router: Rename `Route` to `Tracer` and simplify related code

src/astar.rs

@@ -100,7 +100,7 @@ where
     K: Measure + Copy,
     G::NodeId: Eq + Hash,
 {
-    fn reroute(&mut self, node: G::NodeId, tracker: &PathTracker<G>) -> Option<K>;
+    fn is_goal(&mut self, node: G::NodeId, tracker: &PathTracker<G>) -> bool;
     fn edge_cost(&mut self, edge: G::EdgeRef) -> K;
     fn estimate_cost(&mut self, node: G::NodeId) -> K;
 }
@@ -125,13 +125,12 @@ where
     visit_next.push(MinScored(strategy.estimate_cost(start), start));
 
     while let Some(MinScored(estimate_score, node)) = visit_next.pop() {
-        match strategy.reroute(node, &path_tracker) {
+        if strategy.is_goal(node, &path_tracker) {
-            None => {
             let path = path_tracker.reconstruct_path_to(node);
             let cost = scores[&node];
             return Some((cost, path));
         }
-            Some(route_cost) => {
+
         // This lookup can be unwrapped without fear of panic since the node was
         // necessarily scored before adding it to `visit_next`.
         let node_score = scores[&node];
@@ -152,7 +151,7 @@ where
 
         for edge in graph.edges(node) {
             let next = edge.target();
-                    let next_score = node_score + route_cost + strategy.edge_cost(edge);
+            let next_score = node_score + strategy.edge_cost(edge);
 
             match scores.entry(next) {
                 Occupied(mut entry) => {
@@ -173,8 +172,6 @@ where
             visit_next.push(MinScored(next_estimate_score, next));
         }
     }
-        }
-    }
 
     None
 }

src/main.rs

@@ -18,19 +18,18 @@ mod layout;
 mod math;
 mod mesh;
 mod primitive;
-mod route;
 mod router;
 mod rules;
 mod segbend;
 mod shape;
+mod tracer;
 
 use geo::point;
-use graph::{DotIndex, SegWeight, Tag, TaggedIndex};
+use graph::{DotIndex, SegWeight};
 use layout::Layout;
 use mesh::{Mesh, MeshEdgeReference, VertexIndex};
 use petgraph::visit::{EdgeRef, IntoEdgeReferences};
-use route::Route;
+use router::RouterObserver;
-use router::{DefaultRouteStrategy, RouteStrategy};
 use sdl2::event::Event;
 use sdl2::gfx::primitives::DrawRenderer;
 use sdl2::keyboard::Keycode;
@@ -41,6 +40,7 @@ use sdl2::EventPump;
 use shape::Shape;
 use std::panic;
 use std::time::Duration;
+use tracer::Tracer;
 
 use crate::graph::DotWeight;
 use crate::math::Circle;
@@ -52,48 +52,36 @@ enum RouterOrLayout<'a> {
     Layout(&'a Layout),
 }
 
-struct DebugRouteStrategy<'a, RS: RouteStrategy> {
+struct DebugRouterObserver<'a> {
-    strategy: RS,
     event_pump: &'a mut sdl2::EventPump,
     canvas: &'a mut sdl2::render::Canvas<Window>,
 }
 
-impl<'a, RS: RouteStrategy> DebugRouteStrategy<'a, RS> {
+impl<'a> DebugRouterObserver<'a> {
     pub fn new(
-        strategy: RS,
         event_pump: &'a mut sdl2::EventPump,
         canvas: &'a mut sdl2::render::Canvas<Window>,
     ) -> Self {
-        Self {
+        Self { event_pump, canvas }
-            strategy,
-            event_pump,
-            canvas,
-        }
     }
 }
 
-impl<'a, RS: RouteStrategy> RouteStrategy for DebugRouteStrategy<'a, RS> {
+impl<'a> RouterObserver for DebugRouterObserver<'a> {
-    fn route_cost(&mut self, route: &Route, path: &[VertexIndex]) -> u64 {
+    fn on_rework(&mut self, tracer: &Tracer, path: &[VertexIndex]) {
         render_times(
             self.event_pump,
             self.canvas,
-            RouterOrLayout::Layout(route.layout),
+            RouterOrLayout::Layout(tracer.layout),
             None,
             None,
-            Some(route.mesh.clone()),
+            Some(tracer.mesh.clone()),
             path,
             10,
         );
-        self.strategy.route_cost(route, path)
     }
 
-    fn edge_cost(&mut self, route: &Route, edge: MeshEdgeReference) -> u64 {
+    fn on_probe(&mut self, _tracer: &Tracer, _edge: MeshEdgeReference) {}
-        self.strategy.edge_cost(route, edge)
+    fn on_estimate(&mut self, _tracer: &Tracer, _vertex: VertexIndex) {}
-    }
-
-    fn estimate_cost(&mut self, route: &Route, vertex: VertexIndex) -> u64 {
-        self.strategy.estimate_cost(route, vertex)
-    }
 }
 
 fn main() {
@@ -304,11 +292,7 @@ fn render_times(
                             .reroute(
                                 from,
                                 point! {x: state.x() as f64, y: state.y() as f64},
-                                &mut DebugRouteStrategy::new(
+                                &mut DebugRouterObserver::new(event_pump, canvas),
-                                    DefaultRouteStrategy::new(),
-                                    event_pump,
-                                    canvas,
-                                ),
                             )
                             .ok();
                     }

src/router.rs

@@ -1,91 +1,63 @@
 use geo::geometry::Point;
-use petgraph::visit::{EdgeRef, IntoEdgeReferences};
+use petgraph::visit::EdgeRef;
 use spade::InsertionError;
 
 use crate::astar::{astar, AstarStrategy, PathTracker};
-use crate::bow::Bow;
+use crate::graph::{DotIndex, DotWeight, Ends};
-use crate::draw::{Draw, Head};
-use crate::graph::{BendIndex, DotIndex, Ends, SegIndex, TaggedIndex};
-use crate::graph::{BendWeight, DotWeight, SegWeight};
-use crate::guide::Guide;
 use crate::layout::Layout;
 
 use crate::math::Circle;
 use crate::mesh::{Mesh, MeshEdgeReference, VertexIndex};
-use crate::route::{Route, Trace};
+use crate::rules::Rules;
-use crate::rules::{Conditions, Rules};
+use crate::tracer::{Trace, Tracer};
-use crate::segbend::Segbend;
+
+pub trait RouterObserver {
+    fn on_rework(&mut self, tracer: &Tracer, path: &[VertexIndex]);
+    fn on_probe(&mut self, tracer: &Tracer, edge: MeshEdgeReference);
+    fn on_estimate(&mut self, tracer: &Tracer, vertex: VertexIndex);
+}
 
 pub struct Router {
     pub layout: Layout,
     rules: Rules,
 }
 
-pub trait RouteStrategy {
+struct RouterAstarStrategy<'a, RO: RouterObserver> {
-    fn route_cost(&mut self, route: &Route, path: &[VertexIndex]) -> u64;
+    tracer: Tracer<'a>,
-    fn edge_cost(&mut self, route: &Route, edge: MeshEdgeReference) -> u64;
-    fn estimate_cost(&mut self, route: &Route, vertex: VertexIndex) -> u64;
-}
-
-pub struct DefaultRouteStrategy {}
-
-impl DefaultRouteStrategy {
-    pub fn new() -> Self {
-        Self {}
-    }
-}
-
-impl RouteStrategy for DefaultRouteStrategy {
-    fn route_cost(&mut self, route: &Route, path: &[VertexIndex]) -> u64 {
-        0
-    }
-
-    fn edge_cost(&mut self, route: &Route, edge: MeshEdgeReference) -> u64 {
-        1
-    }
-
-    fn estimate_cost(&mut self, route: &Route, vertex: VertexIndex) -> u64 {
-        0
-    }
-}
-
-struct RouterAstarStrategy<'a, RS: RouteStrategy> {
-    route: Route<'a>,
     trace: Trace,
     to: VertexIndex,
-    strategy: &'a mut RS,
+    observer: &'a mut RO,
 }
 
-impl<'a, RS: RouteStrategy> RouterAstarStrategy<'a, RS> {
+impl<'a, RO: RouterObserver> RouterAstarStrategy<'a, RO> {
-    pub fn new(route: Route<'a>, trace: Trace, to: VertexIndex, strategy: &'a mut RS) -> Self {
+    pub fn new(tracer: Tracer<'a>, trace: Trace, to: VertexIndex, observer: &'a mut RO) -> Self {
         Self {
-            route,
+            tracer,
             trace,
             to,
-            strategy,
+            observer,
         }
     }
 }
 
-impl<'a, RS: RouteStrategy> AstarStrategy<&Mesh, u64> for RouterAstarStrategy<'a, RS> {
+impl<'a, RO: RouterObserver> AstarStrategy<&Mesh, u64> for RouterAstarStrategy<'a, RO> {
-    fn reroute(&mut self, vertex: VertexIndex, tracker: &PathTracker<&Mesh>) -> Option<u64> {
+    fn is_goal(&mut self, vertex: VertexIndex, tracker: &PathTracker<&Mesh>) -> bool {
         let new_path = tracker.reconstruct_path_to(vertex);
 
-        self.route.rework_path(&mut self.trace, &new_path, 5.0);
+        self.tracer.rework_path(&mut self.trace, &new_path, 5.0);
+        self.observer.on_rework(&self.tracer, &new_path);
 
-        if self.route.finish(&mut self.trace, self.to, 5.0).is_ok() {
+        self.tracer.finish(&mut self.trace, self.to, 5.0).is_ok()
-            return None;
-        }
-
-        Some(self.strategy.route_cost(&self.route, &new_path))
     }
 
     fn edge_cost(&mut self, edge: MeshEdgeReference) -> u64 {
-        self.strategy.edge_cost(&self.route, edge)
+        self.observer.on_probe(&self.tracer, edge);
+        1
     }
 
     fn estimate_cost(&mut self, vertex: VertexIndex) -> u64 {
-        self.strategy.estimate_cost(&self.route, vertex)
+        self.observer.on_estimate(&self.tracer, vertex);
+        0
     }
 }
 
@@ -101,7 +73,7 @@ impl Router {
         &mut self,
         from: DotIndex,
         to: DotIndex,
-        strategy: &mut impl RouteStrategy,
+        observer: &mut impl RouterObserver,
     ) -> Result<Mesh, InsertionError> {
         // XXX: Should we actually store the mesh? May be useful for debugging, but doesn't look
         // right.
@@ -109,13 +81,13 @@ impl Router {
         let mut mesh = Mesh::new();
         mesh.triangulate(&self.layout)?;
 
-        let mut route = self.route(&mesh);
+        let mut tracer = self.tracer(&mesh);
-        let trace = route.start(mesh.vertex(from));
+        let trace = tracer.start(mesh.vertex(from));
 
         let (_cost, path) = astar(
             &mesh,
             mesh.vertex(from),
-            &mut RouterAstarStrategy::new(route, trace, mesh.vertex(to), strategy),
+            &mut RouterAstarStrategy::new(tracer, trace, mesh.vertex(to), observer),
         )
         .unwrap(); // TODO.
 
@@ -126,7 +98,7 @@ impl Router {
         &mut self,
         from: DotIndex,
         to: Point,
-        strategy: &mut impl RouteStrategy,
+        observer: &mut impl RouterObserver,
     ) -> Result<Mesh, InsertionError> {
         let to_dot = if let Some(band) = self.layout.next_band(from) {
             let to_dot = band.ends().1;
@@ -144,7 +116,7 @@ impl Router {
                 .unwrap() // TODO.
         };
 
-        self.enroute(from, to_dot, strategy)
+        self.enroute(from, to_dot, observer)
     }
 
     /*pub fn squeeze_around_dot(
@@ -259,8 +231,8 @@ impl Router {
         Ok(())
     }*/
 
-    pub fn route<'a>(&'a mut self, mesh: &'a Mesh) -> Route {
+    pub fn tracer<'a>(&'a mut self, mesh: &'a Mesh) -> Tracer {
-        Route::new(&mut self.layout, &self.rules, mesh)
+        Tracer::new(&mut self.layout, &self.rules, mesh)
     }
 
     /*pub fn routeedges(&self) -> impl Iterator<Item = (Point, Point)> + '_ {

src/tracer.rs

@@ -3,7 +3,7 @@ use contracts::debug_ensures;
 use crate::{
     draw::{BareHead, Draw, Head},
     layout::Layout,
-    mesh::{Mesh, VertexIndex},
+    mesh::{Mesh, MeshEdgeReference, VertexIndex},
     rules::Rules,
 };
 
@@ -13,15 +13,15 @@ pub struct Trace {
     head: Head,
 }
 
-pub struct Route<'a> {
+pub struct Tracer<'a> {
     pub layout: &'a mut Layout,
     pub rules: &'a Rules,
     pub mesh: &'a Mesh,
 }
 
-impl<'a> Route<'a> {
+impl<'a> Tracer<'a> {
     pub fn new(layout: &'a mut Layout, rules: &'a Rules, mesh: &'a Mesh) -> Self {
-        Route {
+        Tracer {
             layout,
             rules,
             mesh,