autorouter: sort by pairwise total detour lengths before autorouting

src/autorouter/autorouter.rs

@@ -88,20 +88,25 @@ impl<M: AccessMesadata> Autorouter<M> {
         todo!();
     }
 
-    pub fn compare(&mut self, selection: &PinSelection) -> Result<CompareDetours, AutorouterError> {
-        self.compare_ratlines(self.selected_ratlines(selection))
-    }
-
-    fn compare_ratlines(
+    pub fn compare_detours(
         &mut self,
-        ratlines: Vec<EdgeIndex<usize>>,
+        selection: &PinSelection,
     ) -> Result<CompareDetours, AutorouterError> {
+        let ratlines = self.selected_ratlines(selection);
         let ratline1 = *ratlines
             .get(0)
             .ok_or(AutorouterError::NeedExactlyTwoRatlines)?;
         let ratline2 = *ratlines
             .get(1)
             .ok_or(AutorouterError::NeedExactlyTwoRatlines)?;
+        self.compare_detours_ratlines(ratline1, ratline2)
+    }
+
+    pub(super) fn compare_detours_ratlines(
+        &mut self,
+        ratline1: EdgeIndex<usize>,
+        ratline2: EdgeIndex<usize>,
+    ) -> Result<CompareDetours, AutorouterError> {
         CompareDetours::new(self, ratline1, ratline2)
     }
 
@@ -136,7 +141,7 @@ impl<M: AccessMesadata> Autorouter<M> {
         (source_dot, target_dot)
     }
 
-    fn selected_ratlines(&self, selection: &PinSelection) -> Vec<EdgeIndex<usize>> {
+    pub(super) fn selected_ratlines(&self, selection: &PinSelection) -> Vec<EdgeIndex<usize>> {
         self.ratsnest
             .graph()
             .edge_indices()

src/autorouter/invoker.rs

@@ -240,9 +240,18 @@ impl<M: AccessMesadata> Invoker<M> {
     #[debug_requires(self.ongoing_command.is_none())]
     fn dispatch_command(&mut self, command: &Command) -> Result<Execute, InvokerError> {
         match command {
-            Command::Autoroute(selection) => Ok::<Execute, InvokerError>(Execute::Autoroute(
-                self.autorouter.autoroute(selection)?,
-            )),
+            Command::Autoroute(selection) => {
+                let mut ratlines = self.autorouter.selected_ratlines(selection);
+                ratlines.sort_unstable_by(|a, b| {
+                    let mut compare_detours =
+                        self.autorouter.compare_detours_ratlines(*a, *b).unwrap();
+                    let (al, bl) = compare_detours.finish(&mut self.autorouter).unwrap();
+                    PartialOrd::partial_cmp(&al, &bl).unwrap()
+                });
+                Ok::<Execute, InvokerError>(Execute::Autoroute(
+                    self.autorouter.autoroute_ratlines(ratlines)?,
+                ))
+            }
             Command::PlaceVia(weight) => {
                 Ok::<Execute, InvokerError>(Execute::PlaceVia(self.autorouter.place_via(*weight)?))
             }
@@ -250,7 +259,7 @@ impl<M: AccessMesadata> Invoker<M> {
                 self.autorouter.remove_bands(selection)?,
             )),
             Command::CompareDetours(selection) => Ok::<Execute, InvokerError>(
-                Execute::CompareDetours(self.autorouter.compare(selection)?),
+                Execute::CompareDetours(self.autorouter.compare_detours(selection)?),
             ),
         }
     }