Cheese
This example demonstrates how to read and manipulate a layout with boolean operations between two layers.
The input layout contains the outline on layer 1/0, the cheese holes on layer 2/0.
Code:
import klayout.db as db
import math
ly = db.Layout()
ly.read("input.gds")
top_cell = ly.top_cell()
l1 = ly.layer(1, 0)
l2 = ly.layer(2, 0)
r1 = db.Region(top_cell.begin_shapes_rec(l1))
r2 = db.Region(top_cell.begin_shapes_rec(l2))
cheese = r1 - r2
l100 = ly.layer(100, 0)
top_cell.shapes(l100).insert(r2)
# Note: as r2 links to l2 (copy on write), we must
# not clear these layers before using r2.
ly.clear_layer(l1)
ly.clear_layer(l2)
top_cell.shapes(l1).insert(cheese)
ly.write("cheese.gds")
Input input.gds (layer 1 is red, layer 2 is blue):
Result (boolean result in red, holes shown in white):
