[BlackBerry] Rounding error of destination rect of checkerboard

[Leo Yang]

1302 void BackingStorePrivate::blitContents(const Platform::IntRect& dstRect,
1303                                        const Platform::IntRect& srcRect,
1304                                        bool force)
1305 {
...
1407             // Blit checkered to those parts that are not covered by the backingStoreRect.
1408             IntRectList checkeredRects = checkeredRegion.rects();
1409             for (size_t i = 0; i < checkeredRects.size(); ++i) {
1410                 Platform::IntRect dstRect = transformation.mapRect(Platform::IntRect(
1411                     Platform::IntPoint(checkeredRects.at(i).x() - origin.x(), checkeredRects.at(i).y() - origin.y()),
1412                                        checkeredRects.at(i).size()));
1413 #if DEBUG_CHECKERBOARD
1414                 blitCheckered = true;
1415 #endif
1416                 fillWindow(BlackBerry::Platform::Graphics::CheckerboardPattern,
1417                     dstRect, checkeredRects.at(i).location(), transformation.a());
1418             }
1419         }
...
}

The dstRect in line 1401 might get rounding error +1/-1 pixel due to transformation. We need to intersect it with the original dstRect passed into this function.

Patch is coming soon.

[Leo Yang]

Created attachment 156134 [details]
Patch

[Rob Buis]

Comment on attachment 156134 [details]
Patch

LGTM.

[WebKit Review Bot]

Comment on attachment 156134 [details]
Patch

Clearing flags on attachment: 156134

Committed r124487: <http://trac.webkit.org/changeset/124487>

[WebKit Review Bot]

All reviewed patches have been landed.  Closing bug.