Don't overdraw TileGrids

Given the visible area info, we can just tune the shader and matrix to draw
partial tile at the edge of TileGrids. This could save a lot of GPU time.

Change-Id: I1a45aa9a3a76ab5894096828bfff83057b1c9272

1 files changed, 7 insertions, 2 deletions

diff --git a/Source/WebCore/platform/graphics/android/rendering/Tile.cpp b/Source/WebCore/platform/graphics/android/rendering/Tile.cpp
index f2aa9a0..0501777 100644
--- a/Source/WebCore/platform/graphics/android/rendering/Tile.cpp
+++ b/Source/WebCore/platform/graphics/android/rendering/Tile.cpp
@@ -209,7 +209,8 @@ void Tile::setRepaintPending(bool pending)
 
 bool Tile::drawGL(float opacity, const SkRect& rect, float scale,
                   const TransformationMatrix* transform,
-                  bool forceBlending, bool usePointSampling)
+                  bool forceBlending, bool usePointSampling,
+                  const FloatPoint& fillPortion)
 {
     if (m_x < 0 || m_y < 0 || m_scale != scale)
         return false;
@@ -219,8 +220,12 @@ bool Tile::drawGL(float opacity, const SkRect& rect, float scale,
     if (!m_frontTexture)
         return false;
 
+    if (fillPortion.x() < 1.0f || fillPortion.y() < 1.0f)
+        ALOGV("drawing tile %p (%d, %d with fill portions %f %f",
+              this, m_x, m_y, fillPortion.x(), fillPortion.y());
+
     m_frontTexture->drawGL(isLayerTile(), rect, opacity, transform,
-                           forceBlending, usePointSampling);
+                           forceBlending, usePointSampling, fillPortion);
     return true;
 }