path.h

#pragma once
 
#include "sdl_painter/export.h"
#include "sdl_painter/geometry.h"
 
#include <cstddef>
#include <cstdint>
#include <vector>
 
namespace sdl_painter {

inline constexpr float kDefaultFlatness = 0.25F;

struct SubPath {
  std::vector<Point> points;

  bool closed{false};
};

class SDLPAINTER_API Path {
 public:
  Path() = default;

  explicit Path(float flatness);

  void MoveTo(float x, float y);

  void MoveTo(const Point& point);

  void LineTo(float x, float y);

  void LineTo(const Point& point);

  void QuadTo(float cx, float cy, float x, float y);

  void QuadTo(const Point& control, const Point& end);

  void CubicTo(float c1x, float c1y, float c2x, float c2y, float x, float y);

  void CubicTo(const Point& control1, const Point& control2, const Point& end);

  void Close();

  void Clear() noexcept;

  [[nodiscard]] bool IsEmpty() const noexcept;

  [[nodiscard]] Point CurrentPoint() const noexcept { return mCurrent; }

  [[nodiscard]] const std::vector<SubPath>& SubPaths() const noexcept {
    return mSubPaths;
  }

  [[nodiscard]] float Flatness() const noexcept { return mFlatness; }

  [[nodiscard]] std::size_t PointCount() const noexcept;
 
 private:
  void AppendPoint(const Point& point);

  void DropDegenerateSubPath();

  void EnsureStarted();

  [[nodiscard]] int32_t SegmentsForCurve(float second_derivative_bound) const;

  static constexpr int32_t kMaxCurveSegments = 256;
 
  std::vector<SubPath> mSubPaths;

  Point mCurrent;

  Point mSubPathStart;

  bool mPendingStart{false};
 
  float mFlatness{kDefaultFlatness};
};
 
}  // namespace sdl_painter