Bug 45792 – Drawing an image outside the bounds of a canvas still causes repaints

• Component: Layout and Rendering
• Status: RESOLVED FIXED

[Simon Fraser (smfr)]

http://www.phoboslab.org/biolab/ seems to draw all the tiles in the game on every frame, even ones that are far outside the bounds of the canvas. Stupidly, we still turn these into repaints.

[Simon Fraser (smfr)]

diff --git a/WebCore/html/HTMLCanvasElement.cpp b/WebCore/html/HTMLCanvasElement.cpp
index 3838f14..6f46ab4 100644
--- a/WebCore/html/HTMLCanvasElement.cpp
+++ b/WebCore/html/HTMLCanvasElement.cpp
@@ -193,7 +193,7 @@ void HTMLCanvasElement::didDraw(const FloatRect& rect)
         FloatRect destRect = ro->contentBoxRect();
         FloatRect r = mapRect(rect, FloatRect(0, 0, size().width(), size().height()), destRect);
         r.intersect(destRect);
-        if (m_dirtyRect.contains(r))
+        if (r.isEmpty() || m_dirtyRect.contains(r))
             return;
 
         m_dirtyRect.unite(r);

I'll make some tests.

[Simon Fraser (smfr)]

Created attachment 67630 [details]
Patch

[Oliver Hunt]

Comment on attachment 67630 [details]
Patch

r=me

[Simon Fraser (smfr)]

http://trac.webkit.org/changeset/67526