refactor(ecs): use same ID for entities & components

1 files changed, 42 insertions, 47 deletions

diff --git a/ecs/src/component.rs b/ecs/src/component.rs
index 0506346..e1f2858 100644
--- a/ecs/src/component.rs
+++ b/ecs/src/component.rs
@@ -1,8 +1,9 @@
-use std::any::{type_name, Any, TypeId};
+use std::any::{type_name, Any};
 use std::fmt::Debug;
 
 use seq_macro::seq;
 
+use crate::uid::Uid;
 use crate::lock::{ReadGuard, WriteGuard};
 use crate::system::{ComponentRef, ComponentRefMut, Input as SystemInput};
 use crate::type_name::TypeName;
@@ -27,8 +28,13 @@ pub trait Component: SystemInput + Any + TypeName
     where
         Self: Sized;
 
-    /// Returns the ID of this component's type.
-    fn id(&self) -> Id;
+    /// Returns the ID of this component.
+    fn id() -> Uid
+    where
+        Self: Sized;
+
+    /// The ID of the component `self`. Returns the same value as [`Component::id`].
+    fn self_id(&self) -> Uid;
 
     #[doc(hidden)]
     fn as_any_mut(&mut self) -> &mut dyn Any;
@@ -36,9 +42,19 @@ pub trait Component: SystemInput + Any + TypeName
     #[doc(hidden)]
     fn as_any(&self) -> &dyn Any;
 
-    fn is_optional(&self) -> bool
+    /// Whether the component `self` is optional. Returns the same value as
+    /// [`Component::is_optional`].
+    fn self_is_optional(&self) -> IsOptional
     {
-        false
+        IsOptional::No
+    }
+
+    /// Returns whether this component is optional.
+    fn is_optional() -> IsOptional
+    where
+        Self: Sized,
+    {
+        IsOptional::No
     }
 }
 
@@ -84,9 +100,14 @@ where
     type Ref<'component> = Option<ComponentRef<'component, ComponentT>>;
     type RefMut<'component> = Option<ComponentRefMut<'component, ComponentT>>;
 
-    fn id(&self) -> Id
+    fn id() -> Uid
+    {
+        ComponentT::id()
+    }
+
+    fn self_id(&self) -> Uid
     {
-        Id::of::<Self>()
+        Self::id()
     }
 
     fn as_any_mut(&mut self) -> &mut dyn Any
@@ -99,9 +120,14 @@ where
         self
     }
 
-    fn is_optional(&self) -> bool
+    fn self_is_optional(&self) -> IsOptional
+    {
+        Self::is_optional()
+    }
+
+    fn is_optional() -> IsOptional
     {
-        true
+        IsOptional::Yes
     }
 }
 
@@ -117,24 +143,6 @@ where
 
 impl<ComponentT> SystemInput for Option<ComponentT> where ComponentT: Component {}
 
-/// The ID of a [`Component`] type.
-#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
-pub struct Id
-{
-    inner: TypeId,
-}
-
-impl Id
-{
-    #[must_use]
-    pub fn of<ComponentT>() -> Self
-    where
-        ComponentT: Component,
-    {
-        Self { inner: TypeId::of::<ComponentT>() }
-    }
-}
-
 /// A sequence of components.
 pub trait Sequence
 {
@@ -172,7 +180,7 @@ pub trait Sequence
 #[non_exhaustive]
 pub struct Metadata
 {
-    pub id: Id,
+    pub id: Uid,
     pub is_optional: IsOptional,
 }
 
@@ -181,8 +189,8 @@ impl Metadata
     pub fn of<ComponentT: Component + ?Sized>(component: &ComponentT) -> Self
     {
         Self {
-            id: component.id(),
-            is_optional: component.is_optional().into(),
+            id: component.self_id(),
+            is_optional: component.self_is_optional(),
         }
     }
 }
@@ -207,19 +215,6 @@ impl From<bool> for IsOptional
     }
 }
 
-/// Returns whether the given component type is a optional component.
-///
-/// Will return `true` if the component is a [`Option`].
-#[must_use]
-pub fn is_optional<ComponentT: Component>() -> bool
-{
-    if Id::of::<ComponentT>() == Id::of::<Option<ComponentT::Component>>() {
-        return true;
-    }
-
-    false
-}
-
 pub trait FromOptionalMut<'comp>
 {
     fn from_optional_mut_component(
@@ -260,8 +255,8 @@ macro_rules! inner {
                     vec![
                         #(
                             Metadata {
-                                id: Id::of::<Comp~I>(),
-                                is_optional: is_optional::<Comp~I>().into()
+                                id: Comp~I::id(),
+                                is_optional: Comp~I::is_optional()
                             },
                         )*
                     ]
@@ -281,7 +276,7 @@ macro_rules! inner {
 
                     for comp in components {
                         #(
-                            if comp.id == Id::of::<Comp~I::Component>() {
+                            if comp.id == Comp~I::Component::id() {
                                 comp_~I = Some(lock_component(comp));
                                 continue;
                             }
@@ -308,7 +303,7 @@ macro_rules! inner {
 
                     for comp in components {
                         #(
-                            if comp.id == Id::of::<Comp~I::Component>() {
+                            if comp.id == Comp~I::Component::id() {
                                 comp_~I = Some(lock_component(comp));
                                 continue;
                             }