Abstract: To provide smoothly scaleable map features on interactive digital maps, a first and a second sets of style parameters for rendering a map feature at a first zoom level and a second zoom level, respectively, are received. The first and second sets of style parameters are provided to a vertex shader. The vertex shader is configured to interpolate the first set of style parameters and the second set of style parameters to generate an interpolated set of style parameters for a certain zoom level between the first zoom level and the second zoom level, and render the map feature at the certain zoom level in accordance with the interpolated set of style parameters.

Abstract: A switch (10) comprises a face plate (16) and a single switch sensing oscillator (18) responsive to a switch activating presence. The oscillator (18) has a resistive component (36) connected to a sensing plate (38) which acts as a first capacitor plate. The face plate (16) is arranged to prevent electrical contact between the user and the oscillator (18). Any object, when placed adjacent the face plate (16), acts as a second capacitor plate which alters the frequency of the oscillator (18). A microprocessor (20) senses the smoke detector (62). In a further aspect the switch includes a mains electricity cable signal transmitter/receiver and a microprocessor whereby each such switch may communicate directly with another such switch.