A host of micro-optimizations and a refactor of TimeForBoundsToIntersect

cc/tiling_data.cc

 // Copyright 2010 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 "cc/tiling_data.h"
 
 #include <algorithm>
 
 #include "ui/gfx/rect.h"
 #include "ui/gfx/vector2d.h"
@@ skipping 83 matching lines @@
     return 0;
 
   DCHECK_GT(max_texture_size_.height() - 2 * border_texels_, 0);
   int inner_tile_size = max_texture_size_.height() - 2 * border_texels_;
   int y = (src_position - 2 * border_texels_) / inner_tile_size;
   return std::min(std::max(y, 0), num_tiles_y_ - 1);
 }
 
 gfx::Rect TilingData::TileBounds(int i, int j) const {
   AssertTile(i, j);
-  int x = TilePositionX(i);
-  int y = TilePositionY(j);
-  int width = TileSizeX(i);
-  int height = TileSizeY(j);
+  int max_texture_size_x = max_texture_size_.width() - 2 * border_texels_;
+  int max_texture_size_y = max_texture_size_.height() - 2 * border_texels_;
+  int total_size_x = total_size_.width();
+  int total_size_y = total_size_.height();
+
+  int lo_x = max_texture_size_x * i;
+  if (i != 0)
+    lo_x += border_texels_;
+
+  int lo_y = max_texture_size_y * j;
+  if (j != 0)
+    lo_y += border_texels_;
+
+  int hi_x = max_texture_size_x * (i + 1) + border_texels_;
+  if (i + 1 == num_tiles_x_)
+    hi_x += border_texels_;
+  if (hi_x > total_size_x)
+    hi_x = total_size_x;
+
+  int hi_y = max_texture_size_y * (j + 1) + border_texels_;
+  if (j + 1 == num_tiles_y_)
+    hi_y += border_texels_;
+  if (hi_y > total_size_y)
+    hi_y = total_size_y;
+
+  int x = lo_x;
+  int y = lo_y;
+  int width = hi_x - lo_x;
+  int height = hi_y - lo_y;
   DCHECK_GE(x, 0);
   DCHECK_GE(y, 0);
   DCHECK_GE(width, 0);
   DCHECK_GE(height, 0);
   DCHECK_LE(x, total_size_.width());
   DCHECK_LE(y, total_size_.height());
   return gfx::Rect(x, y, width, height);
 }
 
 gfx::Rect TilingData::TileBoundsWithBorder(int i, int j) const {
@@ skipping 138 matching lines @@
 TilingData::Iterator::operator bool() const {
   return index_x_ != -1 && index_y_ != -1;
 }
 
 void TilingData::Iterator::done() {
   index_x_ = -1;
   index_y_ = -1;
 }
 
 }  // namespace cc