path with variable width

Comments

• david234589

  April 2014 edited November -1

  Unfortunately I don't think so. Paths are by definition two things: a set of points defining the "hull" and a (single-number) width.

  You will have to draw it as a polygon, I think..

  Here is a script I wrote to draw a PCell polygon -- you can modify it to draw whatever taper shape you like. Then it can be called either via script or just by clicking the "Instance" button then modifying the xy coords.

  module PCell_Poly
  
    include RBA
  
    # Remove any definition of our classes (this helps when reexecuting this code after a change has been applied)
    PCell_Poly.constants.member?(:PCell_Poly) && remove_const(:PCell_Poly)
    PCell_Poly.constants.member?(:MyLib) && remove_const(:MyLib)
  
    # The PCell declaration for the circle
    class PCell_Poly < PCellDeclarationHelper
  
      include RBA
  
      def initialize 
        super
  
        # Declare the params. One of them must be a TypeLayer called "l" (or if called something else, then "l_layer" below needs to also be modified
        param(:x, TypeList,  "List of x coords", :default => ["0","0","10","10"])
        param(:y, TypeList,  "List of y coords", :default => ["0","10","10","0"])
        param(:l, TypeLayer, "Layer", :default => LayerInfo::new(1,0))
      end
  
      def display_text_impl
        "POLY"
      end
  
      def coerce_parameters_impl
        # CODE
      end
  
      def can_create_from_shape_impl # Needs to return true or false based upon analysis of the input shape "shape"
        false
      end
  
      def parameters_from_shape_impl # Needs to call the set_x methods, where x is the shape parameters, to set the parameters for shape "shape"
      end
  
      def transformation_from_shape_impl # Needs to return a transformation for the final PCell based on the original shape "shape"
      end
  
      def produce_impl # This is the main part of the implementation -- into cell "cell" using layer "l_layer", insert the desired shapes
        # Fetch the params
        x_list = x
        y_list = y
  
        # Compute stuff, if needed
        x_list.map! { |v| eval(v) }
        y_list.map! { |v| eval(v) }
        xy_list = [x_list, y_list].transpose # Concatenate the two arrays so you get something like [[0, 0], [0, 10], [10, 10], [10, 0]]
        pts = []
        dbu = layout.dbu
        xy_list.each { |xy|
          xx = xy[0]
          yy = xy[1]
          pts.push(RBA::Point.new(xx/dbu,yy/dbu))
        }
        # Lastly, create the shape
        cell.shapes(l_layer).insert(Polygon.new(pts))
        layout_view = RBA::Application.instance.main_window.current_view
        layout_view.add_missing_layers
      end
  
    end
  end
  

  Note that I use the following separate .lym file with the "Run on startup" selected, to register this PCell (and others) on startup.

  module InitializeLibs
  
    # The library where we will put the PCell into 
    class MyLib < RBA::Library
  
      def initialize  
  
        self.description = "Description"
  
        load File.expand_path('filepath/PCell_Poly.rb')
  
        # PCell declarations
        layout.register_pcell("PCell_Poly", PCell_Poly::PCell_Poly::new)
  
        register("MyLib")
  
      end
    end
  
    # Instantiate and register the library
    MyLib::new
  
  end
  
• david234589

  April 2014 edited November -1

  BTW I believe "extension" for a path is not the width at start and end, but a measure of how far beyond the start and end the path is drawn.

  For example, zero extension means the path terminates exactly at the x and y location specified. Nonzero extension (on the start or end) means the path extends a little beyond what was specified for the start or end.
• lacopt

  April 2014 edited April 2014

  Hi david234589,
  
  Thank you very much for your help with the script code and the elucidation about the "path variable" extension. I will try to work on the code and check the possibility of adapting it for my needs.
  
  Thanks again!
  Bye!
• david234589

  April 2014 edited November -1

  Note that PCell may be overkill, depending on what you are trying to do. If you just want to draw a polygon you could just use ruby script to draw a polygon. I guess my larger point was that a path won't work here, you need to draw a polygon.
• lacopt

  April 2014 edited November -1

  Yes, I understand. I haven't yet had time to try it, but thank you for your comment!