bg_difference

syntax

bg_difference(polygon_data_itemA, polygon_data_itemB)

definition

bg_difference(polygon_data_itemA, polygon_data_itemB) or polygon_data_itemA

polygon_data_itemB results in a new polygon data-item with the element by element difference of the two arguments: polygon_data_itemA and polygon_data_itemB

The left part of the figure illustrates the arguments: polygon_data_itemA and polygon_data_itemB.

The resulting polygon (right side of the image) is the differnce between the original square (polygon_data_itemA) and the ditstrict polygon_data_itemB.

description

applies to

data items polygon_data_itemA and polygon_data_itemB

conditions

The composition type of the arguments items needs to be polygon.
The domain of the arguments must match of be void.

since version

7.112

example

parameter<ipoint> geometry (poly) := bg_difference(square/geometry[0], union_polygon/geometry);