Pass accurate contentsScale to LayerImpl.

cc/layer_impl.cc

 // Copyright 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "config.h"
 
 #include "cc/layer_impl.h"
 
 #include "base/debug/trace_event.h"
 #include "base/stringprintf.h"
@@ skipping 11 matching lines @@
 namespace cc {
 
 LayerImpl::LayerImpl(int id)
     : m_parent(0)
     , m_maskLayerId(-1)
     , m_replicaLayerId(-1)
     , m_layerId(id)
     , m_layerTreeHostImpl(0)
     , m_anchorPoint(0.5, 0.5)
     , m_anchorPointZ(0)
+    , m_contentsScaleX(1.0)
+    , m_contentsScaleY(1.0)
     , m_scrollable(false)
     , m_shouldScrollOnMainThread(false)
     , m_haveWheelEventHandlers(false)
     , m_backgroundColor(0)
     , m_doubleSided(true)
     , m_layerPropertyChanged(false)
     , m_layerSurfacePropertyChanged(false)
     , m_masksToBounds(false)
     , m_contentsOpaque(false)
     , m_opacity(1.0)
@@ skipping 186 matching lines @@
     return InputHandlerClient::ScrollStarted;
 }
 
 bool LayerImpl::drawCheckerboardForMissingTiles() const
 {
     return m_drawCheckerboardForMissingTiles && !Settings::backgroundColorInsteadOfCheckerboard();
 }
 
 IntRect LayerImpl::layerRectToContentRect(const WebKit::WebRect& layerRect)
 {
-    float widthScale = static_cast<float>(contentBounds().width()) / bounds().width();
-    float heightScale = static_cast<float>(contentBounds().height()) / bounds().height();
     FloatRect contentRect(layerRect.x, layerRect.y, layerRect.width, layerRect.height);
-    contentRect.scale(widthScale, heightScale);
+    contentRect.scale(contentsScaleX(), contentsScaleY());
     return enclosingIntRect(contentRect);

[danakj, 2012/10/29 20:06:51]

Intersect+comment here too.

[wangxianzhu, 2012/10/30 02:14:21]

Done.

 }
 
 std::string LayerImpl::indentString(int indent)
 {
     std::string str;
     for (int i = 0; i != indent; ++i)
         str.append("  ");
     return str;
 }
 
@@ skipping 154 matching lines @@
         return;
 
     m_bounds = bounds;
 
     if (masksToBounds())
         noteLayerPropertyChangedForSubtree();
     else
         m_layerPropertyChanged = true;
 }
 
+IntSize LayerImpl::contentBounds() const

[enne (OOO), 2012/10/29 19:19:41]

I don't think this math works out correctly for image layers.  I think you may
need to keep this as a member.

For some values x and y, ceil((x / y) * y) == x + 1, which seems wrong.  I think
LayerImpl::contentBounds() should always equal exactly its
Layer::contentBounds().

[danakj, 2012/10/29 20:06:51]

If contentBounds() is not always equal to ceil(bounds() * contentsScale()), but
sometimes 1 less, then I'm worried that converting rects from layer space to
content space can end up outside the area of the actual contentBounds() for
image layers. I think we need some intersect(), as noted in other comments.

[wangxianzhu, 2012/10/30 02:14:21]

Done.

[wangxianzhu, 2012/10/30 02:14:21]

Done.

+{
+    return IntSize(ceil(bounds().width() * contentsScaleX()),
+                   ceil(bounds().height() * contentsScaleY()));
+}
+
 void LayerImpl::setMaskLayer(scoped_ptr<LayerImpl> maskLayer)
 {
     m_maskLayer = maskLayer.Pass();
 
     int newLayerId = m_maskLayer ? m_maskLayer->id() : -1;
     if (newLayerId == m_maskLayerId)
         return;
 
     m_maskLayerId = newLayerId;
     noteLayerPropertyChangedForSubtree();
@@ skipping 166 matching lines @@
 
     m_debugBorderWidth = debugBorderWidth;
     m_layerPropertyChanged = true;
 }
 
 bool LayerImpl::hasDebugBorders() const
 {
     return SkColorGetA(m_debugBorderColor) && debugBorderWidth() > 0;
 }
 
-void LayerImpl::setContentBounds(const IntSize& contentBounds)
+void LayerImpl::setContentsScale(float contentsScaleX, float contentsScaleY)
 {
-    if (m_contentBounds == contentBounds)
+    if (m_contentsScaleX == contentsScaleX && m_contentsScaleY == contentsScaleY)
         return;
 
-    m_contentBounds = contentBounds;
+    m_contentsScaleX = contentsScaleX;
+    m_contentsScaleY = contentsScaleY;
     m_layerPropertyChanged = true;
 }
 
 void LayerImpl::setScrollPosition(const IntPoint& scrollPosition)
 {
     if (m_scrollPosition == scrollPosition)
         return;
 
     m_scrollPosition = scrollPosition;
     noteLayerPropertyChangedForSubtree();
@@ skipping 66 matching lines @@
 
 void LayerImpl::setVerticalScrollbarLayer(ScrollbarLayerImpl* scrollbarLayer)
 {
     if (!m_scrollbarAnimationController)
         m_scrollbarAnimationController = ScrollbarAnimationController::create(this);
     m_scrollbarAnimationController->setVerticalScrollbarLayer(scrollbarLayer);
     m_scrollbarAnimationController->updateScrollOffset(this);
 }
 
 }