From cf5d54b9dac175489a412dbd0cd2d954e83cbed8 Mon Sep 17 00:00:00 2001
From: yankejustin <yankejustin@hotmail.com>
Date: Fri, 7 Aug 2015 13:58:58 -0400
Subject: [PATCH] Optimize ray intersection calculation

Check to make sure the direction is not 0 only once. Also, check to make
sure it is 0 first so we don't unnecessarily calculate if the position
is greater-than or less-than another without purpose.
---
 TrueCraft.API/Ray.cs | 35 +++++++++++++++++++++++------------
 1 file changed, 23 insertions(+), 12 deletions(-)

diff --git a/TrueCraft.API/Ray.cs b/TrueCraft.API/Ray.cs
index dbd3e57..2da021e 100644
--- a/TrueCraft.API/Ray.cs
+++ b/TrueCraft.API/Ray.cs
@@ -94,18 +94,29 @@ namespace TrueCraft.API
             Vector3 maxT = new Vector3(-1.0f);
             //Vector3 minT = new Vector3(-1.0f);
             //calcul intersection with each faces
-            if (Position.X < box.Min.X && Direction.X != 0.0f)
-                maxT.X = (box.Min.X - Position.X) / Direction.X;
-            else if (Position.X > box.Max.X && Direction.X != 0.0f)
-                maxT.X = (box.Max.X - Position.X) / Direction.X;
-            if (Position.Y < box.Min.Y && Direction.Y != 0.0f)
-                maxT.Y = (box.Min.Y - Position.Y) / Direction.Y;
-            else if (Position.Y > box.Max.Y && Direction.Y != 0.0f)
-                maxT.Y = (box.Max.Y - Position.Y) / Direction.Y;
-            if (Position.Z < box.Min.Z && Direction.Z != 0.0f)
-                maxT.Z = (box.Min.Z - Position.Z) / Direction.Z;
-            else if (Position.Z > box.Max.Z && Direction.Z != 0.0f)
-                maxT.Z = (box.Max.Z - Position.Z) / Direction.Z;
+            if (Direction.X != 0.0f)
+            {
+                if (Position.X < box.Min.X)
+                    maxT.X = (box.Min.X - Position.X) / Direction.X;
+                else if (Position.X > box.Max.X)
+                    maxT.X = (box.Max.X - Position.X) / Direction.X;
+            }
+
+            if (Direction.Y != 0.0f)
+            {
+                if (Position.Y < box.Min.Y)
+                    maxT.Y = (box.Min.Y - Position.Y) / Direction.Y;
+                else if (Position.Y > box.Max.Y)
+                    maxT.Y = (box.Max.Y - Position.Y) / Direction.Y;
+            }
+
+            if (Direction.Z != 0.0f)
+            {
+                if (Position.Z < box.Min.Z)
+                    maxT.Z = (box.Min.Z - Position.Z) / Direction.Z;
+                else if (Position.Z > box.Max.Z)
+                    maxT.Z = (box.Max.Z - Position.Z) / Direction.Z;
+            }
 
             //get the maximum maxT
             if (maxT.X > maxT.Y && maxT.X > maxT.Z)