some system_fn renaming and add system examples

crates/bevy_app/src/system.rs

@@ -1,8 +1,8 @@
 use legion::{
     filter::EntityFilter,
     prelude::{
-        into_resource_system, into_system, IntoQuery, ResourceSet, Resources, Runnable,
-        Schedulable, World,
+        into_resource_system, IntoQuery, ResourceSet, Resources, Runnable,
+        Schedulable, World, into_resource_for_each_system, into_for_each_system,
     },
     query::{DefaultFilter, View},
 };
@@ -34,7 +34,17 @@ where
 }
 
 impl System {
-    pub fn resource_for<'a, Q, F, R, X>(name: &'static str, system: F) -> Self
+    pub fn for_each<'a, Q, F, R>(name: &'static str, system: F) -> Self
+    where
+        Q: IntoQuery + DefaultFilter<Filter = R>,
+        <Q as View<'a>>::Iter: Iterator<Item = Q> + 'a,
+        F: FnMut(Q) + Send + Sync + 'static,
+        R: EntityFilter + Sync + 'static,
+    {
+        into_for_each_system(name, system).into()
+    }
+
+    pub fn resource_for_each<'a, Q, F, R, X>(name: &'static str, system: F) -> Self
     where
         Q: IntoQuery + DefaultFilter<Filter = R>,
         <Q as View<'a>>::Iter: Iterator<Item = Q> + 'a,
@@ -42,7 +52,7 @@ impl System {
         R: EntityFilter + Sync + 'static,
         X: ResourceSet<PreparedResources = X> + 'static,
     {
-        into_system(name, system).into()
+        into_resource_for_each_system(name, system).into()
     }
 
     pub fn resource<'a, F, X>(name: &'static str, system: F) -> Self

crates/bevy_legion/legion_systems/src/lib.rs

@@ -16,6 +16,6 @@ pub mod prelude {
         resource::{ResourceSet, Resources, PreparedRead as Resource, PreparedWrite as ResourceMut},
         schedule::{Executor, Runnable, Schedulable, Schedule},
         System, SystemBuilder,
-        into_system, into_resource_system
+        into_for_each_system, into_resource_system, into_resource_for_each_system,
     };
 }

crates/bevy_legion/legion_systems/src/system_fn.rs

@@ -3,17 +3,56 @@ use crate::{
     schedule::{ArchetypeAccess, Schedulable},
     Access, System, SystemAccess, SystemFnWrapper, SystemQuery,
 };
+use bit_set::BitSet;
 use fxhash::FxHashMap;
 use legion_core::{
-    borrow::{AtomicRefCell},
+    borrow::AtomicRefCell,
     filter::EntityFilter,
     query::{DefaultFilter, IntoQuery, View},
-    storage::{ComponentTypeId},
+    storage::ComponentTypeId,
 };
 use std::marker::PhantomData;
-use bit_set::BitSet;
 
-pub fn into_system<'a, Q, F, R, X>(name: &'static str, mut system: F) -> Box<dyn Schedulable>
+pub fn into_for_each_system<'a, Q, F, R>(name: &'static str, mut system: F) -> Box<dyn Schedulable>
+where
+    Q: IntoQuery + DefaultFilter<Filter = R>,
+    <Q as View<'a>>::Iter: Iterator<Item = Q> + 'a,
+    F: FnMut(Q) + Send + Sync + 'static,
+    R: EntityFilter + Sync + 'static,
+{
+    let resource_access: Access<ResourceTypeId> = Access::default();
+    let mut component_access: Access<ComponentTypeId> = Access::default();
+    component_access.reads.extend(Q::read_types().iter());
+    component_access.writes.extend(Q::write_types().iter());
+
+    let run_fn = SystemFnWrapper(
+        move |_, world, _, query: &mut SystemQuery<Q, <Q as DefaultFilter>::Filter>| {
+            for components in query.iter_mut(world) {
+                system(components);
+            }
+        },
+        PhantomData,
+    );
+
+    Box::new(System {
+        name: name.into(),
+        queries: AtomicRefCell::new(Q::query()),
+        access: SystemAccess {
+            resources: resource_access,
+            components: component_access,
+            tags: Access::default(),
+        },
+        archetypes: ArchetypeAccess::Some(BitSet::default()),
+        _resources: PhantomData::<()>,
+        command_buffer: FxHashMap::default(),
+        run_fn: AtomicRefCell::new(run_fn),
+    })
+}
+
+pub fn into_resource_for_each_system<'a, Q, F, R, X>(
+    name: &'static str,
+    mut system: F,
+) -> Box<dyn Schedulable>
 where
     Q: IntoQuery + DefaultFilter<Filter = R>,
     <Q as View<'a>>::Iter: Iterator<Item = Q> + 'a,
@@ -67,10 +106,7 @@ where
 
     let component_access: Access<ComponentTypeId> = Access::default();
     let run_fn = SystemFnWrapper(
-        move |_,
-              _,
-              resources: &mut X,
-              _| {
+        move |_, _, resources: &mut X, _| {
             system(resources);
         },
         PhantomData,
@@ -93,8 +129,8 @@ where
 
 #[cfg(test)]
 mod tests {
-    use super::into_system;
     use crate::{
+        into_resource_for_each_system,
         resource::{PreparedRead, PreparedWrite, Resources},
     };
     use legion_core::{
@@ -113,15 +149,13 @@ mod tests {
 
     #[test]
     fn test_system_fn() {
-        fn read_write_system(_: &mut (), (_x, mut y): (Ref<X>, RefMut<Y>)) {
-            y.0 += 1;
-        }
+        fn read_write_system(_: &mut (), (_x, mut y): (Ref<X>, RefMut<Y>)) { y.0 += 1; }
 
         let mut world = World::new();
         let mut resources = Resources::default();
         world.insert((), vec![(X(1), Y(1)), (X(2), Y(2))]);
 
-        let mut system = into_system("read_write", read_write_system);
+        let mut system = into_resource_for_each_system("read_write", read_write_system);
         system.run(&mut world, &mut resources);
     }
 
@@ -154,7 +188,7 @@ mod tests {
         resources.insert(A(0));
         resources.insert(B(1));
         world.insert((), vec![(X(2), Y(3)), (X(4), Y(5))]);
-        let mut my_system = into_system("read_resources", my_system);
+        let mut my_system = into_resource_for_each_system("read_resources", my_system);
         my_system.run(&mut world, &mut resources);
     }
 }

examples/spawner.rs

@@ -9,7 +9,7 @@ fn main() {
             ..Default::default()
         })
         .add_startup_system(setup)
-        .add_system(System::resource_for("move", move_system))
+        .add_system(System::resource_for_each("move", move_system))
         .run();
 }
 

examples/systems.rs

@@ -1,34 +1,56 @@
-use bevy::{
-    input::mouse::{MouseButtonInput, MouseMotion},
-    prelude::*,
-};
+use bevy::prelude::*;
 
+/// Illustrates the different ways you can declare systems
 fn main() {
     App::build()
         .add_default_plugins()
-        .add_system_init(mouse_input_system)
+        .add_event::<MyEvent>()
+        .add_startup_system(setup)
+        .add_system_init(system_b)
+        .add_system(System::for_each("system_a", system_a))
         .run();
 }
 
-/// prints out mouse events as they come in
-pub fn mouse_input_system(resources: &mut Resources) -> Box<dyn Schedulable> {
-    let mut mouse_button_input_event_reader = resources.get_event_reader::<MouseButtonInput>();
-    let mut mouse_motion_event_reader = resources.get_event_reader::<MouseMotion>();
-    SystemBuilder::new("mouse_input")
-        .read_resource::<Events<MouseButtonInput>>()
-        .read_resource::<Events<MouseMotion>>()
-        .build(
-            move |_command_buffer,
-                  _world,
-                  (mouse_button_input_events, mouse_motion_events),
-                  _queries| {
-                for event in mouse_button_input_event_reader.iter(&mouse_button_input_events) {
-                    println!("{:?}", event);
-                }
+struct MyEvent(usize);
 
-                for event in mouse_motion_event_reader.iter(&mouse_motion_events) {
-                    println!("{:?}", event);
-                }
-            },
-        )
+// resources
+struct A(usize);
+
+// components
+struct X(usize);
+struct Y(usize);
+
+// add our resources and entities
+fn setup(world: &mut World, resources: &mut Resources) {
+    resources.insert(A(0));
+    world.insert((), vec![(X(0), Y(1)), (X(2), Y(3))]);
+}
+
+fn system_a((x, y): (Ref<X>, RefMut<Y>)) {
+
+}
+
+// fn system_a(x: Ref<X>, mut y: RefMut<Y>) {
+
+// }
+// fn system_a((my_events, a): &mut (Resource<Events<MyEvent>>, Resource<A>), (x, mut y): (Ref<X>, RefMut<Y>)) {
+
+// }
+
+fn system_b(resources: &mut Resources) -> Box<dyn Schedulable> {
+    let mut my_event_reader = resources.get_event_reader::<MyEvent>();
+    SystemBuilder::new("example")
+        .read_resource::<Events<MyEvent>>()
+        .write_resource::<A>()
+        .with_query(<(Read<X>, Write<Y>)>::query())
+        .build(move |_command_buffer, world, (my_events, ref mut a), query| {
+            for event in my_event_reader.iter(&my_events) {
+                a.0 += event.0;
+                println!("modified resource A with event: {}", event.0);
+            }
+            for (x, mut y) in query.iter_mut(world) {
+                y.0 += 1;
+                println!("processed entity: {} {}", x.0, y.0);
+            }
+        })
 }

src/prelude.rs

@@ -55,7 +55,6 @@ pub use legion::{
         resource::{ResourceSet, Resources, PreparedRead as Resource, PreparedWrite as ResourceMut},
         schedule::{Executor, Runnable, Schedulable, Schedule},
         SubWorld, SystemBuilder,
-        into_system, into_resource_system
     },
     world::{Universe, World},
 };