Merge 92255 - Source/WebCore: [Chromium] Use edge-distance method for layer anti-aliasing.

Source/WebCore/platform/graphics/gpu/TilingData.cpp

Index: Source/WebCore/platform/graphics/gpu/TilingData.cpp
===================================================================
--- Source/WebCore/platform/graphics/gpu/TilingData.cpp	(revision 92714)
+++ Source/WebCore/platform/graphics/gpu/TilingData.cpp	(working copy)
@@ -44,12 +44,10 @@
 
 static int computeNumTiles(int maxTextureSize, int totalSize, int borderTexels)
 {
-    int totalSizeWithBorder = totalSize + 2 * borderTexels;
-
     if (maxTextureSize - 2 * borderTexels <= 0)
-        return 0;
+        return totalSize > 0 && maxTextureSize >= totalSize ? 1 : 0;
 
-    int numTiles = max(1, 1 + (totalSizeWithBorder - 1 - 2 * borderTexels) / (maxTextureSize - 2 * borderTexels));
+    int numTiles = max(1, 1 + (totalSize - 1 - 2 * borderTexels) / (maxTextureSize - 2 * borderTexels));
     return totalSize > 0 ? numTiles : 0;
 }
 
@@ -81,7 +79,7 @@
         return 0;
 
     ASSERT(m_maxTextureSize - 2 * m_borderTexels);
-    int x = srcPos / (m_maxTextureSize - 2 * m_borderTexels);
+    int x = (srcPos - m_borderTexels) / (m_maxTextureSize - 2 * m_borderTexels);
     return min(max(x, 0), numTilesX() - 1);
 }
 
@@ -91,7 +89,7 @@
         return 0;
 
     ASSERT(m_maxTextureSize - 2 * m_borderTexels);
-    int y = srcPos / (m_maxTextureSize - 2 * m_borderTexels);
+    int y = (srcPos - m_borderTexels) / (m_maxTextureSize - 2 * m_borderTexels);
     return min(max(y, 0), numTilesY() - 1);
 }
 
@@ -134,16 +132,6 @@
     return bounds;
 }
 
-IntRect TilingData::tileBoundsWithOuterBorder(int tile) const
-{
-    IntRect bounds = tileBounds(tile);
-
-    if (m_borderTexels)
-        bounds.inflate(1);
-
-    return bounds;
-}
-
 FloatRect TilingData::tileBoundsNormalized(int tile) const
 {
     assertTile(tile);
@@ -180,6 +168,8 @@
 
     if (!xIndex && m_numTilesX == 1)
         return m_totalSizeX;
+    if (!xIndex && m_numTilesX > 1)
+        return m_maxTextureSize - m_borderTexels;
     if (xIndex < numTilesX() - 1)
         return m_maxTextureSize - 2 * m_borderTexels;
     if (xIndex == numTilesX() - 1)
@@ -195,6 +185,8 @@
 
     if (!yIndex && m_numTilesY == 1)
         return m_totalSizeY;
+    if (!yIndex && m_numTilesY > 1)
+        return m_maxTextureSize - m_borderTexels;
     if (yIndex < numTilesY() - 1)
         return m_maxTextureSize - 2 * m_borderTexels;
     if (yIndex == numTilesY() - 1)
@@ -238,8 +230,8 @@
 
     *newSrc = srcRectIntersected;
     newSrc->move(
-        -tileBounds.x() + m_borderTexels,
-        -tileBounds.y() + m_borderTexels);
+        -tileBounds.x() + ((tileXIndex(tile) > 0) ? m_borderTexels : 0),
+        -tileBounds.y() + ((tileYIndex(tile) > 0) ? m_borderTexels : 0));
 
     *newDst = FloatRect(
         srcRectIntersectedNormX * dstRect.width() + dstRect.x(),
@@ -248,9 +240,12 @@
         srcRectIntersectedNormH * dstRect.height());
 }
 
-IntPoint TilingData::textureOffset() const
+IntPoint TilingData::textureOffset(int xIndex, int yIndex) const
 {
-    return IntPoint(m_borderTexels, m_borderTexels);
+    int left = (!xIndex || m_numTilesX == 1) ? 0 : m_borderTexels;
+    int top = (!yIndex || m_numTilesY == 1) ? 0 : m_borderTexels;
+
+    return IntPoint(left, top);
 }
 
 void TilingData::recomputeNumTiles()