# How to get the projection of the shape on X and Y directions to calculate the curvature.

The above algorithm is used to demonstrate the verification of bend curvature based on the eqDRC theory, but the problem is that how can I get x and y(the projection of the shape on X and Y directions)?
In the meantime, how can I write my own drc model in ruby and pack it so that I can use it in drc script?
If there are eqDRC scripts, that will be better.
The DOI of eqDRC paper is 10.1109/VLSI-SoC.2014.7004173, and I am trying to achieve these eqDRC function in klayout, thanks.

• Thanks for this information.

I'm not a researcher, but the paper seems quite old and I have not retrieved it. But I cannot imagine deriving a curvature is that easy. Could you supply a sketch or any publicly available reference?

The projection of a polygon will basically by the bounding box. I don't see how this can be used to derive the curvature.

Thanks,

Matthias

• The title of a paper about how to calculate the curvature is "Silicon Photonics Design Rule Checking: Application of a Programmable Modeling Engine for Non-Manhattan Geometry Verification"
I also cannot image the process is so easy, but the authout of this paper is also the engineer of SIEMENS EDA Mentor Graphic Calibre. So I think the way in this paper is authentic, but the problem is whether it is easy to be achieved in Klayout by using ruby.
I cannot find other public publication or reference.
I think equation-based DRC is really potential.
Thanks.

• @Matthias The title of a paper about how to calculate the curvature is "Silicon Photonics Design Rule Checking: Application of a Programmable Modeling Engine for Non-Manhattan Geometry Verification"
I also cannot image the process is so easy, but the authout of this paper is also the engineer of SIEMENS EDA Mentor Graphic Calibre. So I think the way in this paper is authentic, but the problem is whether it is easy to be achieved in Klayout by using ruby.
I cannot find other public publication or reference.
I think equation-based DRC is really potential.
Thanks.

• Thanks - but first of all, it is pretty old, not specific and I'm lacking a picture here. To what kind of situations will it apply?

I don't want to request the paper. I think it's a honey pot, not serious research. The term eqDRC is not used anywhere else, but it may be a registered trademark or patented.

Matthias