From 1eb5351a9ccd0b07ace294672e24c3871a687af6 Mon Sep 17 00:00:00 2001
From: Nolan Darilek <nolan@thewordnerd.info>
Date: Tue, 27 Jul 2021 11:17:06 -0500
Subject: [PATCH] Round 1 of pathfinding optimizations.

---
 src/pathfinding.rs | 49 +++++++++++++++++++++++++++++++++-------------
 1 file changed, 35 insertions(+), 14 deletions(-)

diff --git a/src/pathfinding.rs b/src/pathfinding.rs
index ef2dc3d..19ebafd 100644
--- a/src/pathfinding.rs
+++ b/src/pathfinding.rs
@@ -22,6 +22,10 @@ pub struct Destination(pub (i32, i32));
 
 impl_pointlike_for_tuple_component!(Destination);
 
+#[derive(Clone, Debug, Default, Reflect)]
+#[reflect(Component)]
+pub struct NoPath;
+
 #[derive(Clone, Debug, Default, Deref, DerefMut, Reflect)]
 #[reflect(Component)]
 pub struct Path(pub Vec<(i32, i32)>);
@@ -170,13 +174,12 @@ fn find_path_for_shape(
             |p| (p.distance_squared(&destination) * 100.) as u32,
             |p| *p == destination,
         );
-        channel_clone
-            .send(if let Some(path) = path {
-                Some(Path(path.0))
-            } else {
-                None
-            })
-            .ok();
+        let rv = if let Some(path) = path {
+            Some(Path(path.0))
+        } else {
+            None
+        };
+        channel_clone.send(rv).ok();
     })
     .detach();
 }
@@ -189,7 +192,7 @@ fn calculate_path(
     collider_query: QueryPipelineColliderComponentsQuery,
     mut calculating: Local<HashMap<Entity, Receiver<Option<Path>>>>,
     query: Query<(Entity, &Destination, &Coordinates, &ColliderShape), Changed<Destination>>,
-    destinations: Query<&Destination>,
+    destinations: Query<&Destination, Without<NoPath>>,
     map: Query<&Map>,
 ) {
     let calculating_clone = calculating.clone();
@@ -199,7 +202,8 @@ fn calculate_path(
                 if let Some(path) = msg {
                     commands.entity(*entity).insert(path);
                 } else {
-                    commands.entity(*entity).remove::<Destination>();
+                    println!("No path, tagging {:?}", entity);
+                    commands.entity(*entity).insert(NoPath);
                 }
                 calculating.remove(&entity);
             }
@@ -212,8 +216,11 @@ fn calculate_path(
             continue;
         }
         if coordinates.i32() == **destination {
-            commands.entity(entity).remove::<Path>();
-            commands.entity(entity).remove::<Destination>();
+            println!("Removing path1: {:?}", entity);
+            commands
+                .entity(entity)
+                .remove::<Path>()
+                .remove::<Destination>();
             continue;
         }
         let (tx, rx) = unbounded();
@@ -273,6 +280,7 @@ fn negotiate_path(
                 continue;
             }
         } else {
+            println!("Removing path2");
             commands.entity(entity).remove::<Path>();
             velocity.linvel = Vec2::ZERO.into();
         }
@@ -294,18 +302,31 @@ fn negotiate_path(
             direction *= **speed;
             velocity.linvel = direction.into();
         } else {
-            commands.entity(entity).remove::<Path>();
+            println!("Removing path3");
             velocity.linvel = Vec2::ZERO.into();
-            commands.entity(entity).remove::<Destination>();
+            commands
+                .entity(entity)
+                .remove::<Path>()
+                .remove::<Destination>();
         }
     }
 }
 
+fn remove_no_path(
+    mut commands: Commands,
+    query: Query<Entity, (With<NoPath>, Changed<Destination>)>,
+) {
+    for entity in query.iter() {
+        commands.entity(entity).remove::<NoPath>();
+    }
+}
+
 pub struct PathfindingPlugin;
 
 impl Plugin for PathfindingPlugin {
     fn build(&self, app: &mut AppBuilder) {
         app.add_system_to_stage(CoreStage::PostUpdate, calculate_path.system())
-            .add_system(negotiate_path.system());
+            .add_system(negotiate_path.system())
+            .add_system(remove_no_path.system());
     }
 }