Tracing method

A method of carrying out a tracing operation in a region designated by a wire limit defined by limit line segments connecting a plurality of limit points, comprising the steps of:

• (a) determining a first limit point, nearest to a first tracing point, from among the limit points;
• (b) setting a pick feed angle relative to a first coordinate axis;
• (c) determining a second tracing point lying on a straight line passing through a second limit point adjacent the first limit point and forming the pick feed angle with the first coordinate axis, so that a first tracing line segment connecting the first and second tracing points is parallel to a first limit line segment connecting the first and second limit points;
• (d) tracing a stylus in a first tracing direction along the first tracing line segment;
• (e) repeating steps (c) and (d) until the stylus reaches an end point of a first tracing path;
• (f) performing a pick feed to move the stylus a predetermined distance in a pick feed direction along a first pick feed line forming the pick feed angle with the first coordinate axis, to position the stylus at a new tracing start point;
• (g) repeating steps (c)-(f) to trace the stylus along a second tracing path in a second direction opposite to the first direction until an end point of the second tracing path is reached and the pick feed is performed in the pick feed direction along a second pick feed line parallel to the first pick feed line;
• and
• (h) repeating steps (c)-(g) alternating the first and second tracing direction and the pick feed along the first and second pick feed lines.