cc/caching_bitmap_content_layer_updater.cc

   1 // Copyright 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "caching_bitmap_content_layer_updater.h"
   6
   7 #include "cc/layer_painter.h"
   8 #include "skia/ext/platform_canvas.h"
   9
  10 namespace cc {
  11
  12 scoped_refptr<CachingBitmapContentLayerUpdater>
  13 CachingBitmapContentLayerUpdater::Create(
  14     scoped_ptr<LayerPainter> painter) {
  15   return make_scoped_refptr(new CachingBitmapContentLayerUpdater(
  16       painter.Pass()));
  17 }
  18
  19 CachingBitmapContentLayerUpdater::CachingBitmapContentLayerUpdater(
  20     scoped_ptr<LayerPainter> painter)
  21     : BitmapContentLayerUpdater(painter.Pass()),
  22       pixels_did_change_(false) {
  23 }
  24
  25 CachingBitmapContentLayerUpdater::
  26   ~CachingBitmapContentLayerUpdater()
  27 {
  28 }
  29
  30 void CachingBitmapContentLayerUpdater::prepareToUpdate(
  31     const gfx::Rect& content_rect,
  32     const gfx::Size& tile_size,
  33     float contents_width_scale,
  34     float contents_height_scale,
  35     gfx::Rect& resulting_opaque_rect,
  36     RenderingStats& stats) {
  37   BitmapContentLayerUpdater::prepareToUpdate(
  38       content_rect,
  39       tile_size,
  40       contents_width_scale,
  41       contents_height_scale,
  42       resulting_opaque_rect,
  43       stats);
  44
  45   const SkBitmap& new_bitmap = m_canvas->getDevice()->accessBitmap(false);
  46   SkAutoLockPixels lock(new_bitmap);
  47   DCHECK(new_bitmap.bytesPerPixel() > 0);
  48   pixels_did_change_ = new_bitmap.config() != cached_bitmap_.config() ||
  49                        new_bitmap.height() != cached_bitmap_.height() ||
  50                        new_bitmap.width() != cached_bitmap_.width() ||
  51                        memcmp(new_bitmap.getPixels(),
  52                               cached_bitmap_.getPixels(),
  53                               new_bitmap.getSafeSize());
  54
  55   if (pixels_did_change_)
  56     new_bitmap.deepCopyTo(&cached_bitmap_, new_bitmap.config());
  57 }
  58
  59 bool CachingBitmapContentLayerUpdater::pixelsDidChange() const
  60 {
  61   return pixels_did_change_;
  62 }
  63
  64 }  // namespace cc