dl_path.h

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// 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_GEOMETRY_DL_PATH_H_
#define FLUTTER_DISPLAY_LIST_GEOMETRY_DL_PATH_H_
 
#include <functional>
 
#include "flutter/display_list/geometry/dl_geometry_types.h"
#include "flutter/impeller/geometry/path_source.h"
#include "flutter/third_party/skia/include/core/SkPath.h"
 
namespace flutter {
 
using DlPathFillType = impeller::FillType;
using DlPathReceiver = impeller::PathReceiver;
 
class DlPath : public impeller::PathSource {
 public:
  static constexpr uint32_t kMaxVolatileUses = 2;
 
  static DlPath MakeRect(const DlRect& rect);
  static DlPath MakeRectLTRB(DlScalar left,
                             DlScalar top,
                             DlScalar right,
                             DlScalar bottom);
  static DlPath MakeRectXYWH(DlScalar x,
                             DlScalar y,
                             DlScalar width,
                             DlScalar height);
 
  static DlPath MakeOval(const DlRect& bounds);
  static DlPath MakeOvalLTRB(DlScalar left,
                             DlScalar top,
                             DlScalar right,
                             DlScalar bottom);
 
  static DlPath MakeCircle(const DlPoint center, DlScalar radius);
 
  static DlPath MakeRoundRect(const DlRoundRect& rrect);
  static DlPath MakeRoundRectXY(const DlRect& rect,
                                DlScalar x_radius,
                                DlScalar y_radius,
                                bool counter_clock_wise = false);
  static DlPath MakeRoundSuperellipse(const DlRoundSuperellipse& rse);
 
  static DlPath MakeLine(const DlPoint a, const DlPoint b);
  static DlPath MakePoly(const DlPoint pts[],
                         int count,
                         bool close,
                         DlPathFillType fill_type = DlPathFillType::kNonZero);
 
  static DlPath MakeArc(const DlRect& bounds,
                        DlDegrees start,
                        DlDegrees sweep,
                        bool use_center);
 
  DlPath() : data_(std::make_shared<Data>(SkPath())) {}
  explicit DlPath(const SkPath& path) : data_(std::make_shared<Data>(path)) {}
 
  DlPath(const DlPath& path) = default;
  DlPath(DlPath&& path) = default;
  DlPath& operator=(const DlPath&) = default;
 
  ~DlPath() override = default;
 
  const SkPath& GetSkPath() const;
 
  void Dispatch(DlPathReceiver& receiver) const override;
 
  /// Intent to render an SkPath multiple times will make the path
  /// non-volatile to enable caching in Skia. Calling this method
  /// before every rendering call that uses the SkPath will count
  /// down the uses and eventually reset the volatile flag.
  ///
  /// @see |kMaxVolatileUses|
  void WillRenderSkPath() const;
 
  [[nodiscard]] DlPath WithOffset(const DlPoint offset) const;
  [[nodiscard]] DlPath WithFillType(DlPathFillType type) const;
 
  bool IsEmpty() const;
  bool IsRect(DlRect* rect = nullptr, bool* is_closed = nullptr) const;
  bool IsOval(DlRect* bounds = nullptr) const;
  bool IsLine(DlPoint* start = nullptr, DlPoint* end = nullptr) const;
  bool IsRoundRect(DlRoundRect* rrect = nullptr) const;
 
  bool Contains(const DlPoint point) const;
 
  DlRect GetBounds() const override;
  DlPathFillType GetFillType() const override;
 
  bool operator==(const DlPath& other) const;
 
  bool IsVolatile() const;
  bool IsConvex() const override;
 
  DlPath operator+(const DlPath& other) const;
 
 private:
  struct Data {
    explicit Data(const SkPath& path) : sk_path(path) {
      FML_DCHECK(!SkPathFillType_IsInverse(path.getFillType()));
    }
 
    SkPath sk_path;
    uint32_t render_count = 0u;
  };
 
  std::shared_ptr<Data> data_;
 
  static void ReduceConic(DlPathReceiver& receiver,
                          const DlPoint& p1,
                          const DlPoint& cp,
                          const DlPoint& p2,
                          DlScalar weight);
};
 
}  // namespace flutter
 
#endif  // FLUTTER_DISPLAY_LIST_GEOMETRY_DL_PATH_H_