chore: rename ecs* crates to engine-ecs*HEADmaster

1 files changed, 269 insertions, 0 deletions

diff --git a/engine-ecs/src/system/stateful.rs b/engine-ecs/src/system/stateful.rs
new file mode 100644
index 0000000..3e0076a
--- /dev/null
+++ b/engine-ecs/src/system/stateful.rs
@@ -0,0 +1,269 @@
+use std::any::type_name;
+use std::mem::transmute;
+
+use seq_macro::seq;
+
+use crate::World;
+use crate::component::Parts as ComponentParts;
+use crate::component::local::SystemWithLocalComponents;
+use crate::event::Emitted as EmittedEvent;
+use crate::system::initializable::{Initializable, MaybeInitializableParamTuple};
+use crate::system::observer::{
+    Observe,
+    Observed,
+    Observer,
+    WrapperComponent as ObserverWrapperComponent,
+};
+use crate::system::{
+    Into as IntoSystem,
+    Metadata,
+    Param,
+    ReturnValue,
+    System,
+    TypeErased,
+};
+
+/// A stateful system.
+pub struct Stateful<Func>
+{
+    func: Func,
+    local_components: Vec<ComponentParts>,
+}
+
+macro_rules! impl_system {
+    ($c: tt) => {
+        seq!(I in 0..$c {
+            impl<'world, Func, Ret, #(TParam~I,)*>
+                System<'world, fn(#(TParam~I,)*) -> Ret> for Stateful<Func>
+            where
+                Func: Fn(#(TParam~I,)*) -> Ret + 'static,
+                Ret: ReturnValue,
+                #(TParam~I: Param<'world, Input: 'static>,)*
+            {
+                type Callbacks = Callbacks;
+
+                fn finish(self) -> (TypeErased, Self::Callbacks)
+                {
+                    let Self { func, local_components } = self;
+
+                    let callbacks = Callbacks { local_components };
+
+                    let type_erased = TypeErased {
+                        run: Box::new(move |world, metadata| {
+                            // SAFETY: The caller of TypeErased::run ensures the lifetime
+                            // is correct
+                            let world = unsafe { &*std::ptr::from_ref(world) };
+
+                            func(#({
+                                TParam~I::new(&world, &metadata)
+                            },)*);
+
+                            Ok(())
+                        }),
+                        name: type_name::<Func>()
+                    };
+
+
+                    (type_erased, callbacks)
+                }
+            }
+
+            impl<'world, Func, Ret, #(TParam~I,)*>
+                Initializable<'world, fn(#(TParam~I,)*) -> Ret> for Stateful<Func>
+            where
+                Func: Fn(#(TParam~I,)*) -> Ret + 'static,
+                Ret: ReturnValue,
+                #(TParam~I: Param<'world, Input: 'static>,)*
+                (#(TParam~I,)*): MaybeInitializableParamTuple<'world, Self>
+            {
+                type Inputs = <
+                    (#(TParam~I,)*) as MaybeInitializableParamTuple<'world, Self>
+                >::Inputs;
+
+                fn initialize(mut self, inputs: Self::Inputs) -> Self
+                {
+                    init_initializable_params::<_, (#(TParam~I,)*)>(&mut self, inputs);
+
+                    self
+                }
+            }
+
+            impl<'world, Func, Ret, #(TParam~I,)*>
+                IntoSystem<'world, fn(#(TParam~I,)*) -> Ret> for Func
+            where
+                Func: Fn(#(TParam~I,)*) -> Ret + 'static,
+                Ret: ReturnValue,
+                #(TParam~I: Param<'world>,)*
+            {
+                type System = Stateful<Func>;
+
+                fn into_system(self) -> Self::System
+                {
+                    Self::System {
+                        func: self,
+                        local_components: Vec::new(), // TODO: Use Vec::with_capacity
+                    }
+                }
+            }
+        });
+    };
+}
+
+seq!(C in 1..16 {
+    impl_system!(C);
+});
+
+impl<Func> SystemWithLocalComponents for Stateful<Func>
+{
+    fn add_local_component(&mut self, component_parts: ComponentParts)
+    {
+        self.local_components.push(component_parts);
+    }
+}
+
+#[derive(Debug)]
+pub struct Callbacks
+{
+    local_components: Vec<ComponentParts>,
+}
+
+impl crate::system::Callbacks for Callbacks
+{
+    fn on_created(&mut self, world: &mut World, metadata: Metadata)
+    {
+        for local_comp_parts in self.local_components.drain(..) {
+            world.add_component(metadata.ent_id, local_comp_parts);
+        }
+    }
+}
+
+fn init_initializable_params<'world, SystemT, Params>(
+    system: &mut SystemT,
+    inputs: Params::Inputs,
+) where
+    Params: MaybeInitializableParamTuple<'world, SystemT>,
+{
+    Params::init_initializable(system, inputs);
+}
+
+macro_rules! impl_observer {
+    ($c: tt) => {
+        seq!(I in 0..$c {
+            impl<'world, ObservedT, Func, Ret, #(TParam~I,)*> System<
+                'world,
+                fn(Observe<'world, ObservedT>, #(TParam~I,)*) -> Ret
+            > for Stateful<Func>
+            where
+                ObservedT: Observed,
+                Func: Fn(Observe<'world, ObservedT>, #(TParam~I,)*) -> Ret + 'static,
+                Ret: ReturnValue,
+                #(TParam~I: Param<'world>,)*
+            {
+                type Callbacks = Callbacks;
+
+                fn finish(self) -> (TypeErased, Callbacks)
+                {
+                    unimplemented!();
+                }
+            }
+
+            impl<'world, ObservedT, Func, Ret, #(TParam~I,)*> Initializable<
+                'world,
+                fn(Observe<'world, ObservedT>, #(TParam~I,)*) -> Ret
+            > for Stateful<Func>
+            where
+                ObservedT: Observed,
+                Func: Fn(Observe<'world, ObservedT>, #(TParam~I,)*) -> Ret + 'static,
+                Ret: ReturnValue,
+                #(TParam~I: Param<'world>,)*
+                (#(TParam~I,)*): MaybeInitializableParamTuple<'world, Self>
+            {
+                type Inputs = <
+                    (#(TParam~I,)*) as MaybeInitializableParamTuple<'world, Self>
+                >::Inputs;
+
+                fn initialize(mut self, inputs: Self::Inputs) -> Self
+                {
+                    init_initializable_params::<_, (#(TParam~I,)*)>(&mut self, inputs);
+
+                    self
+                }
+            }
+
+            impl<'world, ObservedT, Func, Ret, #(TParam~I,)*> Observer<
+                'world,
+                fn(Observe<'world, ObservedT>, #(TParam~I,)*) -> Ret
+            > for Stateful<Func>
+            where
+                ObservedT: Observed,
+                Func: Fn(Observe<'world, ObservedT>, #(TParam~I,)*) -> Ret + 'static,
+                Ret: ReturnValue,
+                #(TParam~I: Param<'world>,)*
+            {
+                type ObservedEvents = ObservedT::Events;
+
+                fn observed_events() -> Self::ObservedEvents
+                {
+                    ObservedT::events()
+                }
+
+                fn finish_observer(self) -> (ObserverWrapperComponent, Callbacks)
+                {
+                    #![allow(unused)]
+
+                    let Self { func, local_components } = self;
+
+                    let callbacks = Callbacks { local_components };
+
+                    let wrapper_comp = ObserverWrapperComponent::new(
+                        move |world, metadata, emitted_event| {
+                            // SAFETY: The caller of TypeErased::run ensures the lifetime
+                            // is correct
+                            let world = unsafe { &*std::ptr::from_ref(world) };
+
+                            // SAFETY: The caller of TypeErased::run ensures the lifetime
+                            // is correct
+                            let emitted_event = unsafe {
+                                transmute::<EmittedEvent<'_>, EmittedEvent<'_>>(
+                                    emitted_event
+                                )
+                            };
+
+                            func(Observe::new(world, emitted_event), #({
+                                TParam~I::new(world, &metadata)
+                            },)*).into_result()
+                        },
+                        type_name::<Func>()
+                    );
+
+                    (wrapper_comp, callbacks)
+                }
+            }
+
+            impl<'world, Func, Ret, ObservedT, #(TParam~I,)*> IntoSystem<
+                'world,
+                fn(Observe<'world, ObservedT>, #(TParam~I,)*) -> Ret
+            > for Func
+            where
+                ObservedT: Observed,
+                Func: Fn(Observe<'world, ObservedT>, #(TParam~I,)*) -> Ret + 'static,
+                Ret: ReturnValue,
+                #(TParam~I: Param<'world>,)*
+            {
+                type System = Stateful<Func>;
+
+                fn into_system(self) -> Stateful<Func>
+                {
+                    Stateful {
+                        func: self,
+                        local_components: Vec::new(), // TODO: Use Vec::with_capacity
+                    }
+                }
+            }
+        });
+    };
+}
+
+seq!(C in 0..16 {
+    impl_observer!(C);
+});