cc/trees/draw_property_utils.cc

   1 // Copyright 2014 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/trees/draw_property_utils.h"
   6
   7 #include <vector>
   8
   9 #include "cc/base/math_util.h"
  10 #include "cc/layers/layer.h"
  11 #include "cc/layers/layer_impl.h"
  12 #include "cc/trees/layer_tree_impl.h"
  13 #include "cc/trees/property_tree.h"
  14 #include "cc/trees/property_tree_builder.h"
  15 #include "ui/gfx/geometry/rect_conversions.h"
  16
  17 namespace cc {
  18
  19 namespace {
  20
  21 template <typename LayerType>
  22 void CalculateVisibleRects(const std::vector<LayerType*>& visible_layer_list,
  23                            const ClipTree& clip_tree,
  24                            const TransformTree& transform_tree) {
  25   for (auto& layer : visible_layer_list) {
  26     // TODO(ajuma): Compute content_scale rather than using it. Note that for
  27     // PictureLayer and PictureImageLayers, content_bounds == bounds and
  28     // content_scale_x == content_scale_y == 1.0, so once impl painting is on
  29     // everywhere, this code will be unnecessary.
  30     gfx::Size layer_bounds = layer->bounds();
  31     const bool has_clip = layer->clip_tree_index() > 0;
  32     const TransformNode* transform_node =
  33         transform_tree.Node(layer->transform_tree_index());
  34     if (has_clip) {
  35       const ClipNode* clip_node = clip_tree.Node(layer->clip_tree_index());
  36       const TransformNode* clip_transform_node =
  37           transform_tree.Node(clip_node->data.transform_id);
  38       const bool target_is_root_surface =
  39           transform_node->data.content_target_id == 1;
  40       // When the target is the root surface, we need to include the root
  41       // transform by walking up to the root of the transform tree.
  42       const int target_id =
  43           target_is_root_surface ? 0 : transform_node->data.content_target_id;
  44       const TransformNode* target_node = transform_tree.Node(target_id);
  45
  46       gfx::Transform content_to_target = transform_node->data.to_target;
  47
  48       content_to_target.Translate(layer->offset_to_transform_parent().x(),
  49                                   layer->offset_to_transform_parent().y());
  50
  51       gfx::Rect combined_clip_rect_in_target_space;
  52       gfx::Rect clip_rect_in_target_space;
  53       gfx::Transform clip_to_target;
  54       bool success = true;
  55       if (clip_transform_node->data.target_id == target_node->id) {
  56         clip_to_target = clip_transform_node->data.to_target;
  57       } else {
  58         success = transform_tree.ComputeTransformWithDestinationSublayerScale(
  59             clip_transform_node->id, target_node->id, &clip_to_target);
  60       }
  61       if (target_node->id > clip_node->data.transform_id) {
  62         if (!success) {
  63           DCHECK(target_node->data.to_screen_is_animated);
  64
  65           // An animated singular transform may become non-singular during the
  66           // animation, so we still need to compute a visible rect. In this
  67           // situation, we treat the entire layer as visible.
  68           layer->set_visible_rect_from_property_trees(gfx::Rect(layer_bounds));
  69           layer->set_clip_rect_in_target_space_from_property_trees(
  70               gfx::ToEnclosingRect(clip_node->data.combined_clip));
  71           continue;
  72         }
  73
  74         combined_clip_rect_in_target_space =
  75             gfx::ToEnclosingRect(MathUtil::ProjectClippedRect(
  76                 clip_to_target, clip_node->data.combined_clip));
  77         clip_rect_in_target_space = gfx::ToEnclosingRect(
  78             MathUtil::ProjectClippedRect(clip_to_target, clip_node->data.clip));
  79       } else {
  80         // Computing a transform to an ancestor should always succeed.
  81         DCHECK(success);
  82         combined_clip_rect_in_target_space =
  83             gfx::ToEnclosingRect(MathUtil::MapClippedRect(
  84                 clip_to_target, clip_node->data.combined_clip));
  85         clip_rect_in_target_space = gfx::ToEnclosingRect(
  86             MathUtil::MapClippedRect(clip_to_target, clip_node->data.clip));
  87       }
  88
  89       gfx::Rect layer_content_rect = gfx::Rect(layer_bounds);
  90       gfx::Rect layer_content_bounds_in_target_space =
  91           MathUtil::MapEnclosingClippedRect(content_to_target,
  92                                             layer_content_rect);
  93       combined_clip_rect_in_target_space.Intersect(
  94           layer_content_bounds_in_target_space);
  95       clip_rect_in_target_space.Intersect(layer_content_bounds_in_target_space);
  96       if (clip_node->data.requires_tight_clip_rect) {
  97         layer->set_clip_rect_in_target_space_from_property_trees(
  98             combined_clip_rect_in_target_space);
  99       } else {
 100         layer->set_clip_rect_in_target_space_from_property_trees(
 101             clip_rect_in_target_space);
 102       }
 103       if (combined_clip_rect_in_target_space.IsEmpty()) {
 104         layer->set_visible_rect_from_property_trees(gfx::Rect());
 105         continue;
 106       }
 107
 108       // If the layer is fully contained within the clip, treat it as fully
 109       // visible. Since clip_rect_in_target_space has already been intersected
 110       // with layer_content_bounds_in_target_space, the layer is fully contained
 111       // within the clip iff these rects are equal.
 112       if (combined_clip_rect_in_target_space ==
 113           layer_content_bounds_in_target_space) {
 114         layer->set_visible_rect_from_property_trees(gfx::Rect(layer_bounds));
 115         continue;
 116       }
 117
 118       gfx::Transform target_to_content;
 119       gfx::Transform target_to_layer;
 120
 121       if (transform_node->data.ancestors_are_invertible) {
 122         target_to_layer = transform_node->data.from_target;
 123         success = true;
 124       } else {
 125         success = transform_tree.ComputeTransformWithSourceSublayerScale(
 126             target_node->id, transform_node->id, &target_to_layer);
 127       }
 128
 129       if (!success) {
 130         // An animated singular transform may become non-singular during the
 131         // animation, so we still need to compute a visible rect. In this
 132         // situation, we treat the entire layer as visible.
 133         layer->set_visible_rect_from_property_trees(gfx::Rect(layer_bounds));
 134         continue;
 135       }
 136
 137       target_to_content.Translate(-layer->offset_to_transform_parent().x(),
 138                                   -layer->offset_to_transform_parent().y());
 139       target_to_content.PreconcatTransform(target_to_layer);
 140
 141       gfx::Rect visible_rect = MathUtil::ProjectEnclosingClippedRect(
 142           target_to_content, combined_clip_rect_in_target_space);
 143
 144       visible_rect.Intersect(gfx::Rect(layer_bounds));
 145
 146       layer->set_visible_rect_from_property_trees(visible_rect);
 147     } else {
 148       layer->set_visible_rect_from_property_trees(gfx::Rect(layer_bounds));
 149       layer->set_clip_rect_in_target_space_from_property_trees(
 150           gfx::Rect(layer_bounds));
 151     }
 152   }
 153 }
 154
 155 template <typename LayerType>
 156 static bool IsRootLayerOfNewRenderingContext(LayerType* layer) {
 157   if (layer->parent())
 158     return !layer->parent()->Is3dSorted() && layer->Is3dSorted();
 159   return layer->Is3dSorted();
 160 }
 161
 162 template <typename LayerType>
 163 static inline bool LayerIsInExisting3DRenderingContext(LayerType* layer) {
 164   return layer->Is3dSorted() && layer->parent() &&
 165          layer->parent()->Is3dSorted() &&
 166          layer->parent()->sorting_context_id() == layer->sorting_context_id();
 167 }
 168
 169 template <typename LayerType>
 170 static bool TransformToScreenIsKnown(LayerType* layer,
 171                                      const TransformTree& tree) {
 172   const TransformNode* node = tree.Node(layer->transform_tree_index());
 173   return !node->data.to_screen_is_animated;
 174 }
 175
 176 template <typename LayerType>
 177 static bool HasSingularTransform(LayerType* layer, const TransformTree& tree) {
 178   const TransformNode* node = tree.Node(layer->transform_tree_index());
 179   return !node->data.is_invertible || !node->data.ancestors_are_invertible;
 180 }
 181
 182 template <typename LayerType>
 183 static bool IsLayerBackFaceVisible(LayerType* layer,
 184                                    const TransformTree& tree) {
 185   // The current W3C spec on CSS transforms says that backface visibility should
 186   // be determined differently depending on whether the layer is in a "3d
 187   // rendering context" or not. For Chromium code, we can determine whether we
 188   // are in a 3d rendering context by checking if the parent preserves 3d.
 189
 190   if (LayerIsInExisting3DRenderingContext(layer))
 191     return DrawTransformFromPropertyTrees(layer, tree).IsBackFaceVisible();
 192
 193   // In this case, either the layer establishes a new 3d rendering context, or
 194   // is not in a 3d rendering context at all.
 195   return layer->transform().IsBackFaceVisible();
 196 }
 197
 198 template <typename LayerType>
 199 static bool IsSurfaceBackFaceVisible(LayerType* layer,
 200                                      const TransformTree& tree) {
 201   if (LayerIsInExisting3DRenderingContext(layer)) {
 202     const TransformNode* node = tree.Node(layer->transform_tree_index());
 203     // Draw transform as a contributing render surface.
 204     // TODO(enne): we shouldn't walk the tree during a tree walk.
 205     gfx::Transform surface_draw_transform;
 206     tree.ComputeTransform(node->id, node->data.target_id,
 207                           &surface_draw_transform);
 208     return surface_draw_transform.IsBackFaceVisible();
 209   }
 210
 211   if (IsRootLayerOfNewRenderingContext(layer))
 212     return layer->transform().IsBackFaceVisible();
 213
 214   // If the render_surface is not part of a new or existing rendering context,
 215   // then the layers that contribute to this surface will decide back-face
 216   // visibility for themselves.
 217   return false;
 218 }
 219
 220 template <typename LayerType>
 221 static bool IsAnimatingTransformToScreen(LayerType* layer,
 222                                          const TransformTree& tree) {
 223   const TransformNode* node = tree.Node(layer->transform_tree_index());
 224   return node->data.to_screen_is_animated;
 225 }
 226
 227 static inline bool TransformToScreenIsKnown(Layer* layer,
 228                                             const TransformTree& tree) {
 229   return !IsAnimatingTransformToScreen(layer, tree);
 230 }
 231
 232 static inline bool TransformToScreenIsKnown(LayerImpl* layer,
 233                                             const TransformTree& tree) {
 234   return true;
 235 }
 236
 237 template <typename LayerType>
 238 static bool HasInvertibleOrAnimatedTransform(LayerType* layer) {
 239   return layer->transform_is_invertible() ||
 240          layer->HasPotentiallyRunningTransformAnimation();
 241 }
 242
 243 static inline bool SubtreeShouldBeSkipped(LayerImpl* layer,
 244                                           bool layer_is_drawn,
 245                                           const TransformTree& tree) {
 246   // If the layer transform is not invertible, it should not be drawn.
 247   // TODO(ajuma): Correctly process subtrees with singular transform for the
 248   // case where we may animate to a non-singular transform and wish to
 249   // pre-raster.
 250   if (!HasInvertibleOrAnimatedTransform(layer))
 251     return true;
 252
 253   // When we need to do a readback/copy of a layer's output, we can not skip
 254   // it or any of its ancestors.
 255   if (layer->draw_properties().layer_or_descendant_has_copy_request)
 256     return false;
 257
 258   // We cannot skip the the subtree if a descendant has a wheel or touch handler
 259   // or the hit testing code will break (it requires fresh transforms, etc).
 260   if (layer->draw_properties().layer_or_descendant_has_input_handler)
 261     return false;
 262
 263   // If the layer is not drawn, then skip it and its subtree.
 264   if (!layer_is_drawn)
 265     return true;
 266
 267   if (layer->render_surface() && !layer->double_sided() &&
 268       IsSurfaceBackFaceVisible(layer, tree))
 269     return true;
 270
 271   // If layer is on the pending tree and opacity is being animated then
 272   // this subtree can't be skipped as we need to create, prioritize and
 273   // include tiles for this layer when deciding if tree can be activated.
 274   if (layer->layer_tree_impl()->IsPendingTree() &&
 275       layer->HasPotentiallyRunningOpacityAnimation())
 276     return false;
 277
 278   // The opacity of a layer always applies to its children (either implicitly
 279   // via a render surface or explicitly if the parent preserves 3D), so the
 280   // entire subtree can be skipped if this layer is fully transparent.
 281   return !layer->opacity();
 282 }
 283
 284 static inline bool SubtreeShouldBeSkipped(Layer* layer,
 285                                           bool layer_is_drawn,
 286                                           const TransformTree& tree) {
 287   // If the layer transform is not invertible, it should not be drawn.
 288   if (!layer->transform_is_invertible() &&
 289       !layer->HasPotentiallyRunningTransformAnimation())
 290     return true;
 291
 292   // When we need to do a readback/copy of a layer's output, we can not skip
 293   // it or any of its ancestors.
 294   if (layer->draw_properties().layer_or_descendant_has_copy_request)
 295     return false;
 296
 297   // We cannot skip the the subtree if a descendant has a wheel or touch handler
 298   // or the hit testing code will break (it requires fresh transforms, etc).
 299   if (layer->draw_properties().layer_or_descendant_has_input_handler)
 300     return false;
 301
 302   // If the layer is not drawn, then skip it and its subtree.
 303   if (!layer_is_drawn)
 304     return true;
 305
 306   if (layer->render_surface() && !layer->double_sided() &&
 307       !layer->HasPotentiallyRunningTransformAnimation() &&
 308       IsSurfaceBackFaceVisible(layer, tree))
 309     return true;
 310
 311   // If the opacity is being animated then the opacity on the main thread is
 312   // unreliable (since the impl thread may be using a different opacity), so it
 313   // should not be trusted.
 314   // In particular, it should not cause the subtree to be skipped.
 315   // Similarly, for layers that might animate opacity using an impl-only
 316   // animation, their subtree should also not be skipped.
 317   return !layer->opacity() && !layer->HasPotentiallyRunningOpacityAnimation() &&
 318          !layer->OpacityCanAnimateOnImplThread();
 319 }
 320
 321 template <typename LayerType>
 322 static bool LayerShouldBeSkipped(LayerType* layer,
 323                                  bool layer_is_drawn,
 324                                  const TransformTree& tree) {
 325   // Layers can be skipped if any of these conditions are met.
 326   //   - is not drawn due to it or one of its ancestors being hidden (or having
 327   //     no copy requests).
 328   //   - does not draw content.
 329   //   - is transparent.
 330   //   - has empty bounds
 331   //   - the layer is not double-sided, but its back face is visible.
 332   //
 333   // Some additional conditions need to be computed at a later point after the
 334   // recursion is finished.
 335   //   - the intersection of render_surface content and layer clip_rect is empty
 336   //   - the visible_layer_rect is empty
 337   //
 338   // Note, if the layer should not have been drawn due to being fully
 339   // transparent, we would have skipped the entire subtree and never made it
 340   // into this function, so it is safe to omit this check here.
 341   if (!layer_is_drawn)
 342     return true;
 343
 344   if (!layer->DrawsContent() || layer->bounds().IsEmpty())
 345     return true;
 346
 347   LayerType* backface_test_layer = layer;
 348   if (layer->use_parent_backface_visibility()) {
 349     DCHECK(layer->parent());
 350     DCHECK(!layer->parent()->use_parent_backface_visibility());
 351     backface_test_layer = layer->parent();
 352   }
 353
 354   // The layer should not be drawn if (1) it is not double-sided and (2) the
 355   // back of the layer is known to be facing the screen.
 356   if (!backface_test_layer->double_sided() &&
 357       TransformToScreenIsKnown(backface_test_layer, tree) &&
 358       IsLayerBackFaceVisible(backface_test_layer, tree))
 359     return true;
 360
 361   return false;
 362 }
 363
 364 template <typename LayerType>
 365 void FindLayersThatNeedUpdates(
 366     LayerType* layer,
 367     const TransformTree& tree,
 368     bool subtree_is_visible_from_ancestor,
 369     typename LayerType::LayerListType* update_layer_list,
 370     std::vector<LayerType*>* visible_layer_list) {
 371   bool layer_is_drawn =
 372       layer->HasCopyRequest() ||
 373       (subtree_is_visible_from_ancestor && !layer->hide_layer_and_subtree());
 374
 375   if (layer->parent() && SubtreeShouldBeSkipped(layer, layer_is_drawn, tree))
 376     return;
 377
 378   if (!LayerShouldBeSkipped(layer, layer_is_drawn, tree)) {
 379     visible_layer_list->push_back(layer);
 380     update_layer_list->push_back(layer);
 381   }
 382
 383   // Append mask layers to the update layer list.  They don't have valid visible
 384   // rects, so need to get added after the above calculation.  Replica layers
 385   // don't need to be updated.
 386   if (LayerType* mask_layer = layer->mask_layer())
 387     update_layer_list->push_back(mask_layer);
 388   if (LayerType* replica_layer = layer->replica_layer()) {
 389     if (LayerType* mask_layer = replica_layer->mask_layer())
 390       update_layer_list->push_back(mask_layer);
 391   }
 392
 393   for (size_t i = 0; i < layer->children().size(); ++i) {
 394     FindLayersThatNeedUpdates(layer->child_at(i), tree, layer_is_drawn,
 395                               update_layer_list, visible_layer_list);
 396   }
 397 }
 398
 399 }  // namespace
 400
 401 void ComputeClips(ClipTree* clip_tree, const TransformTree& transform_tree) {
 402   if (!clip_tree->needs_update())
 403     return;
 404   for (int i = 0; i < static_cast<int>(clip_tree->size()); ++i) {
 405     ClipNode* clip_node = clip_tree->Node(i);
 406
 407     // Only descendants of a real clipping layer (i.e., not 0) may have their
 408     // clip adjusted due to intersecting with an ancestor clip.
 409     const bool is_clipped = clip_node->parent_id > 0;
 410     if (!is_clipped) {
 411       DCHECK(!clip_node->data.inherit_parent_target_space_clip);
 412       clip_node->data.combined_clip = clip_node->data.clip;
 413       continue;
 414     }
 415
 416     ClipNode* parent_clip_node = clip_tree->parent(clip_node);
 417     const TransformNode* parent_transform_node =
 418         transform_tree.Node(parent_clip_node->data.transform_id);
 419     const TransformNode* transform_node =
 420         transform_tree.Node(clip_node->data.transform_id);
 421
 422     // Clips must be combined in target space. We cannot, for example, combine
 423     // clips in the space of the child clip. The reason is non-affine
 424     // transforms. Say we have the following tree T->A->B->C, and B clips C, but
 425     // draw into target T. It may be the case that A applies a perspective
 426     // transform, and B and C are at different z positions. When projected into
 427     // target space, the relative sizes and positions of B and C can shift.
 428     // Since it's the relationship in target space that matters, that's where we
 429     // must combine clips.
 430     gfx::Transform parent_to_target;
 431     gfx::Transform clip_to_target;
 432     gfx::Transform target_to_clip;
 433     gfx::Transform parent_to_transform_target;
 434     gfx::Transform transform_target_to_target;
 435
 436     const bool target_is_root_surface = clip_node->data.target_id == 1;
 437     // When the target is the root surface, we need to include the root
 438     // transform by walking up to the root of the transform tree.
 439     const int target_id =
 440         target_is_root_surface ? 0 : clip_node->data.target_id;
 441
 442     bool success = true;
 443     // When render surface applies clip, we need the clip from the target's
 444     // target space. But, as the combined clip is in parent clip's target
 445     // space, we need to first transform it from parent's target space to
 446     // target's target space.
 447     if (clip_node->data.inherit_parent_target_space_clip) {
 448       success &= transform_tree.ComputeTransformWithDestinationSublayerScale(
 449           parent_transform_node->id, transform_node->data.target_id,
 450           &parent_to_transform_target);
 451       success &= transform_tree.ComputeTransformWithSourceSublayerScale(
 452           transform_node->data.target_id, target_id,
 453           &transform_target_to_target);
 454       transform_target_to_target.matrix().postScale(
 455           transform_node->data.sublayer_scale.x(),
 456           transform_node->data.sublayer_scale.y(), 1.0);
 457     } else if (parent_transform_node->data.content_target_id ==
 458                clip_node->data.target_id) {
 459       parent_to_target = parent_transform_node->data.to_target;
 460     } else {
 461       success &= transform_tree.ComputeTransformWithDestinationSublayerScale(
 462           parent_transform_node->id, target_id, &parent_to_target);
 463     }
 464
 465     if (transform_node->data.content_target_id == clip_node->data.target_id) {
 466       clip_to_target = transform_node->data.to_target;
 467     } else {
 468       success &= transform_tree.ComputeTransformWithDestinationSublayerScale(
 469           transform_node->id, target_id, &clip_to_target);
 470     }
 471
 472     if (transform_node->data.content_target_id == clip_node->data.target_id &&
 473         transform_node->data.ancestors_are_invertible) {
 474       target_to_clip = transform_node->data.from_target;
 475     } else {
 476       success &= clip_to_target.GetInverse(&target_to_clip);
 477     }
 478
 479     // If we can't compute a transform, it's because we had to use the inverse
 480     // of a singular transform. We won't draw in this case, so there's no need
 481     // to compute clips.
 482     if (!success) {
 483       continue;
 484     }
 485
 486     // In order to intersect with as small a rect as possible, we do a
 487     // preliminary clip in target space so that when we project back, there's
 488     // less likelihood of intersecting the view plane.
 489     gfx::RectF inherited_clip_in_target_space;
 490     if (clip_node->data.inherit_parent_target_space_clip) {
 491       gfx::RectF combined_clip_in_transform_target_space;
 492       if (parent_transform_node->id > transform_node->data.target_id)
 493         combined_clip_in_transform_target_space = MathUtil::MapClippedRect(
 494             parent_to_transform_target, parent_clip_node->data.combined_clip);
 495       else
 496         combined_clip_in_transform_target_space = MathUtil::ProjectClippedRect(
 497             parent_to_transform_target, parent_clip_node->data.combined_clip);
 498       inherited_clip_in_target_space = MathUtil::ProjectClippedRect(
 499           transform_target_to_target, combined_clip_in_transform_target_space);
 500     } else if (parent_transform_node->id > target_id) {
 501       inherited_clip_in_target_space = MathUtil::MapClippedRect(
 502           parent_to_target, parent_clip_node->data.combined_clip);
 503     } else {
 504       inherited_clip_in_target_space = MathUtil::ProjectClippedRect(
 505           parent_to_target, parent_clip_node->data.combined_clip);
 506     }
 507
 508     // When render surface inherits its parent target space clip, the layer
 509     // that created the clip node doesn't apply any clip. So, we shouldn't clip
 510     // using the clip value stored in the clip node.
 511     gfx::RectF intersected_in_target_space;
 512     if (!clip_node->data.inherit_parent_target_space_clip) {
 513       gfx::RectF clip_in_target_space =
 514           MathUtil::MapClippedRect(clip_to_target, clip_node->data.clip);
 515
 516       intersected_in_target_space = gfx::IntersectRects(
 517           inherited_clip_in_target_space, clip_in_target_space);
 518     } else {
 519       intersected_in_target_space = inherited_clip_in_target_space;
 520     }
 521
 522     clip_node->data.combined_clip = MathUtil::ProjectClippedRect(
 523         target_to_clip, intersected_in_target_space);
 524
 525     if (!clip_node->data.inherit_parent_target_space_clip)
 526       clip_node->data.combined_clip.Intersect(clip_node->data.clip);
 527   }
 528   clip_tree->set_needs_update(false);
 529 }
 530
 531 void ComputeTransforms(TransformTree* transform_tree) {
 532   if (!transform_tree->needs_update())
 533     return;
 534   for (int i = 1; i < static_cast<int>(transform_tree->size()); ++i)
 535     transform_tree->UpdateTransforms(i);
 536   transform_tree->set_needs_update(false);
 537 }
 538
 539 void ComputeOpacities(OpacityTree* opacity_tree) {
 540   if (!opacity_tree->needs_update())
 541     return;
 542   for (int i = 1; i < static_cast<int>(opacity_tree->size()); ++i)
 543     opacity_tree->UpdateOpacities(i);
 544   opacity_tree->set_needs_update(false);
 545 }
 546
 547 template <typename LayerType>
 548 void ComputeVisibleRectsUsingPropertyTreesInternal(
 549     LayerType* root_layer,
 550     PropertyTrees* property_trees,
 551     typename LayerType::LayerListType* update_layer_list) {
 552   if (property_trees->transform_tree.needs_update())
 553     property_trees->clip_tree.set_needs_update(true);
 554   ComputeTransforms(&property_trees->transform_tree);
 555   ComputeClips(&property_trees->clip_tree, property_trees->transform_tree);
 556   ComputeOpacities(&property_trees->opacity_tree);
 557
 558   const bool subtree_is_visible_from_ancestor = true;
 559   std::vector<LayerType*> visible_layer_list;
 560   FindLayersThatNeedUpdates(root_layer, property_trees->transform_tree,
 561                             subtree_is_visible_from_ancestor, update_layer_list,
 562                             &visible_layer_list);
 563   CalculateVisibleRects<LayerType>(visible_layer_list,
 564                                    property_trees->clip_tree,
 565                                    property_trees->transform_tree);
 566 }
 567
 568 void BuildPropertyTreesAndComputeVisibleRects(
 569     Layer* root_layer,
 570     const Layer* page_scale_layer,
 571     const Layer* inner_viewport_scroll_layer,
 572     const Layer* outer_viewport_scroll_layer,
 573     float page_scale_factor,
 574     float device_scale_factor,
 575     const gfx::Rect& viewport,
 576     const gfx::Transform& device_transform,
 577     PropertyTrees* property_trees,
 578     LayerList* update_layer_list) {
 579   PropertyTreeBuilder::BuildPropertyTrees(
 580       root_layer, page_scale_layer, inner_viewport_scroll_layer,
 581       outer_viewport_scroll_layer, page_scale_factor, device_scale_factor,
 582       viewport, device_transform, property_trees);
 583   ComputeVisibleRectsUsingPropertyTrees(root_layer, property_trees,
 584                                         update_layer_list);
 585 }
 586
 587 void BuildPropertyTreesAndComputeVisibleRects(
 588     LayerImpl* root_layer,
 589     const LayerImpl* page_scale_layer,
 590     const LayerImpl* inner_viewport_scroll_layer,
 591     const LayerImpl* outer_viewport_scroll_layer,
 592     float page_scale_factor,
 593     float device_scale_factor,
 594     const gfx::Rect& viewport,
 595     const gfx::Transform& device_transform,
 596     PropertyTrees* property_trees,
 597     LayerImplList* update_layer_list) {
 598   PropertyTreeBuilder::BuildPropertyTrees(
 599       root_layer, page_scale_layer, inner_viewport_scroll_layer,
 600       outer_viewport_scroll_layer, page_scale_factor, device_scale_factor,
 601       viewport, device_transform, property_trees);
 602   ComputeVisibleRectsUsingPropertyTrees(root_layer, property_trees,
 603                                         update_layer_list);
 604 }
 605
 606 void ComputeVisibleRectsUsingPropertyTrees(Layer* root_layer,
 607                                            PropertyTrees* property_trees,
 608                                            LayerList* update_layer_list) {
 609   ComputeVisibleRectsUsingPropertyTreesInternal(root_layer, property_trees,
 610                                                 update_layer_list);
 611 }
 612
 613 void ComputeVisibleRectsUsingPropertyTrees(LayerImpl* root_layer,
 614                                            PropertyTrees* property_trees,
 615                                            LayerImplList* update_layer_list) {
 616   ComputeVisibleRectsUsingPropertyTreesInternal(root_layer, property_trees,
 617                                                 update_layer_list);
 618 }
 619
 620 template <typename LayerType>
 621 gfx::Transform DrawTransformFromPropertyTreesInternal(
 622     const LayerType* layer,
 623     const TransformTree& tree) {
 624   const TransformNode* node = tree.Node(layer->transform_tree_index());
 625
 626   gfx::Transform xform;
 627   const bool owns_non_root_surface = layer->parent() && layer->render_surface();
 628   if (!owns_non_root_surface) {
 629     // If you're not the root, or you don't own a surface, you need to apply
 630     // your local offset.
 631     xform = node->data.to_target;
 632     if (layer->should_flatten_transform_from_property_tree())
 633       xform.FlattenTo2d();
 634     xform.Translate(layer->offset_to_transform_parent().x(),
 635                     layer->offset_to_transform_parent().y());
 636   } else {
 637     // Surfaces need to apply their sublayer scale.
 638     xform.Scale(node->data.sublayer_scale.x(), node->data.sublayer_scale.y());
 639   }
 640   return xform;
 641 }
 642
 643 gfx::Transform DrawTransformFromPropertyTrees(const Layer* layer,
 644                                               const TransformTree& tree) {
 645   return DrawTransformFromPropertyTreesInternal(layer, tree);
 646 }
 647
 648 gfx::Transform DrawTransformFromPropertyTrees(const LayerImpl* layer,
 649                                               const TransformTree& tree) {
 650   return DrawTransformFromPropertyTreesInternal(layer, tree);
 651 }
 652
 653 gfx::Transform DrawTransformOfRenderSurfaceFromPropertyTrees(
 654     const RenderSurfaceImpl* render_surface,
 655     const TransformTree& tree) {
 656   const TransformNode* node = tree.Node(render_surface->TransformTreeIndex());
 657   gfx::Transform render_surface_transform;
 658   // The draw transform of root render surface is identity tranform.
 659   if (node->id == 1)
 660     return render_surface_transform;
 661   const TransformNode* target_node = tree.Node(node->data.target_id);
 662   if (target_node->id == 1)
 663     target_node = tree.Node(0);
 664   tree.ComputeTransformWithDestinationSublayerScale(node->id, target_node->id,
 665                                                     &render_surface_transform);
 666   render_surface_transform.Scale(1.0 / node->data.sublayer_scale.x(),
 667                                  1.0 / node->data.sublayer_scale.y());
 668   return render_surface_transform;
 669 }
 670
 671 template <typename LayerType>
 672 gfx::Transform ScreenSpaceTransformFromPropertyTreesInternal(
 673     LayerType* layer,
 674     const TransformTree& tree) {
 675   gfx::Transform xform(1, 0, 0, 1, layer->offset_to_transform_parent().x(),
 676                        layer->offset_to_transform_parent().y());
 677   if (layer->transform_tree_index() >= 0) {
 678     gfx::Transform ssxform =
 679         tree.Node(layer->transform_tree_index())->data.to_screen;
 680     xform.ConcatTransform(ssxform);
 681     if (layer->should_flatten_transform_from_property_tree())
 682       xform.FlattenTo2d();
 683   }
 684   return xform;
 685 }
 686
 687 gfx::Transform ScreenSpaceTransformFromPropertyTrees(
 688     const Layer* layer,
 689     const TransformTree& tree) {
 690   return ScreenSpaceTransformFromPropertyTreesInternal(layer, tree);
 691 }
 692
 693 gfx::Transform ScreenSpaceTransformFromPropertyTrees(
 694     const LayerImpl* layer,
 695     const TransformTree& tree) {
 696   return ScreenSpaceTransformFromPropertyTreesInternal(layer, tree);
 697 }
 698
 699 template <typename LayerType>
 700 bool ScreenSpaceTransformIsAnimatingFromPropertyTreesInternal(
 701     LayerType* layer,
 702     const TransformTree& tree) {
 703   return tree.Node(layer->transform_tree_index())->data.to_screen_is_animated;
 704 }
 705
 706 bool ScreenSpaceTransformIsAnimatingFromPropertyTrees(
 707     const Layer* layer,
 708     const TransformTree& tree) {
 709   return ScreenSpaceTransformIsAnimatingFromPropertyTreesInternal(layer, tree);
 710 }
 711
 712 bool ScreenSpaceTransformIsAnimatingFromPropertyTrees(
 713     const LayerImpl* layer,
 714     const TransformTree& tree) {
 715   return ScreenSpaceTransformIsAnimatingFromPropertyTreesInternal(layer, tree);
 716 }
 717
 718 template <typename LayerType>
 719 float DrawOpacityFromPropertyTreesInternal(LayerType layer,
 720                                            const OpacityTree& tree) {
 721   if (!layer->render_target())
 722     return 0.f;
 723
 724   const OpacityNode* target_node =
 725       tree.Node(layer->render_target()->opacity_tree_index());
 726   const OpacityNode* node = tree.Node(layer->opacity_tree_index());
 727   if (node == target_node)
 728     return 1.f;
 729
 730   float draw_opacity = 1.f;
 731   while (node != target_node) {
 732     draw_opacity *= node->data.opacity;
 733     node = tree.parent(node);
 734   }
 735   return draw_opacity;
 736 }
 737
 738 float DrawOpacityFromPropertyTrees(const Layer* layer,
 739                                    const OpacityTree& tree) {
 740   return DrawOpacityFromPropertyTreesInternal(layer, tree);
 741 }
 742
 743 float DrawOpacityFromPropertyTrees(const LayerImpl* layer,
 744                                    const OpacityTree& tree) {
 745   return DrawOpacityFromPropertyTreesInternal(layer, tree);
 746 }
 747
 748 bool CanUseLcdTextFromPropertyTrees(const LayerImpl* layer,
 749                                     bool layers_always_allowed_lcd_text,
 750                                     bool can_use_lcd_text,
 751                                     PropertyTrees* property_trees) {
 752   if (layers_always_allowed_lcd_text)
 753     return true;
 754   if (!can_use_lcd_text)
 755     return false;
 756   if (!layer->contents_opaque())
 757     return false;
 758   DCHECK(!property_trees->transform_tree.needs_update());
 759   DCHECK(!property_trees->opacity_tree.needs_update());
 760
 761   const OpacityNode* opacity_node =
 762       property_trees->opacity_tree.Node(layer->opacity_tree_index());
 763   if (opacity_node->data.screen_space_opacity != 1.f)
 764     return false;
 765   const TransformNode* transform_node =
 766       property_trees->transform_tree.Node(layer->transform_tree_index());
 767   if (!transform_node->data.node_and_ancestors_have_only_integer_translation)
 768     return false;
 769   if (static_cast<int>(layer->offset_to_transform_parent().x()) !=
 770       layer->offset_to_transform_parent().x())
 771     return false;
 772   if (static_cast<int>(layer->offset_to_transform_parent().y()) !=
 773       layer->offset_to_transform_parent().y())
 774     return false;
 775   return true;
 776 }
 777
 778 gfx::Rect DrawableContentRectFromPropertyTrees(
 779     const LayerImpl* layer,
 780     const TransformTree& transform_tree) {
 781   gfx::Rect drawable_content_rect = MathUtil::MapEnclosingClippedRect(
 782       DrawTransformFromPropertyTrees(layer, transform_tree),
 783       gfx::Rect(layer->bounds()));
 784   if (layer->is_clipped() && layer->clip_tree_index() > 0) {
 785     drawable_content_rect.Intersect(
 786         layer->clip_rect_in_target_space_from_property_trees());
 787   }
 788   return drawable_content_rect;
 789 }
 790
 791 }  // namespace cc