Function recurBoundingSphereCreate

trinity/Utilities/BoundingSphere.cpp:203–258

-------------------------------------------------------------------------------- Description: Local recursive function used by the bounding sphere generation algorithm --------------------------------------------------------------------------------

//   Local recursive function used by the bounding sphere generation algorithm
// --------------------------------------------------------------------------------
Vector4d recurBoundingSphereCreate( Vector3 const** p, size_t len, size_t b )
{
	const double radiusEpsilon = 1e-4;

	Vector4d mb;

	// in case of the "trivial" ones we have an easy solution
	switch( b )
	{
	case 0:
		BoundingSphereFromPoints( mb, nullptr, 0 );
		break;
	case 1:
		BoundingSphereFromPoints( mb, &p[-1], 1 );
		break;
	case 2:
		BoundingSphereFromPoints( mb, &p[-2], 2 );
		break;
	case 3:
		BoundingSphereFromPoints( mb, &p[-3], 3 );
		break;
	case 4:
		BoundingSphereFromPoints( mb, &p[-4], 4 );
		return mb;
	}

	for( size_t i = 0; i < len; ++i )
	{
		Vector3d delta = Vector3d( *p[i] ) - Vector3d( mb );
		// outside?
		if( LengthSq( delta ) > mb.w * mb.w + radiusEpsilon )
		{
			// avoid duplicates in the four points
			bool isDuplicate = false;
			for( size_t j = 0; j < b; ++j )
			{
				if( TriVectorIsIdentical( p[i], p[-(int32_t)j - 1] ) )
				{
					isDuplicate = true;
					break;
				}
			}
			if( !isDuplicate )
			{
				for( size_t j = i; j > 0; --j )
				{
					std::swap( p[j], p[j - 1] );
				}

				mb = recurBoundingSphereCreate( p + 1, i, b + 1 );
			}
		}
	}

	return mb;
}

// --------------------------------------------------------------------------------