|cad_parea [-i input] [-o output]|
cad_parea reads from input (standard input if not given) a series of polygon vertex (x,y) coordinate values and writes to output (standard output if not given) the polygons area. Lines not beginning with a number are silently skipped. Vertices are assumed to be given in counter-clockwise cyclic order.
A hole can be accommodated as a clockwise section connected to the periphery by a line segment traced in both directions.
Disjoint pieces may be connected by a line segment traced in both directions.
$ cad_parea # comment 1 0 2 0 2 1 3 1 3 2 2 2 1 2 0 2 0 1 1 1 ^D 4
Improperly formatted input produces an error message and terminates cad_parea with non-zero exit status.
cad_parea outputs "0" for the area of a degenerate polygon.
Douglas A. Gwyn, BRL/VLD-VMB
This software is Copyright (c) 1991-2013 by the United States Government as represented by U.S. Army Research Laboratory.
Reports of bugs or problems should be submitted via electronic mail to <firstname.lastname@example.org>.