From b931abb73542454902825d1ef227db9cba1b8bcb Mon Sep 17 00:00:00 2001
From: Syntriax <syntriax@gmail.com>
Date: Tue, 6 Feb 2024 12:06:13 +0300
Subject: [PATCH] feat: Shape to Vector2D Overlap

---
 Engine.Physics2D/Physics2D.cs | 30 +++++++++++++++++++++++++-----
 1 file changed, 25 insertions(+), 5 deletions(-)

diff --git a/Engine.Physics2D/Physics2D.cs b/Engine.Physics2D/Physics2D.cs
index a9f722b..5cc4f7a 100644
--- a/Engine.Physics2D/Physics2D.cs
+++ b/Engine.Physics2D/Physics2D.cs
@@ -1,13 +1,33 @@
-using System;
-
 using Syntriax.Engine.Core;
-using Syntriax.Engine.Physics2D;
 using Syntriax.Engine.Physics2D.Primitives;
 
 namespace Engine.Physics2D;
 
 public static partial class Physics2D
 {
+    public static bool Overlaps(this Shape shape, Vector2D point) => Overlaps(shape, point, out var _);
+    public static bool Overlaps(this Shape shape, Vector2D point, out float depth)
+    {
+        depth = float.MaxValue;
+        var vertices = shape.Vertices;
+        int count = vertices.Count;
+
+        for (int indexProjection = 0; indexProjection < count; indexProjection++)
+        {
+            Vector2D projectionVector = vertices[indexProjection].FromTo(vertices[(indexProjection + 1) % count]).Perpendicular().Normalized;
+
+            Projection shapeProjection = shape.ToProjection(projectionVector);
+            float projectedPoint = point.Dot(projectionVector);
+
+            if (shapeProjection.Max < projectedPoint || shapeProjection.Min > projectedPoint)
+                return false;
+
+            depth = Math.Min(depth, Math.Abs(Math.AbsMin(shapeProjection.Max - projectedPoint, shapeProjection.Min - projectedPoint)));
+        }
+
+        return true;
+    }
+
     public static bool Overlaps(this Circle left, Circle right)
     {
         float distanceSquared = left.Center.FromTo(right.Center).LengthSquared();
@@ -27,7 +47,7 @@ public static partial class Physics2D
         normal = distanceVector.Normalized;
 
         if (isOverlapping)
-            depth = MathF.Sqrt(radiusSumSquared - distanceSquared);
+            depth = Math.Sqrt(radiusSumSquared - distanceSquared);
 
         return isOverlapping;
     }
@@ -44,7 +64,7 @@ public static partial class Physics2D
         normal = distanceVector.Normalized;
 
         if (isOverlapping)
-            depth = MathF.Sqrt(radiusSquared - distanceSquared);
+            depth = Math.Sqrt(radiusSquared - distanceSquared);
 
         return isOverlapping;
     }