DRC to check 45degree angle shapes

The DRC needs to find non-45 degree shapes for Metal, so I coded this way :

(M1.edges - M1.edges.with_angle(0) - M1.edges.with_angle(45) - M1.edges.with_angle(90) - M1.edges.with_angle(135) - M1.edges.with_angle(180) - M1.edges.with_angle(225) - M1.edges.with_angle(270) - M1.edges.with_angle(315)).output("M1_angle", "Non 45 degree angle ME1")

If I missed with_angles(225), I missed some errors. But is there a better and simpler way to code it ?



  • edited November 9

    Hi Laurent,

    I'd suggest this solution:

    e = M1.edges
    [0, 90, -45, 45].each do |a|
      e = e.without_angle(a)
    e.output("M1_angle", "Non 45 degree angle ME1")

    You don't need 135, 180 etc. angle checks. Angles are measured in a ]-90..90] degree range, so -45 and 45 are enough to check for 45 edges with positive and negative slope:

    The solution with "without_angle" is somewhat more efficient as it avoids boolean operations. I also assume that the first two steps quickly eliminate most of the edges leaving only few for the 45 and -45 degree analysis.

    One more remark from my side: when your code is like

    M1.edges - M1.edges.with_angle(0) - M1.edges.with_angle(45) - ...

    "M1.edges" will be executed multiple times. It is not a very expensive operation, yet it can be avoided by computing the edges first:

    M1_edges = M1.edges
    M1_edges - M1_edges.with_angle(0) - M1_edges.with_angle(45) - ...

    Still I suggest the "without_angle" solution and the loop above.

    Also note the angle rulers above which are a 0.28 feature :)

    Best regards,


  • Thank you Matthias, it more efficient than my command. As I like to have the all DRC check in 1 line I have compacted as follows : ;)

    M1.edges.without_angle(0).without_angle(90).without_angle(45).without_angle(-45).output("M1_angle", "Non 45 degree angle ME1")
  • Very good. I agree it could be easier. I have created a ticket for this: https://github.com/KLayout/klayout/issues/1185


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