From 6038a5b701ee9ea3bd3b5da50d7d06930cd9a270 Mon Sep 17 00:00:00 2001
From: HampusM <hampus@hampusmat.com>
Date: Sat, 6 Apr 2024 15:35:51 +0200
Subject: refactor(ecs): make stopping into a action

---
 ecs/examples/event_loop.rs |  6 ++---
 ecs/src/actions.rs         | 15 +++++++++++
 ecs/src/flags.rs           | 66 ----------------------------------------------
 ecs/src/lib.rs             | 29 +++++---------------
 4 files changed, 24 insertions(+), 92 deletions(-)
 delete mode 100644 ecs/src/flags.rs

diff --git a/ecs/examples/event_loop.rs b/ecs/examples/event_loop.rs
index f9fd85f..b6a10e3 100644
--- a/ecs/examples/event_loop.rs
+++ b/ecs/examples/event_loop.rs
@@ -1,5 +1,5 @@
+use ecs::actions::Actions;
 use ecs::event::{Event, Id as EventId};
-use ecs::flags::Flags;
 use ecs::{Component, Query, World};
 
 #[derive(Component)]
@@ -45,7 +45,7 @@ fn feed(query: Query<(Health, Name)>)
     }
 }
 
-fn age(query: Query<(Health, Name)>, mut flags: Flags)
+fn age(query: Query<(Health, Name)>, mut actions: Actions)
 {
     for (mut health, name) in &query {
         if health.health <= 2 {
@@ -53,7 +53,7 @@ fn age(query: Query<(Health, Name)>, mut flags: Flags)
 
             println!("{} passed away", name.name);
 
-            flags.stop();
+            actions.stop();
 
             continue;
         }
diff --git a/ecs/src/actions.rs b/ecs/src/actions.rs
index ea4837a..a5aaf0c 100644
--- a/ecs/src/actions.rs
+++ b/ecs/src/actions.rs
@@ -26,6 +26,20 @@ impl<'world> Actions<'world>
             .expect("Failed to aquire read-write action queue lock")
             .push(Action::Spawn(components.into_vec()));
     }
+
+    /// Adds stopping the loop in [`Engine::event_loop`] at the next oppertune time to the
+    /// action queue.
+    ///
+    /// # Panics
+    /// Will panic if a mutable internal lock cannot be acquired.
+    pub fn stop(&mut self)
+    {
+        self.world_data
+            .action_queue
+            .write_nonblock()
+            .expect("Failed to aquire read-write action queue lock")
+            .push(Action::Stop);
+    }
 }
 
 unsafe impl<'world> SystemParam<'world> for Actions<'world>
@@ -66,6 +80,7 @@ unsafe impl<'world> SystemParam<'world> for Actions<'world>
 pub(crate) enum Action
 {
     Spawn(Vec<Box<dyn Component>>),
+    Stop,
 }
 
 struct Comparable;
diff --git a/ecs/src/flags.rs b/ecs/src/flags.rs
deleted file mode 100644
index ad10a0f..0000000
--- a/ecs/src/flags.rs
+++ /dev/null
@@ -1,66 +0,0 @@
-use std::any::Any;
-
-use crate::lock::WriteGuard;
-use crate::system::{
-    NoInitParamFlag as NoInitSystemParamFlag,
-    Param as SystemParam,
-    System,
-};
-use crate::tuple::FilterExclude as TupleFilterExclude;
-use crate::{WorldData, WorldFlags};
-
-#[derive(Debug)]
-pub struct Flags<'world>
-{
-    world_flags: WriteGuard<'world, WorldFlags>,
-}
-
-impl<'world> Flags<'world>
-{
-    /// Calling this function makes the loop in [`Engine::event_loop`] stop at the next
-    /// opportune time.
-    pub fn stop(&mut self)
-    {
-        self.world_flags.stop = true;
-    }
-}
-
-unsafe impl<'world> SystemParam<'world> for Flags<'world>
-{
-    type Flags = NoInitSystemParamFlag;
-    type Input = TupleFilterExclude;
-
-    fn initialize<SystemImpl>(
-        _system: &mut impl System<'world, SystemImpl>,
-        _input: Self::Input,
-    )
-    {
-    }
-
-    fn new<SystemImpl>(
-        _system: &'world impl System<'world, SystemImpl>,
-        world_data: &'world WorldData,
-    ) -> Self
-    {
-        Self {
-            world_flags: world_data
-                .flags
-                .write_nonblock()
-                .expect("Failed to acquire read-write world flags lock"),
-        }
-    }
-
-    fn is_compatible<Other: SystemParam<'world>>() -> bool
-    {
-        let other_comparable = Other::get_comparable();
-
-        other_comparable.downcast_ref::<Comparable>().is_none()
-    }
-
-    fn get_comparable() -> Box<dyn Any>
-    {
-        Box::new(Comparable)
-    }
-}
-
-struct Comparable;
diff --git a/ecs/src/lib.rs b/ecs/src/lib.rs
index 5273b67..1c4e44f 100644
--- a/ecs/src/lib.rs
+++ b/ecs/src/lib.rs
@@ -7,6 +7,7 @@ use std::marker::PhantomData;
 use std::mem::ManuallyDrop;
 use std::ops::RangeBounds;
 use std::slice::Iter as SliceIter;
+use std::sync::atomic::{AtomicBool, Ordering};
 use std::sync::{Arc, Weak};
 use std::vec::Drain;
 
@@ -26,7 +27,6 @@ use crate::type_name::TypeName;
 pub mod actions;
 pub mod component;
 pub mod event;
-pub mod flags;
 pub mod lock;
 pub mod system;
 pub mod tuple;
@@ -53,6 +53,7 @@ pub struct World
 {
     systems: Vec<TypeErasedSystem>,
     data: WorldData,
+    stop: AtomicBool,
 }
 
 impl World
@@ -160,6 +161,9 @@ impl World
                                 .collect(),
                         });
                 }
+                Action::Stop => {
+                    self.stop.store(true, Ordering::Relaxed);
+                }
             }
         }
     }
@@ -179,13 +183,7 @@ impl World
 
             self.perform_queued_actions();
 
-            let flags = self
-                .data
-                .flags
-                .read_nonblock()
-                .expect("Failed to aquire lock to flags");
-
-            if flags.stop {
+            if self.stop.load(Ordering::Relaxed) {
                 break;
             }
         }
@@ -208,27 +206,12 @@ impl World
     }
 }
 
-#[derive(Debug, Default)]
-struct WorldFlags
-{
-    stop: bool,
-}
-
-impl TypeName for WorldFlags
-{
-    fn type_name(&self) -> &'static str
-    {
-        type_name::<Self>()
-    }
-}
-
 #[derive(Debug, Default)]
 pub struct WorldData
 {
     events: HashMap<EventId, Vec<usize>>,
     component_storage: Arc<Lock<ComponentStorage>>,
     action_queue: Lock<ActionQueue>,
-    flags: Lock<WorldFlags>,
 }
 
 #[derive(Debug, Default)]
-- 
cgit v1.2.3-18-g5258