cc: Move computing borderless max texture size to function.

cc/base/tiling_data.cc

Index: cc/base/tiling_data.cc
diff --git a/cc/base/tiling_data.cc b/cc/base/tiling_data.cc
index cf2bb57f64c623a09329ee9eecc257358b3bdd7f..c1f1098c47c6248e864fb2287b04dcd41c3c4cc6 100644
--- a/cc/base/tiling_data.cc
+++ b/cc/base/tiling_data.cc
@@ -10,10 +10,9 @@
 #include "ui/gfx/geometry/vector2d.h"
 
 namespace cc {
+namespace {
 
-static int ComputeNumTiles(int max_texture_size,
-                           int total_size,
-                           int border_texels) {
+int ComputeNumTiles(int max_texture_size, int total_size, int border_texels) {
   if (max_texture_size - 2 * border_texels <= 0)
     return total_size > 0 && max_texture_size >= total_size ? 1 : 0;
 
@@ -23,6 +22,8 @@ static int ComputeNumTiles(int max_texture_size,
   return total_size > 0 ? num_tiles : 0;
 }
 
+}  // namespace
+
 TilingData::TilingData()
     : border_texels_(0) {
   RecomputeNumTiles();
@@ -46,6 +47,10 @@ TilingData::TilingData(const gfx::Size& max_texture_size,
   RecomputeNumTiles();
 }
 
+TilingData::TilingData(const TilingData& other) = default;
+
+TilingData::~TilingData() = default;
+
 void TilingData::SetTilingSize(const gfx::Size& tiling_size) {
   tiling_size_ = tiling_size;
   RecomputeNumTiles();
@@ -70,9 +75,8 @@ int TilingData::TileXIndexFromSrcCoord(int src_position) const {
   if (num_tiles_x_ <= 1)
     return 0;
 
-  DCHECK_GT(max_texture_size_.width() - 2 * border_texels_, 0);
-  int x = (src_position - border_texels_) /
-      (max_texture_size_.width() - 2 * border_texels_);
+  int x =
+      (src_position - border_texels_) / borderless_max_texture_size_.width();
   return std::min(std::max(x, 0), num_tiles_x_ - 1);
 }
 
@@ -80,9 +84,8 @@ int TilingData::TileYIndexFromSrcCoord(int src_position) const {
   if (num_tiles_y_ <= 1)
     return 0;
 
-  DCHECK_GT(max_texture_size_.height() - 2 * border_texels_, 0);
-  int y = (src_position - border_texels_) /
-      (max_texture_size_.height() - 2 * border_texels_);
+  int y =
+      (src_position - border_texels_) / borderless_max_texture_size_.height();
   return std::min(std::max(y, 0), num_tiles_y_ - 1);
 }
 
@@ -90,9 +93,8 @@ int TilingData::FirstBorderTileXIndexFromSrcCoord(int src_position) const {
   if (num_tiles_x_ <= 1)
     return 0;
 
-  DCHECK_GT(max_texture_size_.width() - 2 * border_texels_, 0);
-  int inner_tile_size = max_texture_size_.width() - 2 * border_texels_;
-  int x = (src_position - 2 * border_texels_) / inner_tile_size;
+  int x = (src_position - 2 * border_texels_) /
+          borderless_max_texture_size_.width();
   return std::min(std::max(x, 0), num_tiles_x_ - 1);
 }
 
@@ -100,9 +102,8 @@ int TilingData::FirstBorderTileYIndexFromSrcCoord(int src_position) const {
   if (num_tiles_y_ <= 1)
     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;
+  int y = (src_position - 2 * border_texels_) /
+          borderless_max_texture_size_.height();
   return std::min(std::max(y, 0), num_tiles_y_ - 1);
 }
 
@@ -110,9 +111,7 @@ int TilingData::LastBorderTileXIndexFromSrcCoord(int src_position) const {
   if (num_tiles_x_ <= 1)
     return 0;
 
-  DCHECK_GT(max_texture_size_.width() - 2 * border_texels_, 0);
-  int inner_tile_size = max_texture_size_.width() - 2 * border_texels_;
-  int x = src_position / inner_tile_size;
+  int x = src_position / borderless_max_texture_size_.width();
   return std::min(std::max(x, 0), num_tiles_x_ - 1);
 }
 
@@ -120,9 +119,7 @@ int TilingData::LastBorderTileYIndexFromSrcCoord(int src_position) const {
   if (num_tiles_y_ <= 1)
     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 / inner_tile_size;
+  int y = src_position / borderless_max_texture_size_.height();
   return std::min(std::max(y, 0), num_tiles_y_ - 1);
 }
 
@@ -161,22 +158,20 @@ gfx::Rect TilingData::ExpandRectToTileBounds(const gfx::Rect& rect) const {
 
 gfx::Rect TilingData::TileBounds(int i, int j) const {
   AssertTile(i, 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 lo_x = max_texture_size_x * i;
+  int lo_x = borderless_max_texture_size_.width() * i;
   if (i != 0)
     lo_x += border_texels_;
 
-  int lo_y = max_texture_size_y * j;
+  int lo_y = borderless_max_texture_size_.height() * j;
   if (j != 0)
     lo_y += border_texels_;
 
-  int hi_x = max_texture_size_x * (i + 1) + border_texels_;
+  int hi_x = borderless_max_texture_size_.width() * (i + 1) + border_texels_;
   if (i + 1 == num_tiles_x_)
     hi_x += border_texels_;
 
-  int hi_y = max_texture_size_y * (j + 1) + border_texels_;
+  int hi_y = borderless_max_texture_size_.height() * (j + 1) + border_texels_;
   if (j + 1 == num_tiles_y_)
     hi_y += border_texels_;
 
@@ -198,14 +193,12 @@ gfx::Rect TilingData::TileBounds(int i, int j) const {
 
 gfx::Rect TilingData::TileBoundsWithBorder(int i, int j) const {
   AssertTile(i, 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 lo_x = max_texture_size_x * i;
-  int lo_y = max_texture_size_y * j;
+  int lo_x = borderless_max_texture_size_.width() * i;
+  int lo_y = borderless_max_texture_size_.height() * j;
 
-  int hi_x = lo_x + max_texture_size_x + 2 * border_texels_;
-  int hi_y = lo_y + max_texture_size_y + 2 * border_texels_;
+  int hi_x = lo_x + borderless_max_texture_size_.width() + 2 * border_texels_;
+  int hi_y = lo_y + borderless_max_texture_size_.height() + 2 * border_texels_;
 
   hi_x = std::min(hi_x, tiling_size_.width());
   hi_y = std::min(hi_y, tiling_size_.height());
@@ -227,7 +220,7 @@ int TilingData::TilePositionX(int x_index) const {
   DCHECK_GE(x_index, 0);
   DCHECK_LT(x_index, num_tiles_x_);
 
-  int pos = (max_texture_size_.width() - 2 * border_texels_) * x_index;
+  int pos = (borderless_max_texture_size_.width()) * x_index;
   if (x_index != 0)
     pos += border_texels_;
 
@@ -238,7 +231,7 @@ int TilingData::TilePositionY(int y_index) const {
   DCHECK_GE(y_index, 0);
   DCHECK_LT(y_index, num_tiles_y_);
 
-  int pos = (max_texture_size_.height() - 2 * border_texels_) * y_index;
+  int pos = (borderless_max_texture_size_.height()) * y_index;
   if (y_index != 0)
     pos += border_texels_;
 
@@ -254,7 +247,7 @@ int TilingData::TileSizeX(int x_index) const {
   if (!x_index && num_tiles_x_ > 1)
     return max_texture_size_.width() - border_texels_;
   if (x_index < num_tiles_x_ - 1)
-    return max_texture_size_.width() - 2 * border_texels_;
+    return borderless_max_texture_size_.width();
   if (x_index == num_tiles_x_ - 1)
     return tiling_size_.width() - TilePositionX(x_index);
 
@@ -271,7 +264,7 @@ int TilingData::TileSizeY(int y_index) const {
   if (!y_index && num_tiles_y_ > 1)
     return max_texture_size_.height() - border_texels_;
   if (y_index < num_tiles_y_ - 1)
-    return max_texture_size_.height() - 2 * border_texels_;
+    return borderless_max_texture_size_.height();
   if (y_index == num_tiles_y_ - 1)
     return tiling_size_.height() - TilePositionY(y_index);
 
@@ -291,6 +284,13 @@ void TilingData::RecomputeNumTiles() {
       max_texture_size_.width(), tiling_size_.width(), border_texels_);
   num_tiles_y_ = ComputeNumTiles(
       max_texture_size_.height(), tiling_size_.height(), border_texels_);
+
+  borderless_max_texture_size_.set_width(max_texture_size_.width() -
+                                         2 * border_texels_);
+  borderless_max_texture_size_.set_height(max_texture_size_.height() -
+                                          2 * border_texels_);
+  DCHECK_GT(borderless_max_texture_size_.width(), 0);

[prashant.n, 2016/06/15 10:09:18]

Should we have CHECK_GT here instead, as with negative or zero renderable area,
it will crash somewhere else?

[vmpstr, 2016/06/15 20:37:53]

DCHECK is fine I think. If the calling code needs a CHECK it can check
independently for valid state. 

+  DCHECK_GT(borderless_max_texture_size_.height(), 0);
 }
 
 TilingData::BaseIterator::BaseIterator() : index_x_(-1), index_y_(-1) {