DRC to check 45degree angle shapes

Comments

• Matthias

  November 2022 edited November 2022

  Hi Laurent,

  I'd suggest this solution:

  e = M1.edges
  [0, 90, -45, 45].each do |a|
    e = e.without_angle(a)
  end
  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,

  Matthias
• laurent_c

  November 2022

  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")
  
• Matthias

  November 2022

  Very good. I agree it could be easier. I have created a ticket for this: https://github.com/KLayout/klayout/issues/1185

  Matthias