Function IntersectAxisAlignedBoxRay

trinity/Utilities/BoundingBox.cpp:356–381

-------------------------------------------------------------------------------------- Description: A ray AABB intersection check. Arguments: minBounds, maxBounds - The min/max bounds of the AABB rayOrigin, rayDir - The ray origin and direction (normalized) intersection - The intersection point if there is any Return Value: false if ray does not intersect AABB true if ray may intersect AABB ------

//   true if ray may intersect AABB
// --------------------------------------------------------------------------------------
bool IntersectAxisAlignedBoxRay( const Vector3& minBounds, const Vector3& maxBounds, const Vector3& rayOrigin, const Vector3& rayDir, Vector3& intersection )
{
	if( minBounds == maxBounds )
	{
		// we are actually dealing with a point but not a box
		intersection = minBounds;
		return LengthSq( Normalize( minBounds - rayOrigin ) - rayDir ) < 1e10;
	}

	XMVECTOR minA = XMVectorSet( minBounds.x, minBounds.y, minBounds.z, 0.0f );
	XMVECTOR maxA = XMVectorSet( maxBounds.x, maxBounds.y, maxBounds.z, 0.0f );

	XMVECTOR invRayDir = XMVectorReciprocal( rayDir );

	XMVECTOR t0 = ( minA - rayOrigin ) * invRayDir;
	XMVECTOR t1 = ( maxA - rayOrigin ) * invRayDir;

	XMVECTOR smallerIntersection = XMVectorMin( t0, t1 );
	XMVECTOR biggerIntersection = XMVectorMax( t0, t1 );

	float minT = max( XMVectorGetX( smallerIntersection ), max( XMVectorGetY( smallerIntersection ), XMVectorGetZ( smallerIntersection ) ) );
	float maxT = min( XMVectorGetX( biggerIntersection ), min( XMVectorGetY( biggerIntersection ), XMVectorGetZ( biggerIntersection ) ) );

	intersection = rayOrigin + minT * rayDir;
	return minT < maxT;
}

bool IntersectOrientedBoxAxisAlignedBox( const Vector3& centerA, const Vector3& extentsA, const Quaternion& orientationA, const Vector3& minBounds, const Vector3& maxBounds )
{