From e33e19d0587146859d48a134ec9fd94e7b7ba5cd Mon Sep 17 00:00:00 2001
From: "FWoltermann@gmail.com"
 <FWoltermann@gmail.com@076cb2c4-205e-83fd-5cf3-1be9aa105544>
Date: Thu, 8 Dec 2011 14:53:40 +0000
Subject: Initial upload

---
 Opcode/OpcodeLib/Ice/IceRay.cpp | 84 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 84 insertions(+)
 create mode 100644 Opcode/OpcodeLib/Ice/IceRay.cpp

(limited to 'Opcode/OpcodeLib/Ice/IceRay.cpp')

diff --git a/Opcode/OpcodeLib/Ice/IceRay.cpp b/Opcode/OpcodeLib/Ice/IceRay.cpp
new file mode 100644
index 0000000..20970ac
--- /dev/null
+++ b/Opcode/OpcodeLib/Ice/IceRay.cpp
@@ -0,0 +1,84 @@
+///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+/**
+ *	Contains code for rays.
+ *	\file		IceRay.cpp
+ *	\author		Pierre Terdiman
+ *	\date		April, 4, 2000
+ */
+///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+
+///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+/**
+ *	Ray class.
+ *	A ray is a half-line P(t) = mOrig + mDir * t, with 0 <= t <= +infinity
+ *	\class		Ray
+ *	\author		Pierre Terdiman
+ *	\version	1.0
+ */
+///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+
+/*
+	O = Origin = impact point
+	i = normalized vector along the x axis
+	j = normalized vector along the y axis = actually the normal vector in O
+	D = Direction vector, norm |D| = 1
+	N = Projection of D on y axis, norm |N| = normal reaction
+	T = Projection of D on x axis, norm |T| = tangential reaction
+	R = Reflexion vector
+
+              ^y
+              |
+              |
+              |
+       _  _  _| _ _ _
+       *      *      *|
+        \     |     /
+         \    |N   /  |
+         R\   |   /D
+           \  |  /    |
+            \ | /
+    _________\|/______*_______>x
+               O    T
+
+	Let define theta = angle between D and N. Then cos(theta) = |N| / |D| = |N| since D is normalized.
+
+	j|D = |j|*|D|*cos(theta) => |N| = j|D
+
+	Then we simply have:
+
+	D = N + T
+
+	To compute tangential reaction :
+
+	T = D - N
+
+	To compute reflexion vector :
+
+	R = N - T = N - (D-N) = 2*N - D
+*/
+
+///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+// Precompiled Header
+#include "Stdafx.h"
+
+using namespace IceMaths;
+
+float Ray::SquareDistance(const IcePoint& point, float* t)	const
+{
+	IcePoint Diff = point - mOrig;
+	float fT = Diff | mDir;
+
+	if(fT<=0.0f)
+	{
+		fT = 0.0f;
+	}
+	else
+	{
+		fT /= mDir.SquareMagnitude();
+		Diff -= fT*mDir;
+	}
+
+	if(t) *t = fT;
+
+	return Diff.SquareMagnitude();
+}
-- 
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