src/cc/layers/layer_iterator.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 "cc/layers/layer_iterator.h"
   6
   7 #include <vector>
   8
   9 #include "cc/layers/layer.h"
  10 #include "cc/layers/layer_impl.h"
  11 #include "cc/layers/render_surface.h"
  12 #include "cc/layers/render_surface_impl.h"
  13
  14 namespace cc {
  15
  16 template <typename LayerType,
  17           typename LayerList,
  18           typename RenderSurfaceType,
  19           typename ActionType>
  20 void LayerIteratorActions::FrontToBack::Begin(
  21     LayerIterator<LayerType, LayerList, RenderSurfaceType, ActionType>* it) {
  22   it->target_render_surface_layer_index_ = 0;
  23   it->current_layer_index_ = it->target_render_surface_children().size() - 1;
  24   GoToHighestInSubtree(it);
  25 }
  26
  27 template <typename LayerType,
  28           typename LayerList,
  29           typename RenderSurfaceType,
  30           typename ActionType>
  31 void LayerIteratorActions::FrontToBack::End(
  32     LayerIterator<LayerType, LayerList, RenderSurfaceType, ActionType>* it) {
  33   it->target_render_surface_layer_index_ =
  34       LayerIteratorValue::kInvalidTargetRenderSurfaceLayerIndex;
  35   it->current_layer_index_ = 0;
  36 }
  37
  38 template <typename LayerType,
  39           typename LayerList,
  40           typename RenderSurfaceType,
  41           typename ActionType>
  42 void LayerIteratorActions::FrontToBack::Next(
  43     LayerIterator<LayerType, LayerList, RenderSurfaceType, ActionType>* it) {
  44   // Moves to the previous layer in the current RS layer list.
  45   // Then we check if the new current layer has its own RS,
  46   // in which case there are things in that RS layer list that are higher,
  47   // so we find the highest layer in that subtree.
  48   // If we move back past the front of the list,
  49   // we jump up to the previous RS layer list, picking up again where we
  50   // had previously recursed into the current RS layer list.
  51
  52   if (!it->current_layer_represents_target_render_surface()) {
  53     // Subtracting one here will eventually cause the current layer
  54     // to become that layer representing the target render surface.
  55     --it->current_layer_index_;
  56     GoToHighestInSubtree(it);
  57   } else {
  58     while (it->current_layer_represents_target_render_surface()) {
  59       if (!it->target_render_surface_layer_index_) {
  60         // End of the list
  61         it->target_render_surface_layer_index_ =
  62             LayerIteratorValue::kInvalidTargetRenderSurfaceLayerIndex;
  63         it->current_layer_index_ = 0;
  64         return;
  65       }
  66       it->target_render_surface_layer_index_ = it->target_render_surface()
  67           ->target_render_surface_layer_index_history_;
  68       it->current_layer_index_ =
  69           it->target_render_surface()->current_layer_index_history_;
  70     }
  71   }
  72 }
  73
  74 template <typename LayerType,
  75           typename LayerList,
  76           typename RenderSurfaceType,
  77           typename ActionType>
  78 void LayerIteratorActions::FrontToBack::GoToHighestInSubtree(
  79     LayerIterator<LayerType, LayerList, RenderSurfaceType, ActionType>* it) {
  80   if (it->current_layer_represents_target_render_surface())
  81     return;
  82   while (it->current_layer_represents_contributing_render_surface()) {
  83     // Save where we were in the current target surface, move to the next one,
  84     // and save the target surface that we came from there
  85     // so we can go back to it.
  86     it->target_render_surface()->current_layer_index_history_ =
  87         it->current_layer_index_;
  88     int previous_target_render_surface_layer =
  89         it->target_render_surface_layer_index_;
  90
  91     for (LayerType* layer = it->current_layer();
  92          it->target_render_surface_layer() != layer;
  93          ++it->target_render_surface_layer_index_) {
  94     }
  95     it->current_layer_index_ = it->target_render_surface_children().size() - 1;
  96
  97     it->target_render_surface()->target_render_surface_layer_index_history_ =
  98         previous_target_render_surface_layer;
  99   }
 100 }
 101
 102 // Declare each of the above functions for Layer and LayerImpl classes
 103 // so that they are linked.
 104 template CC_EXPORT void LayerIteratorActions::FrontToBack::Next(
 105     LayerIterator<Layer, RenderSurfaceLayerList, RenderSurface, FrontToBack>*
 106         it);
 107 template CC_EXPORT void LayerIteratorActions::FrontToBack::End(
 108     LayerIterator<Layer, RenderSurfaceLayerList, RenderSurface, FrontToBack>*
 109         it);
 110 template CC_EXPORT void LayerIteratorActions::FrontToBack::Begin(
 111     LayerIterator<Layer, RenderSurfaceLayerList, RenderSurface, FrontToBack>*
 112         it);
 113 template CC_EXPORT void LayerIteratorActions::FrontToBack::GoToHighestInSubtree(
 114     LayerIterator<Layer, RenderSurfaceLayerList, RenderSurface, FrontToBack>*
 115         it);
 116
 117 template CC_EXPORT void LayerIteratorActions::FrontToBack::Next(
 118     LayerIterator<LayerImpl, LayerImplList, RenderSurfaceImpl, FrontToBack>*
 119         it);
 120 template CC_EXPORT void LayerIteratorActions::FrontToBack::End(
 121     LayerIterator<LayerImpl, LayerImplList, RenderSurfaceImpl, FrontToBack>*
 122         it);
 123 template CC_EXPORT void LayerIteratorActions::FrontToBack::Begin(
 124     LayerIterator<LayerImpl, LayerImplList, RenderSurfaceImpl, FrontToBack>*
 125         it);
 126 template CC_EXPORT void LayerIteratorActions::FrontToBack::GoToHighestInSubtree(
 127     LayerIterator<LayerImpl, LayerImplList, RenderSurfaceImpl, FrontToBack>*
 128         it);
 129
 130 }  // namespace cc