From 2f7cee62a6bef0a25084ce661fd59a8b373c8c05 Mon Sep 17 00:00:00 2001
From: Mikolaj Wielgus <wielgusmikolaj@gmail.com>
Date: Fri, 17 Oct 2025 23:21:32 +0200
Subject: [PATCH] fix(autorouter/anterouter): Use correct ratline principal
 layer instead of layer 0

---
 src/autorouter/anterouter.rs | 19 +++++++++++++++----
 src/autorouter/autorouter.rs |  2 +-
 src/layout/layout.rs         |  1 -
 3 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/src/autorouter/anterouter.rs b/src/autorouter/anterouter.rs
index 902243d..652d301 100644
--- a/src/autorouter/anterouter.rs
+++ b/src/autorouter/anterouter.rs
@@ -25,7 +25,7 @@ use crate::{
     },
     geometry::{shape::AccessShape, GenericNode, GetLayer},
     graph::{GenericIndex, MakeRef},
-    layout::{poly::MakePolygon, via::ViaWeight, LayoutEdit},
+    layout::{poly::MakePolygon, via::ViaWeight},
     math::Circle,
 };
 
@@ -79,7 +79,7 @@ impl Anterouter {
                 match terminating_scheme {
                     TerminatingScheme::ExistingFixedDot(terminating_dot) => autorouter
                         .ratsnests
-                        .on_principal_layer_mut(0)
+                        .on_principal_layer_mut(ratline.principal_layer)
                         .assign_terminating_dot_to_ratvertex(
                             endpoint_indices.0,
                             *layer,
@@ -105,7 +105,7 @@ impl Anterouter {
                 match terminating_scheme {
                     TerminatingScheme::ExistingFixedDot(terminating_dot) => autorouter
                         .ratsnests
-                        .on_principal_layer_mut(0)
+                        .on_principal_layer_mut(ratline.principal_layer)
                         .assign_terminating_dot_to_ratvertex(
                             endpoint_indices.1,
                             *layer,
@@ -166,6 +166,7 @@ impl Anterouter {
                 autorouter,
                 recorder,
                 ratvertex,
+                ratline,
                 source_dot,
                 small_bbox,
                 target_layer,
@@ -200,6 +201,7 @@ impl Anterouter {
                 autorouter,
                 recorder,
                 ratvertex,
+                ratline,
                 source_dot,
                 large_bbox,
                 target_layer,
@@ -216,6 +218,7 @@ impl Anterouter {
                 autorouter,
                 recorder,
                 ratvertex,
+                ratline,
                 source_dot,
                 small_bbox,
                 target_layer,
@@ -232,6 +235,7 @@ impl Anterouter {
                 autorouter,
                 recorder,
                 ratvertex,
+                ratline,
                 source_dot,
                 large_bbox,
                 target_layer,
@@ -251,6 +255,7 @@ impl Anterouter {
         autorouter: &mut Autorouter<impl AccessMesadata>,
         recorder: &mut BoardEdit,
         ratvertex: NodeIndex<usize>,
+        ratline: RatlineUid,
         source_dot: FixedDotIndex,
         bbox: AABB<[f64; 2]>,
         target_layer: usize,
@@ -262,6 +267,7 @@ impl Anterouter {
                 autorouter,
                 recorder,
                 ratvertex,
+                ratline,
                 source_dot,
                 bbox,
                 target_layer,
@@ -285,6 +291,7 @@ impl Anterouter {
                     autorouter,
                     recorder,
                     ratvertex,
+                    ratline,
                     source_dot,
                     bbox,
                     target_layer,
@@ -304,6 +311,7 @@ impl Anterouter {
                     autorouter,
                     recorder,
                     ratvertex,
+                    ratline,
                     source_dot,
                     bbox,
                     target_layer,
@@ -328,6 +336,7 @@ impl Anterouter {
         autorouter: &mut Autorouter<impl AccessMesadata>,
         recorder: &mut BoardEdit,
         ratvertex: NodeIndex<usize>,
+        ratline: RatlineUid,
         source_dot: FixedDotIndex,
         bbox: AABB<[f64; 2]>,
         target_layer: usize,
@@ -338,6 +347,7 @@ impl Anterouter {
             autorouter,
             recorder,
             ratvertex,
+            ratline,
             source_dot,
             bbox,
             target_layer,
@@ -385,6 +395,7 @@ impl Anterouter {
         autorouter: &mut Autorouter<impl AccessMesadata>,
         recorder: &mut BoardEdit,
         ratvertex: NodeIndex<usize>,
+        ratline: RatlineUid,
         source_dot: FixedDotIndex,
         bbox: AABB<[f64; 2]>,
         target_layer: usize,
@@ -451,7 +462,7 @@ impl Anterouter {
                 .unwrap();
             autorouter
                 .ratsnests
-                .on_principal_layer_mut(0)
+                .on_principal_layer_mut(ratline.principal_layer)
                 .assign_terminating_dot_to_ratvertex(ratvertex, target_layer, *terminating_dot);
             Ok((via, dots))
         } else {
diff --git a/src/autorouter/autorouter.rs b/src/autorouter/autorouter.rs
index f72870a..0183fe4 100644
--- a/src/autorouter/autorouter.rs
+++ b/src/autorouter/autorouter.rs
@@ -95,7 +95,7 @@ impl<M: AccessMesadata> Autorouter<M> {
             .unwrap();
         let origin_dot = match self
             .ratsnests
-            .on_principal_layer_mut(0)
+            .on_principal_layer_mut(options.principal_layer)
             .graph()
             .node_weight(ratvertex)
             .unwrap()
diff --git a/src/layout/layout.rs b/src/layout/layout.rs
index 04478c0..521d84a 100644
--- a/src/layout/layout.rs
+++ b/src/layout/layout.rs
@@ -150,7 +150,6 @@ impl<R: AccessRules> Layout<R> {
 
     #[debug_ensures(ret.is_ok() -> self.drawing.node_count() == old(self.drawing.node_count()) + weight.to_layer - weight.from_layer + 2)]
     #[debug_ensures(ret.is_err() -> self.drawing.node_count() == old(self.drawing.node_count()))]
-    /// Insert [`Via`] into the [`Layout`]
     pub fn add_via(
         &mut self,
         recorder: &mut LayoutEdit,