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Headless vs non-headless

Hi,
I created a gds that works fine when I open it via Klayout; but when I try to
open it in headless mode, both the geometries that I've drawn and the layers that I've
assigned, are wrong. What could be causing this problem?
Thank you,

Alessandro

Comments

  • Hi Alessandro,

    stupid question: how can you "open" a layout in headless mode? "headless" to me means: without display ...

    Matthias

  • Hi,
    yes maybe it was better to say "run". When I run it through the cmd prompt

  • Is this Windows?

    And then, what's the command you're using?

    "klayout myfile.gds" should give you exactly the file you saved, provided this "klayout" is the same binary.

    Matthias

  • Yes, it is windows. I'm using this:
    klayout_app.exe -b -r mydrcrules.lydrc -rd input_file=mygds.gds -rd db_file_out=mydbfileout.lyrdb -rd output_file=mygdsout.gds

  • Thanks for this line. It's actually the intended use model ... however this takes me to the next question. I assume that "mydrcrules.lydrc" does something with the layout (e.g. perform boolean operations).

    I guess the .lydrc file also contains a statement like "source($input_file)" and "target($output_file)". It also needs to have "input(layer, datatype)" statements.

    In which sense is the file "wrong" then? Wrong geometry? Missing layers?

    Matthias

  • We have included the "source($input_file)" and "target($output_file)" statements. The "input(layer, datatype)" statement is only included for the input layers. We have not specified the output layers using "input(layer, datatype)", is this required?

    Example:

    source($input_file)
    target($output_file)
    
    layerA = input (1, 0)
    layerA.width(20.um, projection).output(A_width_check)
    

    When the DRC file is run in Klayout via the UI, the layer is named "A_width_check". When the same DRC is run in headless mode, a layer number is assigned, and this is different to the layer number assigned in headless mode.

    The output when using the UI is a layer called "A_width_check" with number/datatype (99, 0).
    When run in headless mode, the layer/datatype is (2,0) with no name.

  • edited August 4

    Thanks for this example. I think I understand the issue.

    You should include layer and datatype into the output statement, like

    layerA.width(20.um, projection).output(17, 0, A_width_check)
    

    Otherwise, KLayout will pick a number itself and this will differ in batch from. In interactive mode, it will pick another free number which isn't clashing with the input file. In batch mode I think the number just starts with 1. Using a fixed layer/datatype pair will avoid this.

    But then, the "output" statement won't work with "report", but only with a target layout. If you want output to work both with report and target layout, I'm afraid you have to use "ifs" to differentiate:

    check = layerA.width(20.um, projection)
    if $target_file
      check.output(17, 0, A_width_check)
    else
      check.output(A_width_check)
    end
    

    or

    if $target_file
      A_width_check = [ 17, 0, "A width_check" ]
    else
      A_width_check = [ "A width check" ]
    end
    ...
    layerA.width(20.um, projection).output(*A_width_check)
    

    Regards,

    Matthias

  • Thank you! Problem solved.

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