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diff --git a/Source/external/Box2D/Collision/b2Collision.cpp b/Source/external/Box2D/Collision/b2Collision.cpp
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+++ b/Source/external/Box2D/Collision/b2Collision.cpp
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+/*
+* Copyright (c) 2007-2009 Erin Catto http://www.box2d.org
+*
+* This software is provided 'as-is', without any express or implied
+* warranty.  In no event will the authors be held liable for any damages
+* arising from the use of this software.
+* Permission is granted to anyone to use this software for any purpose,
+* including commercial applications, and to alter it and redistribute it
+* freely, subject to the following restrictions:
+* 1. The origin of this software must not be misrepresented; you must not
+* claim that you wrote the original software. If you use this software
+* in a product, an acknowledgment in the product documentation would be
+* appreciated but is not required.
+* 2. Altered source versions must be plainly marked as such, and must not be
+* misrepresented as being the original software.
+* 3. This notice may not be removed or altered from any source distribution.
+*/
+
+#include "Box2D/Collision/b2Collision.h"
+#include "Box2D/Collision/b2Distance.h"
+
+void b2WorldManifold::Initialize(const b2Manifold* manifold,
+						  const b2Transform& xfA, float32 radiusA,
+						  const b2Transform& xfB, float32 radiusB)
+{
+	if (manifold->pointCount == 0)
+	{
+		return;
+	}
+
+	switch (manifold->type)
+	{
+	case b2Manifold::e_circles:
+		{
+			normal.Set(1.0f, 0.0f);
+			b2Vec2 pointA = b2Mul(xfA, manifold->localPoint);
+			b2Vec2 pointB = b2Mul(xfB, manifold->points[0].localPoint);
+			if (b2DistanceSquared(pointA, pointB) > b2_epsilon * b2_epsilon)
+			{
+				normal = pointB - pointA;
+				normal.Normalize();
+			}
+
+			b2Vec2 cA = pointA + radiusA * normal;
+			b2Vec2 cB = pointB - radiusB * normal;
+			points[0] = 0.5f * (cA + cB);
+			separations[0] = b2Dot(cB - cA, normal);
+		}
+		break;
+
+	case b2Manifold::e_faceA:
+		{
+			normal = b2Mul(xfA.q, manifold->localNormal);
+			b2Vec2 planePoint = b2Mul(xfA, manifold->localPoint);
+			
+			for (int32 i = 0; i < manifold->pointCount; ++i)
+			{
+				b2Vec2 clipPoint = b2Mul(xfB, manifold->points[i].localPoint);
+				b2Vec2 cA = clipPoint + (radiusA - b2Dot(clipPoint - planePoint, normal)) * normal;
+				b2Vec2 cB = clipPoint - radiusB * normal;
+				points[i] = 0.5f * (cA + cB);
+				separations[i] = b2Dot(cB - cA, normal);
+			}
+		}
+		break;
+
+	case b2Manifold::e_faceB:
+		{
+			normal = b2Mul(xfB.q, manifold->localNormal);
+			b2Vec2 planePoint = b2Mul(xfB, manifold->localPoint);
+
+			for (int32 i = 0; i < manifold->pointCount; ++i)
+			{
+				b2Vec2 clipPoint = b2Mul(xfA, manifold->points[i].localPoint);
+				b2Vec2 cB = clipPoint + (radiusB - b2Dot(clipPoint - planePoint, normal)) * normal;
+				b2Vec2 cA = clipPoint - radiusA * normal;
+				points[i] = 0.5f * (cA + cB);
+				separations[i] = b2Dot(cA - cB, normal);
+			}
+
+			// Ensure normal points from A to B.
+			normal = -normal;
+		}
+		break;
+	}
+}
+
+void b2GetPointStates(b2PointState state1[b2_maxManifoldPoints], b2PointState state2[b2_maxManifoldPoints],
+					  const b2Manifold* manifold1, const b2Manifold* manifold2)
+{
+	for (int32 i = 0; i < b2_maxManifoldPoints; ++i)
+	{
+		state1[i] = b2_nullState;
+		state2[i] = b2_nullState;
+	}
+
+	// Detect persists and removes.
+	for (int32 i = 0; i < manifold1->pointCount; ++i)
+	{
+		b2ContactID id = manifold1->points[i].id;
+
+		state1[i] = b2_removeState;
+
+		for (int32 j = 0; j < manifold2->pointCount; ++j)
+		{
+			if (manifold2->points[j].id.key == id.key)
+			{
+				state1[i] = b2_persistState;
+				break;
+			}
+		}
+	}
+
+	// Detect persists and adds.
+	for (int32 i = 0; i < manifold2->pointCount; ++i)
+	{
+		b2ContactID id = manifold2->points[i].id;
+
+		state2[i] = b2_addState;
+
+		for (int32 j = 0; j < manifold1->pointCount; ++j)
+		{
+			if (manifold1->points[j].id.key == id.key)
+			{
+				state2[i] = b2_persistState;
+				break;
+			}
+		}
+	}
+}
+
+// From Real-time Collision Detection, p179.
+bool b2AABB::RayCast(b2RayCastOutput* output, const b2RayCastInput& input) const
+{
+	float32 tmin = -b2_maxFloat;
+	float32 tmax = b2_maxFloat;
+
+	b2Vec2 p = input.p1;
+	b2Vec2 d = input.p2 - input.p1;
+	b2Vec2 absD = b2Abs(d);
+
+	b2Vec2 normal;
+
+	for (int32 i = 0; i < 2; ++i)
+	{
+		if (absD(i) < b2_epsilon)
+		{
+			// Parallel.
+			if (p(i) < lowerBound(i) || upperBound(i) < p(i))
+			{
+				return false;
+			}
+		}
+		else
+		{
+			float32 inv_d = 1.0f / d(i);
+			float32 t1 = (lowerBound(i) - p(i)) * inv_d;
+			float32 t2 = (upperBound(i) - p(i)) * inv_d;
+
+			// Sign of the normal vector.
+			float32 s = -1.0f;
+
+			if (t1 > t2)
+			{
+				b2Swap(t1, t2);
+				s = 1.0f;
+			}
+
+			// Push the min up
+			if (t1 > tmin)
+			{
+				normal.SetZero();
+				normal(i) = s;
+				tmin = t1;
+			}
+
+			// Pull the max down
+			tmax = b2Min(tmax, t2);
+
+			if (tmin > tmax)
+			{
+				return false;
+			}
+		}
+	}
+
+	// Does the ray start inside the box?
+	// Does the ray intersect beyond the max fraction?
+	if (tmin < 0.0f || input.maxFraction < tmin)
+	{
+		return false;
+	}
+
+	// Intersection.
+	output->fraction = tmin;
+	output->normal = normal;
+	return true;
+}
+
+// Sutherland-Hodgman clipping.
+int32 b2ClipSegmentToLine(b2ClipVertex vOut[2], const b2ClipVertex vIn[2],
+						const b2Vec2& normal, float32 offset, int32 vertexIndexA)
+{
+	// Start with no output points
+	int32 numOut = 0;
+
+	// Calculate the distance of end points to the line
+	float32 distance0 = b2Dot(normal, vIn[0].v) - offset;
+	float32 distance1 = b2Dot(normal, vIn[1].v) - offset;
+
+	// If the points are behind the plane
+	if (distance0 <= 0.0f) vOut[numOut++] = vIn[0];
+	if (distance1 <= 0.0f) vOut[numOut++] = vIn[1];
+
+	// If the points are on different sides of the plane
+	if (distance0 * distance1 < 0.0f)
+	{
+		// Find intersection point of edge and plane
+		float32 interp = distance0 / (distance0 - distance1);
+		vOut[numOut].v = vIn[0].v + interp * (vIn[1].v - vIn[0].v);
+
+		// VertexA is hitting edgeB.
+		vOut[numOut].id.cf.indexA = static_cast<uint8>(vertexIndexA);
+		vOut[numOut].id.cf.indexB = vIn[0].id.cf.indexB;
+		vOut[numOut].id.cf.typeA = b2ContactFeature::e_vertex;
+		vOut[numOut].id.cf.typeB = b2ContactFeature::e_face;
+		++numOut;
+	}
+
+	return numOut;
+}
+
+bool b2TestOverlap(	const b2Shape* shapeA, int32 indexA,
+					const b2Shape* shapeB, int32 indexB,
+					const b2Transform& xfA, const b2Transform& xfB)
+{
+	b2DistanceInput input;
+	input.proxyA.Set(shapeA, indexA);
+	input.proxyB.Set(shapeB, indexB);
+	input.transformA = xfA;
+	input.transformB = xfB;
+	input.useRadii = true;
+
+	b2SimplexCache cache;
+	cache.count = 0;
+
+	b2DistanceOutput output;
+
+	b2Distance(&output, &cache, &input);
+
+	return output.distance < 10.0f * b2_epsilon;
+}