Search for a specific sized feature

sedborg

Can you search for specific sized feature. i.e can I search to find in particular layer
all areas that are 0.7um x 0.7um or smaller? It would be nice to input the x and y size and
have Klayout highlight those features.

Thanks

Scott E.

Matthias

Hi Scott,

There is no built-in functionality of this kind (yet). However, Here is a script that searches the current layout for shapes with a size smaller than a given threshold. It will install itself in the layer list's context menu (right mouse button) as a menu item "Find Small Shapes On Selected Layers".

When this menu item is selected, it will ask for a size and scan all selected layers for shapes with a bounding box which is smaller than the given size in both directions. When finished, it will open a marker browser containing all the found shapes.

This version of the script will report shapes per cell. That means, if a cell is placed twice, a shape inside that cell will be reported only once. That reduces the number of reported items but since a cell can be placed in different orientations, the distinction of x and y size does not make sense then.

Please also note that this script will report small areas on a per-shape basis. If an area is actually larger, because it is formed by two small adjacent or overlapping shapes, the smaller parts are still reported. The solution to that problem is to merge all shapes before using this function. That is currently not quite efficient for larger layouts and a efficient implementation for that case is the domain of real (expensive) DRC tools.

Anyway, I hope that script is useful.

Best regards,

Matthias

Here is the script:

def find_small_shapes

  sz = RBA::InputDialog::get_double("Find Objects Smaller Than", "Enter the desired threshold size.\nObjects with a bounding box smaller than the given size (in both directions) are put into a marker DB.", 1.0, 6)
  if ! sz.has_value?
    return
  end

  app = RBA::Application.instance
  mw = app.main_window
  view = mw.current_view
  return unless view

  layers = view.selected_layers
  return unless layers.size > 0

  cv_index = -1
  view.selected_layers.each do |l|
    if cv_index >= 0 
      if l.current.source_cellview(true) >= 0 && cv_index != l.current.source_cellview(true)
        raise "Selected layers must originate from the same layout"
      end
    else
      cv_index = l.current.source_cellview(true)
    end
  end

  cv = view.cellview(cv_index)
  return unless cv.is_valid?

  layout = cv.layout
  sz_dbu = (sz.value / layout.dbu + 0.5).floor.to_i

  dbu_trans = RBA::CplxTrans::new(layout.dbu)

  # remove a RDB called "find_small_shapes"
  (0..(view.num_rdbs-1)).each do |rdb_index|
    if view.rdb(rdb_index).name == "find_small_shapes"
      view.remove_rdb(rdb_index)
      break
    end
  end

  rdb_index = view.create_rdb("find_small_shapes")
  rdb = view.rdb(rdb_index)
  rdb.top_cell_name = layout.cell_name(cv.cell_index)

  view.selected_layers.each do |l|

    if cv_index == l.current.source_cellview(true)

      layer_index = l.current.layer_index
      if layout.is_valid_layer?(layer_index)

        cat_name = l.current.source(true)
        rdb_cat = rdb.create_category(cat_name)
        rdb_cat_id = rdb_cat.rdb_id

        cells = layout.cell(cv.cell_index).called_cells
        cells.push(cv.cell_index) 

        cells.each do |ci|

          rdb_cell = rdb.create_cell(layout.cell_name(ci))
          rdb_cell_id = rdb_cell.rdb_id

          cell = layout.cell(ci)
          cell.shapes(layer_index).each do |shape|

            bbox = shape.bbox
            if (shape.is_box? || shape.is_polygon? || shape.is_path?) && bbox.width <= sz_dbu && bbox.height <= sz_dbu 

              rdb_item = rdb.create_item(rdb_cell_id, rdb_cat_id)

              if shape.is_box?
                dbox = shape.box.transformed_cplx(dbu_trans)
                rdb_item.add_value(RBA::RdbItemValue::new(dbox))
              elsif shape.is_path?
                # in 0.21 there are no path markers -> convert to polygon
                dpath = shape.path.polygon.transformed_cplx(dbu_trans)
                rdb_item.add_value(RBA::RdbItemValue::new(dpath))
              elsif shape.is_polygon?
                dpolygon = shape.polygon.transformed_cplx(dbu_trans)
                rdb_item.add_value(RBA::RdbItemValue::new(dpolygon))
              end

            end

          end

        end

      end

    end

  end

  # Hint a corresponding cm_... method is missing
  action_path = "tools_menu.browse_markers"
  if mw.menu.is_valid(action_path)
    mw.menu.action(action_path).trigger
  end

end


# A helper class for a menu bound action
class MenuAction < RBA::Action
  def initialize( title, shortcut, &action ) 
    self.title = title
    self.shortcut = shortcut
    @action = action
  end
  def triggered 
    @action.call( self ) 
  end
private
  @action
end

# register the function in the toolbar
# TODO: add shortcut, correct title etc.
app = RBA::Application.instance
mw = app.main_window

menu = mw.menu
menu.insert_separator("@lcp_context_menu.end", "tb_separator")
menu.insert_item("@lcp_context_menu.end", "find_small_shapes", MenuAction.new("Find Small Shapes On Selected Layers", "") { find_small_shapes })