display_list/display_list.h - mirrors/engine - Git at Google

 // Copyright 2013 The Flutter Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.

 #ifndef FLUTTER_DISPLAY_LIST_DISPLAY_LIST_H_
 #define FLUTTER_DISPLAY_LIST_DISPLAY_LIST_H_

 #include <memory>
 #include <optional>

 #include "flutter/display_list/display_list_rtree.h"
 #include "flutter/display_list/display_list_sampling_options.h"
 #include "flutter/display_list/types.h"
 #include "flutter/fml/logging.h"

 // The Flutter DisplayList mechanism encapsulates a persistent sequence of
 // rendering operations.
 //
 // This file contains the definitions for:
 // DisplayList: the base class that holds the information about the
 //              sequence of operations and can dispatch them to a Dispatcher
 // Dispatcher: a pure virtual interface which can be implemented to field
 //             the requests for purposes such as sending them to an SkCanvas
 //             or detecting various rendering optimization scenarios
 // DisplayListBuilder: a class for constructing a DisplayList from the same
 //                     calls defined in the Dispatcher
 //
 // Other files include various class definitions for dealing with display
 // lists, such as:
 // display_list_canvas.h: classes to interact between SkCanvas and DisplayList
 //                        (SkCanvas->DisplayList adapter and vice versa)
 //
 // display_list_utils.h: various utility classes to ease implementing
 //                       a Dispatcher, including NOP implementations of
 //                       the attribute, clip, and transform methods,
 //                       classes to track attributes, clips, and transforms
 //                       and a class to compute the bounds of a DisplayList
 //                       Any class implementing Dispatcher can inherit from
 //                       these utility classes to simplify its creation
 //
 // The Flutter DisplayList mechanism can be used in place of the Skia
 // SkPicture mechanism. The primary means of communication into and out
 // of the DisplayList is through the Dispatcher virtual class which
 // provides a nearly 1:1 translation between the records of the DisplayList
 // to method calls.
 //
 // A DisplayList can be created directly using a DisplayListBuilder and
 // the Dispatcher methods that it implements, or it can be created from
 // a sequence of SkCanvas calls using the DisplayListCanvasRecorder class.
 //
 // A DisplayList can be read back by implementing the Dispatcher virtual
 // methods (with help from some of the classes in the utils file) and
 // passing an instance to the dispatch() method, or it can be rendered
 // to Skia using a DisplayListCanvasDispatcher or simply by passing an
 // SkCanvas pointer to its renderTo() method.
 //
 // The mechanism is inspired by the SkLiteDL class that is not directly
 // supported by Skia, but has been recommended as a basis for custom
 // display lists for a number of their customers.

 namespace flutter {

 #define FOR_EACH_DISPLAY_LIST_OP(V) \
   V(SetAntiAlias)                   \
   V(SetDither)                      \
   V(SetInvertColors)                \
                                     \
   V(SetStrokeCap)                   \
   V(SetStrokeJoin)                  \
                                     \
   V(SetStyle)                       \
   V(SetStrokeWidth)                 \
   V(SetStrokeMiter)                 \
                                     \
   V(SetColor)                       \
   V(SetBlendMode)                   \
                                     \
   V(SetBlender)                     \
   V(ClearBlender)                   \
                                     \
   V(SetSkPathEffect)                \
   V(SetPodPathEffect)               \
   V(ClearPathEffect)                \
                                     \
   V(ClearColorFilter)               \
   V(SetPodColorFilter)              \
   V(SetSkColorFilter)               \
                                     \
   V(ClearColorSource)               \
   V(SetPodColorSource)              \
   V(SetSkColorSource)               \
   V(SetImageColorSource)            \
   V(SetRuntimeEffectColorSource)    \
                                     \
   V(ClearImageFilter)               \
   V(SetPodImageFilter)              \
   V(SetSkImageFilter)               \
   V(SetSharedImageFilter)           \
                                     \
   V(ClearMaskFilter)                \
   V(SetPodMaskFilter)               \
   V(SetSkMaskFilter)                \
                                     \
   V(Save)                           \
   V(SaveLayer)                      \
   V(SaveLayerBounds)                \
   V(SaveLayerBackdrop)              \
   V(SaveLayerBackdropBounds)        \
   V(Restore)                        \
                                     \
   V(Translate)                      \
   V(Scale)                          \
   V(Rotate)                         \
   V(Skew)                           \
   V(Transform2DAffine)              \
   V(TransformFullPerspective)       \
   V(TransformReset)                 \
                                     \
   V(ClipIntersectRect)              \
   V(ClipIntersectRRect)             \
   V(ClipIntersectPath)              \
   V(ClipDifferenceRect)             \
   V(ClipDifferenceRRect)            \
   V(ClipDifferencePath)             \
                                     \
   V(DrawPaint)                      \
   V(DrawColor)                      \
                                     \
   V(DrawLine)                       \
   V(DrawRect)                       \
   V(DrawOval)                       \
   V(DrawCircle)                     \
   V(DrawRRect)                      \
   V(DrawDRRect)                     \
   V(DrawArc)                        \
   V(DrawPath)                       \
                                     \
   V(DrawPoints)                     \
   V(DrawLines)                      \
   V(DrawPolygon)                    \
   V(DrawVertices)                   \
   V(DrawSkVertices)                 \
                                     \
   V(DrawImage)                      \
   V(DrawImageWithAttr)              \
   V(DrawImageRect)                  \
   V(DrawImageNine)                  \
   V(DrawImageNineWithAttr)          \
   V(DrawImageLattice)               \
   V(DrawAtlas)                      \
   V(DrawAtlasCulled)                \
                                     \
   V(DrawSkPicture)                  \
   V(DrawSkPictureMatrix)            \
   V(DrawDisplayList)                \
   V(DrawTextBlob)                   \
                                     \
   V(DrawShadow)                     \
   V(DrawShadowTransparentOccluder)

 #define DL_OP_TO_ENUM_VALUE(name) k##name,
 enum class DisplayListOpType { FOR_EACH_DISPLAY_LIST_OP(DL_OP_TO_ENUM_VALUE) };
 #undef DL_OP_TO_ENUM_VALUE

 class Dispatcher;
 class DisplayListBuilder;

 class SaveLayerOptions {
  public:
   static const SaveLayerOptions kWithAttributes;
   static const SaveLayerOptions kNoAttributes;

   SaveLayerOptions() : flags_(0) {}
   SaveLayerOptions(const SaveLayerOptions& options) : flags_(options.flags_) {}
   SaveLayerOptions(const SaveLayerOptions* options) : flags_(options->flags_) {}

   SaveLayerOptions without_optimizations() const {
     SaveLayerOptions options;
     options.fRendersWithAttributes = fRendersWithAttributes;
     return options;
   }

   bool renders_with_attributes() const { return fRendersWithAttributes; }
   SaveLayerOptions with_renders_with_attributes() const {
     SaveLayerOptions options(this);
     options.fRendersWithAttributes = true;
     return options;
   }

   bool can_distribute_opacity() const { return fCanDistributeOpacity; }
   SaveLayerOptions with_can_distribute_opacity() const {
     SaveLayerOptions options(this);
     options.fCanDistributeOpacity = true;
     return options;
   }

   SaveLayerOptions& operator=(const SaveLayerOptions& other) {
     flags_ = other.flags_;
     return *this;
   }
   bool operator==(const SaveLayerOptions& other) const {
     return flags_ == other.flags_;
   }
   bool operator!=(const SaveLayerOptions& other) const {
     return flags_ != other.flags_;
   }

  private:
   union {
     struct {
       unsigned fRendersWithAttributes : 1;
       unsigned fCanDistributeOpacity : 1;
     };
     uint32_t flags_;
   };
 };

 // The base class that contains a sequence of rendering operations
 // for dispatch to a Dispatcher. These objects must be instantiated
 // through an instance of DisplayListBuilder::build().
 class DisplayList : public SkRefCnt {
  public:
   DisplayList();

   ~DisplayList();

   void Dispatch(Dispatcher& ctx) const {
     uint8_t* ptr = storage_.get();
     Dispatch(ctx, ptr, ptr + byte_count_);
   }

   void RenderTo(DisplayListBuilder* builder,
                 SkScalar opacity = SK_Scalar1) const;

   void RenderTo(SkCanvas* canvas, SkScalar opacity = SK_Scalar1) const;

   // SkPicture always includes nested bytes, but nested ops are
   // only included if requested. The defaults used here for these
   // accessors follow that pattern.
   size_t bytes(bool nested = true) const {
     return sizeof(DisplayList) + byte_count_ +
            (nested ? nested_byte_count_ : 0);
   }

   unsigned int op_count(bool nested = false) const {
     return op_count_ + (nested ? nested_op_count_ : 0);
   }

   uint32_t unique_id() const { return unique_id_; }

   const SkRect& bounds() {
     if (bounds_.width() < 0.0) {
       // ComputeBounds() will leave the variable with a
       // non-negative width and height
       ComputeBounds();
     }
     return bounds_;
   }

   sk_sp<const DlRTree> rtree() {
     if (!rtree_) {
       ComputeRTree();
     }
     return rtree_;
   }

   bool Equals(const DisplayList* other) const;
   bool Equals(const DisplayList& other) const { return Equals(&other); }
   bool Equals(sk_sp<const DisplayList> other) const {
     return Equals(other.get());
   }

   bool can_apply_group_opacity() { return can_apply_group_opacity_; }

   static void DisposeOps(uint8_t* ptr, uint8_t* end);

  private:
   DisplayList(uint8_t* ptr,
               size_t byte_count,
               unsigned int op_count,
               size_t nested_byte_count,
               unsigned int nested_op_count,
               const SkRect& cull_rect,
               bool can_apply_group_opacity);

   struct SkFreeDeleter {
     void operator()(uint8_t* p) { sk_free(p); }
   };
   std::unique_ptr<uint8_t, SkFreeDeleter> storage_;
   size_t byte_count_;
   unsigned int op_count_;

   size_t nested_byte_count_;
   unsigned int nested_op_count_;

   uint32_t unique_id_;
   SkRect bounds_;
   sk_sp<const DlRTree> rtree_;

   // Only used for drawPaint() and drawColor()
   SkRect bounds_cull_;

   bool can_apply_group_opacity_;

   void ComputeBounds();
   void ComputeRTree();
   void Dispatch(Dispatcher& ctx, uint8_t* ptr, uint8_t* end) const;

   friend class DisplayListBuilder;
 };

 }  // namespace flutter

 #endif  // FLUTTER_DISPLAY_LIST_DISPLAY_LIST_H_
	// Copyright 2013 The Flutter Authors. All rights reserved.
	// Use of this source code is governed by a BSD-style license that can be
	// found in the LICENSE file.

	#ifndef FLUTTER_DISPLAY_LIST_DISPLAY_LIST_H_
	#define FLUTTER_DISPLAY_LIST_DISPLAY_LIST_H_

	#include <memory>
	#include <optional>

	#include "flutter/display_list/display_list_rtree.h"
	#include "flutter/display_list/display_list_sampling_options.h"
	#include "flutter/display_list/types.h"
	#include "flutter/fml/logging.h"

	// The Flutter DisplayList mechanism encapsulates a persistent sequence of
	// rendering operations.
	//
	// This file contains the definitions for:
	// DisplayList: the base class that holds the information about the
	// sequence of operations and can dispatch them to a Dispatcher
	// Dispatcher: a pure virtual interface which can be implemented to field
	// the requests for purposes such as sending them to an SkCanvas
	// or detecting various rendering optimization scenarios
	// DisplayListBuilder: a class for constructing a DisplayList from the same
	// calls defined in the Dispatcher
	//
	// Other files include various class definitions for dealing with display
	// lists, such as:
	// display_list_canvas.h: classes to interact between SkCanvas and DisplayList
	// (SkCanvas->DisplayList adapter and vice versa)
	//
	// display_list_utils.h: various utility classes to ease implementing
	// a Dispatcher, including NOP implementations of
	// the attribute, clip, and transform methods,
	// classes to track attributes, clips, and transforms
	// and a class to compute the bounds of a DisplayList
	// Any class implementing Dispatcher can inherit from
	// these utility classes to simplify its creation
	//
	// The Flutter DisplayList mechanism can be used in place of the Skia
	// SkPicture mechanism. The primary means of communication into and out
	// of the DisplayList is through the Dispatcher virtual class which
	// provides a nearly 1:1 translation between the records of the DisplayList
	// to method calls.
	//
	// A DisplayList can be created directly using a DisplayListBuilder and
	// the Dispatcher methods that it implements, or it can be created from
	// a sequence of SkCanvas calls using the DisplayListCanvasRecorder class.
	//
	// A DisplayList can be read back by implementing the Dispatcher virtual
	// methods (with help from some of the classes in the utils file) and
	// passing an instance to the dispatch() method, or it can be rendered
	// to Skia using a DisplayListCanvasDispatcher or simply by passing an
	// SkCanvas pointer to its renderTo() method.
	//
	// The mechanism is inspired by the SkLiteDL class that is not directly
	// supported by Skia, but has been recommended as a basis for custom
	// display lists for a number of their customers.

	namespace flutter {

	#define FOR_EACH_DISPLAY_LIST_OP(V) \
	V(SetAntiAlias) \
	V(SetDither) \
	V(SetInvertColors) \
	\
	V(SetStrokeCap) \
	V(SetStrokeJoin) \
	\
	V(SetStyle) \
	V(SetStrokeWidth) \
	V(SetStrokeMiter) \
	\
	V(SetColor) \
	V(SetBlendMode) \
	\
	V(SetBlender) \
	V(ClearBlender) \
	\
	V(SetSkPathEffect) \
	V(SetPodPathEffect) \
	V(ClearPathEffect) \
	\
	V(ClearColorFilter) \
	V(SetPodColorFilter) \
	V(SetSkColorFilter) \
	\
	V(ClearColorSource) \
	V(SetPodColorSource) \
	V(SetSkColorSource) \
	V(SetImageColorSource) \
	V(SetRuntimeEffectColorSource) \
	\
	V(ClearImageFilter) \
	V(SetPodImageFilter) \
	V(SetSkImageFilter) \
	V(SetSharedImageFilter) \
	\
	V(ClearMaskFilter) \
	V(SetPodMaskFilter) \
	V(SetSkMaskFilter) \
	\
	V(Save) \
	V(SaveLayer) \
	V(SaveLayerBounds) \
	V(SaveLayerBackdrop) \
	V(SaveLayerBackdropBounds) \
	V(Restore) \
	\
	V(Translate) \
	V(Scale) \
	V(Rotate) \
	V(Skew) \
	V(Transform2DAffine) \
	V(TransformFullPerspective) \
	V(TransformReset) \
	\
	V(ClipIntersectRect) \
	V(ClipIntersectRRect) \
	V(ClipIntersectPath) \
	V(ClipDifferenceRect) \
	V(ClipDifferenceRRect) \
	V(ClipDifferencePath) \
	\
	V(DrawPaint) \
	V(DrawColor) \
	\
	V(DrawLine) \
	V(DrawRect) \
	V(DrawOval) \
	V(DrawCircle) \
	V(DrawRRect) \
	V(DrawDRRect) \
	V(DrawArc) \
	V(DrawPath) \
	\
	V(DrawPoints) \
	V(DrawLines) \
	V(DrawPolygon) \
	V(DrawVertices) \
	V(DrawSkVertices) \
	\
	V(DrawImage) \
	V(DrawImageWithAttr) \
	V(DrawImageRect) \
	V(DrawImageNine) \
	V(DrawImageNineWithAttr) \
	V(DrawImageLattice) \
	V(DrawAtlas) \
	V(DrawAtlasCulled) \
	\
	V(DrawSkPicture) \
	V(DrawSkPictureMatrix) \
	V(DrawDisplayList) \
	V(DrawTextBlob) \
	\
	V(DrawShadow) \
	V(DrawShadowTransparentOccluder)

	#define DL_OP_TO_ENUM_VALUE(name) k##name,
	enum class DisplayListOpType { FOR_EACH_DISPLAY_LIST_OP(DL_OP_TO_ENUM_VALUE) };
	#undef DL_OP_TO_ENUM_VALUE

	class Dispatcher;
	class DisplayListBuilder;

	class SaveLayerOptions {
	public:
	static const SaveLayerOptions kWithAttributes;
	static const SaveLayerOptions kNoAttributes;

	SaveLayerOptions() : flags_(0) {}
	SaveLayerOptions(const SaveLayerOptions& options) : flags_(options.flags_) {}
	SaveLayerOptions(const SaveLayerOptions* options) : flags_(options->flags_) {}

	SaveLayerOptions without_optimizations() const {
	SaveLayerOptions options;
	options.fRendersWithAttributes = fRendersWithAttributes;
	return options;
	}

	bool renders_with_attributes() const { return fRendersWithAttributes; }
	SaveLayerOptions with_renders_with_attributes() const {
	SaveLayerOptions options(this);
	options.fRendersWithAttributes = true;
	return options;
	}

	bool can_distribute_opacity() const { return fCanDistributeOpacity; }
	SaveLayerOptions with_can_distribute_opacity() const {
	SaveLayerOptions options(this);
	options.fCanDistributeOpacity = true;
	return options;
	}

	SaveLayerOptions& operator=(const SaveLayerOptions& other) {
	flags_ = other.flags_;
	return *this;
	}
	bool operator==(const SaveLayerOptions& other) const {
	return flags_ == other.flags_;
	}
	bool operator!=(const SaveLayerOptions& other) const {
	return flags_ != other.flags_;
	}

	private:
	union {
	struct {
	unsigned fRendersWithAttributes : 1;
	unsigned fCanDistributeOpacity : 1;
	};
	uint32_t flags_;
	};
	};

	// The base class that contains a sequence of rendering operations
	// for dispatch to a Dispatcher. These objects must be instantiated
	// through an instance of DisplayListBuilder::build().
	class DisplayList : public SkRefCnt {
	public:
	DisplayList();

	~DisplayList();

	void Dispatch(Dispatcher& ctx) const {
	uint8_t* ptr = storage_.get();
	Dispatch(ctx, ptr, ptr + byte_count_);
	}

	void RenderTo(DisplayListBuilder* builder,
	SkScalar opacity = SK_Scalar1) const;

	void RenderTo(SkCanvas* canvas, SkScalar opacity = SK_Scalar1) const;

	// SkPicture always includes nested bytes, but nested ops are
	// only included if requested. The defaults used here for these
	// accessors follow that pattern.
	size_t bytes(bool nested = true) const {
	return sizeof(DisplayList) + byte_count_ +
	(nested ? nested_byte_count_ : 0);
	}

	unsigned int op_count(bool nested = false) const {
	return op_count_ + (nested ? nested_op_count_ : 0);
	}

	uint32_t unique_id() const { return unique_id_; }

	const SkRect& bounds() {
	if (bounds_.width() < 0.0) {
	// ComputeBounds() will leave the variable with a
	// non-negative width and height
	ComputeBounds();
	}
	return bounds_;
	}

	sk_sp<const DlRTree> rtree() {
	if (!rtree_) {
	ComputeRTree();
	}
	return rtree_;
	}

	bool Equals(const DisplayList* other) const;
	bool Equals(const DisplayList& other) const { return Equals(&other); }
	bool Equals(sk_sp<const DisplayList> other) const {
	return Equals(other.get());
	}

	bool can_apply_group_opacity() { return can_apply_group_opacity_; }

	static void DisposeOps(uint8_t* ptr, uint8_t* end);

	private:
	DisplayList(uint8_t* ptr,
	size_t byte_count,
	unsigned int op_count,
	size_t nested_byte_count,
	unsigned int nested_op_count,
	const SkRect& cull_rect,
	bool can_apply_group_opacity);

	struct SkFreeDeleter {
	void operator()(uint8_t* p) { sk_free(p); }
	};
	std::unique_ptr<uint8_t, SkFreeDeleter> storage_;
	size_t byte_count_;
	unsigned int op_count_;

	size_t nested_byte_count_;
	unsigned int nested_op_count_;

	uint32_t unique_id_;
	SkRect bounds_;
	sk_sp<const DlRTree> rtree_;

	// Only used for drawPaint() and drawColor()
	SkRect bounds_cull_;

	bool can_apply_group_opacity_;

	void ComputeBounds();
	void ComputeRTree();
	void Dispatch(Dispatcher& ctx, uint8_t* ptr, uint8_t* end) const;

	friend class DisplayListBuilder;
	};

	} // namespace flutter

	#endif // FLUTTER_DISPLAY_LIST_DISPLAY_LIST_H_