Adding Contact extension

axios/Engine/Extensions/Contact.cs

@@ -0,0 +1,53 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using FarseerPhysics.Dynamics.Contacts;
+using Microsoft.Xna.Framework;
+
+namespace Axios.Engine.Extensions
+{
+    public enum CollisionDirection
+    {
+        Right,
+        Left,
+        Top,
+        Bottom
+    }
+    public static class AxiosExtensions_Contact
+    {
+        /// http://farseerphysics.codeplex.com/discussions/281783
+        /// <summary>
+        /// Returns the direction that the collision happened.
+        /// Should be used in the event OnAfterCollision
+        /// </summary>
+        /// <param name="c"></param>
+        /// <returns></returns>
+        public static CollisionDirection Direction(this Contact c)
+        {
+            CollisionDirection direction;
+            // Work out collision direction
+            Vector2 colNorm = c.Manifold.LocalNormal;
+            if (Math.Abs(colNorm.X) > Math.Abs(colNorm.Y))
+            {
+                // X direction is dominant
+                if (colNorm.X > 0)
+                    direction = CollisionDirection.Right;
+                else
+                    direction = CollisionDirection.Left;
+            }
+            else
+            {
+                // Y direction is dominant
+                if (colNorm.Y > 0)
+                    direction = CollisionDirection.Top;
+                else
+                    direction = CollisionDirection.Bottom;
+            }
+
+
+
+            return direction;
+        }
+    }
+}