Shapes

For the original documentation see Shapes Class Reference.

Cells carry the geometrical shapes. Geometrical shapes are:

• Boxes (Rectangles)
• Polygons
• Paths (Lines with a certain width tracing a sequence of points)
• Labels (Text strings placed at a specific location)

A cell object carries one list of geometrical objects per logical layer. This list as represented by the Shapes class. To get the Shapes object for a specific layer handle, use the Cell’s shapes method. Once obtained, the Shapes object can be manipulated to add or remove shapes.

import klayout.db as db

ly = db.Layout()

top_cell = ly.create_cell("TOP")
layer1 = ly.layer(1, 0)

shapes1 = top_cell.shapes(layer1)

shapes1.insert(db.DBox(0, 0, 1.0, 1.0))

ly.write("sample.gds")

The Shape Class

The original documentation of the Shape class is found here: Shape class reference

When you retrieve shapes from a Shapes container, you will receive Shape objects. These objects are generic shapes and can represent boxes, polygons, paths or texts. You can ask the Shape for the kind of shape it is and convert to the plain geometrical object:

import klayout.db as db

ly = db.Layout()
ly.read("my_layout.gds")

top_cell = ly.top_cell()
layer1 = ly.layer(1, 0)

for shape in top_cell.shapes(layer1).each():

  if shape.is_polygon():
    print("Polygon: " + str(shape.dpolygon))
  elif shape.is_path():
    print("Path: " + str(shape.dpath))
  elif shape.is_text():
    print("Text: " + str(shape.dtext))
  elif shape.is_box():
    print("Box: " + str(shape.dbox))

Assigning Shape properties will change the shape in the database. The following example will substitute all polygons by their bounding boxes:

import klayout.db as db

# NOTE: manipulations are safe only in editable mode
ly = db.Layout(True)
ly.read("my_layout.gds")

top_cell = ly.top_cell()
layer1 = ly.layer(1, 0)

for shape in top_cell.shapes(layer1).each():
  if shape.is_polygon():
    shape.dbox = shape.dpolygon.bbox

Note: the layout is opened in ‘editable’ mode. Without this, manipulating shapes while iterating them is not safe.

More things you can do with Shapes

• Iterate over all shapes with each. You can specify a selector that allows iterating over specific types of shapes only.
• Efficient region lookups with each_touching and each_overlapping.
• Modify single shapes or the whole collecting with an affine transformation with transform.