feat: 测试覆盖扩展 + 文档更新

include/vde/core/polygon.h

@@ -1,6 +1,8 @@
 #pragma once
 #include "vde/core/point.h"
+#include "vde/core/aabb.h"
 #include <vector>
+#include <array>
 
 namespace vde::core {
 
@@ -19,12 +21,31 @@ public:
     /// Absolute area
     [[nodiscard]] double area() const { return std::abs(signed_area()); }
 
+    /// Perimeter (sum of edge lengths)
+    [[nodiscard]] double perimeter() const;
+
+    /// Area-weighted centroid
+    [[nodiscard]] Point2D centroid() const;
+
+    /// Axis-aligned bounding box (2D, stored in AABB3D with z=0)
+    [[nodiscard]] AABB<double> bounding_box() const;
+
     /// Point-in-polygon test (ray casting)
     [[nodiscard]] bool contains(const Point2D& p) const;
 
     /// Is the polygon counter-clockwise?
     [[nodiscard]] bool is_ccw() const { return signed_area() > 0; }
 
+    /// Douglas-Peucker simplification. Returns a new simplified polygon.
+    [[nodiscard]] Polygon2D simplify(double tolerance) const;
+
+    /// Ear-clipping triangulation. Returns triangles as triples of vertex indices.
+    /// Assumes a simple polygon (no self-intersections). CCW ordering required.
+    [[nodiscard]] std::vector<std::array<int, 3>> triangulate() const;
+
+    /// Andrew's monotone chain convex hull of a point set.
+    static Polygon2D convex_hull_2d(const std::vector<Point2D>& points);
+
 private:
     std::vector<Point2D> vertices_;
 };