Changeset 141333 in webkit

Timestamp:

Jan 30, 2013 3:34:57 PM (11 years ago)

Author:

timothy_horton@apple.com

Message:

[mac] ImageBuffer should create accelerated buffers for small canvases, but we shouldn't force them to create compositing layers
​https://bugs.webkit.org/show_bug.cgi?id=107804
<rdar://problem/11752381>

Reviewed by Simon Fraser.

Make all canvases IOSurface-backed if requested, instead of having a size threshold
under which we won't use accelerated canvas.

Make requiresCompositingForCanvas take the size of the canvas into account, using
the threshold which was previously in ImageBuffer to determine whether or not a
canvas should be forced into a compositing layer.

This improves canvas performance on some benchmarks
(​http://www.mikechambers.com/html5/javascript/QuadTree/examples/collision.html, for example)
significantly, in cases where canvases which fall below the size limit
(and thus are unaccelerated) are being drawn rapidly into either accelerated
tiles or another accelerated canvas, by preventing excessive copying to/from the GPU.

• platform/graphics/cg/ImageBufferCG.cpp:

(WebCore):
(WebCore::ImageBuffer::ImageBuffer):

• rendering/RenderLayerCompositor.cpp:

(WebCore::RenderLayerCompositor::requiresCompositingForCanvas):

Location:

trunk/Source/WebCore

Files:

• ChangeLog (modified) (1 diff)
• platform/graphics/cg/ImageBufferCG.cpp (modified) (2 diffs)
• rendering/RenderLayerCompositor.cpp (modified) (2 diffs)

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2013-01-30  Tim Horton  <timothy_horton@apple.com>
+
+        [mac] ImageBuffer should create accelerated buffers for small canvases, but we shouldn't force them to create compositing layers
+        https://bugs.webkit.org/show_bug.cgi?id=107804
+        <rdar://problem/11752381>
+
+        Reviewed by Simon Fraser.
+
+        Make all canvases IOSurface-backed if requested, instead of having a size threshold
+        under which we won't use accelerated canvas.
+
+        Make requiresCompositingForCanvas take the size of the canvas into account, using
+        the threshold which was previously in ImageBuffer to determine whether or not a
+        canvas should be forced into a compositing layer.
+
+        This improves canvas performance on some benchmarks
+        (http://www.mikechambers.com/html5/javascript/QuadTree/examples/collision.html, for example)
+        significantly, in cases where canvases which fall below the size limit
+        (and thus are unaccelerated) are being drawn rapidly into either accelerated
+        tiles or another accelerated canvas, by preventing excessive copying to/from the GPU.
+
+        * platform/graphics/cg/ImageBufferCG.cpp:
+        (WebCore):
+        (WebCore::ImageBuffer::ImageBuffer):
+        * rendering/RenderLayerCompositor.cpp:
+        (WebCore::RenderLayerCompositor::requiresCompositingForCanvas):
+
 2013-01-30  Alec Flett  <alecflett@chromium.org>
 

trunk/Source/WebCore/platform/graphics/cg/ImageBufferCG.cpp

@@ -63 +63 @@
 #if USE(IOSURFACE_CANVAS_BACKING_STORE)
 static const int maxIOSurfaceDimension = 4096;
-static const int minIOSurfaceArea = 50 * 100;
 
 static RetainPtr<IOSurfaceRef> createIOSurface(const IntSize& size)
@@ -137 +136 @@
 
 #if USE(IOSURFACE_CANVAS_BACKING_STORE)
-    if (width.unsafeGet() >= maxIOSurfaceDimension || height.unsafeGet() >= maxIOSurfaceDimension || (width * height).unsafeGet() < minIOSurfaceArea)
+    if (width.unsafeGet() >= maxIOSurfaceDimension || height.unsafeGet() >= maxIOSurfaceDimension)
         accelerateRendering = false;
 #else

trunk/Source/WebCore/rendering/RenderLayerCompositor.cpp

@@ -81 +81 @@
 #endif
 
+#if !PLATFORM(MAC) && !PLATFORM(IOS)
+#define WTF_USE_COMPOSITING_FOR_SMALL_CANVASES 1
+#endif
+
+static const int canvasAreaThresholdRequiringCompositing = 50 * 100;
+
 namespace WebCore {
 
@@ -1907 +1913 @@
     if (renderer->isCanvas()) {
         HTMLCanvasElement* canvas = static_cast<HTMLCanvasElement*>(renderer->node());
-        return canvas->renderingContext() && canvas->renderingContext()->isAccelerated();
+#if USE(COMPOSITING_FOR_SMALL_CANVASES)
+        bool isCanvasLargeEnoughToForceCompositing = true;
+#else
+        bool isCanvasLargeEnoughToForceCompositing = canvas->size().area() >= canvasAreaThresholdRequiringCompositing;
+#endif
+        return canvas->renderingContext() && canvas->renderingContext()->isAccelerated() && (canvas->renderingContext()->is3d() || isCanvasLargeEnoughToForceCompositing);
     }
     return false;