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/*
* Copyright 2017 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef SkSGNode_DEFINED
#define SkSGNode_DEFINED
#include "SkRect.h"
#include "SkRefCnt.h"
#include <vector>
class SkCanvas;
class SkMatrix;
namespace sksg {
class InvalidationController;
/**
* Base class for all scene graph nodes.
*
* Handles ingress edge management for the DAG (i.e. node -> "parent" node mapping),
* and invalidation.
*
* Note: egress edges are only implemented/supported in container subclasses
* (e.g. Group, Effect, Draw).
*/
class Node : public SkRefCnt {
public:
// Traverse the DAG and revalidate any dependant/invalidated nodes.
// Returns the bounding box for the DAG fragment.
const SkRect& revalidate(InvalidationController*, const SkMatrix&);
protected:
enum InvalTraits {
// Nodes with this trait never generate direct damage -- instead,
// the damage bubbles up to ancestors.
kBubbleDamage_Trait = 1 << 0,
};
explicit Node(uint32_t invalTraits);
~Node() override;
const SkRect& bounds() const {
SkASSERT(!this->hasInval());
return fBounds;
}
// Tag this node for invalidation and optional damage.
void invalidate(bool damage = true);
bool hasInval() const { return fFlags & kInvalidated_Flag; }
// Dispatched on revalidation. Subclasses are expected to recompute/cache their properties
// and return their bounding box in local coordinates.
virtual SkRect onRevalidate(InvalidationController*, const SkMatrix& ctm) = 0;
// Register/unregister |this| to receive invalidation events from a descendant.
void observeInval(const sk_sp<Node>&);
void unobserveInval(const sk_sp<Node>&);
private:
enum Flags {
kInvalidated_Flag = 1 << 0, // the node or its descendants require revalidation
kDamage_Flag = 1 << 1, // the node contributes damage during revalidation
kObserverArray_Flag = 1 << 2, // the node has more than one inval observer
kInTraversal_Flag = 1 << 3, // the node is part of a traversal (cycle detection)
};
template <typename Func>
void forEachInvalObserver(Func&&) const;
class ScopedFlag;
union {
Node* fInvalObserver;
std::vector<Node*>* fInvalObserverArray;
};
SkRect fBounds;
const uint32_t fInvalTraits : 16;
uint32_t fFlags : 16;
typedef SkRefCnt INHERITED;
};
// Helper for defining attribute getters/setters in subclasses.
#define SG_ATTRIBUTE(attr_name, attr_type, attr_container) \
const attr_type& get##attr_name() const { return attr_container; } \
void set##attr_name(const attr_type& v) { \
if (attr_container == v) return; \
attr_container = v; \
this->invalidate(); \
} \
void set##attr_name(attr_type&& v) { \
if (attr_container == v) return; \
attr_container = std::move(v); \
this->invalidate(); \
}
#define SG_MAPPED_ATTRIBUTE(attr_name, attr_type, attr_container) \
attr_type get##attr_name() const { return attr_container.get##attr_name(); } \
void set##attr_name(const attr_type& v) { \
if (attr_container.get##attr_name() == v) return; \
attr_container.set##attr_name(v); \
this->invalidate(); \
} \
void set##attr_name(attr_type&& v) { \
if (attr_container.get##attr_name() == v) return; \
attr_container.set##attr_name(std::move(v)); \
this->invalidate(); \
}
} // namespace sksg
#endif // SkSGNode_DEFINED