org/logviewer.html#?job_id=24434970&repo=mozilla-inbound

Backout: https://hg.mozilla.org/integration/mozilla-inbound/rev/af8f8a484581 https://hg.mozilla.org/integration/mozilla-inbound/rev/52195522dbac

Comment on attachment 8733040 [details] MozReview Request: Bug 1258481 - Add a RegionBuilder for accumulating rects. r=jrmuizel Review request updated; see interdiff: https://reviewboard.mozilla.org/r/41529/diff/1-2/

Comment on attachment 8733041 [details] MozReview Request: Bug 1258481 - Use RegionBuilder for nsRegion IPC. r=jrmuizel Review request updated; see interdiff: https://reviewboard.mozilla.org/r/41523/diff/3-4/

https://hg.mozilla.org/integration/mozilla-inbound/rev/89d767660c10 https://hg.mozilla.org/integration/mozilla-inbound/rev/fea97c450559

https://hg.mozilla.org/mozilla-central/rev/89d767660c10 https://hg.mozilla.org/mozilla-central/rev/fea97c450559

Benoit, is this something manual QA should be looking into for Fx48? If that's the case, could you please expand a bit on what should we focus on while testing this feature?

No need. This is a low level change covered by unit tests.

(In reply to Benoit Girard (:BenWa) from comment #17) > No need. This is a low level change covered by unit tests. Thank you for following up on this!

I had a quick look and this way of region building is still O(n^2), more precisely it's at least O(numOfXYBands * numRects).