茂之钳
54 lines
1.7 KiB
C++
54 lines
1.7 KiB
C++
#pragma once
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#include "vde/core/point.h"
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#include "vde/core/aabb.h"
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#include <vector>
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#include <array>
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namespace vde::core {
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class Polygon2D {
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public:
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Polygon2D() = default;
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explicit Polygon2D(std::vector<Point2D> vertices) : vertices_(std::move(vertices)) {}
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[[nodiscard]] const std::vector<Point2D>& vertices() const { return vertices_; }
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[[nodiscard]] size_t size() const { return vertices_.size(); }
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[[nodiscard]] bool empty() const { return vertices_.empty(); }
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/// Signed area (positive = CCW)
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[[nodiscard]] double signed_area() const;
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/// Absolute area
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[[nodiscard]] double area() const { return std::abs(signed_area()); }
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/// Perimeter (sum of edge lengths)
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[[nodiscard]] double perimeter() const;
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/// Area-weighted centroid
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[[nodiscard]] Point2D centroid() const;
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/// Axis-aligned bounding box (2D, stored in AABB3D with z=0)
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[[nodiscard]] AABB<double> bounding_box() const;
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/// Point-in-polygon test (ray casting)
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[[nodiscard]] bool contains(const Point2D& p) const;
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/// Is the polygon counter-clockwise?
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[[nodiscard]] bool is_ccw() const { return signed_area() > 0; }
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/// Douglas-Peucker simplification. Returns a new simplified polygon.
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[[nodiscard]] Polygon2D simplify(double tolerance) const;
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/// Ear-clipping triangulation. Returns triangles as triples of vertex indices.
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/// Assumes a simple polygon (no self-intersections). CCW ordering required.
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[[nodiscard]] std::vector<std::array<int, 3>> triangulate() const;
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/// Andrew's monotone chain convex hull of a point set.
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static Polygon2D convex_hull_2d(const std::vector<Point2D>& points);
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private:
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std::vector<Point2D> vertices_;
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};
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} // namespace vde::core
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