A method and an apparatus are disclosed for determining the position of a stimulus in two axes on a surface. The apparatus includes: a transparent waveguide panel with parallel top and a bottom surfaces and at least one edge that is perpendicular to the top and bottom surfaces; a light source that is directed to the edge of the waveguide to produce light that is contained within the waveguide by Total Internal Reflection and a light detector for producing an electrical signal that is representative of an image of the light emitted by the waveguide. The light detector is positioned to receive light emitted by Frustrated Total Internal Reflection from the transparent wave guide when a physical stimulus is placed in contact with the top surface of the transparent waveguide.