Methods, systems, computer-readable media, and apparatuses for determining a location fix for optically-based active stylus input recognition technology are presented. The method includes, from an active light source capable of being handled by a user, emitting an electromagnetic wave signal in an initial direction toward a planar layer. The method also includes directing the electromagnetic wave signal in one or more lateral directions different from the initial direction, toward a plurality of detectors positioned at peripheral locations relative to the planar layer. The method further includes receiving the directed electromagnetic wave signal at the plurality of detectors. The method additionally includes, based on the directed electromagnetic wave signal received at the plurality of detectors, estimating a position of the user-controlled light source.