cc/trees/effect_node.h

// Copyright 2016 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CC_TREES_EFFECT_NODE_H_
#define CC_TREES_EFFECT_NODE_H_

#include <optional>

#include "cc/cc_export.h"
#include "cc/paint/element_id.h"
#include "cc/paint/filter_operations.h"
#include "cc/trees/property_ids.h"
#include "components/viz/common/surfaces/subtree_capture_id.h"
#include "components/viz/common/view_transition_element_resource_id.h"
#include "third_party/skia/include/core/SkBlendMode.h"
#include "third_party/skia/include/core/SkPath.h"
#include "ui/gfx/geometry/mask_filter_info.h"
#include "ui/gfx/geometry/point_f.h"
#include "ui/gfx/geometry/rrect_f.h"
#include "ui/gfx/geometry/size.h"
#include "ui/gfx/geometry/size_f.h"

namespace base {
namespace trace_event {
class TracedValue;
}  // namespace trace_event
}  // namespace base

namespace cc {

// Note: mojom::RenderSurfaceReason must be kept in sync with updates to
// this enum.
enum class RenderSurfaceReason : uint8_t {
  kNone,
  kRoot,
  k3dTransformFlattening,
  // Defines the scope of the backdrop for child blend mode or backdrop filter.
  kBackdropScope,
  kBlendMode,
  kBlendModeDstIn,
  kOpacity,
  kOpacityAnimation,
  kFilter,
  kFilterAnimation,
  kBackdropFilter,
  kBackdropFilterAnimation,
  kRoundedCorner,
  kClipPath,
  kClipAxisAlignment,
  kMask,
  kTrilinearFiltering,
  kCache,
  kCopyRequest,
  kMirrored,
  kSubtreeIsBeingCaptured,
  kViewTransitionParticipant,
  kGradientMask,
  k2DScaleTransformWithCompositedDescendants,
  // This must be the last value because it's used in tracing code to know the
  // number of reasons.
  kTest,
};

CC_EXPORT const char* RenderSurfaceReasonToString(RenderSurfaceReason);

struct CC_EXPORT EffectNode {
  EffectNode();
  EffectNode(const EffectNode& other);
  ~EffectNode();

  // The node index of this node in the effect tree node vector.
  int id = kInvalidPropertyNodeId;
  // The node index of the parent node in the effect tree node vector.
  int parent_id = kInvalidPropertyNodeId;

  // An opaque, unique, stable identifier for this effect that persists across
  // frame commits. This id is used only for internal implementation
  // details such as RenderSurface and RenderPass ids, and should not
  // be assumed to have semantic meaning.
  ElementId element_id;

  float opacity = 1.f;
  float screen_space_opacity = 1.f;

  FilterOperations filters;
  FilterOperations backdrop_filters;
  std::optional<SkPath> backdrop_filter_bounds;
  float backdrop_filter_quality = 1.f;

  // The element id corresponding to the mask to apply to the filtered backdrop
  // image.
  ElementId backdrop_mask_element_id;

  // The mask filter information applied to this effect node. The coordinates of
  // in the mask info is in the space of the transform node associated with this
  // effect node.
  gfx::MaskFilterInfo mask_filter_info;

  gfx::Vector2dF surface_contents_scale;

  viz::SubtreeCaptureId subtree_capture_id;
  gfx::Size subtree_size;

  // The transform node index of the transform to apply to this effect
  // node's content when rendering to a surface.
  int transform_id = kRootPropertyNodeId;
  // The clip node index of the clip to apply to this effect node's
  // content when rendering to a surface.
  int clip_id = kRootPropertyNodeId;

  // This is the id of the ancestor effect node that induces a
  // RenderSurfaceImpl.
  // This is set and used for the impl-side effect tree only.
  int target_id = 1;
  // If this node is tagged with a ViewTransitionElementResourceId, it means it
  // produces a snapshot for an element participating in a transition. This
  // target id corresponds to the effect node where the
  // ViewTransitionContentLayer using this resource draws. Can be unset if no
  // layer using this resource is being drawn.
  int view_transition_target_id = kInvalidPropertyNodeId;
  int closest_ancestor_with_cached_render_surface_id = kInvalidPropertyNodeId;
  int closest_ancestor_with_copy_request_id = kInvalidPropertyNodeId;
  int closest_ancestor_being_captured_id = kInvalidPropertyNodeId;
  int closest_ancestor_with_shared_element_id = kInvalidPropertyNodeId;

  // Represents a resource id for a resource cached or generated in the Viz
  // process.
  viz::ViewTransitionElementResourceId view_transition_element_resource_id;

  SkBlendMode blend_mode = SkBlendMode::kSrcOver;

  // RenderSurfaceReason::kNone if this effect node should not create a render
  // surface, or the reason that this effect node should create one.
  RenderSurfaceReason render_surface_reason = RenderSurfaceReason::kNone;

  bool cache_render_surface : 1 = false;

  // This property is set when a copy request is added to the EffectTree,
  // and is not synced from clients for TreesInViz.
  bool has_copy_request : 1 = false;

  // Whether the effect node is hidden by backface visibility, for single sided
  // nodes.
  // This property is computed in EffectTree::UpdateBackfaceVisibility
  // and is not synced from clients for TreesInViz.
  bool hidden_by_backface_visibility : 1 = false;

  // Whether the contents should continue to be visible when rotated such that
  // its back face is facing toward the camera. It's true by default.
  bool double_sided : 1 = true;
  bool trilinear_filtering : 1 = false;

  // Whether the node will be drawn, as determined by the parent node, non-zero
  // opacity, or having copy requests causing a draw to be required.
  // This property is computed in EffectTree::UpdateIsDrawn and is not synced
  // from clients for TreesInViz.
  bool is_drawn : 1 = true;

  // In most cases we only need to draw the visible part of any content
  // contributing to the effect. For copy request case, we would need to copy
  // the entire content, and could not only draw the visible part. In the rare
  // case of a backdrop zoom filter we need to take into consideration the
  // content offscreen to make sure the backdrop zoom filter is applied with the
  // correct center.
  // This property is computed in EffectTree::UpdateOnlyDrawsVisibleContent and
  // is not synced from clients for TreesInViz.
  bool only_draws_visible_content : 1 = true;

  // TODO(crbug.com/40461368): Delete this after implementation of
  // SetHideLayerAndSubtree is cleaned up.
  bool subtree_hidden : 1 = false;
  // Whether this node has a potentially running (i.e., irrespective
  // of exact timeline) filter animation.
  bool has_potential_filter_animation : 1 = false;
  // Whether this node has a potentially running (i.e., irrespective
  // of exact timeline) backdrop-filter animation.
  bool has_potential_backdrop_filter_animation : 1 = false;
  // Whether this node has a potentially running (i.e., irrespective
  // of exact timeline) opacity animation.
  bool has_potential_opacity_animation : 1 = false;

  // Whether this node has a child node with kDstIn blend mode.
  // This property is computed in EffectTree::UpdateHasMaskingChild and is not
  // synced from clients for TreesInViz.
  bool has_masking_child : 1 = false;

  // Whether this node's effect has been changed since the last
  // frame. Needed in order to compute damage rect.
  // This property is set automatically for TreesInViz and is not synced from
  // clients.
  bool effect_changed : 1 = false;

  // If set, the node's subtree has a copy request and the layer should
  // not be skipped for draw property computation.
  bool subtree_has_copy_request : 1 = false;

  // If set, the effect node tries to not trigger a render surface due to it
  // having a rounded corner.
  bool is_fast_rounded_corner : 1 = false;

  // This property is computed in EffectTree::UpdateHasFastRoundedCorner and
  // is not synced from clients for TreesInViz.
  bool node_or_ancestor_has_fast_rounded_corner : 1 = false;

  // This is set to true if the node or any ancestor has filters that don't
  // allow LCD text.
  // This property is computed in EffectTree::UpdateHasFilters and is not
  // synced from clients for TreesInViz.
  bool lcd_text_disallowed_by_filter : 1 = false;

  // All node in the subtree starting from the containing render surface, and
  // before the backdrop filter node in pre tree order, if the backdrop filter
  // doesn't allow LCD text.
  // This is set and used for the impl-side effect tree only.
  // This property is computed in CalculateDrawProperties and is not synced
  // from clients for TreesInViz.
  bool lcd_text_disallowed_by_backdrop_filter : 1 = false;

  // True if a backdrop effect may be present on this effect (and therefore
  // any side-effects on ancestors should be taken into account).
  bool may_have_backdrop_effect : 1 = false;
  // Whether this effect is triggered by a non-identity 2D scale transform
  // (and no other transform).
  bool needs_effect_for_2d_scale_transform : 1 = false;

  bool HasRenderSurface() const {
    return render_surface_reason != RenderSurfaceReason::kNone;
  }

#if DCHECK_IS_ON()
  bool operator==(const EffectNode& other) const;
#endif

  void AsValueInto(base::trace_event::TracedValue* value) const;
};

}  // namespace cc

#endif  // CC_TREES_EFFECT_NODE_H_