no_angle¶

Flags forbidden edge angles on a layer. By default, every non-orthogonal (not horizontal/vertical) edge is forbidden; with the angle param, only edges at one specific orientation are. Used for IHP’s Gat.f: a 45° gate over active area is not allowed.

Semantics¶

Run over the tiled merge cache. Typically pointed at an intersection layer (e.g. GatPolyOverActiv) so only the part of the gate actually crossing the channel is inspected, rather than the whole gate polygon. Each merged region’s edges (rectilinear and oblique alike) are classified by their angle, folded into [0°, 180°):

With no angle param: any edge that isn’t within tolerance degrees of 0° or 90° is flagged.
With angle set: only edges within tolerance degrees of that orientation (or its 180° complement) are flagged — e.g. to forbid only 45° edges while tolerating other non-orthogonal angles.

Layers¶

One layer — every edge of its merged geometry is checked.

Parameters¶

angle: Optional. The one forbidden orientation, in degrees. If omitted, every non-orthogonal edge is forbidden.
tolerance: Optional, in degrees. How close an edge’s angle must be to the forbidden orientation, or to a multiple of step, to count as matching. It defaults to 1.0 with an angle param, where the slack widens the net - an edge that misses the forbidden orientation by half a degree is the orientation the rule is about - and to 0 in the step form, where it would hole it: GF180’s ACUTE is “all shapes must be orthogonal or on a 45°”, and geometry sits on a grid, so an edge is on the lattice exactly or it is not. A degree of slack there is also scale-dependent, since one grid step off over a short edge is a larger angle than over a long one.

Violation markers¶

One edge marker per forbidden edge, spanning its full length.

KLayout equivalent¶

layer.edges.with_angle(0, 90, false) (non-orthogonal edges) or layer.edges.with_angle(angle) for a specific forbidden orientation.

Example¶

- id: Gat.f
  check: no_angle
  layers: [GatPolyOverActiv]
  value: 0.0