Reply To: Subtracting two rectangle polygons

[Xaveer]

Dear Theflyingpengin,

When you put() an object, the return type is None, which explains the error message. You can easily check this by printing e.g. the type of base:

print(type(base))

The polygon operations of the clipper module require lists of polygons, where a polygon is a list of (x,y) values. So the first and second argument of diff_polygons() should be something like [[(1,2),(3,4),(5,1)]].

A small working example similar to your example (but with different polygon placement) would be:

import nazca as nd
import nazca.geometries as geom

base = geom.parallelogram(length=7333.87, height=3803.27, angle=90, position=1, shift=(0, 0))
# base is a polygon and [base] is a list of polygons (with only one polygon).
straights = geom.parallelogram(length=6180.09, height=758, angle=90, position=1, shift=(0, 0))
polygons = nd.clipper.diff_polygons([base], [straights], accuracy=0.001)

for pol in polygons:  # There is only one polygon in the result in this case.
    nd.Polygon(pol, layer=4).put()

nd.export_gds()

Hope that helps you to go on.

Lastly a word of warning: subtracting or combining polygons may result in a “hole”. This is not handled by Nazca, because GDS cannot handle such polygons.

Xaveer