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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.
#pragma once
#include <functional>
#include <optional>
#include <set>
#include <tuple>
#include <vector>
#include "impeller/geometry/path_component.h"
namespace impeller {
enum class FillType {
kNonZero, // The default winding order.
kOdd,
kPositive,
kNegative,
kAbsGeqTwo,
};
//------------------------------------------------------------------------------
/// @brief Paths are lightweight objects that describe a collection of
/// linear, quadratic, or cubic segments. These segments may be
/// broken up by move commands, which are effectively linear
/// commands that pick up the pen rather than continuing to draw.
///
/// All shapes supported by Impeller are paths either directly or
/// via approximation (in the case of circles).
///
/// Creating paths that describe complex shapes is usually done by a
/// path builder.
///
class Path {
public:
enum class ComponentType {
kLinear,
kQuadratic,
kCubic,
kContour,
};
struct PolylineContour {
/// Index that denotes the first point of this contour.
size_t start_index;
/// Denotes whether the last point of this contour is connected to the first
/// point of this contour or not.
bool is_closed;
/// The direction of the contour's start cap.
Vector2 start_direction;
/// The direction of the contour's end cap.
Vector2 end_direction;
};
/// One or more contours represented as a series of points and indices in
/// the point vector representing the start of a new contour.
struct Polyline {
/// Points in the polyline, which may represent multiple contours specified
/// by indices in |breaks|.
std::vector<Point> points;
std::vector<PolylineContour> contours;
/// Convenience method to compute the start (inclusive) and end (exclusive)
/// point of the given contour index.
///
/// The contour_index parameter is clamped to contours.size().
std::tuple<size_t, size_t> GetContourPointBounds(
size_t contour_index) const;
};
Path();
~Path();
size_t GetComponentCount() const;
void SetFillType(FillType fill);
FillType GetFillType() const;
Path& AddLinearComponent(Point p1, Point p2);
Path& AddQuadraticComponent(Point p1, Point cp, Point p2);
Path& AddCubicComponent(Point p1, Point cp1, Point cp2, Point p2);
Path& AddContourComponent(Point destination, bool is_closed = false);
void SetContourClosed(bool is_closed);
template <class T>
using Applier = std::function<void(size_t index, const T& component)>;
void EnumerateComponents(
const Applier<LinearPathComponent>& linear_applier,
const Applier<QuadraticPathComponent>& quad_applier,
const Applier<CubicPathComponent>& cubic_applier,
const Applier<ContourComponent>& contour_applier) const;
bool GetLinearComponentAtIndex(size_t index,
LinearPathComponent& linear) const;
bool GetQuadraticComponentAtIndex(size_t index,
QuadraticPathComponent& quadratic) const;
bool GetCubicComponentAtIndex(size_t index, CubicPathComponent& cubic) const;
bool GetContourComponentAtIndex(size_t index,
ContourComponent& contour) const;
bool UpdateLinearComponentAtIndex(size_t index,
const LinearPathComponent& linear);
bool UpdateQuadraticComponentAtIndex(size_t index,
const QuadraticPathComponent& quadratic);
bool UpdateCubicComponentAtIndex(size_t index, CubicPathComponent& cubic);
bool UpdateContourComponentAtIndex(size_t index,
const ContourComponent& contour);
Polyline CreatePolyline(Scalar tolerance = kDefaultCurveTolerance) const;
std::optional<Rect> GetBoundingBox() const;
std::optional<Rect> GetTransformedBoundingBox(const Matrix& transform) const;
std::optional<std::pair<Point, Point>> GetMinMaxCoveragePoints() const;
private:
struct ComponentIndexPair {
ComponentType type = ComponentType::kLinear;
size_t index = 0;
ComponentIndexPair() {}
ComponentIndexPair(ComponentType a_type, size_t a_index)
: type(a_type), index(a_index) {}
};
FillType fill_ = FillType::kNonZero;
std::vector<ComponentIndexPair> components_;
std::vector<LinearPathComponent> linears_;
std::vector<QuadraticPathComponent> quads_;
std::vector<CubicPathComponent> cubics_;
std::vector<ContourComponent> contours_;
};
} // namespace impeller