question: public boolean isWithinDistance ( Location loc ) { double dx = Math . abs ( location . getX ( ) - loc . getX ( ) ) ; double dz = Math . abs ( location . getZ ( ) - loc . getZ ( ) ) ; return loc . getWorld ( ) == getWorld ( ) && dx <= server . getViewDistance ( ) * GlowChunk . WIDTH && dz <= server . getViewDistance ( ) * GlowChunk . HEIGHT ; }
target:  Checks if this entity is within the visible radius of a location.