next up previous contents index
Next: The !polyrev Command: Reverse Up: Physical Previous: The !split Command: Atomize   Contents   Index


The !manh Command: Convert to Manhattan Polygons

Syntax: !manh min_box_size
This command applies to selected polygons, on the current layer only if layer-specific mode is in effect (all layers otherwise), and will convert each polygon to a Manhattan approximation. The argument is the size, in microns, of the minimum box width/height used to approximate non-Manhattan parts of the polygon.

The operation works by first decomposing the polygon into horizontal trapezoids, each of which is divided horizontally if necessary so that it can be further split into rectangular and triangular pieces. The triangular pieces are approximated with rectangles using min_box_size, then a new polygon is produced from all of the rectangular pieces. This results is a Manhattan polygon that may be very different from that achieved by, for example, a gridding operation.



Stephen R. Whiteley 2006-10-23