cc: Reduce duplicated tiling data difference iterator code

cc/base/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/base/tiling_data.h"
 
 #include <algorithm>
 
 #include "ui/gfx/geometry/rect.h"
 #include "ui/gfx/geometry/vector2d.h"
@@ skipping 332 matching lines @@
   if (index_x_ > right_) {
     index_x_ = left_;
     index_y_++;
     if (index_y_ > bottom_)
       done();
   }
 
   return *this;
 }
 
-TilingData::DifferenceIterator::DifferenceIterator(
+TilingData::BaseDifferenceIterator::BaseDifferenceIterator() {
+  done();
+}
+
+TilingData::BaseDifferenceIterator::BaseDifferenceIterator(
     const TilingData* tiling_data,
     const gfx::Rect& consider_rect,
     const gfx::Rect& ignore_rect)
     : consider_left_(-1),
       consider_top_(-1),
       consider_right_(-1),
       consider_bottom_(-1),
       ignore_left_(-1),
       ignore_top_(-1),
       ignore_right_(-1),
       ignore_bottom_(-1) {
   if (tiling_data->num_tiles_x() <= 0 || tiling_data->num_tiles_y() <= 0) {
     done();
     return;
   }
 
   gfx::Rect tiling_bounds_rect(tiling_data->tiling_size());
   gfx::Rect consider(consider_rect);
-  gfx::Rect ignore(ignore_rect);
   consider.Intersect(tiling_bounds_rect);
-  ignore.Intersect(tiling_bounds_rect);
+
   if (consider.IsEmpty()) {
     done();
     return;
   }
 
   consider_left_ = tiling_data->TileXIndexFromSrcCoord(consider.x());
   consider_top_ = tiling_data->TileYIndexFromSrcCoord(consider.y());
   consider_right_ = tiling_data->TileXIndexFromSrcCoord(consider.right() - 1);
   consider_bottom_ = tiling_data->TileYIndexFromSrcCoord(consider.bottom() - 1);
 
+  gfx::Rect ignore(ignore_rect);
+  ignore.Intersect(tiling_bounds_rect);
+
   if (!ignore.IsEmpty()) {
     ignore_left_ = tiling_data->TileXIndexFromSrcCoord(ignore.x());
     ignore_top_ = tiling_data->TileYIndexFromSrcCoord(ignore.y());
     ignore_right_ = tiling_data->TileXIndexFromSrcCoord(ignore.right() - 1);
     ignore_bottom_ = tiling_data->TileYIndexFromSrcCoord(ignore.bottom() - 1);
 
     // Clamp ignore indices to consider indices.
     ignore_left_ = std::max(ignore_left_, consider_left_);
     ignore_top_ = std::max(ignore_top_, consider_top_);
     ignore_right_ = std::min(ignore_right_, consider_right_);
     ignore_bottom_ = std::min(ignore_bottom_, consider_bottom_);
+
+    if (ignore_left_ == consider_left_ && ignore_right_ == consider_right_ &&
+        ignore_top_ == consider_top_ && ignore_bottom_ == consider_bottom_) {
+      consider_left_ = consider_top_ = consider_right_ = consider_bottom_ = -1;
+      done();
+      return;
+    }
   }
+}
 
-  if (ignore_left_ == consider_left_ && ignore_right_ == consider_right_ &&
-      ignore_top_ == consider_top_ && ignore_bottom_ == consider_bottom_) {
+bool TilingData::BaseDifferenceIterator::HasConsiderRect() const {
+  // Consider indices are either all valid or all equal to -1.
+  DCHECK((0 <= consider_left_ && consider_left_ <= consider_right_ &&
+          0 <= consider_top_ && consider_top_ <= consider_bottom_) ||
+         (consider_left_ == -1 && consider_top_ == -1 &&
+          consider_right_ == -1 && consider_bottom_ == -1));
+  return consider_left_ != -1;
+}
+
+TilingData::DifferenceIterator::DifferenceIterator(
+    const TilingData* tiling_data,
+    const gfx::Rect& consider_rect,
+    const gfx::Rect& ignore_rect)
+    : BaseDifferenceIterator(tiling_data, consider_rect, ignore_rect) {
+  if (!HasConsiderRect()) {
     done();
     return;
   }
 
   index_x_ = consider_left_;
   index_y_ = consider_top_;
 
   if (in_ignore_rect())
     ++(*this);
 }
@@ skipping 29 matching lines @@
 
 TilingData::SpiralDifferenceIterator::SpiralDifferenceIterator() {
   done();
 }
 
 TilingData::SpiralDifferenceIterator::SpiralDifferenceIterator(
     const TilingData* tiling_data,
     const gfx::Rect& consider_rect,
     const gfx::Rect& ignore_rect,
     const gfx::Rect& center_rect)
-    : consider_left_(-1),
-      consider_top_(-1),
-      consider_right_(-1),
-      consider_bottom_(-1),
-      ignore_left_(-1),
-      ignore_top_(-1),
-      ignore_right_(-1),
-      ignore_bottom_(-1),
+    : BaseDifferenceIterator(tiling_data, consider_rect, ignore_rect),
       direction_(RIGHT),
       delta_x_(1),
       delta_y_(0),
       current_step_(0),
       horizontal_step_count_(0),
       vertical_step_count_(0) {
-  if (tiling_data->num_tiles_x() <= 0 || tiling_data->num_tiles_y() <= 0) {
-    done();
-    return;
-  }
-
-  gfx::Rect tiling_bounds_rect(tiling_data->tiling_size());
-  gfx::Rect consider(consider_rect);
-  gfx::Rect ignore(ignore_rect);
-  gfx::Rect center(center_rect);
-  consider.Intersect(tiling_bounds_rect);
-  ignore.Intersect(tiling_bounds_rect);
-  if (consider.IsEmpty()) {
-    done();
-    return;
-  }
-
-  consider_left_ = tiling_data->TileXIndexFromSrcCoord(consider.x());
-  consider_top_ = tiling_data->TileYIndexFromSrcCoord(consider.y());
-  consider_right_ = tiling_data->TileXIndexFromSrcCoord(consider.right() - 1);
-  consider_bottom_ = tiling_data->TileYIndexFromSrcCoord(consider.bottom() - 1);
-
-  if (!ignore.IsEmpty()) {
-    ignore_left_ = tiling_data->TileXIndexFromSrcCoord(ignore.x());
-    ignore_top_ = tiling_data->TileYIndexFromSrcCoord(ignore.y());
-    ignore_right_ = tiling_data->TileXIndexFromSrcCoord(ignore.right() - 1);
-    ignore_bottom_ = tiling_data->TileYIndexFromSrcCoord(ignore.bottom() - 1);
-
-    // Clamp ignore indices to consider indices.
-    ignore_left_ = std::max(ignore_left_, consider_left_);
-    ignore_top_ = std::max(ignore_top_, consider_top_);
-    ignore_right_ = std::min(ignore_right_, consider_right_);
-    ignore_bottom_ = std::min(ignore_bottom_, consider_bottom_);
-  }
-
-  if (ignore_left_ == consider_left_ && ignore_right_ == consider_right_ &&
-      ignore_top_ == consider_top_ && ignore_bottom_ == consider_bottom_) {
+  if (!HasConsiderRect()) {
     done();
     return;
   }
 
   // Determine around left, such that it is between -1 and num_tiles_x.
   int around_left = 0;
-  if (center.x() < 0 || center.IsEmpty())
+  if (center_rect.x() < 0 || center_rect.IsEmpty())
     around_left = -1;
-  else if (center.x() >= tiling_data->tiling_size().width())
+  else if (center_rect.x() >= tiling_data->tiling_size().width())
     around_left = tiling_data->num_tiles_x();
   else
-    around_left = tiling_data->TileXIndexFromSrcCoord(center.x());
+    around_left = tiling_data->TileXIndexFromSrcCoord(center_rect.x());
 
   // Determine around top, such that it is between -1 and num_tiles_y.
   int around_top = 0;
-  if (center.y() < 0 || center.IsEmpty())
+  if (center_rect.y() < 0 || center_rect.IsEmpty())
     around_top = -1;
-  else if (center.y() >= tiling_data->tiling_size().height())
+  else if (center_rect.y() >= tiling_data->tiling_size().height())
     around_top = tiling_data->num_tiles_y();
   else
-    around_top = tiling_data->TileYIndexFromSrcCoord(center.y());
+    around_top = tiling_data->TileYIndexFromSrcCoord(center_rect.y());
 
   // Determine around right, such that it is between -1 and num_tiles_x.
-  int right_src_coord = center.right() - 1;
+  int right_src_coord = center_rect.right() - 1;
   int around_right = 0;
-  if (right_src_coord < 0 || center.IsEmpty()) {
+  if (right_src_coord < 0 || center_rect.IsEmpty()) {
     around_right = -1;
   } else if (right_src_coord >= tiling_data->tiling_size().width()) {
     around_right = tiling_data->num_tiles_x();
   } else {
     around_right = tiling_data->TileXIndexFromSrcCoord(right_src_coord);
   }
 
   // Determine around bottom, such that it is between -1 and num_tiles_y.
-  int bottom_src_coord = center.bottom() - 1;
+  int bottom_src_coord = center_rect.bottom() - 1;
   int around_bottom = 0;
-  if (bottom_src_coord < 0 || center.IsEmpty()) {
+  if (bottom_src_coord < 0 || center_rect.IsEmpty()) {
     around_bottom = -1;
   } else if (bottom_src_coord >= tiling_data->tiling_size().height()) {
     around_bottom = tiling_data->num_tiles_y();
   } else {
     around_bottom = tiling_data->TileYIndexFromSrcCoord(bottom_src_coord);
   }
 
   vertical_step_count_ = around_bottom - around_top + 1;
   horizontal_step_count_ = around_right - around_left + 1;
   current_step_ = horizontal_step_count_ - 1;
@@ skipping 116 matching lines @@
 
 TilingData::ReverseSpiralDifferenceIterator::ReverseSpiralDifferenceIterator() {
   done();
 }
 
 TilingData::ReverseSpiralDifferenceIterator::ReverseSpiralDifferenceIterator(
     const TilingData* tiling_data,
     const gfx::Rect& consider_rect,
     const gfx::Rect& ignore_rect,
     const gfx::Rect& center_rect)
-    : consider_left_(-1),
-      consider_top_(-1),
-      consider_right_(-1),
-      consider_bottom_(-1),
+    : BaseDifferenceIterator(tiling_data, consider_rect, ignore_rect),
       around_left_(-1),
       around_top_(-1),
       around_right_(-1),
       around_bottom_(-1),
-      ignore_left_(-1),
-      ignore_top_(-1),
-      ignore_right_(-1),
-      ignore_bottom_(-1),
       direction_(LEFT),
       delta_x_(-1),
       delta_y_(0),
       current_step_(0),
       horizontal_step_count_(0),
       vertical_step_count_(0) {
-  if (tiling_data->num_tiles_x() <= 0 || tiling_data->num_tiles_y() <= 0) {
-    done();
-    return;
-  }
-
-  gfx::Rect tiling_bounds_rect(tiling_data->tiling_size());
-  gfx::Rect consider(consider_rect);
-  gfx::Rect ignore(ignore_rect);
-  gfx::Rect center(center_rect);
-  consider.Intersect(tiling_bounds_rect);
-  ignore.Intersect(tiling_bounds_rect);
-  if (consider.IsEmpty()) {
-    done();
-    return;
-  }
-
-  consider_left_ = tiling_data->TileXIndexFromSrcCoord(consider.x());
-  consider_top_ = tiling_data->TileYIndexFromSrcCoord(consider.y());
-  consider_right_ = tiling_data->TileXIndexFromSrcCoord(consider.right() - 1);
-  consider_bottom_ = tiling_data->TileYIndexFromSrcCoord(consider.bottom() - 1);
-
-  if (!ignore.IsEmpty()) {
-    ignore_left_ = tiling_data->TileXIndexFromSrcCoord(ignore.x());
-    ignore_top_ = tiling_data->TileYIndexFromSrcCoord(ignore.y());
-    ignore_right_ = tiling_data->TileXIndexFromSrcCoord(ignore.right() - 1);
-    ignore_bottom_ = tiling_data->TileYIndexFromSrcCoord(ignore.bottom() - 1);
-
-    // Clamp ignore indices to consider indices.
-    ignore_left_ = std::max(ignore_left_, consider_left_);
-    ignore_top_ = std::max(ignore_top_, consider_top_);
-    ignore_right_ = std::min(ignore_right_, consider_right_);
-    ignore_bottom_ = std::min(ignore_bottom_, consider_bottom_);
-  }
-
-  if (ignore_left_ == consider_left_ && ignore_right_ == consider_right_ &&
-      ignore_top_ == consider_top_ && ignore_bottom_ == consider_bottom_) {
+  if (!HasConsiderRect()) {
     done();
     return;
   }
 
   // Determine around left, such that it is between -1 and num_tiles_x.
-  if (center.x() < 0 || center.IsEmpty())
+  if (center_rect.x() < 0 || center_rect.IsEmpty())
     around_left_ = -1;
-  else if (center.x() >= tiling_data->tiling_size().width())
+  else if (center_rect.x() >= tiling_data->tiling_size().width())
     around_left_ = tiling_data->num_tiles_x();
   else
-    around_left_ = tiling_data->TileXIndexFromSrcCoord(center.x());
+    around_left_ = tiling_data->TileXIndexFromSrcCoord(center_rect.x());
 
   // Determine around top, such that it is between -1 and num_tiles_y.
-  if (center.y() < 0 || center.IsEmpty())
+  if (center_rect.y() < 0 || center_rect.IsEmpty())
     around_top_ = -1;
-  else if (center.y() >= tiling_data->tiling_size().height())
+  else if (center_rect.y() >= tiling_data->tiling_size().height())
     around_top_ = tiling_data->num_tiles_y();
   else
-    around_top_ = tiling_data->TileYIndexFromSrcCoord(center.y());
+    around_top_ = tiling_data->TileYIndexFromSrcCoord(center_rect.y());
 
   // Determine around right, such that it is between -1 and num_tiles_x.
-  int right_src_coord = center.right() - 1;
-  if (right_src_coord < 0 || center.IsEmpty()) {
+  int right_src_coord = center_rect.right() - 1;
+  if (right_src_coord < 0 || center_rect.IsEmpty()) {
     around_right_ = -1;
   } else if (right_src_coord >= tiling_data->tiling_size().width()) {
     around_right_ = tiling_data->num_tiles_x();
   } else {
     around_right_ = tiling_data->TileXIndexFromSrcCoord(right_src_coord);
   }
 
   // Determine around bottom, such that it is between -1 and num_tiles_y.
-  int bottom_src_coord = center.bottom() - 1;
-  if (bottom_src_coord < 0 || center.IsEmpty()) {
+  int bottom_src_coord = center_rect.bottom() - 1;
+  if (bottom_src_coord < 0 || center_rect.IsEmpty()) {
     around_bottom_ = -1;
   } else if (bottom_src_coord >= tiling_data->tiling_size().height()) {
     around_bottom_ = tiling_data->num_tiles_y();
   } else {
     around_bottom_ = tiling_data->TileYIndexFromSrcCoord(bottom_src_coord);
   }
 
   // Figure out the maximum distance from the around edge to consider edge.
   int max_distance = 0;
   max_distance = std::max(max_distance, around_top_ - consider_top_);
@@ skipping 143 matching lines @@
 
     // We should always end up in an around rect at some point.
     // Since the direction is now vertical, we have to ensure that we will
     // advance.
     DCHECK_GE(horizontal_step_count_, 1);
     DCHECK_GE(vertical_step_count_, 1);
   }
 }
 
 }  // namespace cc