摘要 |
A movable frame may be positioned about a playing surface and defines a substantially straight pathway for a tool to follow while altering a playing surface, such as by cutting or marking the surface. A template that may be used to accurately define key positions of a playing surface, like a tennis court. Various pairs of the key positions may, in turn, be used to define each line that is to be marked or altered on the playing surface. Patterns of sensor circuits are defined for indentifying whether a ball impacts the tennis court at a position that is in play, or out of play.
|