text: //========= Copyright Valve Corporation, All rights reserved. ============//
  //
  // Purpose: Common collision utility methods
  //
  // $Header: $
  // $NoKeywords: $
  //=============================================================================//
  
  #if !defined(_STATIC_LINKED) || defined(_SHARED_LIB)
  
  #include "collisionutils.h"
  #include "cmodel.h"
  #include "mathlib/mathlib.h"
  #include "mathlib/vector.h"
  #include "tier0/dbg.h"
  #include <float.h>
  #include "mathlib/vector4d.h"
  #include "trace.h"
  
  // memdbgon must be the last include file in a .cpp file!!!
  #include "tier0/memdbgon.h"
  
  #define UNINIT		-99999.0
  
  //-----------------------------------------------------------------------------
  // Clears the trace
  //-----------------------------------------------------------------------------
  static void Collision_ClearTrace( const Vector &vecRayStart, const Vector &vecRayDelta, CBaseTrace *pTrace )
  {
  	pTrace->startpos = vecRayStart;
  	pTrace->endpos = vecRayStart;
  	pTrace->endpos += vecRayDelta;
  	pTrace->startsolid = false;
  	pTrace->allsolid = false;
  	pTrace->fraction = 1.0f;
  	pTrace->contents = 0;
  }
  
  
  //-----------------------------------------------------------------------------
  // Compute the offset in t along the ray that we'll use for the collision
  //-----------------------------------------------------------------------------
  static float ComputeBoxOffset( const Ray_t& ray )
  {
  	if (ray.m_IsRay)
  		return 1e-3f;
  
  	// Find the projection of the box diagonal along the ray...
  	float offset = FloatMakePositive(ray.m_Extents[0] * ray.m_Delta[0]) +
  					FloatMakePositive(ray.m_Extents[1] * ray.m_Delta[1]) +
  					FloatMakePositive(ray.m_Extents[2] * ray.m_Delta[2]);
  
  	// We need to divide twice: Once to normalize the computation above
  	// so we get something in units of extents, and the second to normalize
  	// that with respect to the entire raycast.
  	offset *= InvRSquared( ray.m_Delta );
  
  	// 1e-3 is an epsilon
  	return offset + 1e-3;
  }
  
  
  //-----------------------------------------------------------------------------
  // Intersects a swept box against a triangle
  //-----------------------------------------------------------------------------
  float IntersectRayWithTriangle( const Ray_t& ray, 
  		const Vector& v1, const Vector& v2, const Vector& v3, bool oneSided )
  {
  	// This is cute: Use barycentric coordinates to represent the triangle
  	// Vo(1-u-v) + V1u + V2v and intersect that with a line Po + Dt
  	// This gives us 3 equations + 3 unknowns, which we can solve with
  	// Cramer's rule...
  	//		E1x u + E2x v - Dx t = Pox - Vox
  	// There's a couple of other optimizations, Cramer's rule involves
  	// computing the determinant of a matrix which has been constructed
  	// by three vectors. It turns out that 
  	// det | A B C | = -( A x C ) dot B or -(C x B) dot A
  	// which we'll use below..
  
  	Vector edge1, edge2, org;
  	VectorSubtract( v2, v1, edge1 );
  	VectorSubtract( v3, v1, edge2 );
  
  	// Cull out one-sided stuff
  	if (oneSided)
  	{
  		Vector normal;
  		CrossProduct( edge1, edge2, normal );
  		if (DotProduct( normal, ray.m_Delta ) >= 0.0f)
  			return -1.0f;
  	}
  
  	// FIXME: This is inaccurate, but fast for boxes
  	// We want to do a fast separating axis implementation here
  	// with a swept triangle along the reverse direction of the ray.
  
  	// Compute some intermediary terms
  	Vector dirCrossEdge2, orgCrossEdge1;
  	CrossProduct( ray.m_Delta, edge2, dirCrossEdge2 );
  
  	// Compute the denominator of Cramer's rule:
  	//		| -Dx E1x E2x |
  	// det	| -Dy E1y E2y | = (D x E2) dot E1
  	//		| -Dz E1z E2z |
  	float denom = DotProduct( dirCrossEdge2, edge1 );
  	if( FloatMakePositive( denom ) < 1e-6 )
  		return -1.0f;
  	denom = 1.0f / denom;
  
  	// Compute u. It's gotta lie in the range of 0 to 1.
  	//				   | -Dx orgx E2x |
  	// u = denom * det | -Dy orgy E2y | = (D x E2) dot org
  	//				   | -Dz orgz E2z |
  	VectorSubtract( ray.m_Start, v1, org );
  	float u = DotProduct( dirCrossEdge2, org ) * denom;
  	if ((u < 0.0f) || (u > 1.0f))
  		return -1.0f;
  
  	// Compute t and v the same way...
  	// In barycentric coords, u + v < 1
  	CrossProduct( org, edge1, orgCrossEdge1 );
  	float v = DotProduct( orgCrossEdge1, ray.m_Delta ) * denom;
  	if ((v < 0.0f) || (v + u > 1.0f))
  		return -1.0f;
  
  	// Compute the distance along the ray direction that we need to fudge 
  	// when using swept boxes
  	float boxt = ComputeBoxOffset( ray );
  	float t = DotProduct( orgCrossEdge1, edge2 ) * denom;
  	if ((t < -boxt) || (t > 1.0f + boxt))
  		return -1.0f;
  
  	return clamp( t, 0.f, 1.f );
  }
  
  //-----------------------------------------------------------------------------
  // computes the barycentric coordinates of an intersection
  //-----------------------------------------------------------------------------
  
  bool ComputeIntersectionBarycentricCoordinates( const Ray_t& ray, 
  		const Vector& v1, const Vector& v2, const Vector& v3, float& u, float& v,
  		float *t )
  {
  	Vector edge1, edge2, org;
  	VectorSubtract( v2, v1, edge1 );
  	VectorSubtract( v3, v1, edge2 );
  
  	// Compute some intermediary terms
  	Vector dirCrossEdge2, orgCrossEdge1;
  	CrossProduct( ray.m_Delta, edge2, dirCrossEdge2 );
  
  	// Compute the denominator of Cramer's rule:
  	//		| -Dx E1x E2x |
  	// det	| -Dy E1y E2y | = (D x E2) dot E1
  	//		| -Dz E1z E2z |
  	float denom = DotProduct( dirCrossEdge2, edge1 );
  	if( FloatMakePositive( denom ) < 1e-6 )
  		return false;
  	denom = 1.0f / denom;
  
  	// Compute u. It's gotta lie in the range of 0 to 1.
  	//				   | -Dx orgx E2x |
  	// u = denom * det | -Dy orgy E2y | = (D x E2) dot org
  	//				   | -Dz orgz E2z |
  	VectorSubtract( ray.m_Start, v1, org );
  	u = DotProduct( dirCrossEdge2, org ) * denom;
  
  	// Compute t and v the same way...
  	// In barycentric coords, u + v < 1
  	CrossProduct( org, edge1, orgCrossEdge1 );
  	v = DotProduct( orgCrossEdge1, ray.m_Delta ) * denom;
  
  	// Compute the distance along the ray direction that we need to fudge 
  	// when using swept boxes
  	if( t )
  	{
  		float boxt = ComputeBoxOffset( ray );
  		*t = DotProduct( orgCrossEdge1, edge2 ) * denom;
  		if( ( *t < -boxt ) || ( *t > 1.0f + boxt ) )
  			return false;
  	}
  
  	return true;
  }
  
  //-----------------------------------------------------------------------------
  // Intersects a plane with a triangle (requires barycentric definition)
  //-----------------------------------------------------------------------------
  
  int IntersectTriangleWithPlaneBarycentric( const Vector& org, const Vector& edgeU,
  		const Vector& edgeV, const Vector4D& plane, Vector2D* pIntersection )
  {
  	// This uses a barycentric method, since we need that to determine
  	// interpolated points, alphas, and normals
  	// Given the plane equation P dot N + d = 0
  	// and the barycentric coodinate equation P = Org + EdgeU * u + EdgeV * v
  	// Plug em in. Intersection occurs at u = 0 or v = 0 or u + v = 1
  
  	float orgDotNormal = DotProduct( org, plane.AsVector3D() );
  	float edgeUDotNormal = DotProduct( edgeU, plane.AsVector3D() );
  	float edgeVDotNormal = DotProduct( edgeV, plane.AsVector3D() );
  
  	int ptIdx = 0;
  
  	// u = 0
  	if ( edgeVDotNormal != 0.0f )
  	{
  		pIntersection[ptIdx].x = 0.0f;
  		pIntersection[ptIdx].y = - ( orgDotNormal - plane.w ) / edgeVDotNormal;
  		if ((pIntersection[ptIdx].y >= 0.0f) && (pIntersection[ptIdx].y <= 1.0f))
  			++ptIdx;
  	}
  
  	// v = 0
  	if ( edgeUDotNormal != 0.0f )
  	{
  		pIntersection[ptIdx].x = - ( orgDotNormal - plane.w ) / edgeUDotNormal;
  		pIntersection[ptIdx].y = 0.0f;
  		if ((pIntersection[ptIdx].x >= 0.0f) && (pIntersection[ptIdx].x <= 1.0f))
  			++ptIdx;
  	}
  
  	// u + v = 1
  	if (ptIdx == 2)
  		return ptIdx;
  
  	if ( edgeVDotNormal != edgeUDotNormal )
  	{
  		pIntersection[ptIdx].x = - ( orgDotNormal - plane.w + edgeVDotNormal) / 
  			( edgeUDotNormal - edgeVDotNormal);
  		pIntersection[ptIdx].y = 1.0f - pIntersection[ptIdx].x;;
  		if ((pIntersection[ptIdx].x >= 0.0f) && (pIntersection[ptIdx].x <= 1.0f) &&
  			 (pIntersection[ptIdx].y >= 0.0f) && (pIntersection[ptIdx].y <= 1.0f))
  			++ptIdx;
  	}
  
  	Assert( ptIdx < 3 );
  	return ptIdx;
  }
  
  
  //-----------------------------------------------------------------------------
  // Returns true if a box intersects with a sphere
  //-----------------------------------------------------------------------------
  bool IsSphereIntersectingSphere( const Vector& center1, float radius1, 
  								 const Vector& center2, float radius2 )
  {
  	Vector delta;
  	VectorSubtract( center2, center1, delta );
  	float distSq = delta.LengthSqr();
  	float radiusSum = radius1 + radius2;
  	return (distSq <= (radiusSum * radiusSum));
  }
  
  
  //-----------------------------------------------------------------------------
  // Returns true if a box intersects with a sphere
  //-----------------------------------------------------------------------------
  bool IsBoxIntersectingSphere( const Vector& boxMin, const Vector& boxMax, 
  						const Vector& center, float radius )
  {
  	// See Graphics Gems, box-sphere intersection
  	float dmin = 0.0f;
  	float flDelta;
  
  	// Unrolled the loop.. this is a big cycle stealer...
  	if (center[0] < boxMin[0])
  	{
  		flDelta = center[0] - boxMin[0];
  		dmin += flDelta * flDelta;
  	}
  	else if (center[0] > boxMax[0])
  	{
  		flDelta = boxMax[0] - center[0];
  		dmin += flDelta * flDelta;
  	}
  
  	if (center[1] < boxMin[1])
  	{
  		flDelta = center[1] - boxMin[1];
  		dmin += flDelta * flDelta;
  	}
  	else if (center[1] > boxMax[1])
  	{
  		flDelta = boxMax[1] - center[1];
  		dmin += flDelta * flDelta;
  	}
  
  	if (center[2] < boxMin[2])
  	{
  		flDelta = center[2] - boxMin[2];
  		dmin += flDelta * flDelta;
  	}
  	else if (center[2] > boxMax[2])
  	{
  		flDelta = boxMax[2] - center[2];
  		dmin += flDelta * flDelta;
  	}
  
  	return dmin < radius * radius;
  }
  
  bool IsBoxIntersectingSphereExtents( const Vector& boxCenter, const Vector& boxHalfDiag, 
  						const Vector& center, float radius )
  {
  	// See Graphics Gems, box-sphere intersection
  	float dmin = 0.0f;
  	float flDelta, flDiff;
  
  	// Unrolled the loop.. this is a big cycle stealer...
  	flDiff = FloatMakePositive( center.x - boxCenter.x );
  	if (flDiff > boxHalfDiag.x)
  	{
  		flDelta = flDiff - boxHalfDiag.x;
  		dmin += flDelta * flDelta;
  	}
  
  	flDiff = FloatMakePositive( center.y - boxCenter.y );
  	if (flDiff > boxHalfDiag.y)
  	{
  		flDelta = flDiff - boxHalfDiag.y;
  		dmin += flDelta * flDelta;
  	}
  
  	flDiff = FloatMakePositive( center.z - boxCenter.z );
  	if (flDiff > boxHalfDiag.z)
  	{
  		flDelta = flDiff - boxHalfDiag.z;
  		dmin += flDelta * flDelta;
  	}
  
  	return dmin < radius * radius;
  }
  
  
  //-----------------------------------------------------------------------------
  // Returns true if a rectangle intersects with a circle
  //-----------------------------------------------------------------------------
  bool IsCircleIntersectingRectangle( const Vector2D& boxMin, const Vector2D& boxMax, 
  						      const Vector2D& center, float radius )
  {
  	// See Graphics Gems, box-sphere intersection
  	float dmin = 0.0f;
  	float flDelta;
  
  	if (center[0] < boxMin[0])
  	{
  		flDelta = center[0] - boxMin[0];
  		dmin += flDelta * flDelta;
  	}
  	else if (center[0] > boxMax[0])
  	{
  		flDelta = boxMax[0] - center[0];
  		dmin += flDelta * flDelta;
  	}
  
  	if (center[1] < boxMin[1])
  	{
  		flDelta = center[1] - boxMin[1];
  		dmin += flDelta * flDelta;
  	}
  	else if (center[1] > boxMax[1])
  	{
  		flDelta = boxMax[1] - center[1];
  		dmin += flDelta * flDelta;
  	}
  
  	return dmin < radius * radius;
  }
  
  
  //-----------------------------------------------------------------------------
  // returns true if there's an intersection between ray and sphere
  //-----------------------------------------------------------------------------
  bool IsRayIntersectingSphere( const Vector &vecRayOrigin, const Vector &vecRayDelta, 
  		const Vector& vecCenter, float flRadius, float flTolerance )
  {
  	// For this algorithm, find a point on the ray  which is closest to the sphere origin
  	// Do this by making a plane passing through the sphere origin
  	// whose normal is parallel to the ray. Intersect that plane with the ray.
  	// Plane: N dot P = I, N = D (ray direction), I = C dot N = C dot D
  	// Ray: P = O + D * t
  	// D dot ( O + D * t ) = C dot D
  	// D dot O + D dot D * t = C dot D
  	// t = (C - O) dot D / D dot D
  	// Clamp t to (0,1)
  	// Find distance of the point on the ray to the sphere center.
  	Assert( flTolerance >= 0.0f );
  	flRadius += flTolerance;
  
  	Vector vecRayToSphere;
  	VectorSubtract( vecCenter, vecRayOrigin, vecRayToSphere );
  	float flNumerator = DotProduct( vecRayToSphere, vecRayDelta );
  	
  	float t;
  	if (flNumerator <= 0.0f)
  	{
  		t = 0.0f;
  	}
  	else
  	{
  		float flDenominator = DotProduct( vecRayDelta, vecRayDelta );
  		if ( flNumerator > flDenominator )
  			t = 1.0f;
  		else
  			t = flNumerator / flDenominator;
  	}
  	
  	Vector vecClosestPoint;
  	VectorMA( vecRayOrigin, t, vecRayDelta, vecClosestPoint );
  	return ( vecClosestPoint.DistToSqr( vecCenter ) <= flRadius * flRadius );
  
  	// NOTE: This in an alternate algorithm which I didn't use because I'd have to use a sqrt
  	// So it's probably faster to do this other algorithm. I'll leave the comments here
  	// for how to go back if we want to
  
  	// Solve using the ray equation + the sphere equation
  	// P = o + dt
  	// (x - xc)^2 + (y - yc)^2 + (z - zc)^2 = r^2
  	// (ox + dx * t - xc)^2 + (oy + dy * t - yc)^2 + (oz + dz * t - zc)^2 = r^2
  	// (ox - xc)^2 + 2 * (ox-xc) * dx * t + dx^2 * t^2 +
  	//		(oy - yc)^2 + 2 * (oy-yc) * dy * t + dy^2 * t^2 +
  	//		(oz - zc)^2 + 2 * (oz-zc) * dz * t + dz^2 * t^2 = r^2
  	// (dx^2 + dy^2 + dz^2) * t^2 + 2 * ((ox-xc)dx + (oy-yc)dy + (oz-zc)dz) t +
  	//		(ox-xc)^2 + (oy-yc)^2 + (oz-zc)^2 - r^2 = 0
  	// or, t = (-b +/- sqrt( b^2 - 4ac)) / 2a
  	// a = DotProduct( vecRayDelta, vecRayDelta );
  	// b = 2 * DotProduct( vecRayOrigin - vecCenter, vecRayDelta )
  	// c = DotProduct(vecRayOrigin - vecCenter, vecRayOrigin - vecCenter) - flRadius * flRadius;
  	// Valid solutions are possible only if b^2 - 4ac >= 0
  	// Therefore, compute that value + see if we got it	
  }
  
  
  //-----------------------------------------------------------------------------
  //
  // IntersectInfiniteRayWithSphere
  //
  // Returns whether or not there was an intersection. 
  // Returns the two intersection points
  //
  //-----------------------------------------------------------------------------
  bool IntersectInfiniteRayWithSphere( const Vector &vecRayOrigin, const Vector &vecRayDelta, 
  	const Vector &vecSphereCenter, float flRadius, float *pT1, float *pT2 )
  {
  	// Solve using the ray equation + the sphere equation
  	// P = o + dt
  	// (x - xc)^2 + (y - yc)^2 + (z - zc)^2 = r^2
  	// (ox + dx * t - xc)^2 + (oy + dy * t - yc)^2 + (oz + dz * t - zc)^2 = r^2
  	// (ox - xc)^2 + 2 * (ox-xc) * dx * t + dx^2 * t^2 +
  	//		(oy - yc)^2 + 2 * (oy-yc) * dy * t + dy^2 * t^2 +
  	//		(oz - zc)^2 + 2 * (oz-zc) * dz * t + dz^2 * t^2 = r^2
  	// (dx^2 + dy^2 + dz^2) * t^2 + 2 * ((ox-xc)dx + (oy-yc)dy + (oz-zc)dz) t +
  	//		(ox-xc)^2 + (oy-yc)^2 + (oz-zc)^2 - r^2 = 0
  	// or, t = (-b +/- sqrt( b^2 - 4ac)) / 2a
  	// a = DotProduct( vecRayDelta, vecRayDelta );
  	// b = 2 * DotProduct( vecRayOrigin - vecCenter, vecRayDelta )
  	// c = DotProduct(vecRayOrigin - vecCenter, vecRayOrigin - vecCenter) - flRadius * flRadius;
  
  	Vector vecSphereToRay;
  	VectorSubtract(	vecRayOrigin, vecSphereCenter, vecSphereToRay );
  
  	float a = DotProduct( vecRayDelta, vecRayDelta );
  
  	// This would occur in the case of a zero-length ray
  	if ( a == 0.0f )
  	{
  		*pT1 = *pT2 = 0.0f;
  		return vecSphereToRay.LengthSqr() <= flRadius * flRadius;
  	}
  
  	float b = 2 * DotProduct( vecSphereToRay, vecRayDelta );
  	float c = DotProduct( vecSphereToRay, vecSphereToRay ) - flRadius * flRadius;
  	float flDiscrim = b * b - 4 * a * c;
  	if ( flDiscrim < 0.0f )
  		return false;
  
  	flDiscrim = sqrt( flDiscrim );
  	float oo2a = 0.5f / a;
  	*pT1 = ( - b - flDiscrim ) * oo2a;
  	*pT2 = ( - b + flDiscrim ) * oo2a;
  	return true;
  }
  
  
  
  //-----------------------------------------------------------------------------
  //
  // IntersectRayWithSphere
  //
  // Returns whether or not there was an intersection. 
  // Returns the two intersection points, clamped to (0,1)
  //
  //-----------------------------------------------------------------------------
  bool IntersectRayWithSphere( const Vector &vecRayOrigin, const Vector &vecRayDelta, 
  	const Vector &vecSphereCenter, float flRadius, float *pT1, float *pT2 )
  {
  	if ( !IntersectInfiniteRayWithSphere( vecRayOrigin, vecRayDelta, vecSphereCenter, flRadius, pT1, pT2 ) )
  		return false;
  
  	if (( *pT1 > 1.0f ) || ( *pT2 < 0.0f ))
  		return false;
  
  	// Clamp it!
  	if ( *pT1 < 0.0f )
  		*pT1 = 0.0f;
  	if ( *pT2 > 1.0f )
  		*pT2 = 1.0f;
  
  	return true;
  }
  
  
  // returns true if the sphere and cone intersect
  // NOTE: cone sine/cosine are the half angle of the cone
  bool IsSphereIntersectingCone( const Vector &sphereCenter, float sphereRadius, const Vector &coneOrigin, const Vector &coneNormal, float coneSine, float coneCosine )
  {
  	Vector backCenter = coneOrigin - (sphereRadius / coneSine) * coneNormal;
  	Vector delta = sphereCenter - backCenter;
  	float deltaLen = delta.Length();
  	if ( DotProduct(coneNormal, delta) >= deltaLen*coneCosine )
  	{
  		delta = sphereCenter - coneOrigin;
  		deltaLen = delta.Length();
  		if ( -DotProduct(coneNormal, delta) >= deltaLen * coneSine )
  		{
  			return ( deltaLen <= sphereRadius ) ? true : false;
  		}
  		return true;
  	}
  	return false;
  }
  
  
  
  //-----------------------------------------------------------------------------
  // returns true if the point is in the box
  //-----------------------------------------------------------------------------
  bool IsPointInBox( const Vector& pt, const Vector& boxMin, const Vector& boxMax )
  {
  	Assert( boxMin[0] <= boxMax[0] );
  	Assert( boxMin[1] <= boxMax[1] );
  	Assert( boxMin[2] <= boxMax[2] );
  
  	// on x360, force use of SIMD version.
  	if (IsX360())
  	{
  		return IsPointInBox( LoadUnaligned3SIMD(pt.Base()), LoadUnaligned3SIMD(boxMin.Base()), LoadUnaligned3SIMD(boxMax.Base()) ) ;
  	}
  
  	if ( (pt[0] > boxMax[0]) || (pt[0] < boxMin[0]) )
  		return false;
  	if ( (pt[1] > boxMax[1]) || (pt[1] < boxMin[1]) )
  		return false;
  	if ( (pt[2] > boxMax[2]) || (pt[2] < boxMin[2]) )
  		return false;
  	return true;
  }
  
  
  bool IsPointInCone( const Vector &pt, const Vector &origin, const Vector &axis, float cosAngle, float length )
  {
  	Vector delta = pt - origin;
  	float dist = VectorNormalize( delta );
  	float dot = DotProduct( delta, axis );
  	if ( dot < cosAngle )
  		return false;
  	if ( dist * dot > length )
  		return false;
  
  	return true;
  }
  
  
  //-----------------------------------------------------------------------------
  // returns true if there's an intersection between two boxes
  //-----------------------------------------------------------------------------
  bool IsBoxIntersectingBox( const Vector& boxMin1, const Vector& boxMax1, 
  						const Vector& boxMin2, const Vector& boxMax2 )
  {
  	Assert( boxMin1[0] <= boxMax1[0] );
  	Assert( boxMin1[1] <= boxMax1[1] );
  	Assert( boxMin1[2] <= boxMax1[2] );
  	Assert( boxMin2[0] <= boxMax2[0] );
  	Assert( boxMin2[1] <= boxMax2[1] );
  	Assert( boxMin2[2] <= boxMax2[2] );
  
  	if ( (boxMin1[0] > boxMax2[0]) || (boxMax1[0] < boxMin2[0]) )
  		return false;
  	if ( (boxMin1[1] > boxMax2[1]) || (boxMax1[1] < boxMin2[1]) )
  		return false;
  	if ( (boxMin1[2] > boxMax2[2]) || (boxMax1[2] < boxMin2[2]) )
  		return false;
  	return true;
  }
  
  bool IsBoxIntersectingBoxExtents( const Vector& boxCenter1, const Vector& boxHalfDiagonal1, 
  						   const Vector& boxCenter2, const Vector& boxHalfDiagonal2 )
  {
  	Vector vecDelta, vecSize;
  	VectorSubtract( boxCenter1, boxCenter2, vecDelta );
  	VectorAdd( boxHalfDiagonal1, boxHalfDiagonal2, vecSize );
  	return ( FloatMakePositive( vecDelta.x ) <= vecSize.x ) &&
  			( FloatMakePositive( vecDelta.y ) <= vecSize.y ) &&
  			( FloatMakePositive( vecDelta.z ) <= vecSize.z );
  }
  
  
  //-----------------------------------------------------------------------------
  // 
  // IsOBBIntersectingOBB
  //
  // returns true if there's an intersection between two OBBs
  //
  //-----------------------------------------------------------------------------
  bool IsOBBIntersectingOBB( const Vector &vecOrigin1, const QAngle &vecAngles1, const Vector& boxMin1, const Vector& boxMax1, 
  						   const Vector &vecOrigin2, const QAngle &vecAngles2, const Vector& boxMin2, const Vector& boxMax2, float flTolerance )
  {
  	// FIXME: Simple case AABB check doesn't work because the min and max extents are not oriented based on the angle
  	// this fast check would only be good for cubes.
  	/*if ( vecAngles1 == vecAngles2 )
  	{
  		const Vector &vecDelta = vecOrigin2 - vecOrigin1;
  		Vector vecOtherMins, vecOtherMaxs;
  		VectorAdd( boxMin2, vecDelta, vecOtherMins );
  		VectorAdd( boxMax2, vecDelta, vecOtherMaxs );
  		return IsBoxIntersectingBox( boxMin1, boxMax1, vecOtherMins, vecOtherMaxs );
  	}*/
  
  	// OBB test...
  	cplane_t plane;
  	bool bFoundPlane = ComputeSeparatingPlane( vecOrigin1, vecAngles1, boxMin1, boxMax1, 
  		vecOrigin2, vecAngles2, boxMin2, boxMax2, flTolerance, &plane );
  	return (bFoundPlane == false);
  }
  
  // NOTE: This is only very slightly faster on high end PCs and x360
  #define USE_SIMD_RAY_CHECKS 1
  //-----------------------------------------------------------------------------
  // returns true if there's an intersection between box and ray
  //-----------------------------------------------------------------------------
  bool FASTCALL IsBoxIntersectingRay( const Vector& boxMin, const Vector& boxMax, 
  									const Vector& origin, const Vector& vecDelta, float flTolerance )
  {
  	
  #if USE_SIMD_RAY_CHECKS
  	// Load the unaligned ray/box parameters into SIMD registers
  	fltx4 start = LoadUnaligned3SIMD(origin.Base());
  	fltx4 delta = LoadUnaligned3SIMD(vecDelta.Base());
  	fltx4 boxMins = LoadUnaligned3SIMD( boxMin.Base() );
  	fltx4 boxMaxs = LoadUnaligned3SIMD( boxMax.Base() );
  	fltx4 epsilon = ReplicateX4(flTolerance);
  	// compute the mins/maxs of the box expanded by the ray extents
  	// relocate the problem so that the ray start is at the origin.
  	fltx4 offsetMins = SubSIMD(boxMins, start);
  	fltx4 offsetMaxs = SubSIMD(boxMaxs, start);
  	fltx4 offsetMinsExpanded = SubSIMD(offsetMins, epsilon);
  	fltx4 offsetMaxsExpanded = AddSIMD(offsetMaxs, epsilon);
  
  	// Check to see if both the origin (start point) and the end point (delta) are on the front side
  	// of any of the box sides - if so there can be no intersection
  	fltx4 startOutMins = CmpLtSIMD(Four_Zeros, offsetMinsExpanded);
  	fltx4 endOutMins = CmpLtSIMD(delta,offsetMinsExpanded);
  	fltx4 minsMask = AndSIMD( startOutMins, endOutMins );
  	fltx4 startOutMaxs = CmpGtSIMD(Four_Zeros, offsetMaxsExpanded);
  	fltx4 endOutMaxs = CmpGtSIMD(delta,offsetMaxsExpanded);
  	fltx4 maxsMask = AndSIMD( startOutMaxs, endOutMaxs );
  	if ( IsAnyNegative(SetWToZeroSIMD(OrSIMD(minsMask,maxsMask))))
  		return false;
  
  	// now build the per-axis interval of t for intersections
  	fltx4 invDelta = ReciprocalSaturateSIMD(delta);
  	fltx4 tmins = MulSIMD( offsetMinsExpanded, invDelta );
  	fltx4 tmaxs = MulSIMD( offsetMaxsExpanded, invDelta );
  	fltx4 crossPlane = OrSIMD(XorSIMD(startOutMins,endOutMins), XorSIMD(startOutMaxs,endOutMaxs));
  
  	// only consider axes where we crossed a plane
  	tmins = MaskedAssign( crossPlane, tmins, Four_Negative_FLT_MAX );
  	tmaxs = MaskedAssign( crossPlane, tmaxs, Four_FLT_MAX );
  
  	// now sort the interval per axis
  	fltx4 mint = MinSIMD( tmins, tmaxs );
  	fltx4 maxt = MaxSIMD( tmins, tmaxs );
  
  	// now find the intersection of the intervals on all axes
  	fltx4 firstOut = FindLowestSIMD3(maxt);
  	fltx4 lastIn = FindHighestSIMD3(mint);
  	// NOTE: This is really a scalar quantity now [t0,t1] == [lastIn,firstOut]
  	firstOut = MinSIMD(firstOut, Four_Ones);
  	lastIn = MaxSIMD(lastIn, Four_Zeros);
  
  	// If the final interval is valid lastIn<firstOut, check for separation
  	fltx4 separation = CmpGtSIMD(lastIn, firstOut);
  
  	return IsAllZeros(separation);
  #else
  	// On the x360, we force use of the SIMD functions.
  #if defined(_X360) 
  	if (IsX360())
  	{
  		fltx4 delta = LoadUnaligned3SIMD(vecDelta.Base());
  		return IsBoxIntersectingRay( 
  			LoadUnaligned3SIMD(boxMin.Base()), LoadUnaligned3SIMD(boxMax.Base()),
  			LoadUnaligned3SIMD(origin.Base()), delta, ReciprocalSIMD(delta), // ray parameters
  			ReplicateX4(flTolerance) ///< eg from ReplicateX4(flTolerance)
  			);
  	}
  #endif
  	Assert( boxMin[0] <= boxMax[0] );
  	Assert( boxMin[1] <= boxMax[1] );
  	Assert( boxMin[2] <= boxMax[2] );
  
  	// FIXME: Surely there's a faster way
  	float tmin = -FLT_MAX;
  	float tmax = FLT_MAX;
  
  	for (int i = 0; i < 3; ++i)
  	{
  		// Parallel case...
  		if (FloatMakePositive(vecDelta[i]) < 1e-8)
  		{
  			// Check that origin is in the box
  			// if not, then it doesn't intersect..
  			if ( (origin[i] < boxMin[i] - flTolerance) || (origin[i] > boxMax[i] + flTolerance) )
  				return false;
  
  			continue;
  		}
  
  		// non-parallel case
  		// Find the t's corresponding to the entry and exit of
  		// the ray along x, y, and z. The find the furthest entry
  		// point, and the closest exit point. Once that is done,
  		// we know we don't collide if the closest exit point
  		// is behind the starting location. We also don't collide if
  		// the closest exit point is in front of the furthest entry point
  
  		float invDelta = 1.0f / vecDelta[i];
  		float t1 = (boxMin[i] - flTolerance - origin[i]) * invDelta;
  		float t2 = (boxMax[i] + flTolerance - origin[i]) * invDelta;
  		if (t1 > t2)
  		{
  			float temp = t1;
  			t1 = t2;
  			t2 = temp;
  		}
  		if (t1 > tmin)
  			tmin = t1;
  		if (t2 < tmax)
  			tmax = t2;
  		if (tmin > tmax)
  			return false;
  		if (tmax < 0)
  			return false;
  		if (tmin > 1)
  			return false;
  	}
  
  	return true;
  #endif
  }
  
  //-----------------------------------------------------------------------------
  // returns true if there's an intersection between box and ray
  //-----------------------------------------------------------------------------
  bool FASTCALL IsBoxIntersectingRay( const Vector& boxMin, const Vector& boxMax, 
  									const Vector& origin, const Vector& vecDelta,
  									const Vector& vecInvDelta, float flTolerance )
  {	
  #if USE_SIMD_RAY_CHECKS
  	// Load the unaligned ray/box parameters into SIMD registers
  	fltx4 start = LoadUnaligned3SIMD(origin.Base());
  	fltx4 delta = LoadUnaligned3SIMD(vecDelta.Base());
  	fltx4 boxMins = LoadUnaligned3SIMD( boxMin.Base() );
  	fltx4 boxMaxs = LoadUnaligned3SIMD( boxMax.Base() );
  	// compute the mins/maxs of the box expanded by the ray extents
  	// relocate the problem so that the ray start is at the origin.
  	boxMins = SubSIMD(boxMins, start);
  	boxMaxs = SubSIMD(boxMaxs, start);
  
  	// Check to see if both the origin (start point) and the end point (delta) are on the front side
  	// of any of the box sides - if so there can be no intersection
  	fltx4 startOutMins = CmpLtSIMD(Four_Zeros, boxMins);
  	fltx4 endOutMins = CmpLtSIMD(delta,boxMins);
  	fltx4 minsMask = AndSIMD( startOutMins, endOutMins );
  	fltx4 startOutMaxs = CmpGtSIMD(Four_Zeros, boxMaxs);
  	fltx4 endOutMaxs = CmpGtSIMD(delta,boxMaxs);
  	fltx4 maxsMask = AndSIMD( startOutMaxs, endOutMaxs );
  	if ( IsAnyNegative(SetWToZeroSIMD(OrSIMD(minsMask,maxsMask))))
  		return false;
  
  	// now build the per-axis interval of t for intersections
  	fltx4 epsilon = ReplicateX4(flTolerance);
  	fltx4 invDelta = LoadUnaligned3SIMD(vecInvDelta.Base());
  	boxMins = SubSIMD(boxMins, epsilon);
  	boxMaxs = AddSIMD(boxMaxs, epsilon);
  
  	boxMins = MulSIMD( boxMins, invDelta );
  	boxMaxs = MulSIMD( boxMaxs, invDelta );
  
  	fltx4 crossPlane = OrSIMD(XorSIMD(startOutMins,endOutMins), XorSIMD(startOutMaxs,endOutMaxs));
  	// only consider axes where we crossed a plane
  	boxMins = MaskedAssign( crossPlane, boxMins, Four_Negative_FLT_MAX );
  	boxMaxs = MaskedAssign( crossPlane, boxMaxs, Four_FLT_MAX );
  
  	// now sort the interval per axis
  	fltx4 mint = MinSIMD( boxMins, boxMaxs );
  	fltx4 maxt = MaxSIMD( boxMins, boxMaxs );
  
  	// now find the intersection of the intervals on all axes
  	fltx4 firstOut = FindLowestSIMD3(maxt);
  	fltx4 lastIn = FindHighestSIMD3(mint);
  	// NOTE: This is really a scalar quantity now [t0,t1] == [lastIn,firstOut]
  	firstOut = MinSIMD(firstOut, Four_Ones);
  	lastIn = MaxSIMD(lastIn, Four_Zeros);
  
  	// If the final interval is valid lastIn<firstOut, check for separation
  	fltx4 separation = CmpGtSIMD(lastIn, firstOut);
  
  	return IsAllZeros(separation);
  #else
  	// On the x360, we force use of the SIMD functions.
  #if defined(_X360) && !defined(PARANOID_SIMD_ASSERTING)
  	if (IsX360())
  	{
  		return IsBoxIntersectingRay( 
  			LoadUnaligned3SIMD(boxMin.Base()), LoadUnaligned3SIMD(boxMax.Base()),
  			LoadUnaligned3SIMD(origin.Base()), LoadUnaligned3SIMD(vecDelta.Base()), LoadUnaligned3SIMD(vecInvDelta.Base()), // ray parameters
  			ReplicateX4(flTolerance) ///< eg from ReplicateX4(flTolerance)
  			);
  	}
  #endif
  
  	Assert( boxMin[0] <= boxMax[0] );
  	Assert( boxMin[1] <= boxMax[1] );
  	Assert( boxMin[2] <= boxMax[2] );
  
  	// FIXME: Surely there's a faster way
  	float tmin = -FLT_MAX;
  	float tmax = FLT_MAX;
  
  	for ( int i = 0; i < 3; ++i )
  	{
  		// Parallel case...
  		if ( FloatMakePositive( vecDelta[i] ) < 1e-8 )
  		{
  			// Check that origin is in the box, if not, then it doesn't intersect..
  			if ( ( origin[i] < boxMin[i] - flTolerance ) || ( origin[i] > boxMax[i] + flTolerance ) )
  				return false;
  
  			continue;
  		}
  
  		// Non-parallel case
  		// Find the t's corresponding to the entry and exit of
  		// the ray along x, y, and z. The find the furthest entry
  		// point, and the closest exit point. Once that is done,
  		// we know we don't collide if the closest exit point
  		// is behind the starting location. We also don't collide if
  		// the closest exit point is in front of the furthest entry point
  		float t1 = ( boxMin[i] - flTolerance - origin[i] ) * vecInvDelta[i];
  		float t2 = ( boxMax[i] + flTolerance - origin[i] ) * vecInvDelta[i];
  		if ( t1 > t2 )
  		{
  			float temp = t1;
  			t1 = t2;
  			t2 = temp;
  		}
  
  		if (t1 > tmin)
  			tmin = t1;
  
  		if (t2 < tmax)
  			tmax = t2;
  
  		if (tmin > tmax)
  			return false;
  
  		if (tmax < 0)
  			return false;
  
  		if (tmin > 1)
  			return false;
  	}
  
  	return true;
  #endif
  }
  
  //-----------------------------------------------------------------------------
  // Intersects a ray with a aabb, return true if they intersect
  //-----------------------------------------------------------------------------
  bool FASTCALL IsBoxIntersectingRay( const Vector& vecBoxMin, const Vector& vecBoxMax, const Ray_t& ray, float flTolerance )
  {
  	// On the x360, we force use of the SIMD functions.
  #if defined(_X360) 
  	if (IsX360())
  	{
  		return IsBoxIntersectingRay( 
  			LoadUnaligned3SIMD(vecBoxMin.Base()), LoadUnaligned3SIMD(vecBoxMax.Base()),
  			ray, flTolerance);
  	}
  #endif
  
  	if ( !ray.m_IsSwept )
  	{
  		Vector rayMins, rayMaxs;
  		VectorSubtract( ray.m_Start, ray.m_Extents, rayMins );
  		VectorAdd( ray.m_Start, ray.m_Extents, rayMaxs );
  		if ( flTolerance != 0.0f )
  		{
  			rayMins.x -= flTolerance; rayMins.y -= flTolerance; rayMins.z -= flTolerance;
  			rayMaxs.x += flTolerance; rayMaxs.y += flTolerance; rayMaxs.z += flTolerance;
  		}
  		return IsBoxIntersectingBox( vecBoxMin, vecBoxMax, rayMins, rayMaxs );
  	}
  
  	Vector vecExpandedBoxMin, vecExpandedBoxMax;
  	VectorSubtract( vecBoxMin, ray.m_Extents, vecExpandedBoxMin );
  	VectorAdd( vecBoxMax, ray.m_Extents, vecExpandedBoxMax );
  	return IsBoxIntersectingRay( vecExpandedBoxMin, vecExpandedBoxMax, ray.m_Start, ray.m_Delta, flTolerance );
  }
  
  
  //-----------------------------------------------------------------------------
  // returns true if there's an intersection between box and ray (SIMD version)
  //-----------------------------------------------------------------------------
  
  
  #ifdef _X360
  bool FASTCALL IsBoxIntersectingRay( fltx4 boxMin, fltx4 boxMax, 
  								    fltx4 origin, fltx4 delta, fltx4 invDelta, // ray parameters
  									fltx4 vTolerance ///< eg from ReplicateX4(flTolerance)
  									)
  #else
  bool FASTCALL IsBoxIntersectingRay( const fltx4 &inBoxMin, const fltx4 & inBoxMax, 
  								   const fltx4 & origin, const fltx4 & delta, const fltx4 & invDelta, // ray parameters
  								   const fltx4 & vTolerance ///< eg from ReplicateX4(flTolerance)
  								   )
  #endif
  {
  	// Load the unaligned ray/box parameters into SIMD registers
  	// compute the mins/maxs of the box expanded by the ray extents
  	// relocate the problem so that the ray start is at the origin.
  
  #ifdef _X360
  	boxMin = SubSIMD(boxMin, origin);
  	boxMax = SubSIMD(boxMax, origin);
  #else
  	fltx4 boxMin = SubSIMD(inBoxMin, origin);
  	fltx4 boxMax = SubSIMD(inBoxMax, origin);
  #endif
  
  	// Check to see if the origin (start point) and the end point (delta) are on the same side
  	// of any of the box sides - if so there can be no intersection
  	fltx4 startOutMins = AndSIMD( CmpLtSIMD(Four_Zeros, boxMin), CmpLtSIMD(delta,boxMin) );
  	fltx4 startOutMaxs = AndSIMD( CmpGtSIMD(Four_Zeros, boxMax), CmpGtSIMD(delta,boxMax) );
  	if ( IsAnyNegative(SetWToZeroSIMD(OrSIMD(startOutMaxs,startOutMins))))
  		return false;
  
  	// now build the per-axis interval of t for intersections
  	boxMin = SubSIMD(boxMin, vTolerance);
  	boxMax = AddSIMD(boxMax, vTolerance);
  
  	boxMin = MulSIMD( boxMin, invDelta );
  	boxMax = MulSIMD( boxMax, invDelta );
  
  	// now sort the interval per axis
  	fltx4 mint = MinSIMD( boxMin, boxMax );
  	fltx4 maxt = MaxSIMD( boxMin, boxMax );
  
  	// now find the intersection of the intervals on all axes
  	fltx4 firstOut = FindLowestSIMD3(maxt);
  	fltx4 lastIn = FindHighestSIMD3(mint);
  	// NOTE: This is really a scalar quantity now [t0,t1] == [lastIn,firstOut]
  	firstOut = MinSIMD(firstOut, Four_Ones);
  	lastIn = MaxSIMD(lastIn, Four_Zeros);
  
  	// If the final interval is valid lastIn<firstOut, check for separation
  	fltx4 separation = CmpGtSIMD(lastIn, firstOut);
  
  	return IsAllZeros(separation);
  }
  
  
  bool FASTCALL IsBoxIntersectingRay( const fltx4& boxMin, const fltx4& boxMax, 
  								   const Ray_t& ray, float flTolerance )
  {
  	fltx4 vTolerance = ReplicateX4(flTolerance);
  	fltx4 rayStart = LoadAlignedSIMD(ray.m_Start);
  	fltx4 rayExtents = LoadAlignedSIMD(ray.m_Extents);
  	if ( !ray.m_IsSwept )
  	{
  
  		fltx4 rayMins, rayMaxs;
  		rayMins = SubSIMD(rayStart, rayExtents);
  		rayMaxs = AddSIMD(rayStart, rayExtents);
  		rayMins = AddSIMD(rayMins, vTolerance);
  		rayMaxs = AddSIMD(rayMaxs, vTolerance);
  
  		VectorAligned vecBoxMin, vecBoxMax, vecRayMins, vecRayMaxs;
  		StoreAlignedSIMD( vecBoxMin.Base(), boxMin );
  		StoreAlignedSIMD( vecBoxMax.Base(), boxMax );
  		StoreAlignedSIMD( vecRayMins.Base(), rayMins );
  		StoreAlignedSIMD( vecRayMaxs.Base(), rayMaxs );
  
  		return IsBoxIntersectingBox( vecBoxMin, vecBoxMax, vecRayMins, vecRayMaxs );
  	}
  
  	fltx4 rayDelta = LoadAlignedSIMD(ray.m_Delta);
  	fltx4 vecExpandedBoxMin, vecExpandedBoxMax;
  	vecExpandedBoxMin = SubSIMD( boxMin, rayExtents );
  	vecExpandedBoxMax = AddSIMD( boxMax, rayExtents );
  
  	return IsBoxIntersectingRay( vecExpandedBoxMin, vecExpandedBoxMax, rayStart, rayDelta, ReciprocalSIMD(rayDelta), ReplicateX4(flTolerance) );
  }
  
  
  //-----------------------------------------------------------------------------
  // Intersects a ray with a ray, return true if they intersect
  // t, s = parameters of closest approach (if not intersecting!)
  //-----------------------------------------------------------------------------
  bool IntersectRayWithRay( const Ray_t &ray0, const Ray_t &ray1, float &t, float &s )
  {
  	Assert( ray0.m_IsRay && ray1.m_IsRay );
  
  	//
  	// r0 = p0 + v0t
  	// r1 = p1 + v1s
  	//
  	// intersection : r0 = r1 :: p0 + v0t = p1 + v1s
  	// NOTE: v(0,1) are unit direction vectors
  	//
  	// subtract p0 from both sides and cross with v1 (NOTE: v1 x v1 = 0)
  	//  (v0 x v1)t = ((p1 - p0 ) x v1)
  	//
  	// dotting  with (v0 x v1) and dividing by |v0 x v1|^2
  	//	t = Det | (p1 - p0) , v1 , (v0 x v1) | / |v0 x v1|^2
  	//  s = Det | (p1 - p0) , v0 , (v0 x v1) | / |v0 x v1|^2
  	//
  	//  Det | A B C | = -( A x C ) dot B or -( C x B ) dot A
  	// 
  	//  NOTE: if |v0 x v1|^2 = 0, then the lines are parallel
  	//
  	Vector v0( ray0.m_Delta );
  	Vector v1( ray1.m_Delta );
  	VectorNormalize( v0 );
  	VectorNormalize( v1 );
  
  	Vector v0xv1 = v0.Cross( v1 );
  	float lengthSq = v0xv1.LengthSqr();
  	if( lengthSq == 0.0f )
  	{
  		t = 0; s = 0;
  		return false;		// parallel
  	}
  
  	Vector p1p0 = ray1.m_Start - ray0.m_Start;
  
  	Vector AxC = p1p0.Cross( v0xv1 );
  	AxC.Negate();
  	float detT = AxC.Dot( v1 );
  	
  	AxC = p1p0.Cross( v0xv1 );
  	AxC.Negate();
  	float detS = AxC.Dot( v0 );
  
  	t = detT / lengthSq;
  	s = detS / lengthSq;
  
  	// intersection????
  	Vector i0, i1;
  	i0 = v0 * t;
  	i1 = v1 * s;
  	i0 += ray0.m_Start;
  	i1 += ray1.m_Start;
  	if( i0.x == i1.x && i0.y == i1.y && i0.z == i1.z )
  		return true;
  
  	return false;
  }
  
  //-----------------------------------------------------------------------------
  // Intersects a ray with a plane, returns distance t along ray.
  //-----------------------------------------------------------------------------
  float IntersectRayWithPlane( const Ray_t& ray, const cplane_t& plane )
  {
  	float denom	= DotProduct( ray.m_Delta, plane.normal );
  	if (denom == 0.0f)
  		return 0.0f;
  
  	denom = 1.0f / denom;
  	return (plane.dist - DotProduct( ray.m_Start, plane.normal )) * denom;
  }
  
  float IntersectRayWithPlane( const Vector& org, const Vector& dir, const cplane_t& plane )
  {
  	float denom	= DotProduct( dir, plane.normal );
  	if (denom == 0.0f)
  		return 0.0f;
  
  	denom = 1.0f / denom;
  	return (plane.dist - DotProduct( org, plane.normal )) * denom;
  }
  
  float IntersectRayWithPlane( const Vector& org, const Vector& dir, const Vector& normal, float dist )
  {
  	float denom	= DotProduct( dir, normal );
  	if (denom == 0.0f)
  		return 0.0f;
  
  	denom = 1.0f / denom;
  	return (dist - DotProduct( org, normal )) * denom;
  }
  
  float IntersectRayWithAAPlane( const Vector& vecStart, const Vector& vecEnd, int nAxis, float flSign, float flDist )
  {
  	float denom	= flSign * (vecEnd[nAxis] - vecStart[nAxis]);
  	if (denom == 0.0f)
  		return 0.0f;
  
  	denom = 1.0f / denom;
  	return (flDist - flSign * vecStart[nAxis]) * denom;
  }
  
  
  //-----------------------------------------------------------------------------
  // Intersects a ray against a box
  //-----------------------------------------------------------------------------
  bool IntersectRayWithBox( const Vector &vecRayStart, const Vector &vecRayDelta, 
  	const Vector &boxMins, const Vector &boxMaxs, float flTolerance, BoxTraceInfo_t *pTrace )
  {
  	int			i;
  	float		d1, d2;
  	float		f;
  
  	pTrace->t1 = -1.0f;
  	pTrace->t2 = 1.0f;
  	pTrace->hitside = -1;
  
  	// UNDONE: This makes this code a little messy
  	pTrace->startsolid = true;
  
  	for ( i = 0; i < 6; ++i )
  	{
  		if ( i >= 3 )
  		{
  			d1 = vecRayStart[i-3] - boxMaxs[i-3];
  			d2 = d1 + vecRayDelta[i-3];
  		}
  		else
  		{
  			d1 = -vecRayStart[i] + boxMins[i];
  			d2 = d1 - vecRayDelta[i];
  		}
  
  		// if completely in front of face, no intersection
  		if (d1 > 0 && d2 > 0)
  		{
  			// UNDONE: Have to revert this in case it's still set
  			// UNDONE: Refactor to have only 2 return points (true/false) from this function
  			pTrace->startsolid = false;
  			return false;
  		}
  
  		// completely inside, check next face
  		if (d1 <= 0 && d2 <= 0)
  			continue;
  
  		if (d1 > 0)
  		{
  			pTrace->startsolid = false;
  		}
  
  		// crosses face
  		if (d1 > d2)
  		{
  			f = d1 - flTolerance;
  			if ( f < 0 )
  			{
  				f = 0;
  			}
  			f = f / (d1-d2);
  			if (f > pTrace->t1)
  			{
  				pTrace->t1 = f;
  				pTrace->hitside = i;
  			}
  		}
  		else
  		{ 
  			// leave
  			f = (d1 + flTolerance) / (d1-d2);
  			if (f < pTrace->t2)
  			{
  				pTrace->t2 = f;
  			}
  		}
  	}
  
  	return pTrace->startsolid || (pTrace->t1 < pTrace->t2 && pTrace->t1 >= 0.0f);
  }
  
  
  //-----------------------------------------------------------------------------
  // Intersects a ray against a box
  //-----------------------------------------------------------------------------
  bool IntersectRayWithBox( const Vector &vecRayStart, const Vector &vecRayDelta, 
  	const Vector &boxMins, const Vector &boxMaxs, float flTolerance, CBaseTrace *pTrace, float *pFractionLeftSolid )
  {
  	Collision_ClearTrace( vecRayStart, vecRayDelta, pTrace );
  
  	BoxTraceInfo_t trace;
  
  	if ( IntersectRayWithBox( vecRayStart, vecRayDelta, boxMins, boxMaxs, flTolerance, &trace ) )
  	{
  		pTrace->startsolid = trace.startsolid;
  		if (trace.t1 < trace.t2 && trace.t1 >= 0.0f)
  		{
  			pTrace->fraction = trace.t1;
  			VectorMA( pTrace->startpos, trace.t1, vecRayDelta, pTrace->endpos );
  			pTrace->contents = CONTENTS_SOLID;
  			pTrace->plane.normal = vec3_origin;
  			if ( trace.hitside >= 3 )
  			{
  				trace.hitside -= 3;
  				pTrace->plane.dist = boxMaxs[trace.hitside];
  				pTrace->plane.normal[trace.hitside] = 1.0f;
  				pTrace->plane.type = trace.hitside;
  			}
  			else
  			{
  				pTrace->plane.dist = -boxMins[trace.hitside];
  				pTrace->plane.normal[trace.hitside] = -1.0f;
  				pTrace->plane.type = trace.hitside;
  			}
  			return true;
  		}
  
  		if ( pTrace->startsolid )
  		{
  			pTrace->allsolid = (trace.t2 <= 0.0f) || (trace.t2 >= 1.0f);
  			pTrace->fraction = 0;
  			if ( pFractionLeftSolid )
  			{
  				*pFractionLeftSolid = trace.t2;
  			}
  			pTrace->endpos = pTrace->startpos;
  			pTrace->contents = CONTENTS_SOLID;
  			pTrace->plane.dist = pTrace->startpos[0];
  			pTrace->plane.normal.Init( 1.0f, 0.0f, 0.0f );
  			pTrace->plane.type = 0;
  			pTrace->startpos = vecRayStart + (trace.t2 * vecRayDelta);
  			return true;
  		}
  	}
  
  	return false;
  }
  
  
  //-----------------------------------------------------------------------------
  // Intersects a ray against a box
  //-----------------------------------------------------------------------------
  bool IntersectRayWithBox( const Ray_t &ray, const Vector &boxMins, const Vector &boxMaxs, 
  						 float flTolerance, CBaseTrace *pTrace, float *pFractionLeftSolid )
  {
  	if ( !ray.m_IsRay )
  	{
  		Vector vecExpandedMins = boxMins - ray.m_Extents;
  		Vector vecExpandedMaxs = boxMaxs + ray.m_Extents;
  		bool bIntersects = IntersectRayWithBox( ray.m_Start, ray.m_Delta, vecExpandedMins, vecExpandedMaxs, flTolerance, pTrace, pFractionLeftSolid );
  		pTrace->startpos += ray.m_StartOffset;
  		pTrace->endpos += ray.m_StartOffset;
  		return bIntersects;
  	}
  	return IntersectRayWithBox( ray.m_Start, ray.m_Delta, boxMins, boxMaxs, flTolerance, pTrace, pFractionLeftSolid );
  }
  
  
  //-----------------------------------------------------------------------------
  // Intersects a ray against an OBB, returns t1 and t2
  //-----------------------------------------------------------------------------
  bool IntersectRayWithOBB( const Vector &vecRayStart, const Vector &vecRayDelta, 
  	const matrix3x4_t &matOBBToWorld, const Vector &vecOBBMins, const Vector &vecOBBMaxs, 
  	float flTolerance, BoxTraceInfo_t *pTrace )
  {
  	// FIXME: Two transforms is pretty expensive. Should we optimize this?
  	Vector start, delta;
  	VectorITransform( vecRayStart, matOBBToWorld, start );
  	VectorIRotate( vecRayDelta, matOBBToWorld, delta );
  
  	return IntersectRayWithBox( start, delta, vecOBBMins, vecOBBMaxs, flTolerance, pTrace ); 
  }
  
  
  
  //-----------------------------------------------------------------------------
  // Intersects a ray against an OBB
  //-----------------------------------------------------------------------------
  bool IntersectRayWithOBB( const Vector &vecRayStart, const Vector &vecRayDelta, 
  	const matrix3x4_t &matOBBToWorld, const Vector &vecOBBMins, const Vector &vecOBBMaxs, 
  	float flTolerance, CBaseTrace *pTrace )
  {
  	Collision_ClearTrace( vecRayStart, vecRayDelta, pTrace );
  
  	// FIXME: Make it work with tolerance
  	Assert( flTolerance == 0.0f );
  
  	// OPTIMIZE: Store this in the box instead of computing it here
  	// compute center in local space
  	Vector vecBoxExtents = (vecOBBMins + vecOBBMaxs) * 0.5; 
  	Vector vecBoxCenter;
  
  	// transform to world space
  	VectorTransform( vecBoxExtents, matOBBToWorld, vecBoxCenter );
  
  	// calc extents from local center
  	vecBoxExtents = vecOBBMaxs - vecBoxExtents;
  
  	// OPTIMIZE: This is optimized for world space.  If the transform is fast enough, it may make more
  	// sense to just xform and call UTIL_ClipToBox() instead.  MEASURE THIS.
  
  	// save the extents of the ray along 
  	Vector extent, uextent;
  	Vector segmentCenter = vecRayStart + vecRayDelta - vecBoxCenter;
  
  	extent.Init();
  
  	// check box axes for separation
  	for ( int j = 0; j < 3; j++ )
  	{
  		extent[j] = vecRayDelta.x * matOBBToWorld[0][j] + vecRayDelta.y * matOBBToWorld[1][j] +	vecRayDelta.z * matOBBToWorld[2][j];
  		uextent[j] = fabsf(extent[j]);
  		float coord = segmentCenter.x * matOBBToWorld[0][j] + segmentCenter.y * matOBBToWorld[1][j] +	segmentCenter.z * matOBBToWorld[2][j];
  		coord = fabsf(coord);
  
  		if ( coord > (vecBoxExtents[j] + uextent[j]) )
  			return false;
  	}
  
  	// now check cross axes for separation
  	float tmp, cextent;
  	Vector cross = vecRayDelta.Cross( segmentCenter );
  	cextent = cross.x * matOBBToWorld[0][0] + cross.y * matOBBToWorld[1][0] + cross.z * matOBBToWorld[2][0];
  	cextent = fabsf(cextent);
  	tmp = vecBoxExtents[1]*uextent[2] + vecBoxExtents[2]*uextent[1];
  	if ( cextent > tmp )
  		return false;
  
  	cextent = cross.x * matOBBToWorld[0][1] + cross.y * matOBBToWorld[1][1] + cross.z * matOBBToWorld[2][1];
  	cextent = fabsf(cextent);
  	tmp = vecBoxExtents[0]*uextent[2] + vecBoxExtents[2]*uextent[0];
  	if ( cextent > tmp )
  		return false;
  
  	cextent = cross.x * matOBBToWorld[0][2] + cross.y * matOBBToWorld[1][2] + cross.z * matOBBToWorld[2][2];
  	cextent = fabsf(cextent);
  	tmp = vecBoxExtents[0]*uextent[1] + vecBoxExtents[1]*uextent[0];
  	if ( cextent > tmp )
  		return false;
  
  	// !!! We hit this box !!! compute intersection point and return
  	// Compute ray start in bone space
  	Vector start;
  	VectorITransform( vecRayStart, matOBBToWorld, start );
  
  	// extent is ray.m_Delta in bone space, recompute delta in bone space
  	extent *= 2.0f;
  
  	// delta was prescaled by the current t, so no need to see if this intersection
  	// is closer
  	trace_t boxTrace;
  	if ( !IntersectRayWithBox( start, extent, vecOBBMins, vecOBBMaxs, flTolerance, pTrace ) )
  		return false;
  
  	// Fix up the start/end pos and fraction
  	Vector vecTemp;
  	VectorTransform( pTrace->endpos, matOBBToWorld, vecTemp );
  	pTrace->endpos = vecTemp;
  
  	pTrace->startpos = vecRayStart;
  	pTrace->fraction *= 2.0f;
  
  	// Fix up the plane information
  	float flSign = pTrace->plane.normal[ pTrace->plane.type ];
  	pTrace->plane.normal[0] = flSign * matOBBToWorld[0][pTrace->plane.type];
  	pTrace->plane.normal[1] = flSign * matOBBToWorld[1][pTrace->plane.type];
  	pTrace->plane.normal[2] = flSign * matOBBToWorld[2][pTrace->plane.type];
  	pTrace->plane.dist = DotProduct( pTrace->endpos, pTrace->plane.normal );
  	pTrace->plane.type = 3;
  
  	return true;
  }
  
  
  //-----------------------------------------------------------------------------
  // Intersects a ray against an OBB
  //-----------------------------------------------------------------------------
  bool IntersectRayWithOBB( const Vector &vecRayOrigin, const Vector &vecRayDelta, 
  	const Vector &vecBoxOrigin, const QAngle &angBoxRotation,
  	const Vector &vecOBBMins, const Vector &vecOBBMaxs, float flTolerance, CBaseTrace *pTrace )
  {
  	if (angBoxRotation == vec3_angle)
  	{
  		Vector vecAbsMins, vecAbsMaxs;
  		VectorAdd( vecBoxOrigin, vecOBBMins, vecAbsMins );
  		VectorAdd( vecBoxOrigin, vecOBBMaxs, vecAbsMaxs );
  		return IntersectRayWithBox( vecRayOrigin, vecRayDelta, vecAbsMins, vecAbsMaxs, flTolerance, pTrace ); 
  	}
  
  	matrix3x4_t obbToWorld;
  	AngleMatrix( angBoxRotation, vecBoxOrigin, obbToWorld );
  	return IntersectRayWithOBB( vecRayOrigin, vecRayDelta, obbToWorld, vecOBBMins, vecOBBMaxs, flTolerance, pTrace );
  }
  
  
  //-----------------------------------------------------------------------------
  // Box support map
  //-----------------------------------------------------------------------------
  inline void ComputeSupportMap( const Vector &vecDirection, const Vector &vecBoxMins, 
  				const Vector &vecBoxMaxs, float pDist[2] )
  {
  	int nIndex = (vecDirection.x > 0.0f);
  	pDist[nIndex] = vecBoxMaxs.x * vecDirection.x;
  	pDist[1 - nIndex] = vecBoxMins.x * vecDirection.x;
  
  	nIndex = (vecDirection.y > 0.0f);
  	pDist[nIndex] += vecBoxMaxs.y * vecDirection.y;
  	pDist[1 - nIndex] += vecBoxMins.y * vecDirection.y;
  
  	nIndex = (vecDirection.z > 0.0f);
  	pDist[nIndex] += vecBoxMaxs.z * vecDirection.z;
  	pDist[1 - nIndex] += vecBoxMins.z * vecDirection.z;
  }
  
  inline void ComputeSupportMap( const Vector &vecDirection, int i1, int i2, 
  	const Vector &vecBoxMins, const Vector &vecBoxMaxs, float pDist[2] )
  {
  	int nIndex = (vecDirection[i1] > 0.0f);
  	pDist[nIndex] = vecBoxMaxs[i1] * vecDirection[i1];
  	pDist[1 - nIndex] = vecBoxMins[i1] * vecDirection[i1];
  
  	nIndex = (vecDirection[i2] > 0.0f);
  	pDist[nIndex] += vecBoxMaxs[i2] * vecDirection[i2];
  	pDist[1 - nIndex] += vecBoxMins[i2] * vecDirection[i2];
  }
  
  //-----------------------------------------------------------------------------
  // Intersects a ray against an OBB
  //-----------------------------------------------------------------------------
  static int s_ExtIndices[3][2] = 
  {
  	{ 2, 1 },
  	{ 0, 2 },
  	{ 0, 1 },
  };
  
  static int s_MatIndices[3][2] = 
  {
  	{ 1, 2 },
  	{ 2, 0 },
  	{ 1, 0 },
  };
  
  bool IntersectRayWithOBB( const Ray_t &ray, const matrix3x4_t &matOBBToWorld,
  	const Vector &vecOBBMins, const Vector &vecOBBMaxs, float flTolerance, CBaseTrace *pTrace )
  {
  	if ( ray.m_IsRay )
  	{
  		return IntersectRayWithOBB( ray.m_Start, ray.m_Delta, matOBBToWorld, 
  			vecOBBMins, vecOBBMaxs, flTolerance, pTrace );
  	}
  
  	Collision_ClearTrace( ray.m_Start + ray.m_StartOffset, ray.m_Delta, pTrace );
  
  	// Compute a bounding sphere around the bloated OBB
  	Vector vecOBBCenter;
  	VectorAdd( vecOBBMins, vecOBBMaxs, vecOBBCenter );
  	vecOBBCenter *= 0.5f;
  	vecOBBCenter.x += matOBBToWorld[0][3];
  	vecOBBCenter.y += matOBBToWorld[1][3];
  	vecOBBCenter.z += matOBBToWorld[2][3];
  
  	Vector vecOBBHalfDiagonal;
  	VectorSubtract( vecOBBMaxs, vecOBBMins, vecOBBHalfDiagonal );
  	vecOBBHalfDiagonal *= 0.5f;
  
  	float flRadius = vecOBBHalfDiagonal.Length() + ray.m_Extents.Length();
  	if ( !IsRayIntersectingSphere( ray.m_Start, ray.m_Delta, vecOBBCenter, flRadius, flTolerance ) )
  		return false;
  
  	// Ok, we passed the trivial reject, so lets do the dirty deed.
  	// Basically we're going to do the GJK thing explicitly. We'll shrink the ray down
  	// to a point, and bloat the OBB by the ray's extents. This will generate facet
  	// planes which are perpendicular to all of the separating axes typically seen in
  	// a standard seperating axis implementation.
  
  	// We're going to create a number of planes through various vertices in the OBB
  	// which represent all of the separating planes. Then we're going to bloat the planes
  	// by the ray extents.
  	
  	// We're going to do all work in OBB-space because it's easier to do the
  	// support-map in this case
  
  	// First, transform the ray into the space of the OBB
  	Vector vecLocalRayOrigin, vecLocalRayDirection;
  	VectorITransform( ray.m_Start, matOBBToWorld, vecLocalRayOrigin );
  	VectorIRotate( ray.m_Delta, matOBBToWorld, vecLocalRayDirection );
  
  	// Next compute all separating planes
  	Vector pPlaneNormal[15];
  	float ppPlaneDist[15][2];
  
  	int i;
  	for ( i = 0; i < 3; ++i )
  	{
  		// Each plane needs to be bloated an amount = to the abs dot product of 
  		// the ray extents with the plane normal
  		// For the OBB planes, do it in world space; 
  		// and use the direction of the OBB (the ith column of matOBBToWorld) in world space vs extents
  		pPlaneNormal[i].Init( );
  		pPlaneNormal[i][i] = 1.0f;
  
  		float flExtentDotNormal = 
  			FloatMakePositive( matOBBToWorld[0][i] * ray.m_Extents.x ) +
  			FloatMakePositive( matOBBToWorld[1][i] * ray.m_Extents.y ) +
  			FloatMakePositive( matOBBToWorld[2][i] * ray.m_Extents.z );
  
  		ppPlaneDist[i][0] = vecOBBMins[i] - flExtentDotNormal; 
  		ppPlaneDist[i][1] = vecOBBMaxs[i] + flExtentDotNormal;
  
  		// For the ray-extents planes, they are bloated by the extents
  		// Use the support map to determine which
  		VectorCopy( matOBBToWorld[i], pPlaneNormal[i+3].Base() ); 
  		ComputeSupportMap( pPlaneNormal[i+3], vecOBBMins, vecOBBMaxs, ppPlaneDist[i+3] );
  		ppPlaneDist[i+3][0] -= ray.m_Extents[i];
  		ppPlaneDist[i+3][1] += ray.m_Extents[i];
  
  		// Now the edge cases... (take the cross product of x,y,z axis w/ ray extent axes
  		// given by the rows of the obb to world matrix. 
  		// Compute the ray extent bloat in world space because it's easier...
  
  		// These are necessary to compute the world-space versions of
  		// the edges so we can compute the extent dot products
  		float flRayExtent0 = ray.m_Extents[s_ExtIndices[i][0]];
  		float flRayExtent1 = ray.m_Extents[s_ExtIndices[i][1]];
  		const float *pMatRow0 = matOBBToWorld[s_MatIndices[i][0]];
  		const float *pMatRow1 = matOBBToWorld[s_MatIndices[i][1]];
  
  		// x axis of the OBB + world ith axis
  		pPlaneNormal[i+6].Init( 0.0f, -matOBBToWorld[i][2], matOBBToWorld[i][1] );
  		ComputeSupportMap( pPlaneNormal[i+6], 1, 2, vecOBBMins, vecOBBMaxs, ppPlaneDist[i+6] );
  		flExtentDotNormal = 
  			FloatMakePositive( pMatRow0[0] ) * flRayExtent0 +
  			FloatMakePositive( pMatRow1[0] ) * flRayExtent1;
  		ppPlaneDist[i+6][0] -= flExtentDotNormal;
  		ppPlaneDist[i+6][1] += flExtentDotNormal;
  		
  		// y axis of the OBB + world ith axis
  		pPlaneNormal[i+9].Init( matOBBToWorld[i][2], 0.0f, -matOBBToWorld[i][0] );
  		ComputeSupportMap( pPlaneNormal[i+9], 0, 2, vecOBBMins, vecOBBMaxs, ppPlaneDist[i+9] );
  		flExtentDotNormal = 
  			FloatMakePositive( pMatRow0[1] ) * flRayExtent0 +
  			FloatMakePositive( pMatRow1[1] ) * flRayExtent1;
  		ppPlaneDist[i+9][0] -= flExtentDotNormal;
  		ppPlaneDist[i+9][1] += flExtentDotNormal;
  
  		// z axis of the OBB + world ith axis
  		pPlaneNormal[i+12].Init( -matOBBToWorld[i][1], matOBBToWorld[i][0], 0.0f );
  		ComputeSupportMap( pPlaneNormal[i+12], 0, 1, vecOBBMins, vecOBBMaxs, ppPlaneDist[i+12] );
  		flExtentDotNormal = 
  			FloatMakePositive( pMatRow0[2] ) * flRayExtent0 +
  			FloatMakePositive( pMatRow1[2] ) * flRayExtent1;
  		ppPlaneDist[i+12][0] -= flExtentDotNormal;
  		ppPlaneDist[i+12][1] += flExtentDotNormal;
  	}
  
  	float enterfrac, leavefrac;
  	float d1[2], d2[2];
  	float f;
  
  	int hitplane = -1;
  	int hitside = -1;
  	enterfrac = -1.0f;
  	leavefrac = 1.0f;
  
  	pTrace->startsolid = true;
  
  	Vector vecLocalRayEnd;
  	VectorAdd( vecLocalRayOrigin, vecLocalRayDirection, vecLocalRayEnd );
  
  	for ( i = 0; i < 15; ++i )
  	{
  		// FIXME: Not particularly optimal since there's a lot of 0's in the plane normals
  		float flStartDot = DotProduct( pPlaneNormal[i], vecLocalRayOrigin );
  		float flEndDot = DotProduct( pPlaneNormal[i], vecLocalRayEnd );
  
  		// NOTE: Negative here is because the plane normal + dist 
  		// are defined in negative terms for the far plane (plane dist index 0)
  		d1[0] = -(flStartDot - ppPlaneDist[i][0]);
  		d2[0] = -(flEndDot - ppPlaneDist[i][0]);
  
  		d1[1] = flStartDot - ppPlaneDist[i][1];
  		d2[1] = flEndDot - ppPlaneDist[i][1];
  
  		int j;
  		for ( j = 0; j < 2; ++j )
  		{
  			// if completely in front near plane or behind far plane no intersection
  			if (d1[j] > 0 && d2[j] > 0)
  				return false;
  
  			// completely inside, check next plane set
  			if (d1[j] <= 0 && d2[j] <= 0)
  				continue;
  
  			if (d1[j] > 0)
  			{
  				pTrace->startsolid = false;
  			}
  
  			// crosses face
  			float flDenom = 1.0f / (d1[j] - d2[j]);
  			if (d1[j] > d2[j])
  			{
  				f = d1[j] - flTolerance;
  				if ( f < 0 )
  				{
  					f = 0;
  				}
  				f *= flDenom;
  				if (f > enterfrac)
  				{
  					enterfrac = f;
  					hitplane = i;
  					hitside = j;
  				}
  			}
  			else
  			{ 
  				// leave
  				f = (d1[j] + flTolerance) * flDenom;
  				if (f < leavefrac)
  				{
  					leavefrac = f;
  				}
  			}
  		}
  	}
  
  	if (enterfrac < leavefrac && enterfrac >= 0.0f)
  	{
  		pTrace->fraction = enterfrac;
  		VectorMA( pTrace->startpos, enterfrac, ray.m_Delta, pTrace->endpos );
  		pTrace->contents = CONTENTS_SOLID;
  
  		// Need to transform the plane into world space...
  		cplane_t temp;
  		temp.normal = pPlaneNormal[hitplane];
  		temp.dist = ppPlaneDist[hitplane][hitside];
  		if (hitside == 0)
  		{
  			temp.normal *= -1.0f;
  			temp.dist *= -1.0f;
  		}
  		temp.type = 3;
  
  		MatrixITransformPlane( matOBBToWorld, temp, pTrace->plane );
  		return true;
  	}
  
  	if ( pTrace->startsolid )
  	{
  		pTrace->allsolid = (leavefrac <= 0.0f) || (leavefrac >= 1.0f);
  		pTrace->fraction = 0;
  		pTrace->endpos = pTrace->startpos;
  		pTrace->contents = CONTENTS_SOLID;
  		pTrace->plane.dist = pTrace->startpos[0];
  		pTrace->plane.normal.Init( 1.0f, 0.0f, 0.0f );
  		pTrace->plane.type = 0;
  		return true;
  	}
  
  	return false;
  }
  
  
  //-----------------------------------------------------------------------------
  // Intersects a ray against an OBB
  //-----------------------------------------------------------------------------
  bool IntersectRayWithOBB( const Ray_t &ray, const Vector &vecBoxOrigin, const QAngle &angBoxRotation,
  	const Vector &vecOBBMins, const Vector &vecOBBMaxs, float flTolerance, CBaseTrace *pTrace )
  {
  	if ( angBoxRotation == vec3_angle )
  	{
  		Vector vecWorldMins, vecWorldMaxs;
  		VectorAdd( vecBoxOrigin, vecOBBMins, vecWorldMins );
  		VectorAdd( vecBoxOrigin, vecOBBMaxs, vecWorldMaxs );
  		return IntersectRayWithBox( ray, vecWorldMins, vecWorldMaxs, flTolerance, pTrace );
  	}
  
  	if ( ray.m_IsRay )
  	{
  		return IntersectRayWithOBB( ray.m_Start, ray.m_Delta, vecBoxOrigin, angBoxRotation, vecOBBMins, vecOBBMaxs, flTolerance, pTrace );
  	}
  
  	matrix3x4_t matOBBToWorld;
  	AngleMatrix( angBoxRotation, vecBoxOrigin, matOBBToWorld );
  	return IntersectRayWithOBB( ray, matOBBToWorld, vecOBBMins, vecOBBMaxs, flTolerance, pTrace );
  }
  
  	
  //-----------------------------------------------------------------------------
  //
  //-----------------------------------------------------------------------------
  void GetNonMajorAxes( const Vector &vNormal, Vector2D &axes )
  {
  	axes[0] = 0;
  	axes[1] = 1;
  
  	if( FloatMakePositive( vNormal.x ) > FloatMakePositive( vNormal.y ) )
  	{
  		if( FloatMakePositive( vNormal.x ) > FloatMakePositive( vNormal.z ) )
  		{
  			axes[0] = 1;
  			axes[1] = 2;
  		}
  	}
  	else
  	{
  		if( FloatMakePositive( vNormal.y ) > FloatMakePositive( vNormal.z ) )
  		{
  			axes[0] = 0;
  			axes[1] = 2;
  		}
  	}
  }
  
  
  //-----------------------------------------------------------------------------
  //-----------------------------------------------------------------------------
  QuadBarycentricRetval_t QuadWithParallelEdges( const Vector &vecOrigin, 
  	const Vector &vecU, float lengthU, const Vector &vecV, float lengthV,
  	const Vector &pt, Vector2D &vecUV )
  {
  	Ray_t rayAxis;
  	Ray_t rayPt;
  
  	//
  	// handle the u axis
  	//
  	rayAxis.m_Start = vecOrigin;
  	rayAxis.m_Delta = vecU;
  	rayAxis.m_IsRay = true;
  
  	rayPt.m_Start = pt;
  	rayPt.m_Delta = vecV * -( lengthV * 10.0f );
  	rayPt.m_IsRay = true;
  
  	float s, t;
  	IntersectRayWithRay( rayAxis, rayPt, t, s );
  	vecUV[0] = t / lengthU;
  
  	//
  	// handle the v axis
  	//
  	rayAxis.m_Delta = vecV;
  
  	rayPt.m_Delta = vecU * -( lengthU * 10.0f );
  
  	IntersectRayWithRay( rayAxis, rayPt, t, s );
  	vecUV[1] = t / lengthV;
  
  	// inside of the quad??
  	if( ( vecUV[0] < 0.0f ) || ( vecUV[0] > 1.0f ) || 
  		( vecUV[1] < 0.0f ) || ( vecUV[1] > 1.0f ) )
  		return BARY_QUADRATIC_FALSE;
  
  	return BARY_QUADRATIC_TRUE;
  }
  
  
  //-----------------------------------------------------------------------------
  //-----------------------------------------------------------------------------
  void ResolveQuadratic( double tPlus, double tMinus, 
  					   const Vector axisU0, const Vector axisU1,
  					   const Vector axisV0, const Vector axisV1,
  					   const Vector axisOrigin, const Vector pt,
  					   int projU, double &s, double &t )
  {
  	// calculate the sPlus, sMinus pair(s)
  	double sDenomPlus = ( axisU0[projU] * ( 1 - tPlus ) ) + ( axisU1[projU] * tPlus );
  	double sDenomMinus = ( axisU0[projU] * ( 1 - tMinus ) ) + ( axisU1[projU] * tMinus );
  
  	double sPlus = UNINIT, sMinus = UNINIT;
  	if( FloatMakePositive( sDenomPlus ) >= 1e-5 )
  	{
  		sPlus = ( pt[projU] - axisOrigin[projU] - ( axisV0[projU] * tPlus ) ) / sDenomPlus; 
  	}
  
  	if( FloatMakePositive( sDenomMinus ) >= 1e-5 )
  	{
  		sMinus = ( pt[projU] - axisOrigin[projU] - ( axisV0[projU] * tMinus ) ) / sDenomMinus; 
  	}
  	
  	if( ( tPlus >= 0.0 ) && ( tPlus <= 1.0 ) && ( sPlus >= 0.0 ) && ( sPlus <= 1.0 ) )
  	{
  		s = sPlus;
  		t = tPlus;
  		return;
  	}
  
  	if( ( tMinus >= 0.0 ) && ( tMinus <= 1.0 ) && ( sMinus >= 0.0 ) && ( sMinus <= 1.0 ) )
  	{
  		s = sMinus;
  		t = tMinus;
  		return;
  	}
  
  	double s0, t0, s1, t1;
  
  	s0 = sPlus;
  	t0 = tPlus;
  	if( s0 >= 1.0 ) { s0 -= 1.0; }
  	if( t0 >= 1.0 ) { t0 -= 1.0; }
  
  	s1 = sMinus;
  	t1 = tMinus;
  	if( s1 >= 1.0 ) { s1 -= 1.0; }
  	if( t1 >= 1.0 ) { t1 -= 1.0; }
  
  	s0 = FloatMakePositive( s0 );
  	t0 = FloatMakePositive( t0 );
  	s1 = FloatMakePositive( s1 );
  	t1 = FloatMakePositive( t1 );
  
  	double max0, max1;
  	max0 = s0;
  	if( t0 > max0 ) { max0 = t0; }
  	max1 = s1;
  	if( t1 > max1 ) { max1 = t1; }
  
  	if( max0 > max1 )
  	{
  		s = sMinus;
  		t = tMinus;
  	}
  	else
  	{
  		s = sPlus;
  		t = tPlus;
  	}
  }
  
  
  //-----------------------------------------------------------------------------
  //
  //-----------------------------------------------------------------------------
  
  QuadBarycentricRetval_t PointInQuadToBarycentric( const Vector &v1, const Vector &v2, 
  	const Vector &v3, const Vector &v4, const Vector &point, Vector2D &uv )
  {
  #define PIQ_TEXTURE_EPSILON		0.001
  #define PIQ_PLANE_EPSILON		0.1
  #define PIQ_DOT_EPSILON			0.99f
  
  	//
  	// Think of a quad with points v1, v2, v3, v4 and u, v line segments
  	// u0 = v2 - v1
  	// u1 = v3 - v4
  	// v0 = v4 - v1
  	// v1 = v3 - v2
  	//
  	Vector axisU[2], axisV[2];
  	Vector axisUNorm[2], axisVNorm[2];
  	axisU[0] = axisUNorm[0] = v2 - v1;
  	axisU[1] = axisUNorm[1] = v3 - v4;
  	axisV[0] = axisVNorm[0] = v4 - v1;
  	axisV[1] = axisVNorm[1] = v3 - v2;
  
  	float lengthU[2], lengthV[2];
  	lengthU[0] = VectorNormalize( axisUNorm[0] );
  	lengthU[1] = VectorNormalize( axisUNorm[1] );
  	lengthV[0] = VectorNormalize( axisVNorm[0] );
  	lengthV[1] = VectorNormalize( axisVNorm[1] );
  
  	//
  	// check for an early out - parallel opposite edges!
  	// NOTE: quad property if 1 set of opposite edges is parallel and equal
  	//       in length, then the other set of edges is as well
  	//
  	if( axisUNorm[0].Dot( axisUNorm[1] ) > PIQ_DOT_EPSILON )
  	{
  		if( FloatMakePositive( lengthU[0] - lengthU[1] ) < PIQ_PLANE_EPSILON )
  		{
  			return QuadWithParallelEdges( v1, axisUNorm[0], lengthU[0], axisVNorm[0], lengthV[0], point, uv );
  		}
  	}
  
  	//
  	// since we are solving for s in our equations below we need to ensure that
  	// the v axes are non-parallel
  	//
  	bool bFlipped = false;
  	if( axisVNorm[0].Dot( axisVNorm[1] ) > PIQ_DOT_EPSILON )
  	{
  		Vector tmp[2];
  		tmp[0] = axisV[0];
  		tmp[1] = axisV[1];
  		axisV[0] = axisU[0];
  		axisV[1] = axisU[1];
  		axisU[0] = tmp[0];
  		axisU[1] = tmp[1];
  		bFlipped = true;
  	}
  
  	//
  	// get the "projection" axes
  	//
  	Vector2D projAxes;
  	Vector vNormal = axisU[0].Cross( axisV[0] );
  	GetNonMajorAxes( vNormal, projAxes );
  
  	//
  	// NOTE: axisU[0][projAxes[0]] < axisU[0][projAxes[1]], 
  	//       this is done to decrease error when dividing later
  	//
  	if( FloatMakePositive( axisU[0][projAxes[0]] ) < FloatMakePositive( axisU[0][projAxes[1]] ) )
  	{
  		int tmp = projAxes[0];
  		projAxes[0] = projAxes[1];
  		projAxes[1] = tmp;
  	}
  
  	// Here's how we got these equations:
  	//
  	// Given the points and u,v line segments above...
  	//
  	// Then:
  	//
  	// (1.0) PT = P0 + U0 * s + V * t
  	//
  	// where
  	//
  	// (1.1) V = V0 + s * (V1 - V0)
  	// (1.2) U = U0 + t * (U1 - U0)
  	// 
  	// Therefore (from 1.1 + 1.0):
  	// PT - P0 = U0 * s + (V0 + s * (V1-V0)) * t
  	// Group s's:
  	// PT - P0 - t * V0 = s * (U0 + t * (V1-V0))
  	// Two equations and two unknowns in x and y get you the following quadratic:
  	//
  	// solve the quadratic
  	//
  	double s = 0.0, t = 0.0;
  	double A, negB, C;
  
  	A = ( axisU[0][projAxes[1]] * axisV[0][projAxes[0]] ) - 
  		( axisU[0][projAxes[0]] * axisV[0][projAxes[1]] ) - 
  		( axisU[1][projAxes[1]] * axisV[0][projAxes[0]] ) + 
  		( axisU[1][projAxes[0]] * axisV[0][projAxes[1]] );
  	C = ( v1[projAxes[1]] * axisU[0][projAxes[0]] ) - 
  		( point[projAxes[1]] * axisU[0][projAxes[0]] ) - 
  		( v1[projAxes[0]] * axisU[0][projAxes[1]] ) + 
  		( point[projAxes[0]] * axisU[0][projAxes[1]] );
  	negB = C - 
  		  ( v1[projAxes[1]] * axisU[1][projAxes[0]] ) + 
  		  ( point[projAxes[1]] * axisU[1][projAxes[0]] ) + 
  		  ( v1[projAxes[0]] * axisU[1][projAxes[1]] ) - 
  		  ( point[projAxes[0]] * axisU[1][projAxes[1]] ) + 
  		  ( axisU[0][projAxes[1]] * axisV[0][projAxes[0]] ) - 
  		  ( axisU[0][projAxes[0]] * axisV[0][projAxes[1]] );
  
  	if( ( A > -PIQ_PLANE_EPSILON ) && ( A < PIQ_PLANE_EPSILON ) )
  	{
  		// shouldn't be here -- this should have been take care of in the "early out"
  //		Assert( 0 );
  
  		Vector vecUAvg, vecVAvg;
  		vecUAvg = ( axisUNorm[0] + axisUNorm[1] ) * 0.5f;
  		vecVAvg = ( axisVNorm[0] + axisVNorm[1] ) * 0.5f;
  		
  		float fLengthUAvg = ( lengthU[0] + lengthU[1] ) * 0.5f;
  		float fLengthVAvg = ( lengthV[0] + lengthV[1] ) * 0.5f;
  
  		return QuadWithParallelEdges( v1, vecUAvg, fLengthUAvg, vecVAvg, fLengthVAvg, point, uv );
  
  #if 0
  		// legacy code -- kept here for completeness!
  
  		// not a quadratic -- solve linearly
  		t = C / negB;
  
  		// See (1.2) above
  		float ui = axisU[0][projAxes[0]] + t * ( axisU[1][projAxes[0]] - axisU[0][projAxes[0]] );
  		if( FloatMakePositive( ui ) >= 1e-5 )
  		{
  			// See (1.0) above
  			s = ( point[projAxes[0]] - v1[projAxes[0]] - axisV[0][projAxes[0]] * t ) / ui;
  		}
  #endif
  	}
  	else
  	{
  		// (-b +/- sqrt( b^2 - 4ac )) / 2a
  		double discriminant = (negB*negB) - (4.0f * A * C);
  		if( discriminant < 0.0f )
  		{
  			uv[0] = -99999.0f;
  			uv[1] = -99999.0f;
  			return BARY_QUADRATIC_NEGATIVE_DISCRIMINANT;
  		}
  
  		double quad = sqrt( discriminant );
  		double QPlus = ( negB + quad ) / ( 2.0f * A );
  		double QMinus = ( negB - quad ) / ( 2.0f * A );
  
  		ResolveQuadratic( QPlus, QMinus, axisU[0], axisU[1], axisV[0], axisV[1], v1, point, projAxes[0], s, t );
  	}
  
  	if( !bFlipped )
  	{
  		uv[0] = ( float )s;
  		uv[1] = ( float )t;
  	}
  	else
  	{
  		uv[0] = ( float )t;
  		uv[1] = ( float )s;
  	}
  
  	// inside of the quad??
  	if( ( uv[0] < 0.0f ) || ( uv[0] > 1.0f ) || ( uv[1] < 0.0f ) || ( uv[1] > 1.0f ) )
  		return BARY_QUADRATIC_FALSE;
  	
  	return BARY_QUADRATIC_TRUE;
  
  #undef PIQ_TEXTURE_EPSILON
  #undef PIQ_PLANE_EPSILON
  }
  
  
  //-----------------------------------------------------------------------------
  //-----------------------------------------------------------------------------
  void PointInQuadFromBarycentric( const Vector &v1, const Vector &v2, const Vector &v3, const Vector &v4,
  								 const Vector2D &uv, Vector &point )
  {
  	//
  	// Think of a quad with points v1, v2, v3, v4 and u, v line segments
  	// find the ray from v0 edge to v1 edge at v
  	//
  	Vector vPts[2];
  	VectorLerp( v1, v4, uv[1], vPts[0] );
  	VectorLerp( v2, v3, uv[1], vPts[1] );
  	VectorLerp( vPts[0], vPts[1], uv[0], point ); 
  }
  
  
  //-----------------------------------------------------------------------------
  //-----------------------------------------------------------------------------
  void TexCoordInQuadFromBarycentric( const Vector2D &v1, const Vector2D &v2, const Vector2D &v3, const Vector2D &v4,
  								    const Vector2D &uv, Vector2D &texCoord )
  {
  	//
  	// Think of a quad with points v1, v2, v3, v4 and u, v line segments
  	// find the ray from v0 edge to v1 edge at v
  	//
  	Vector2D vCoords[2];
  	Vector2DLerp( v1, v4, uv[1], vCoords[0] );
  	Vector2DLerp( v2, v3, uv[1], vCoords[1] );
  	Vector2DLerp( vCoords[0], vCoords[1], uv[0], texCoord ); 
  }
  
  
  //-----------------------------------------------------------------------------
  // Compute point from barycentric specification
  // Edge u goes from v0 to v1, edge v goes from v0 to v2
  //-----------------------------------------------------------------------------
  void ComputePointFromBarycentric( const Vector& v0, const Vector& v1, const Vector& v2, 
  								 float u, float v, Vector& pt )
  {
  	Vector edgeU, edgeV;
  	VectorSubtract( v1, v0, edgeU );
  	VectorSubtract( v2, v0, edgeV );
  	VectorMA( v0, u, edgeU, pt );
  	VectorMA( pt, v, edgeV, pt );
  }
  
  void ComputePointFromBarycentric( const Vector2D& v0, const Vector2D& v1, const Vector2D& v2, 
  								 float u, float v, Vector2D& pt )
  {
  	Vector2D edgeU, edgeV;
  	Vector2DSubtract( v1, v0, edgeU );
  	Vector2DSubtract( v2, v0, edgeV );
  	Vector2DMA( v0, u, edgeU, pt );
  	Vector2DMA( pt, v, edgeV, pt );
  }
  
  
  //-----------------------------------------------------------------------------
  // Compute a matrix that has the correct orientation but which has an origin at
  // the center of the bounds
  //-----------------------------------------------------------------------------
  static void ComputeCenterMatrix( const Vector& origin, const QAngle& angles, 
  	const Vector& mins, const Vector& maxs, matrix3x4_t& matrix )
  {
  	Vector centroid;
  	VectorAdd( mins, maxs, centroid );
  	centroid *= 0.5f;
  	AngleMatrix( angles, matrix );
  
  	Vector worldCentroid;
  	VectorRotate( centroid, matrix, worldCentroid );
  	worldCentroid += origin;
  	MatrixSetColumn( worldCentroid, 3, matrix );
  }
  
  static void ComputeCenterIMatrix( const Vector& origin, const QAngle& angles, 
  	const Vector& mins, const Vector& maxs, matrix3x4_t& matrix )
  {
  	Vector centroid;
  	VectorAdd( mins, maxs, centroid );
  	centroid *= -0.5f;
  	AngleIMatrix( angles, matrix );
  
  	// For the translational component here, note that the origin in world space
  	// is T = R * C + O, (R = rotation matrix, C = centroid in local space, O = origin in world space)
  	// The IMatrix translation = - transpose(R) * T = -C - transpose(R) * 0
  	Vector localOrigin;
  	VectorRotate( origin, matrix, localOrigin );
  	centroid -= localOrigin;
  	MatrixSetColumn( centroid, 3, matrix );
  }
  
  
  //-----------------------------------------------------------------------------
  // Compute a matrix which is the absolute value of another
  //-----------------------------------------------------------------------------
  static inline void ComputeAbsMatrix( const matrix3x4_t& in, matrix3x4_t& out )
  {
  	FloatBits(out[0][0]) = FloatAbsBits(in[0][0]);
  	FloatBits(out[0][1]) = FloatAbsBits(in[0][1]);
  	FloatBits(out[0][2]) = FloatAbsBits(in[0][2]);
  	FloatBits(out[1][0]) = FloatAbsBits(in[1][0]);
  	FloatBits(out[1][1]) = FloatAbsBits(in[1][1]);
  	FloatBits(out[1][2]) = FloatAbsBits(in[1][2]);
  	FloatBits(out[2][0]) = FloatAbsBits(in[2][0]);
  	FloatBits(out[2][1]) = FloatAbsBits(in[2][1]);
  	FloatBits(out[2][2]) = FloatAbsBits(in[2][2]);
  }
  
  
  //-----------------------------------------------------------------------------
  // Compute a separating plane between two boxes (expensive!)
  // Returns false if no separating plane exists
  //-----------------------------------------------------------------------------
  static bool ComputeSeparatingPlane( const matrix3x4_t &worldToBox1, const matrix3x4_t &box2ToWorld, 
  	const Vector& box1Size, const Vector& box2Size, float tolerance, cplane_t* pPlane )
  {
  	// The various separating planes can be either
  	// 1) A plane parallel to one of the box face planes
  	// 2) A plane parallel to the cross-product of an edge from each box
  
  	// First, compute the basis of second box in the space of the first box
  	// NOTE: These basis place the origin at the centroid of each box!
  	matrix3x4_t	box2ToBox1;
  	ConcatTransforms( worldToBox1, box2ToWorld, box2ToBox1 );
  
  	// We're going to be using the origin of box2 in the space of box1 alot,
  	// lets extract it from the matrix....
  	Vector box2Origin;
  	MatrixGetColumn( box2ToBox1, 3, box2Origin );
  
  	// Next get the absolute values of these entries and store in absbox2ToBox1.
  	matrix3x4_t absBox2ToBox1;
  	ComputeAbsMatrix( box2ToBox1, absBox2ToBox1 );
  
  	// There are 15 tests to make.  The first 3 involve trying planes parallel
  	// to the faces of the first box.
  
  	// NOTE: The algorithm here involves finding the projections of the two boxes
  	// onto a particular line. If the projections on the line do not overlap,
  	// that means that there's a plane perpendicular to the line which separates 
  	// the two boxes; and we've therefore found a separating plane.
  
  	// The way we check for overlay is we find the projections of the two boxes
  	// onto the line, and add them up. We compare the sum with the projection
  	// of the relative center of box2 onto the same line.
  
  	Vector tmp;
  	float boxProjectionSum;
  	float originProjection;
  	
  	// NOTE: For these guys, we're taking advantage of the fact that the ith
  	// row of the box2ToBox1 is the direction of the box1 (x,y,z)-axis
  	// transformed into the space of box2.
  
  	// First side of box 1
  	boxProjectionSum = box1Size.x + MatrixRowDotProduct( absBox2ToBox1, 0, box2Size );
  	originProjection = FloatMakePositive( box2Origin.x ) + tolerance;
  	if ( FloatBits(originProjection) > FloatBits(boxProjectionSum) )
  	{
  		VectorCopy( worldToBox1[0], pPlane->normal.Base() );
  		return true;
  	}
  	
  	// Second side of box 1
  	boxProjectionSum = box1Size.y + MatrixRowDotProduct( absBox2ToBox1, 1, box2Size );
  	originProjection = FloatMakePositive( box2Origin.y ) + tolerance;
  	if ( FloatBits(originProjection) > FloatBits(boxProjectionSum) )
  	{
  		VectorCopy( worldToBox1[1], pPlane->normal.Base() );
  		return true;
  	}
  	
  	// Third side of box 1
  	boxProjectionSum = box1Size.z + MatrixRowDotProduct( absBox2ToBox1, 2, box2Size );
  	originProjection = FloatMakePositive( box2Origin.z ) + tolerance;
  	if ( FloatBits(originProjection) > FloatBits(boxProjectionSum) )
  	{
  		VectorCopy( worldToBox1[2], pPlane->normal.Base() );
  		return true;
  	}
  	
  	// The next three involve checking splitting planes parallel to the
  	// faces of the second box.
  
  	// NOTE: For these guys, we're taking advantage of the fact that the 0th
  	// column of the box2ToBox1 is the direction of the box2 x-axis
  	// transformed into the space of box1.
  	// Here, we're determining the distance of box2's center from box1's center
  	// by projecting it onto a line parallel to box2's axis
  	
  	// First side of box 2
  	boxProjectionSum = box2Size.x +	MatrixColumnDotProduct( absBox2ToBox1, 0, box1Size );
  	originProjection = FloatMakePositive( MatrixColumnDotProduct( box2ToBox1, 0, box2Origin ) ) + tolerance;
  	if ( FloatBits(originProjection) > FloatBits(boxProjectionSum) )
  	{
  		MatrixGetColumn( box2ToWorld, 0, pPlane->normal );	
  		return true;
  	}
  	
  	// Second side of box 2
  	boxProjectionSum = box2Size.y +	MatrixColumnDotProduct( absBox2ToBox1, 1, box1Size );
  	originProjection = FloatMakePositive( MatrixColumnDotProduct( box2ToBox1, 1, box2Origin ) ) + tolerance;
  	if ( FloatBits(originProjection) > FloatBits(boxProjectionSum) )
  	{
  		MatrixGetColumn( box2ToWorld, 1, pPlane->normal );	
  		return true;
  	}
  	
  	// Third side of box 2
  	boxProjectionSum = box2Size.z +	MatrixColumnDotProduct( absBox2ToBox1, 2, box1Size );
  	originProjection = FloatMakePositive( MatrixColumnDotProduct( box2ToBox1, 2, box2Origin ) ) + tolerance;
  	if ( FloatBits(originProjection) > FloatBits(boxProjectionSum) )
  	{
  		MatrixGetColumn( box2ToWorld, 2, pPlane->normal );	
  		return true;
  	}
  	
  	// Next check the splitting planes which are orthogonal to the pairs
  	// of edges, one from box1 and one from box2.  As only direction matters,
  	// there are 9 pairs since each box has 3 distinct edge directions.
  	
  	// Here, we take advantage of the fact that the edges from box 1 are all
  	// axis aligned; therefore the crossproducts are simplified. Let's walk through
  	// the example of b1e1 x b2e1:
  
  	// In this example, the line to check is perpendicular to b1e1 + b2e2
  	// we can compute this line by taking the cross-product:
  	//
  	// [  i  j  k ]
  	// [  1  0  0 ] = - ez j + ey k = l1
  	// [ ex ey ez ]
  
  	// Where ex, ey, ez is the components of box2's x axis in the space of box 1,
  	// which is == to the 0th column of of box2toBox1
  
  	// The projection of box1 onto this line = the absolute dot product of the box size
  	// against the line, which =
  	// AbsDot( box1Size, l1 ) = abs( -ez * box1.y ) + abs( ey * box1.z )
  
  	// To compute the projection of box2 onto this line, we'll do it in the space of box 2
  	//
  	// [  i  j  k ]
  	// [ fx fy fz ] = fz j - fy k = l2
  	// [  1  0  0 ]
  
  	// Where fx, fy, fz is the components of box1's x axis in the space of box 2,
  	// which is == to the 0th row of of box2toBox1
  
  	// The projection of box2 onto this line = the absolute dot product of the box size
  	// against the line, which =
  	// AbsDot( box2Size, l2 ) = abs( fz * box2.y ) + abs ( fy * box2.z )
  
  	// The projection of the relative origin position on this line is done in the 
  	// space of box 1:
  	//
  	// originProjection = DotProduct( <-ez j + ey k>, box2Origin ) =
  	//		-ez * box2Origin.y + ey * box2Origin.z
  
  	// NOTE: These checks can be bogus if both edges are parallel. The if
  	// checks at the beginning of each block are designed to catch that case
  	
  	// b1e1 x b2e1
  	if ( absBox2ToBox1[0][0] < 1.0f - 1e-3f )
  	{
  		boxProjectionSum =
  			box1Size.y * absBox2ToBox1[2][0] + box1Size.z * absBox2ToBox1[1][0] +
  			box2Size.y * absBox2ToBox1[0][2] + box2Size.z * absBox2ToBox1[0][1];
  		originProjection = FloatMakePositive( -box2Origin.y * box2ToBox1[2][0] + box2Origin.z * box2ToBox1[1][0] ) + tolerance;
  		if ( FloatBits(originProjection) > FloatBits(boxProjectionSum) )
  		{
  			MatrixGetColumn( box2ToWorld, 0, tmp );	
  			CrossProduct( worldToBox1[0], tmp.Base(), pPlane->normal.Base() ); 
  			return true;
  		}
  	}
  
  	// b1e1 x b2e2
  	if ( absBox2ToBox1[0][1] < 1.0f - 1e-3f )
  	{
  		boxProjectionSum =
  			box1Size.y * absBox2ToBox1[2][1] + box1Size.z * absBox2ToBox1[1][1] +
  			box2Size.x * absBox2ToBox1[0][2] + box2Size.z * absBox2ToBox1[0][0];
  		originProjection = FloatMakePositive( -box2Origin.y * box2ToBox1[2][1] + box2Origin.z * box2ToBox1[1][1] ) + tolerance;
  		if ( FloatBits(originProjection) > FloatBits(boxProjectionSum) )
  		{
  			MatrixGetColumn( box2ToWorld, 1, tmp );	
  			CrossProduct( worldToBox1[0], tmp.Base(), pPlane->normal.Base() ); 
  			return true;
  		}
  	}
  
  	// b1e1 x b2e3
  	if ( absBox2ToBox1[0][2] < 1.0f - 1e-3f )
  	{
  		boxProjectionSum =
  			box1Size.y * absBox2ToBox1[2][2] + box1Size.z * absBox2ToBox1[1][2] +
  			box2Size.x * absBox2ToBox1[0][1] + box2Size.y * absBox2ToBox1[0][0];
  		originProjection = FloatMakePositive( -box2Origin.y * box2ToBox1[2][2] + box2Origin.z * box2ToBox1[1][2] ) + tolerance;
  		if ( FloatBits(originProjection) > FloatBits(boxProjectionSum) )
  		{
  			MatrixGetColumn( box2ToWorld, 2, tmp );	
  			CrossProduct( worldToBox1[0], tmp.Base(), pPlane->normal.Base() ); 
  			return true;
  		}
  	}
  
  	// b1e2 x b2e1
  	if ( absBox2ToBox1[1][0] < 1.0f - 1e-3f )
  	{
  		boxProjectionSum =
  			box1Size.x * absBox2ToBox1[2][0] + box1Size.z * absBox2ToBox1[0][0] +
  			box2Size.y * absBox2ToBox1[1][2] + box2Size.z * absBox2ToBox1[1][1];
  		originProjection = FloatMakePositive( box2Origin.x * box2ToBox1[2][0] - box2Origin.z * box2ToBox1[0][0] ) + tolerance;
  		if ( FloatBits(originProjection) > FloatBits(boxProjectionSum) )
  		{
  			MatrixGetColumn( box2ToWorld, 0, tmp );	
  			CrossProduct( worldToBox1[1], tmp.Base(), pPlane->normal.Base() ); 
  			return true;
  		}
  	}
  
  	// b1e2 x b2e2
  	if ( absBox2ToBox1[1][1] < 1.0f - 1e-3f )
  	{
  		boxProjectionSum =
  			box1Size.x * absBox2ToBox1[2][1] + box1Size.z * absBox2ToBox1[0][1] +
  			box2Size.x * absBox2ToBox1[1][2] + box2Size.z * absBox2ToBox1[1][0];
  		originProjection = FloatMakePositive( box2Origin.x * box2ToBox1[2][1] - box2Origin.z * box2ToBox1[0][1] ) + tolerance;
  		if ( FloatBits(originProjection) > FloatBits(boxProjectionSum) )
  		{
  			MatrixGetColumn( box2ToWorld, 1, tmp );	
  			CrossProduct( worldToBox1[1], tmp.Base(), pPlane->normal.Base() ); 
  			return true;
  		}
  	}
  
  	// b1e2 x b2e3
  	if ( absBox2ToBox1[1][2] < 1.0f - 1e-3f )
  	{
  		boxProjectionSum =
  			box1Size.x * absBox2ToBox1[2][2] + box1Size.z * absBox2ToBox1[0][2] +
  			box2Size.x * absBox2ToBox1[1][1] + box2Size.y * absBox2ToBox1[1][0];
  		originProjection = FloatMakePositive( box2Origin.x * box2ToBox1[2][2] - box2Origin.z * box2ToBox1[0][2] ) + tolerance;
  		if ( FloatBits(originProjection) > FloatBits(boxProjectionSum) )
  		{
  			MatrixGetColumn( box2ToWorld, 2, tmp );	
  			CrossProduct( worldToBox1[1], tmp.Base(), pPlane->normal.Base() ); 
  			return true;
  		}
  	}
  
  	// b1e3 x b2e1
  	if ( absBox2ToBox1[2][0] < 1.0f - 1e-3f )
  	{
  		boxProjectionSum =
  			box1Size.x * absBox2ToBox1[1][0] + box1Size.y * absBox2ToBox1[0][0] +
  			box2Size.y * absBox2ToBox1[2][2] + box2Size.z * absBox2ToBox1[2][1];
  		originProjection = FloatMakePositive( -box2Origin.x * box2ToBox1[1][0] + box2Origin.y * box2ToBox1[0][0] ) + tolerance;
  		if ( FloatBits(originProjection) > FloatBits(boxProjectionSum) )
  		{
  			MatrixGetColumn( box2ToWorld, 0, tmp );	
  			CrossProduct( worldToBox1[2], tmp.Base(), pPlane->normal.Base() ); 
  			return true;
  		}
  	}
  
  	// b1e3 x b2e2
  	if ( absBox2ToBox1[2][1] < 1.0f - 1e-3f )
  	{
  		boxProjectionSum =
  			box1Size.x * absBox2ToBox1[1][1] + box1Size.y * absBox2ToBox1[0][1] +
  			box2Size.x * absBox2ToBox1[2][2] + box2Size.z * absBox2ToBox1[2][0];
  		originProjection = FloatMakePositive( -box2Origin.x * box2ToBox1[1][1] + box2Origin.y * box2ToBox1[0][1] ) + tolerance;
  		if ( FloatBits(originProjection) > FloatBits(boxProjectionSum) )
  		{
  			MatrixGetColumn( box2ToWorld, 1, tmp );	
  			CrossProduct( worldToBox1[2], tmp.Base(), pPlane->normal.Base() ); 
  			return true;
  		}
  	}
  
  	// b1e3 x b2e3
  	if ( absBox2ToBox1[2][2] < 1.0f - 1e-3f )
  	{
  		boxProjectionSum =
  			box1Size.x * absBox2ToBox1[1][2] + box1Size.y * absBox2ToBox1[0][2] +
  			box2Size.x * absBox2ToBox1[2][1] + box2Size.y * absBox2ToBox1[2][0];
  		originProjection = FloatMakePositive( -box2Origin.x * box2ToBox1[1][2] + box2Origin.y * box2ToBox1[0][2] ) + tolerance;
  		if ( FloatBits(originProjection) > FloatBits(boxProjectionSum) )
  		{
  			MatrixGetColumn( box2ToWorld, 2, tmp );	
  			CrossProduct( worldToBox1[2], tmp.Base(), pPlane->normal.Base() ); 
  			return true;
  		}
  	}
  	return false;
  }
  
  
  //-----------------------------------------------------------------------------
  // Compute a separating plane between two boxes (expensive!)
  // Returns false if no separating plane exists
  //-----------------------------------------------------------------------------
  bool ComputeSeparatingPlane( const Vector& org1, const QAngle& angles1, const Vector& min1, const Vector& max1, 
  	const Vector& org2, const QAngle& angles2, const Vector& min2, const Vector& max2, 
  	float tolerance, cplane_t* pPlane )
  {
  	matrix3x4_t	worldToBox1, box2ToWorld;
  	ComputeCenterIMatrix( org1, angles1, min1, max1, worldToBox1 );
  	ComputeCenterMatrix( org2, angles2, min2, max2, box2ToWorld );
  
  	// Then compute the size of the two boxes
  	Vector box1Size, box2Size;
  	VectorSubtract( max1, min1, box1Size );
  	VectorSubtract( max2, min2, box2Size );
  	box1Size *= 0.5f;
  	box2Size *= 0.5f;
  
  	return ComputeSeparatingPlane( worldToBox1, box2ToWorld, box1Size, box2Size, tolerance, pPlane );
  }
  
  
  //-----------------------------------------------------------------------------
  // Swept OBB test
  //-----------------------------------------------------------------------------
  bool IsRayIntersectingOBB( const Ray_t &ray, const Vector& org, const QAngle& angles, 
  						  const Vector& mins, const Vector& maxs )
  {
  	if ( angles == vec3_angle )
  	{
  		Vector vecWorldMins, vecWorldMaxs;
  		VectorAdd( org, mins, vecWorldMins );
  		VectorAdd( org, maxs, vecWorldMaxs );
  		return IsBoxIntersectingRay( vecWorldMins, vecWorldMaxs, ray ); 
  	}
  
  	if ( ray.m_IsRay )
  	{
  		matrix3x4_t worldToBox;
  		AngleIMatrix( angles, org, worldToBox );
  
  		Ray_t rotatedRay;
  		VectorTransform( ray.m_Start, worldToBox, rotatedRay.m_Start );
  		VectorRotate( ray.m_Delta, worldToBox, rotatedRay.m_Delta );
  		rotatedRay.m_StartOffset = vec3_origin;
  		rotatedRay.m_Extents = vec3_origin;
  		rotatedRay.m_IsRay = ray.m_IsRay;
  		rotatedRay.m_IsSwept = ray.m_IsSwept;
  
  		return IsBoxIntersectingRay( mins, maxs, rotatedRay ); 
  	}
  
  	if ( !ray.m_IsSwept )
  	{
  		cplane_t plane;
  		return ComputeSeparatingPlane( ray.m_Start, vec3_angle, -ray.m_Extents, ray.m_Extents,
  			org, angles, mins, maxs, 0.0f, &plane ) == false;
  	}
  
  	// NOTE: See the comments in ComputeSeparatingPlane to understand this math
  
  	// First, compute the basis of box in the space of the ray
  	// NOTE: These basis place the origin at the centroid of each box!
  	matrix3x4_t	worldToBox1, box2ToWorld;
  	ComputeCenterMatrix( org, angles, mins, maxs, box2ToWorld );
  
  	// Find the center + extents of an AABB surrounding the ray
  	Vector vecRayCenter;
  	VectorMA( ray.m_Start, 0.5, ray.m_Delta, vecRayCenter );
  	vecRayCenter *= -1.0f;
  	SetIdentityMatrix( worldToBox1 );
  	MatrixSetColumn( vecRayCenter, 3, worldToBox1 );
  
  	Vector box1Size;
  	box1Size.x = ray.m_Extents.x + FloatMakePositive( ray.m_Delta.x ) * 0.5f;
  	box1Size.y = ray.m_Extents.y + FloatMakePositive( ray.m_Delta.y ) * 0.5f;
  	box1Size.z = ray.m_Extents.z + FloatMakePositive( ray.m_Delta.z ) * 0.5f;
  
  	// Then compute the size of the box
  	Vector box2Size;
  	VectorSubtract( maxs, mins, box2Size );
  	box2Size *= 0.5f;
  
  	// Do an OBB test of the box with the AABB surrounding the ray
  	cplane_t plane;
  	if ( ComputeSeparatingPlane( worldToBox1, box2ToWorld, box1Size, box2Size, 0.0f, &plane ) )
  		return false;
  
  	// Now deal with the planes which are the cross products of the ray sweep direction vs box edges
  	Vector vecRayDirection = ray.m_Delta;
  	VectorNormalize( vecRayDirection );
  
  	// Need a vector between ray center vs box center measured in the space of the ray (world)
  	Vector vecCenterDelta;
  	vecCenterDelta.x = box2ToWorld[0][3] - ray.m_Start.x;
  	vecCenterDelta.y = box2ToWorld[1][3] - ray.m_Start.y;
  	vecCenterDelta.z = box2ToWorld[2][3] - ray.m_Start.z;
  
  	// Rotate the ray direction into the space of the OBB
  	Vector vecAbsRayDirBox2;
  	VectorIRotate( vecRayDirection, box2ToWorld, vecAbsRayDirBox2 );
  
  	// Make abs versions of the ray in world space + ray in box2 space
  	VectorAbs( vecAbsRayDirBox2, vecAbsRayDirBox2 );
  
  	// Now do the work for the planes which are perpendicular to the edges of the AABB
  	// and the sweep direction edges...
  
  	// In this example, the line to check is perpendicular to box edge x + ray delta
  	// we can compute this line by taking the cross-product:
  	//
  	// [  i  j  k ]
  	// [  1  0  0 ] = - dz j + dy k = l1
  	// [ dx dy dz ]
  
  	// Where dx, dy, dz is the ray delta (normalized)
  
  	// The projection of the box onto this line = the absolute dot product of the box size
  	// against the line, which =
  	// AbsDot( vecBoxHalfDiagonal, l1 ) = abs( -dz * vecBoxHalfDiagonal.y ) + abs( dy * vecBoxHalfDiagonal.z )
  
  	// Because the plane contains the sweep direction, the sweep will produce
  	// no extra projection onto the line normal to the plane. 
  	// Therefore all we need to do is project the ray extents onto this line also:
  	// AbsDot( ray.m_Extents, l1 ) = abs( -dz * ray.m_Extents.y ) + abs( dy * ray.m_Extents.z )
  
  	Vector vecPlaneNormal;
  
  	// box x x ray delta
  	CrossProduct( vecRayDirection, Vector( box2ToWorld[0][0], box2ToWorld[1][0], box2ToWorld[2][0] ), vecPlaneNormal );
  	float flCenterDeltaProjection = FloatMakePositive( DotProduct( vecPlaneNormal, vecCenterDelta ) );
  	float flBoxProjectionSum = 
  		vecAbsRayDirBox2.z * box2Size.y + vecAbsRayDirBox2.y * box2Size.z +
  		DotProductAbs( vecPlaneNormal, ray.m_Extents );
  	if ( FloatBits(flCenterDeltaProjection) > FloatBits(flBoxProjectionSum) )
  		return false;
  
  	// box y x ray delta
  	CrossProduct( vecRayDirection, Vector( box2ToWorld[0][1], box2ToWorld[1][1], box2ToWorld[2][1] ), vecPlaneNormal );
  	flCenterDeltaProjection = FloatMakePositive( DotProduct( vecPlaneNormal, vecCenterDelta ) );
  	flBoxProjectionSum = 
  		vecAbsRayDirBox2.z * box2Size.x + vecAbsRayDirBox2.x * box2Size.z +
  		DotProductAbs( vecPlaneNormal, ray.m_Extents );
  	if ( FloatBits(flCenterDeltaProjection) > FloatBits(flBoxProjectionSum) )
  		return false;
  
  	// box z x ray delta
  	CrossProduct( vecRayDirection, Vector( box2ToWorld[0][2], box2ToWorld[1][2], box2ToWorld[2][2] ), vecPlaneNormal );
  	flCenterDeltaProjection = FloatMakePositive( DotProduct( vecPlaneNormal, vecCenterDelta ) );
  	flBoxProjectionSum = 
  		vecAbsRayDirBox2.y * box2Size.x + vecAbsRayDirBox2.x * box2Size.y +
  		DotProductAbs( vecPlaneNormal, ray.m_Extents );
  	if ( FloatBits(flCenterDeltaProjection) > FloatBits(flBoxProjectionSum) )
  		return false;
  	
  	return true;
  }
  
  //--------------------------------------------------------------------------
  // Purpose:
  //
  // NOTE:
  //	triangle points are given in clockwise order (aabb-triangle test)
  //
  //    1				edge0 = 1 - 0
  //    | \           edge1 = 2 - 1
  //    |  \          edge2 = 0 - 2
  //    |   \			.
  //    |    \		.
  //    0-----2		.
  //
  //--------------------------------------------------------------------------
  
  //-----------------------------------------------------------------------------
  // Purpose: find the minima and maxima of the 3 given values
  //-----------------------------------------------------------------------------
  inline void FindMinMax( float v1, float v2, float v3, float &min, float &max )
  {
  	min = max = v1;
  	if ( v2 < min ) { min = v2; }
  	if ( v2 > max ) { max = v2; }
  	if ( v3 < min ) { min = v3; }
  	if ( v3 > max ) { max = v3; }
  }
  
  //-----------------------------------------------------------------------------
  // Purpose:
  //-----------------------------------------------------------------------------
  inline bool AxisTestEdgeCrossX2( float flEdgeZ, float flEdgeY, float flAbsEdgeZ, float flAbsEdgeY,
  							     const Vector &p1, const Vector &p3, const Vector &vecExtents,
  								 float flTolerance )
  {
  	// Cross Product( axialX(1,0,0) x edge ): x = 0.0f, y = edge.z, z = -edge.y
  	// Triangle Point Distances: dist(x) = normal.y * pt(x).y + normal.z * pt(x).z
  	float flDist1 = flEdgeZ * p1.y - flEdgeY * p1.z;
  	float flDist3 = flEdgeZ * p3.y - flEdgeY * p3.z;
  
  	// Extents are symmetric: dist = abs( normal.y ) * extents.y + abs( normal.z ) * extents.z
  	float flDistBox = flAbsEdgeZ * vecExtents.y + flAbsEdgeY * vecExtents.z;
  
  	// Either dist1, dist3 is the closest point to the box, determine which and test of overlap with box(AABB).
  	if ( flDist1 < flDist3 )
  	{
  		if ( ( flDist1 > ( flDistBox + flTolerance ) ) || ( flDist3 < -( flDistBox + flTolerance ) ) )
  			return false;
  	}
  	else
  	{
  		if ( ( flDist3 > ( flDistBox + flTolerance ) ) || ( flDist1 < -( flDistBox + flTolerance ) ) )
  			return false;
  	}
  
  	return true;
  }
  
  //--------------------------------------------------------------------------
  // Purpose:
  //--------------------------------------------------------------------------
  inline bool AxisTestEdgeCrossX3( float flEdgeZ, float flEdgeY, float flAbsEdgeZ, float flAbsEdgeY,
  								 const Vector &p1, const Vector &p2, const Vector &vecExtents,
  								 float flTolerance )
  {
  	// Cross Product( axialX(1,0,0) x edge ): x = 0.0f, y = edge.z, z = -edge.y 
  	// Triangle Point Distances: dist(x) = normal.y * pt(x).y + normal.z * pt(x).z
  	float flDist1 = flEdgeZ * p1.y - flEdgeY * p1.z;
  	float flDist2 = flEdgeZ * p2.y - flEdgeY * p2.z;
  
  	// Extents are symmetric: dist = abs( normal.y ) * extents.y + abs( normal.z ) * extents.z
  	float flDistBox = flAbsEdgeZ * vecExtents.y + flAbsEdgeY * vecExtents.z;
  
  	// Either dist1, dist2 is the closest point to the box, determine which and test of overlap with box(AABB).
  	if ( flDist1 < flDist2 )
  	{
  		if ( ( flDist1 > ( flDistBox + flTolerance ) ) || ( flDist2 < -( flDistBox + flTolerance ) ) )
  			return false;
  	}
  	else
  	{
  		if ( ( flDist2 > ( flDistBox + flTolerance ) ) || ( flDist1 < -( flDistBox + flTolerance ) ) )
  			return false;
  	}
  
  	return true;
  }
  
  //--------------------------------------------------------------------------
  //--------------------------------------------------------------------------
  inline bool AxisTestEdgeCrossY2( float flEdgeZ, float flEdgeX, float flAbsEdgeZ, float flAbsEdgeX,
  								 const Vector &p1, const Vector &p3, const Vector &vecExtents,
  								 float flTolerance )
  {
  	// Cross Product( axialY(0,1,0) x edge ): x = -edge.z, y = 0.0f, z = edge.x
  	// Triangle Point Distances: dist(x) = normal.x * pt(x).x + normal.z * pt(x).z
  	float flDist1 = -flEdgeZ * p1.x + flEdgeX * p1.z;
  	float flDist3 = -flEdgeZ * p3.x + flEdgeX * p3.z;
  
  	// Extents are symmetric: dist = abs( normal.x ) * extents.x + abs( normal.z ) * extents.z
  	float flDistBox = flAbsEdgeZ * vecExtents.x + flAbsEdgeX * vecExtents.z;
  
  	// Either dist1, dist3 is the closest point to the box, determine which and test of overlap with box(AABB).
  	if ( flDist1 < flDist3 )
  	{
  		if ( ( flDist1 > ( flDistBox + flTolerance ) ) || ( flDist3 < -( flDistBox + flTolerance ) ) )
  			return false;
  	}
  	else
  	{
  		if ( ( flDist3 > ( flDistBox + flTolerance ) ) || ( flDist1 < -( flDistBox + flTolerance ) ) )
  			return false;
  	}
  
  	return true;
  }
  
  //--------------------------------------------------------------------------
  //--------------------------------------------------------------------------
  inline bool AxisTestEdgeCrossY3( float flEdgeZ, float flEdgeX, float flAbsEdgeZ, float flAbsEdgeX,
  								 const Vector &p1, const Vector &p2, const Vector &vecExtents,
  								 float flTolerance )
  {
  	// Cross Product( axialY(0,1,0) x edge ): x = -edge.z, y = 0.0f, z = edge.x
  	// Triangle Point Distances: dist(x) = normal.x * pt(x).x + normal.z * pt(x).z
  	float flDist1 = -flEdgeZ * p1.x + flEdgeX * p1.z;
  	float flDist2 = -flEdgeZ * p2.x + flEdgeX * p2.z;
  
  	// Extents are symmetric: dist = abs( normal.x ) * extents.x + abs( normal.z ) * extents.z
  	float flDistBox = flAbsEdgeZ * vecExtents.x + flAbsEdgeX * vecExtents.z;
  
  	// Either dist1, dist2 is the closest point to the box, determine which and test of overlap with box(AABB).
  	if ( flDist1 < flDist2 )
  	{
  		if ( ( flDist1 > ( flDistBox + flTolerance ) ) || ( flDist2 < -( flDistBox + flTolerance ) ) )
  			return false;
  	}
  	else
  	{
  		if ( ( flDist2 > ( flDistBox + flTolerance ) ) || ( flDist1 < -( flDistBox + flTolerance ) ) )
  			return false;
  	}
  
  	return true;
  }
  
  //--------------------------------------------------------------------------
  //--------------------------------------------------------------------------
  inline bool AxisTestEdgeCrossZ1( float flEdgeY, float flEdgeX, float flAbsEdgeY, float flAbsEdgeX,
  								 const Vector &p2, const Vector &p3, const Vector &vecExtents,
  								 float flTolerance )
  {
  	// Cross Product( axialZ(0,0,1) x edge ): x = edge.y, y = -edge.x, z = 0.0f
  	// Triangle Point Distances: dist(x) = normal.x * pt(x).x + normal.y * pt(x).y
  	float flDist2 = flEdgeY * p2.x - flEdgeX * p2.y;
  	float flDist3 = flEdgeY * p3.x - flEdgeX * p3.y;
  
  	// Extents are symmetric: dist = abs( normal.x ) * extents.x + abs( normal.y ) * extents.y
  	float flDistBox = flAbsEdgeY * vecExtents.x + flAbsEdgeX * vecExtents.y; 
  
  	// Either dist2, dist3 is the closest point to the box, determine which and test of overlap with box(AABB).
  	if ( flDist3 < flDist2 )
  	{
  		if ( ( flDist3 > ( flDistBox + flTolerance ) ) || ( flDist2 < -( flDistBox + flTolerance ) ) ) 
  			return false;
  	}
  	else
  	{
  		if ( ( flDist2 > ( flDistBox + flTolerance ) ) || ( flDist3 < -( flDistBox + flTolerance ) ) )
  			return false;
  	}
  
  	return true;
  }
  
  //--------------------------------------------------------------------------
  //--------------------------------------------------------------------------
  inline bool AxisTestEdgeCrossZ2( float flEdgeY, float flEdgeX, float flAbsEdgeY, float flAbsEdgeX,
  								 const Vector &p1, const Vector &p3, const Vector &vecExtents,
  								 float flTolerance )
  {
  	// Cross Product( axialZ(0,0,1) x edge ): x = edge.y, y = -edge.x, z = 0.0f
  	// Triangle Point Distances: dist(x) = normal.x * pt(x).x + normal.y * pt(x).y
  	float flDist1 = flEdgeY * p1.x - flEdgeX * p1.y;
  	float flDist3 = flEdgeY * p3.x - flEdgeX * p3.y;
  
  	// Extents are symmetric: dist = abs( normal.x ) * extents.x + abs( normal.y ) * extents.y
  	float flDistBox = flAbsEdgeY * vecExtents.x + flAbsEdgeX * vecExtents.y; 
  
  	// Either dist1, dist3 is the closest point to the box, determine which and test of overlap with box(AABB).
  	if ( flDist1 < flDist3 )
  	{
  		if ( ( flDist1 > ( flDistBox + flTolerance ) ) || ( flDist3 < -( flDistBox + flTolerance ) ) ) 
  			return false;
  	}
  	else
  	{
  		if ( ( flDist3 > ( flDistBox + flTolerance ) ) || ( flDist1 < -( flDistBox + flTolerance ) ) )
  			return false;
  	}
  
  	return true;
  }
  
  //-----------------------------------------------------------------------------
  // Purpose: Test for an intersection (overlap) between an axial-aligned bounding 
  //          box (AABB) and a triangle.
  //
  // Using the "Separating-Axis Theorem" to test for intersections between
  // a triangle and an axial-aligned bounding box (AABB).
  // 1. 3 Axis Planes - x, y, z
  // 2. 9 Edge Planes Tests - the 3 edges of the triangle crossed with all 3 axial 
  //                          planes (x, y, z)
  // 3. 1 Face Plane - the triangle plane (cplane_t plane below)
  // Output: false = separating axis (no intersection)
  //         true = intersection
  //-----------------------------------------------------------------------------
  bool IsBoxIntersectingTriangle( const Vector &vecBoxCenter, const Vector &vecBoxExtents,
  						        const Vector &v1, const Vector &v2, const Vector &v3,
  						        const cplane_t &plane, float flTolerance )
  {
  	// Test the axial planes (x,y,z) against the min, max of the triangle.
  	float flMin, flMax;
  	Vector p1, p2, p3;
  
  	// x plane
  	p1.x = v1.x - vecBoxCenter.x;
  	p2.x = v2.x - vecBoxCenter.x;
  	p3.x = v3.x - vecBoxCenter.x;
  	FindMinMax( p1.x, p2.x, p3.x, flMin, flMax );
  	if ( ( flMin > ( vecBoxExtents.x + flTolerance ) ) || ( flMax < -( vecBoxExtents.x + flTolerance ) ) ) 
  		return false; 
  
  	// y plane
  	p1.y = v1.y - vecBoxCenter.y;
  	p2.y = v2.y - vecBoxCenter.y;
  	p3.y = v3.y - vecBoxCenter.y;
  	FindMinMax( p1.y, p2.y, p3.y, flMin, flMax );
  	if ( ( flMin > ( vecBoxExtents.y + flTolerance ) ) || ( flMax < -( vecBoxExtents.y + flTolerance ) ) ) 
  		return false; 
  
  	// z plane
  	p1.z = v1.z - vecBoxCenter.z;
  	p2.z = v2.z - vecBoxCenter.z;
  	p3.z = v3.z - vecBoxCenter.z;
  	FindMinMax( p1.z, p2.z, p3.z, flMin, flMax );
  	if ( ( flMin > ( vecBoxExtents.z + flTolerance ) ) || ( flMax < -( vecBoxExtents.z + flTolerance ) ) ) 
  		return false; 
  
  	// Test the 9 edge cases.
  	Vector vecEdge, vecAbsEdge;
  
  	// edge 0 (cross x,y,z)
  	vecEdge = p2 - p1;
  	vecAbsEdge.y = FloatMakePositive( vecEdge.y );
  	vecAbsEdge.z = FloatMakePositive( vecEdge.z );
  	if ( !AxisTestEdgeCrossX2( vecEdge.z, vecEdge.y, vecAbsEdge.z, vecAbsEdge.y, p1, p3, vecBoxExtents, flTolerance ) ) 
  		return false; 
  
  	vecAbsEdge.x = FloatMakePositive( vecEdge.x );
  	if ( !AxisTestEdgeCrossY2( vecEdge.z, vecEdge.x, vecAbsEdge.z, vecAbsEdge.x, p1, p3, vecBoxExtents, flTolerance ) ) 
  		return false; 
  
  	if ( !AxisTestEdgeCrossZ1( vecEdge.y, vecEdge.x, vecAbsEdge.y, vecAbsEdge.x, p2, p3, vecBoxExtents, flTolerance ) ) 
  		return false; 
  
  	// edge 1 (cross x,y,z)
  	vecEdge = p3 - p2;
  	vecAbsEdge.y = FloatMakePositive( vecEdge.y );
  	vecAbsEdge.z = FloatMakePositive( vecEdge.z );
  	if ( !AxisTestEdgeCrossX2( vecEdge.z, vecEdge.y, vecAbsEdge.z, vecAbsEdge.y, p1, p2, vecBoxExtents, flTolerance ) ) 
  		return false; 
  
  	vecAbsEdge.x = FloatMakePositive( vecEdge.x );
  	if ( !AxisTestEdgeCrossY2( vecEdge.z, vecEdge.x, vecAbsEdge.z, vecAbsEdge.x, p1, p2, vecBoxExtents, flTolerance ) ) 
  		return false; 
  
  	if ( !AxisTestEdgeCrossZ2( vecEdge.y, vecEdge.x, vecAbsEdge.y, vecAbsEdge.x, p1, p3, vecBoxExtents, flTolerance ) ) 
  		return false; 
  
  	// edge 2 (cross x,y,z)
  	vecEdge = p1 - p3;
  	vecAbsEdge.y = FloatMakePositive( vecEdge.y );
  	vecAbsEdge.z = FloatMakePositive( vecEdge.z );
  	if ( !AxisTestEdgeCrossX3( vecEdge.z, vecEdge.y, vecAbsEdge.z, vecAbsEdge.y, p1, p2, vecBoxExtents, flTolerance ) ) 
  		return false; 
  
  	vecAbsEdge.x = FloatMakePositive( vecEdge.x );
  	if ( !AxisTestEdgeCrossY3( vecEdge.z, vecEdge.x, vecAbsEdge.z, vecAbsEdge.x, p1, p2, vecBoxExtents, flTolerance ) ) 
  		return false; 
  
  	if ( !AxisTestEdgeCrossZ1( vecEdge.y, vecEdge.x, vecAbsEdge.y, vecAbsEdge.x, p2, p3, vecBoxExtents, flTolerance ) ) 
  		return false; 
  
  	// Test against the triangle face plane.
  	Vector vecMin, vecMax;
  	VectorSubtract( vecBoxCenter, vecBoxExtents, vecMin );
  	VectorAdd( vecBoxCenter, vecBoxExtents, vecMax );
  	if ( BoxOnPlaneSide( vecMin, vecMax, &plane ) != 3 ) 
  		return false; 
  
  	return true;
  }
  
  // NOTE: JAY: This is untested code based on Real-time Collision Detection by Ericson
  #if 0
  Vector CalcClosestPointOnTriangle( const Vector &P, const Vector &v0, const Vector &v1, const Vector &v2 )
  {
  	Vector e0 = v1 - v0;
  	Vector e1 = v2 - v0;
  	Vector p0 = P - v0;
  
  	// voronoi region of v0
  	float d1 = DotProduct( e0, p0 );
  	float d2 = DotProduct( e1, p0 );
  	if (d1 <= 0.0f && d2 <= 0.0f)
  		return v0;
  
  	// voronoi region of v1
  	Vector p1 = P - v1;
  	float d3 = DotProduct( e0, p1 );
  	float d4 = DotProduct( e1, p1 );
  	if (d3 >=0.0f && d4 <= d3)
  		return v1;
  
  	// voronoi region of e0 (v0-v1)
  	float ve2 = d1*d4 - d3*d2;
  	if ( ve2 <= 0.0f && d1 >= 0.0f && d3 <= 0.0f )
  	{
  		float v = d1 / (d1-d3);
  		return v0 + v * e0;
  	}
  	// voronoi region of v2
  	Vector p2 = P - v2;
  	float d5 = DotProduct( e0, p2 );
  	float d6 = DotProduct( e1, p2 );
  	if (d6 >= 0.0f && d5 <= d6)
  		return v2;
  	// voronoi region of e1
  	float ve1 = d5*d2 - d1*d6;
  	if (ve1 <= 0.0f && d2 >= 0.0f && d6 >= 0.0f)
  	{
  		float w = d2 / (d2-d6);
  		return v0 + w * e1;
  	}
  	// voronoi region on e2
  	float ve0 = d3*d6 - d5*d4;
  	if ( ve0 <= 0.0f && (d4-d3) >= 0.0f && (d5-d6) >= 0.0f )
  	{
  		float w = (d4-d3)/((d4-d3) + (d5-d6));
  		return v1 + w * (v2-v1);
  	}
  	// voronoi region of v0v1v2 triangle
  	float denom = 1.0f / (ve0+ve1+ve2);
  	float v = ve1*denom;
  	float w = ve2 * denom;
  	return v0 + e0 * v + e1 * w;
  }
  #endif
  
  
  bool OBBHasFullyContainedIntersectionWithQuad( const Vector &vOBBExtent1_Scaled, const Vector &vOBBExtent2_Scaled, const Vector &vOBBExtent3_Scaled, const Vector &ptOBBCenter,
  											  const Vector &vQuadNormal, float fQuadPlaneDist, const Vector &ptQuadCenter,
  											  const Vector &vQuadExtent1_Normalized, float fQuadExtent1Length, 
  											  const Vector &vQuadExtent2_Normalized, float fQuadExtent2Length )
  {
  	Vector ptOBB[8]; //this specific ordering helps us web out from a point to its 3 connecting points with some bit math (most importantly, no if's)
  	ptOBB[0] = ptOBBCenter - vOBBExtent1_Scaled - vOBBExtent2_Scaled - vOBBExtent3_Scaled;
  	ptOBB[1] = ptOBBCenter - vOBBExtent1_Scaled - vOBBExtent2_Scaled + vOBBExtent3_Scaled;
  	ptOBB[2] = ptOBBCenter - vOBBExtent1_Scaled + vOBBExtent2_Scaled + vOBBExtent3_Scaled;
  	ptOBB[3] = ptOBBCenter - vOBBExtent1_Scaled + vOBBExtent2_Scaled - vOBBExtent3_Scaled;
  	ptOBB[4] = ptOBBCenter + vOBBExtent1_Scaled - vOBBExtent2_Scaled - vOBBExtent3_Scaled;
  	ptOBB[5] = ptOBBCenter + vOBBExtent1_Scaled - vOBBExtent2_Scaled + vOBBExtent3_Scaled;
  	ptOBB[6] = ptOBBCenter + vOBBExtent1_Scaled + vOBBExtent2_Scaled + vOBBExtent3_Scaled;
  	ptOBB[7] = ptOBBCenter + vOBBExtent1_Scaled + vOBBExtent2_Scaled - vOBBExtent3_Scaled;
  
  	float fDists[8];
  	for( int i = 0; i != 8; ++i )
  		fDists[i] = vQuadNormal.Dot( ptOBB[i] ) - fQuadPlaneDist;
  
  	int iSides[8];
  	int iSideMask = 0;
  	for( int i = 0; i != 8; ++i )
  	{
  		if( fDists[i] > 0.0f )
  		{
  			iSides[i] = 1;
  			iSideMask |= 1;
  		}
  		else
  		{
  			iSides[i] = 2;
  			iSideMask |= 2;
  		}
  	}
  
  	if( iSideMask != 3 ) //points reside entirely on one side of the quad's plane
  		return false;
  
  	Vector ptPlaneIntersections[12]; //only have 12 lines, can only possibly generate 12 split points
  	int iPlaneIntersectionsCount = 0;
  
  	for( int i = 0; i != 8; ++i )
  	{
  		if( iSides[i] == 2 ) //point behind the plane
  		{
  			int iAxisCrossings[3];
  			iAxisCrossings[0] = i ^ 4; //upper 4 vs lower 4 crosses vOBBExtent1 axis
  			iAxisCrossings[1] = ((i + 1) & 3) + (i & 4); //cycle to the next element while staying within the upper 4 or lower 4, this will cross either vOBBExtent2 or vOBBExtent3 axis, we don't care which
  			iAxisCrossings[2] = ((i - 1) & 3) + (i & 4); //cylce to the previous element while staying within the upper 4 or lower 4, this will cross the axis iAxisCrossings[1] didn't cross
  
  			for( int j = 0; j != 3; ++j )
  			{
  				if( iSides[iAxisCrossings[j]] == 1 ) //point in front of the plane
  				{
  					//line between ptOBB[i] and ptOBB[iAxisCrossings[j]] intersects the plane, generate a point at the intersection for further testing
  					float fTotalDist = fDists[iAxisCrossings[j]] - fDists[i]; //remember that fDists[i] is a negative value
  					ptPlaneIntersections[iPlaneIntersectionsCount] = (ptOBB[iAxisCrossings[j]] * (-fDists[i]/fTotalDist)) + (ptOBB[i] * (fDists[iAxisCrossings[j]]/fTotalDist));
  
  					Assert( fabs( ptPlaneIntersections[iPlaneIntersectionsCount].Dot( vQuadNormal ) - fQuadPlaneDist ) < 0.1f ); //intersection point is on plane
  
  					++iPlaneIntersectionsCount;
  				}
  			}
  		}
  	}
  
  	Assert( iPlaneIntersectionsCount != 0 );
  
  	for( int i = 0; i != iPlaneIntersectionsCount; ++i )
  	{
  		//these points are guaranteed to be on the plane, now just check to see if they're within the quad's extents
  		Vector vToPointFromQuadCenter = ptPlaneIntersections[i] - ptQuadCenter;
  
  		float fExt1Dist = vQuadExtent1_Normalized.Dot( vToPointFromQuadCenter );
  		if( fabs( fExt1Dist ) > fQuadExtent1Length )
  			return false; //point is outside boundaries
  
  		//vToPointFromQuadCenter -= vQuadExtent1_Normalized * fExt1Dist; //to handle diamond shaped quads
  
  		float fExt2Dist = vQuadExtent2_Normalized.Dot( vToPointFromQuadCenter );
  		if( fabs( fExt2Dist ) > fQuadExtent2Length )
  			return false; //point is outside boundaries
  	}
  
  	return true; //there were lines crossing the quad plane, and every line crossing that plane had its intersection with the plane within the quad's boundaries
  }
  
  //-----------------------------------------------------------------------------
  // Compute if the Ray intersects the quad plane, and whether the entire
  // Ray/Quad intersection is contained within the quad itself
  //
  // False if no intersection exists, or if part of the intersection is
  // outside the quad's extents
  //-----------------------------------------------------------------------------
  bool RayHasFullyContainedIntersectionWithQuad( const Ray_t &ray,
  											  const Vector &vQuadNormal, float fQuadPlaneDist, const Vector &ptQuadCenter,
  											  const Vector &vQuadExtent1_Normalized, float fQuadExtent1Length, 
  											  const Vector &vQuadExtent2_Normalized, float fQuadExtent2Length )
  {
  	Vector ptPlaneIntersections[(12 + 12 + 8)]; //absolute max possible: 12 lines to connect the start box, 12 more to connect the end box, 8 to connect the boxes to eachother
  	
  	//8 points to make an AABB, 8 lines to connect each point from it's start to end point along the ray, 8 possible intersections
  	int iPlaneIntersectionsCount = 0;
  
  	if( ray.m_IsRay )
  	{
  		//just 1 line
  		if( ray.m_IsSwept )
  		{
  			Vector ptEndPoints[2];
  			ptEndPoints[0] = ray.m_Start;
  			ptEndPoints[1] = ptEndPoints[0] + ray.m_Delta;
  
  			int i;
  			float fDists[2];
  			for( i = 0; i != 2; ++i )
  				fDists[i] = vQuadNormal.Dot( ptEndPoints[i] ) - fQuadPlaneDist;
  	       
  			for( i = 0; i != 2; ++i )
  			{
  				if( fDists[i] <= 0.0f )
  				{
  					int j = 1-i;
  					if( fDists[j] >= 0.0f )
  					{
  						float fInvTotalDist = 1.0f / (fDists[j] - fDists[i]); //fDists[i] <= 0, ray is swept so no chance that the denom was 0
  						ptPlaneIntersections[0] = (ptEndPoints[i] * (fDists[j] * fInvTotalDist)) - (ptEndPoints[j] * (fDists[i] * fInvTotalDist)); //fDists[i] <= 0 
  						Assert( fabs( ptPlaneIntersections[iPlaneIntersectionsCount].Dot( vQuadNormal ) - fQuadPlaneDist ) < 0.1f ); //intersection point is on plane
  						iPlaneIntersectionsCount = 1;
  					}
  					else 
  					{
  						return false;
  					}
  					break;
  				}
  			}
  
  			if( i == 2 )
  				return false;
  		}
  		else //not swept, so this is actually a point on quad question
  		{
  			if( fabs( vQuadNormal.Dot( ray.m_Start ) - fQuadPlaneDist ) < 1e-6 )
  			{
  				ptPlaneIntersections[0] = ray.m_Start;
  				iPlaneIntersectionsCount = 1;
  			}
  			else
  			{
  				return false;
  			}
  		}
  	}
  	else
  	{
  		Vector ptEndPoints[2][8];
  		//this specific ordering helps us web out from a point to its 3 connecting points with some bit math (most importantly, no if's)
  		ptEndPoints[0][0] = ray.m_Start; ptEndPoints[0][0].x -= ray.m_Extents.x; ptEndPoints[0][0].y -= ray.m_Extents.y; ptEndPoints[0][0].z -= ray.m_Extents.z;
  		ptEndPoints[0][1] = ray.m_Start; ptEndPoints[0][1].x -= ray.m_Extents.x; ptEndPoints[0][1].y -= ray.m_Extents.y; ptEndPoints[0][1].z += ray.m_Extents.z;
  		ptEndPoints[0][2] = ray.m_Start; ptEndPoints[0][2].x -= ray.m_Extents.x; ptEndPoints[0][2].y += ray.m_Extents.y; ptEndPoints[0][2].z += ray.m_Extents.z;
  		ptEndPoints[0][3] = ray.m_Start; ptEndPoints[0][3].x -= ray.m_Extents.x; ptEndPoints[0][3].y += ray.m_Extents.y; ptEndPoints[0][3].z -= ray.m_Extents.z;
  		ptEndPoints[0][4] = ray.m_Start; ptEndPoints[0][4].x += ray.m_Extents.x; ptEndPoints[0][4].y -= ray.m_Extents.y; ptEndPoints[0][4].z -= ray.m_Extents.z;
  		ptEndPoints[0][5] = ray.m_Start; ptEndPoints[0][5].x += ray.m_Extents.x; ptEndPoints[0][5].y -= ray.m_Extents.y; ptEndPoints[0][5].z += ray.m_Extents.z;
  		ptEndPoints[0][6] = ray.m_Start; ptEndPoints[0][6].x += ray.m_Extents.x; ptEndPoints[0][6].y += ray.m_Extents.y; ptEndPoints[0][6].z += ray.m_Extents.z;
  		ptEndPoints[0][7] = ray.m_Start; ptEndPoints[0][7].x += ray.m_Extents.x; ptEndPoints[0][7].y += ray.m_Extents.y; ptEndPoints[0][7].z -= ray.m_Extents.z;
  
  		float fDists[2][8];
  		int iSides[2][8];
  		int iSideMask[2] = { 0, 0 };
  		for( int i = 0; i != 8; ++i )
  		{
  			fDists[0][i] = vQuadNormal.Dot( ptEndPoints[0][i] ) - fQuadPlaneDist;
  			if( fDists[0][i] > 0.0f )
  			{
  				iSides[0][i] = 1;
  				iSideMask[0] |= 1;
  			}
  			else
  			{
  				iSides[0][i] = 2;
  				iSideMask[0] |= 2;
  			}
  		}
  
  		if( ray.m_IsSwept )
  		{
  			for( int i = 0; i != 8; ++i )
  				ptEndPoints[1][i] = ptEndPoints[0][i] + ray.m_Delta;
  
  			for( int i = 0; i != 8; ++i )
  			{
  				fDists[1][i] = vQuadNormal.Dot( ptEndPoints[1][i] ) - fQuadPlaneDist;
  				if( fDists[1][i] > 0.0f )
  				{
  					iSides[1][i] = 1;
  					iSideMask[1] |= 1;
  				}
  				else
  				{
  					iSides[1][i] = 2;
  					iSideMask[1] |= 2;
  				}
  			}
  		}
  
  		if( (iSideMask[0] | iSideMask[1]) != 3 )
  		{
  			//Assert( (iSideMask[0] | iSideMask[1]) != 2 );
  			return false; //all points resides entirely on one side of the quad
  		}
  
  
  		//generate intersections for boxes split by the plane at either end of the ray
  		for( int k = 0; k != 2; ++k )
  		{
  			if( iSideMask[k] == 3 ) //box is split by the plane
  			{
  				for( int i = 0; i != 8; ++i )
  				{
  					if( iSides[k][i] == 2 ) //point behind the plane
  					{
  						int iAxisCrossings[3];
  						iAxisCrossings[0] = i ^ 4; //upper 4 vs lower 4 crosses X axis
  						iAxisCrossings[1] = ((i + 1) & 3) + (i & 4); //cycle to the next element while staying within the upper 4 or lower 4, this will cross either Y or Z axis, we don't care which
  						iAxisCrossings[2] = ((i - 1) & 3) + (i & 4); //cylce to the previous element while staying within the upper 4 or lower 4, this will cross the axis iAxisCrossings[1] didn't cross
  
  						for( int j = 0; j != 3; ++j )
  						{
  							if( iSides[k][iAxisCrossings[j]] == 1 ) //point in front of the plane
  							{
  								//line between ptEndPoints[i] and ptEndPoints[iAxisCrossings[j]] intersects the plane, generate a point at the intersection for further testing
  								float fInvTotalDist = 1.0f / (fDists[k][iAxisCrossings[j]] - fDists[k][i]); //remember that fDists[k][i] is a negative value
  								ptPlaneIntersections[iPlaneIntersectionsCount] = (ptEndPoints[k][iAxisCrossings[j]] * (-fDists[k][i] * fInvTotalDist)) + (ptEndPoints[k][i] * (fDists[k][iAxisCrossings[j]] * fInvTotalDist));
  
  								Assert( fabs( ptPlaneIntersections[iPlaneIntersectionsCount].Dot( vQuadNormal ) - fQuadPlaneDist ) < 0.1f ); //intersection point is on plane
  
  								++iPlaneIntersectionsCount;
  							}
  						}
  					}
  				}
  			}
  		}		
  
  		if( ray.m_IsSwept )
  		{
  			for( int i = 0; i != 8; ++i )
  			{
  				if( iSides[0][i] != iSides[1][i] )
  				{
  					int iPosSide, iNegSide;
  					if( iSides[0][i] == 1 )
  					{
  						iPosSide = 0;
  						iNegSide = 1;
  					}
  					else
  					{
  						iPosSide = 1;
  						iNegSide = 0;
  					}
  
  					Assert( (fDists[iPosSide][i] >= 0.0f) && (fDists[iNegSide][i] <= 0.0f) );
  
  					float fInvTotalDist = 1.0f / (fDists[iPosSide][i] - fDists[iNegSide][i]); //remember that fDists[iNegSide][i] is a negative value
  					ptPlaneIntersections[iPlaneIntersectionsCount] = (ptEndPoints[iPosSide][i] * (-fDists[iNegSide][i] * fInvTotalDist)) + (ptEndPoints[iNegSide][i] * (fDists[iPosSide][i] * fInvTotalDist));
  
  					Assert( fabs( ptPlaneIntersections[iPlaneIntersectionsCount].Dot( vQuadNormal ) - fQuadPlaneDist ) < 0.1f ); //intersection point is on plane
  
  					++iPlaneIntersectionsCount;
  				}
  			}
  		}
  	}
  
  	//down here, we should simply have a collection of plane intersections, now we see if they reside within the quad
  	Assert( iPlaneIntersectionsCount != 0 );
  
  	for( int i = 0; i != iPlaneIntersectionsCount; ++i )
  	{
  		//these points are guaranteed to be on the plane, now just check to see if they're within the quad's extents
  		Vector vToPointFromQuadCenter = ptPlaneIntersections[i] - ptQuadCenter;
  
  		float fExt1Dist = vQuadExtent1_Normalized.Dot( vToPointFromQuadCenter );
  		if( fabs( fExt1Dist ) > fQuadExtent1Length )
  			return false; //point is outside boundaries
  
  		//vToPointFromQuadCenter -= vQuadExtent1_Normalized * fExt1Dist; //to handle diamond shaped quads
  
  		float fExt2Dist = vQuadExtent2_Normalized.Dot( vToPointFromQuadCenter );
  		if( fabs( fExt2Dist ) > fQuadExtent2Length )
  			return false; //point is outside boundaries
  	}
  
  	return true; //there were lines crossing the quad plane, and every line crossing that plane had its intersection with the plane within the quad's boundaries
  }
  
  #endif // !_STATIC_LINKED || _SHARED_LIB
  