optimize simplex equality

Bonk/Simplex.cs

@@ -1,5 +1,4 @@
-using System.Linq;
+using System.Collections.Generic;
-using System.Collections.Generic;
 using System.Numerics;
 using MoonTools.Core.Structs;
 using System;
@@ -80,11 +79,15 @@ namespace MoonTools.Core.Bonk
 
         public bool Equals(Simplex2D other)
         {
-            var q = from a in Vertices
+            if (Count != other.Count) { return false; }
-                    join b in other.Vertices on a equals b
-                    select a;
 
-            return Count == other.Count && q.Count() == Count;
+            return
+                (A == other.A && B == other.B && C == other.C) ||
+                (A == other.A && B == other.C && C == other.B) ||
+                (A == other.B && B == other.A && C == other.C) ||
+                (A == other.B && B == other.C && C == other.A) ||
+                (A == other.C && B == other.A && C == other.B) ||
+                (A == other.C && B == other.B && C == other.A);
         }
 
         public override int GetHashCode()

Test/Equality.cs

@@ -455,14 +455,26 @@ namespace Tests
             public void TwoSimplexEquals()
             {
                 var simplexA = new Simplex2D(Vector2.One, Vector2.Zero, Vector2.UnitX);
+
                 var simplexB = new Simplex2D(Vector2.One, Vector2.Zero, Vector2.UnitX);
 
                 simplexA.Equals(simplexB).Should().BeTrue();
 
-                var simplexC = new Simplex2D(Vector2.One, Vector2.Zero, Vector2.UnitX);
+                var simplexC = new Simplex2D(Vector2.Zero, Vector2.One, Vector2.UnitX);
-                var simplexD = new Simplex2D(Vector2.Zero, Vector2.One, Vector2.UnitX);
 
-                simplexC.Equals(simplexD).Should().BeTrue();
+                simplexA.Equals(simplexC).Should().BeTrue();
+
+                var simplexD = new Simplex2D(Vector2.UnitX, Vector2.Zero, Vector2.One);
+
+                simplexA.Equals(simplexD).Should().BeTrue();
+
+                var simplexE = new Simplex2D(Vector2.One, Vector2.UnitX, Vector2.Zero);
+
+                simplexA.Equals(simplexE).Should().BeTrue();
+
+                var simplexF = new Simplex2D(Vector2.Zero, Vector2.UnitX, Vector2.One);
+
+                simplexA.Equals(simplexF).Should().BeTrue();
             }
 
             [Test]