Added Dohya

Assets/Plugins/VolumetricLightBeam/Scripts/PolygonHelper.cs

@@ -0,0 +1,84 @@
+using System.Collections.Generic;
+using UnityEngine;
+
+namespace VLB
+{
+    public class PolygonHelper : MonoBehaviour
+    {
+        public struct Plane2D
+        {
+            public Vector2 normal;
+            public float distance;
+
+            public float Distance(Vector2 point) { return Vector2.Dot(normal, point) + distance; }
+
+            public Vector2 ClosestPoint(Vector2 pt) { return pt - normal * Distance(pt); }
+
+            public Vector2 Intersect(Vector2 p1, Vector2 p2)
+            {
+                float denominator = Vector2.Dot(normal, p1 - p2);
+
+                if (Utils.IsAlmostZero(denominator))
+                    return (p1 + p2) * 0.5f;
+
+                float u = (normal.x * p1.x + normal.y * p1.y + distance) / denominator;
+                return (p1 + u * (p2 - p1));
+            }
+
+            public bool GetSide(Vector2 point) { return Distance(point) > 0.0f; }
+
+            public static Plane2D FromPoints(Vector3 p1, Vector3 p2)
+            {
+                var v = (p2 - p1).normalized;
+
+                return new Plane2D
+                {
+                    normal = new Vector2(v.y, -v.x),
+                    distance = (-v.y * p1.x + v.x * p1.y)
+                };
+            }
+
+            public static Plane2D FromNormalAndPoint(Vector3 normalizedNormal, Vector3 p1)
+            {
+                return new Plane2D
+                {
+                    normal = normalizedNormal,
+                    distance = (-normalizedNormal.x * p1.x - normalizedNormal.y * p1.y)
+                };
+            }
+
+            public void Flip() { normal = -normal; distance = -distance; }
+
+            public Vector2[] CutConvex(Vector2[] poly)
+            {
+                Debug.Assert(poly.Length >= 3);
+                var polyOut = new List<Vector2>(poly.Length);
+
+                Vector2 startingPoint = poly[poly.Length - 1];
+                foreach (var endPoint in poly)
+                {
+                    var startingSide = GetSide(startingPoint);
+                    var endSide = GetSide(endPoint);
+                    if (startingSide && endSide)
+                    {
+                        polyOut.Add(endPoint);
+                    }
+                    else if (startingSide && !endSide)
+                    {
+                        polyOut.Add(Intersect(startingPoint, endPoint));
+                    }
+                    else if (!startingSide && endSide)
+                    {
+                        polyOut.Add(Intersect(startingPoint, endPoint));
+                        polyOut.Add(endPoint);
+                    }
+                    startingPoint = endPoint;
+                }
+
+                return polyOut.ToArray();
+            }
+
+            public override string ToString() { return string.Format("{0} x {1} + {2}", normal.x, normal.y, distance); }
+        }
+    }
+}