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2024-11-25 18:32:05 +08:00
parent 72d1f89b54
commit 84243e75a8
353 changed files with 17666 additions and 3206 deletions
@@ -0,0 +1,133 @@
+using System.Collections;
+using System.Collections.Generic;
+using System.Linq;
+using UnityEngine;
+
+/// <summary>
+/// 多边形耳切法
+/// </summary>
+public class UnitAlgorithmEarCutting : UnitAlgorithm<DataPlate> {
+    /// <summary> 多边形耳切法 </summary>
+    public UnitAlgorithmEarCutting() { }
+
+    public class Auriculare {
+        public int index;
+        public Vector3 aPoint;//+0
+        public Vector3 bPoint;//-1
+        public Vector3 cPoint;//+1
+    }
+
+    public void Compute(DataPlate data) {
+        List<Vector3> points = new List<Vector3>(data.edgePoints);
+        //判断散列点排序方向
+        Vector3[] allArray = points.ToArray();
+        bool isClockWise = IsClockWise(allArray);
+        //耳切法生成三角形
+        List<DataTriangle> triangles = new List<DataTriangle>();
+        ComputeAuriculare(triangles, points, allArray, isClockWise);
+        data.triangles = triangles;
+    }
+
+    #region 函数
+    /// <summary> 循环计算有效的耳点 </summary>
+    public static void ComputeAuriculare(List<DataTriangle> triangles, List<Vector3> edgePoints, Vector3[] allArray, bool isClockWise) {
+        List<DataTriangle> temp = ComputeAuriculare(edgePoints, allArray, isClockWise);
+        if (temp.Count == 0) { return; }
+        triangles.AddRange(temp);
+        ComputeAuriculare(triangles, edgePoints, allArray, isClockWise);
+    }
+    /// <summary> 计算一个有效的耳点 </summary>
+    public static List<DataTriangle> ComputeAuriculare(List<Vector3> edgePoints, Vector3[] allArray, bool isClockWise) {
+        Vector3[] array = edgePoints.ToArray();
+        List<DataTriangle> polygons = new List<DataTriangle>();
+        for (int i = 0; i < array.Length; i++) {
+            Auriculare auriculare = CreateAuriculare(i, array);
+            // 等于180，大于180，不可能为耳点
+            if (!GetAngleType(auriculare, isClockWise)) { continue; }
+            // 包含其他点，不可能为耳点
+            if (IsInsideTriangle(auriculare, allArray)) { continue; }
+            // 包含其他耳点，不可能成为耳点
+            if (!IsInsideAuriculare(auriculare, edgePoints)) { continue; }
+            edgePoints.Remove(auriculare.aPoint);
+            polygons.Add(CreateAuriculareToTriangle(auriculare));
+        }
+        return polygons;
+    }
+    /// <summary> 创建耳点 </summary>
+    public static Auriculare CreateAuriculare(int index, Vector3[] array) {
+        Auriculare auriculare = new Auriculare();
+        auriculare.index = index;
+        auriculare.bPoint = array.LoopIndex(index - 1);
+        auriculare.aPoint = array.LoopIndex(index);
+        auriculare.cPoint = array.LoopIndex(index + 1);
+        return auriculare;
+    }
+    /// <summary> 计算三角形内是否包含其他点 </summary>
+    public static bool IsInsideTriangle(Auriculare auriculare, Vector3[] array) {
+        for (int i = 0; i < array.Length; i++) {
+            if (array[i] == auriculare.aPoint) { continue; }
+            if (array[i] == auriculare.bPoint) { continue; }
+            if (array[i] == auriculare.cPoint) { continue; }
+            if (IsInsideTriangle(auriculare, array[i])) { return true; }
+        }
+        return false;
+    }
+    /// <summary> 计算三角形内是否包含其他点 </summary>
+    public static bool IsInsideAuriculare(Auriculare auriculare, List<Vector3> edgePoints) {
+        if (!edgePoints.Contains(auriculare.aPoint)) { return false; }
+        if (!edgePoints.Contains(auriculare.bPoint)) { return false; }
+        if (!edgePoints.Contains(auriculare.cPoint)) { return false; }
+        return true;
+    }
+    /// <summary> 从节点创建三角形 </summary>
+    public static DataTriangle CreateAuriculareToTriangle(Auriculare auriculare) {
+        DataTriangle triangle = new DataTriangle();
+        triangle.a = auriculare.aPoint;
+        triangle.b = auriculare.bPoint;
+        triangle.c = auriculare.cPoint;
+        return triangle;
+    }
+    #endregion
+
+    #region 算法
+    /// <summary> 当前的点方向是否为顺时针 </summary>
+    public static bool IsClockWise(Vector3[] array) {
+        // 通过计算叉乘来确定方向
+        float sum = 0f;
+        double count = array.Length;
+        Vector3 va, vb;
+        for (int i = 0; i < array.Length; i++) {
+            va = array[i];
+            vb = (i == count - 1) ? array[0] : array[i + 1];
+            sum += va.x * vb.y - va.y * vb.x;
+        }
+        return sum < 0;
+    }
+    /// <summary> 判断角的类型 </summary>
+    public static bool GetAngleType(Auriculare auriculare, bool isClockWise) {
+        // 角度是否小于180
+        // oa & ob 之间的夹角，（右手法则）
+        // 逆时针顺序是相反的
+        Vector2 a = auriculare.aPoint;
+        Vector2 b = auriculare.bPoint;
+        Vector2 c = auriculare.cPoint;
+        float f = (b.x - a.x) * (c.y - a.y) - (b.y - a.y) * (c.x - a.x);
+        bool flag = isClockWise ? f > 0 : f < 0;
+        if (f == 0) { return false;/*平角*/ }
+        else if (flag) { return true;/*劣角*/ }
+        else { return false;/*优角*/ }
+    }
+    /// <summary> p点是否在点a,b,c组成的三角形内,或边上 </summary>
+    public static bool IsInsideTriangle(Auriculare auriculare, Vector2 p) {
+        // p点是否在abc三角形内
+        Vector2 a = auriculare.aPoint;
+        Vector2 b = auriculare.bPoint;
+        Vector2 c = auriculare.cPoint;
+        float c1 = (b.x - a.x) * (p.y - b.y) - (b.y - a.y) * (p.x - b.x);
+        float c2 = (c.x - b.x) * (p.y - c.y) - (c.y - b.y) * (p.x - c.x);
+        float c3 = (a.x - c.x) * (p.y - a.y) - (a.y - c.y) * (p.x - a.x);
+        return (c1 > 0f && c2 >= 0f && c3 >= 0f) || (c1 < 0f && c2 <= 0f && c3 <= 0f);
+    }
+    #endregion
+
+}