/**
 * Returns the direction of a corner in relation to the centre of the tile
 *
 * @param corner A #Corner.
 * @return The direction the corner is in relation to the center of the tile. Or INVALID_DIR if the corner is not valid.
 */
static inline Direction GetCornerDirection(Corner corner)
{
	switch (corner) {
		case CORNER_W: return DIR_W;
		case CORNER_S: return DIR_S;
		case CORNER_E: return DIR_E;
		case CORNER_N: return DIR_N;
		default: return INVALID_DIR;
	}
}