cc/trees/property_tree_builder.cc - mojo-tools - Git at Google

 // Copyright 2014 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/trees/property_tree_builder.h"

 #include <map>
 #include <set>

 #include "cc/base/math_util.h"
 #include "cc/layers/layer.h"
 #include "cc/trees/layer_tree_host.h"
 #include "ui/gfx/geometry/point_f.h"

 namespace cc {

 class LayerTreeHost;

 namespace {

 struct DataForRecursion {
   TransformTree* transform_tree;
   ClipTree* clip_tree;
   Layer* transform_tree_parent;
   Layer* transform_fixed_parent;
   Layer* render_target;
   int clip_tree_parent;
   gfx::Vector2dF offset_to_transform_tree_parent;
   gfx::Vector2dF offset_to_transform_fixed_parent;
   const Layer* page_scale_layer;
   float page_scale_factor;
   float device_scale_factor;
 };

 static Layer* GetTransformParent(const DataForRecursion& data, Layer* layer) {
   return layer->position_constraint().is_fixed_position()
              ? data.transform_fixed_parent
              : data.transform_tree_parent;
 }

 static ClipNode* GetClipParent(const DataForRecursion& data, Layer* layer) {
   const bool inherits_clip = !layer->parent() || !layer->clip_parent();
   const int id = inherits_clip ? data.clip_tree_parent
                                : layer->clip_parent()->clip_tree_index();
   return data.clip_tree->Node(id);
 }

 static bool RequiresClipNode(Layer* layer,
                              bool axis_aligned_with_respect_to_parent) {
   const bool render_surface_applies_non_axis_aligned_clip =
       layer->render_surface() && !axis_aligned_with_respect_to_parent &&
       layer->is_clipped();
   const bool render_surface_may_grow_due_to_clip_children =
       layer->render_surface() && layer->num_unclipped_descendants() > 0;

   return !layer->parent() || layer->masks_to_bounds() || layer->mask_layer() ||
          render_surface_applies_non_axis_aligned_clip ||
          render_surface_may_grow_due_to_clip_children;
 }

 void AddClipNodeIfNeeded(const DataForRecursion& data_from_ancestor,
                          Layer* layer,
                          DataForRecursion* data_for_children) {
   ClipNode* parent = GetClipParent(data_from_ancestor, layer);
   int parent_id = parent->id;
   const bool axis_aligned_with_respect_to_parent =
       data_from_ancestor.transform_tree->Are2DAxisAligned(
           layer->transform_tree_index(), parent->data.transform_id);

   // TODO(vollick): once Andrew refactors the surface determinations out of
   // CDP, the the layer->render_surface() check will be invalid.
   const bool has_unclipped_surface =
       layer->render_surface() &&
       !layer->render_surface()->is_clipped() &&
       layer->num_unclipped_descendants() == 0;

   if (has_unclipped_surface)
     parent_id = 0;

   if (!RequiresClipNode(layer, axis_aligned_with_respect_to_parent)) {
     // Unclipped surfaces reset the clip rect.
     data_for_children->clip_tree_parent = parent_id;
   } else if (layer->parent()) {
     // Note the root clip gets handled elsewhere.
     Layer* transform_parent = GetTransformParent(*data_for_children, layer);
     ClipNode node;
     node.data.clip = gfx::RectF(
         gfx::PointF() + layer->offset_to_transform_parent(), layer->bounds());
     node.data.transform_id = transform_parent->transform_tree_index();
     node.data.target_id =
         data_from_ancestor.render_target->transform_tree_index();

     data_for_children->clip_tree_parent =
         data_for_children->clip_tree->Insert(node, parent_id);
   }

   layer->set_clip_tree_index(
       has_unclipped_surface ? 0 : data_for_children->clip_tree_parent);

   // TODO(awoloszyn): Right now when we hit a node with a replica, we reset the
   // clip for all children since we may need to draw. We need to figure out a
   // better way, since we will need both the clipped and unclipped versions.
 }

 void AddTransformNodeIfNeeded(const DataForRecursion& data_from_ancestor,
                               Layer* layer,
                               DataForRecursion* data_for_children) {
   const bool is_root = !layer->parent();
   const bool is_page_scale_application_layer =
       layer->parent() && layer->parent() == data_from_ancestor.page_scale_layer;
   const bool is_scrollable = layer->scrollable();
   const bool is_fixed = layer->position_constraint().is_fixed_position();

   const bool has_significant_transform =
       !layer->transform().IsIdentityOr2DTranslation();

   const bool has_animated_transform =
       layer->layer_animation_controller()->IsAnimatingProperty(
           Animation::Transform);

   const bool has_transform_origin = layer->transform_origin() != gfx::Point3F();

   const bool has_surface = !!layer->render_surface();

   const bool flattening_change = layer->parent() &&
                                  layer->should_flatten_transform() &&
                                  !layer->parent()->should_flatten_transform();

   bool requires_node = is_root || is_scrollable || is_fixed ||
                        has_significant_transform || has_animated_transform ||
                        is_page_scale_application_layer || flattening_change ||
                        has_transform_origin || has_surface;

   Layer* transform_parent = GetTransformParent(data_from_ancestor, layer);

   // May be non-zero if layer is fixed or has a scroll parent.
   gfx::Vector2dF parent_offset;
   if (transform_parent) {
     // TODO(vollick): This is to mimic existing bugs (crbug.com/441447).
     if (!is_fixed)
       parent_offset = transform_parent->offset_to_transform_parent();

     gfx::Transform to_parent;
     Layer* source = data_from_ancestor.transform_tree_parent;
     if (layer->scroll_parent()) {
       source = layer->parent();
       parent_offset += layer->parent()->offset_to_transform_parent();
     }
     data_from_ancestor.transform_tree->ComputeTransform(
         source->transform_tree_index(),
         transform_parent->transform_tree_index(), &to_parent);

     parent_offset += to_parent.To2dTranslation();
   }

   if (layer->IsContainerForFixedPositionLayers() || is_root)
     data_for_children->transform_fixed_parent = layer;
   data_for_children->transform_tree_parent = layer;

   if (!requires_node) {
     gfx::Vector2dF local_offset = layer->position().OffsetFromOrigin() +
                                   layer->transform().To2dTranslation();
     layer->set_offset_to_transform_parent(parent_offset + local_offset);
     layer->set_transform_tree_index(transform_parent->transform_tree_index());
     return;
   }

   if (!is_root) {
     data_for_children->transform_tree->Insert(
         TransformNode(), transform_parent->transform_tree_index());
   }

   TransformNode* node = data_for_children->transform_tree->back();

   node->data.flattens = layer->should_flatten_transform();
   node->data.target_id =
       data_from_ancestor.render_target->transform_tree_index();
   node->data.is_animated = layer->TransformIsAnimating();

   gfx::Transform transform;
   float device_and_page_scale_factors = 1.0f;
   if (is_root)
     device_and_page_scale_factors = data_from_ancestor.device_scale_factor;
   if (is_page_scale_application_layer)
     device_and_page_scale_factors *= data_from_ancestor.page_scale_factor;

   transform.Scale(device_and_page_scale_factors, device_and_page_scale_factors);

   // TODO(vollick): We've accounted for the scroll offset here but we haven't
   // taken into account snapping to screen space pixels. For the purposes of
   // computing rects we need to record, this should be fine (the visible rects
   // we compute may be slightly different than what we'd compute with snapping,
   // but since we significantly expand the visible rect when determining what to
   // record, the slight difference should be inconsequential).
   gfx::Vector2dF position = layer->position().OffsetFromOrigin();
   if (!layer->scroll_parent()) {
     position -= gfx::Vector2dF(layer->TotalScrollOffset().x(),
         layer->TotalScrollOffset().y());
   }

   position += parent_offset;

   transform.Translate3d(position.x() + layer->transform_origin().x(),
                         position.y() + layer->transform_origin().y(),
                         layer->transform_origin().z());
   transform.PreconcatTransform(layer->transform());
   transform.Translate3d(-layer->transform_origin().x(),
                         -layer->transform_origin().y(),
                         -layer->transform_origin().z());

   node->data.to_parent = transform;
   node->data.is_invertible = transform.GetInverse(&node->data.from_parent);

   data_from_ancestor.transform_tree->UpdateScreenSpaceTransform(node->id);

   layer->set_offset_to_transform_parent(gfx::Vector2dF());
   layer->set_transform_tree_index(node->id);
 }

 void BuildPropertyTreesInternal(Layer* layer,
                                 const DataForRecursion& data_from_parent) {
   DataForRecursion data_for_children(data_from_parent);
   if (layer->render_surface())
     data_for_children.render_target = layer;

   AddTransformNodeIfNeeded(data_from_parent, layer, &data_for_children);
   AddClipNodeIfNeeded(data_from_parent, layer, &data_for_children);

   for (size_t i = 0; i < layer->children().size(); ++i) {
     if (!layer->children()[i]->scroll_parent())
       BuildPropertyTreesInternal(layer->children()[i].get(), data_for_children);
   }

   if (layer->scroll_children()) {
     for (Layer* scroll_child : *layer->scroll_children()) {
       BuildPropertyTreesInternal(scroll_child, data_for_children);
     }
   }

   if (layer->has_replica())
     BuildPropertyTreesInternal(layer->replica_layer(), data_for_children);
 }

 }  // namespace

 void PropertyTreeBuilder::BuildPropertyTrees(
     Layer* root_layer,
     const Layer* page_scale_layer,
     float page_scale_factor,
     float device_scale_factor,
     const gfx::Rect& viewport,
     const gfx::Transform& device_transform,
     TransformTree* transform_tree,
     ClipTree* clip_tree) {
   DataForRecursion data_for_recursion;
   data_for_recursion.transform_tree = transform_tree;
   data_for_recursion.clip_tree = clip_tree;
   data_for_recursion.transform_tree_parent = nullptr;
   data_for_recursion.transform_fixed_parent = nullptr;
   data_for_recursion.render_target = root_layer;
   data_for_recursion.clip_tree_parent = 0;
   data_for_recursion.page_scale_layer = page_scale_layer;
   data_for_recursion.page_scale_factor = page_scale_factor;
   data_for_recursion.device_scale_factor = device_scale_factor;

   int transform_root_id = transform_tree->Insert(TransformNode(), 0);

   ClipNode root_clip;
   root_clip.data.clip = viewport;
   root_clip.data.transform_id = 0;
   data_for_recursion.clip_tree_parent = clip_tree->Insert(root_clip, 0);

   BuildPropertyTreesInternal(root_layer, data_for_recursion);

   TransformNode* transform_root = transform_tree->Node(transform_root_id);
   transform_root->data.set_to_parent(device_transform *
                                      transform_root->data.to_parent);
 }

 }  // namespace cc
	// Copyright 2014 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/trees/property_tree_builder.h"

	#include <map>
	#include <set>

	#include "cc/base/math_util.h"
	#include "cc/layers/layer.h"
	#include "cc/trees/layer_tree_host.h"
	#include "ui/gfx/geometry/point_f.h"

	namespace cc {

	class LayerTreeHost;

	namespace {

	struct DataForRecursion {
	TransformTree* transform_tree;
	ClipTree* clip_tree;
	Layer* transform_tree_parent;
	Layer* transform_fixed_parent;
	Layer* render_target;
	int clip_tree_parent;
	gfx::Vector2dF offset_to_transform_tree_parent;
	gfx::Vector2dF offset_to_transform_fixed_parent;
	const Layer* page_scale_layer;
	float page_scale_factor;
	float device_scale_factor;
	};

	static Layer* GetTransformParent(const DataForRecursion& data, Layer* layer) {
	return layer->position_constraint().is_fixed_position()
	? data.transform_fixed_parent
	: data.transform_tree_parent;
	}

	static ClipNode* GetClipParent(const DataForRecursion& data, Layer* layer) {
	const bool inherits_clip = !layer->parent() \|\| !layer->clip_parent();
	const int id = inherits_clip ? data.clip_tree_parent
	: layer->clip_parent()->clip_tree_index();
	return data.clip_tree->Node(id);
	}

	static bool RequiresClipNode(Layer* layer,
	bool axis_aligned_with_respect_to_parent) {
	const bool render_surface_applies_non_axis_aligned_clip =
	layer->render_surface() && !axis_aligned_with_respect_to_parent &&
	layer->is_clipped();
	const bool render_surface_may_grow_due_to_clip_children =
	layer->render_surface() && layer->num_unclipped_descendants() > 0;

	return !layer->parent() \|\| layer->masks_to_bounds() \|\| layer->mask_layer() \|\|
	render_surface_applies_non_axis_aligned_clip \|\|
	render_surface_may_grow_due_to_clip_children;
	}

	void AddClipNodeIfNeeded(const DataForRecursion& data_from_ancestor,
	Layer* layer,
	DataForRecursion* data_for_children) {
	ClipNode* parent = GetClipParent(data_from_ancestor, layer);
	int parent_id = parent->id;
	const bool axis_aligned_with_respect_to_parent =
	data_from_ancestor.transform_tree->Are2DAxisAligned(
	layer->transform_tree_index(), parent->data.transform_id);

	// TODO(vollick): once Andrew refactors the surface determinations out of
	// CDP, the the layer->render_surface() check will be invalid.
	const bool has_unclipped_surface =
	layer->render_surface() &&
	!layer->render_surface()->is_clipped() &&
	layer->num_unclipped_descendants() == 0;

	if (has_unclipped_surface)
	parent_id = 0;

	if (!RequiresClipNode(layer, axis_aligned_with_respect_to_parent)) {
	// Unclipped surfaces reset the clip rect.
	data_for_children->clip_tree_parent = parent_id;
	} else if (layer->parent()) {
	// Note the root clip gets handled elsewhere.
	Layer* transform_parent = GetTransformParent(*data_for_children, layer);
	ClipNode node;
	node.data.clip = gfx::RectF(
	gfx::PointF() + layer->offset_to_transform_parent(), layer->bounds());
	node.data.transform_id = transform_parent->transform_tree_index();
	node.data.target_id =
	data_from_ancestor.render_target->transform_tree_index();

	data_for_children->clip_tree_parent =
	data_for_children->clip_tree->Insert(node, parent_id);
	}

	layer->set_clip_tree_index(
	has_unclipped_surface ? 0 : data_for_children->clip_tree_parent);

	// TODO(awoloszyn): Right now when we hit a node with a replica, we reset the
	// clip for all children since we may need to draw. We need to figure out a
	// better way, since we will need both the clipped and unclipped versions.
	}

	void AddTransformNodeIfNeeded(const DataForRecursion& data_from_ancestor,
	Layer* layer,
	DataForRecursion* data_for_children) {
	const bool is_root = !layer->parent();
	const bool is_page_scale_application_layer =
	layer->parent() && layer->parent() == data_from_ancestor.page_scale_layer;
	const bool is_scrollable = layer->scrollable();
	const bool is_fixed = layer->position_constraint().is_fixed_position();

	const bool has_significant_transform =
	!layer->transform().IsIdentityOr2DTranslation();

	const bool has_animated_transform =
	layer->layer_animation_controller()->IsAnimatingProperty(
	Animation::Transform);

	const bool has_transform_origin = layer->transform_origin() != gfx::Point3F();

	const bool has_surface = !!layer->render_surface();

	const bool flattening_change = layer->parent() &&
	layer->should_flatten_transform() &&
	!layer->parent()->should_flatten_transform();

	bool requires_node = is_root \|\| is_scrollable \|\| is_fixed \|\|
	has_significant_transform \|\| has_animated_transform \|\|
	is_page_scale_application_layer \|\| flattening_change \|\|
	has_transform_origin \|\| has_surface;

	Layer* transform_parent = GetTransformParent(data_from_ancestor, layer);

	// May be non-zero if layer is fixed or has a scroll parent.
	gfx::Vector2dF parent_offset;
	if (transform_parent) {
	// TODO(vollick): This is to mimic existing bugs (crbug.com/441447).
	if (!is_fixed)
	parent_offset = transform_parent->offset_to_transform_parent();

	gfx::Transform to_parent;
	Layer* source = data_from_ancestor.transform_tree_parent;
	if (layer->scroll_parent()) {
	source = layer->parent();
	parent_offset += layer->parent()->offset_to_transform_parent();
	}
	data_from_ancestor.transform_tree->ComputeTransform(
	source->transform_tree_index(),
	transform_parent->transform_tree_index(), &to_parent);

	parent_offset += to_parent.To2dTranslation();
	}

	if (layer->IsContainerForFixedPositionLayers() \|\| is_root)
	data_for_children->transform_fixed_parent = layer;
	data_for_children->transform_tree_parent = layer;

	if (!requires_node) {
	gfx::Vector2dF local_offset = layer->position().OffsetFromOrigin() +
	layer->transform().To2dTranslation();
	layer->set_offset_to_transform_parent(parent_offset + local_offset);
	layer->set_transform_tree_index(transform_parent->transform_tree_index());
	return;
	}

	if (!is_root) {
	data_for_children->transform_tree->Insert(
	TransformNode(), transform_parent->transform_tree_index());
	}

	TransformNode* node = data_for_children->transform_tree->back();

	node->data.flattens = layer->should_flatten_transform();
	node->data.target_id =
	data_from_ancestor.render_target->transform_tree_index();
	node->data.is_animated = layer->TransformIsAnimating();

	gfx::Transform transform;
	float device_and_page_scale_factors = 1.0f;
	if (is_root)
	device_and_page_scale_factors = data_from_ancestor.device_scale_factor;
	if (is_page_scale_application_layer)
	device_and_page_scale_factors *= data_from_ancestor.page_scale_factor;

	transform.Scale(device_and_page_scale_factors, device_and_page_scale_factors);

	// TODO(vollick): We've accounted for the scroll offset here but we haven't
	// taken into account snapping to screen space pixels. For the purposes of
	// computing rects we need to record, this should be fine (the visible rects
	// we compute may be slightly different than what we'd compute with snapping,
	// but since we significantly expand the visible rect when determining what to
	// record, the slight difference should be inconsequential).
	gfx::Vector2dF position = layer->position().OffsetFromOrigin();
	if (!layer->scroll_parent()) {
	position -= gfx::Vector2dF(layer->TotalScrollOffset().x(),
	layer->TotalScrollOffset().y());
	}

	position += parent_offset;

	transform.Translate3d(position.x() + layer->transform_origin().x(),
	position.y() + layer->transform_origin().y(),
	layer->transform_origin().z());
	transform.PreconcatTransform(layer->transform());
	transform.Translate3d(-layer->transform_origin().x(),
	-layer->transform_origin().y(),
	-layer->transform_origin().z());

	node->data.to_parent = transform;
	node->data.is_invertible = transform.GetInverse(&node->data.from_parent);

	data_from_ancestor.transform_tree->UpdateScreenSpaceTransform(node->id);

	layer->set_offset_to_transform_parent(gfx::Vector2dF());
	layer->set_transform_tree_index(node->id);
	}

	void BuildPropertyTreesInternal(Layer* layer,
	const DataForRecursion& data_from_parent) {
	DataForRecursion data_for_children(data_from_parent);
	if (layer->render_surface())
	data_for_children.render_target = layer;

	AddTransformNodeIfNeeded(data_from_parent, layer, &data_for_children);
	AddClipNodeIfNeeded(data_from_parent, layer, &data_for_children);

	for (size_t i = 0; i < layer->children().size(); ++i) {
	if (!layer->children()[i]->scroll_parent())
	BuildPropertyTreesInternal(layer->children()[i].get(), data_for_children);
	}

	if (layer->scroll_children()) {
	for (Layer* scroll_child : *layer->scroll_children()) {
	BuildPropertyTreesInternal(scroll_child, data_for_children);
	}
	}

	if (layer->has_replica())
	BuildPropertyTreesInternal(layer->replica_layer(), data_for_children);
	}

	} // namespace

	void PropertyTreeBuilder::BuildPropertyTrees(
	Layer* root_layer,
	const Layer* page_scale_layer,
	float page_scale_factor,
	float device_scale_factor,
	const gfx::Rect& viewport,
	const gfx::Transform& device_transform,
	TransformTree* transform_tree,
	ClipTree* clip_tree) {
	DataForRecursion data_for_recursion;
	data_for_recursion.transform_tree = transform_tree;
	data_for_recursion.clip_tree = clip_tree;
	data_for_recursion.transform_tree_parent = nullptr;
	data_for_recursion.transform_fixed_parent = nullptr;
	data_for_recursion.render_target = root_layer;
	data_for_recursion.clip_tree_parent = 0;
	data_for_recursion.page_scale_layer = page_scale_layer;
	data_for_recursion.page_scale_factor = page_scale_factor;
	data_for_recursion.device_scale_factor = device_scale_factor;

	int transform_root_id = transform_tree->Insert(TransformNode(), 0);

	ClipNode root_clip;
	root_clip.data.clip = viewport;
	root_clip.data.transform_id = 0;
	data_for_recursion.clip_tree_parent = clip_tree->Insert(root_clip, 0);

	BuildPropertyTreesInternal(root_layer, data_for_recursion);

	TransformNode* transform_root = transform_tree->Node(transform_root_id);
	transform_root->data.set_to_parent(device_transform *
	transform_root->data.to_parent);
	}

	} // namespace cc