Use EntityBuilder Instead of RuntimeBundle

zicklag · zicklag · commit a383a184183a · 2020-10-20T13:56:40.000-05:00
Gets rid of RuntimeBundle and adds the `add_dynamic` function to
EntityBuilder to serve its purpose.
diff --git a/crates/bevy_ecs/hecs/src/bundle.rs b/crates/bevy_ecs/hecs/src/bundle.rs
@@ -42,36 +42,6 @@ pub trait DynamicBundle {
     unsafe fn put(self, f: impl FnMut(*mut u8, ComponentId, usize) -> bool);
 }
 
-/// A bundle that can be created dynamically at runtime
-#[derive(Debug)]
-pub struct RuntimeBundle {
-    /// The information for each component in this bundle
-    pub components: Vec<TypeInfo>,
-    /// The raw data for all of the components in the bundle
-    pub data: Vec<Vec<u8>>,
-}
-
-impl DynamicBundle for RuntimeBundle {
-    fn with_ids<T>(&self, f: impl FnOnce(&[ComponentId]) -> T) -> T {
-        let ids: Vec<_> = self.components.iter().map(|x| x.id()).collect();
-        f(ids.as_slice())
-    }
-
-    fn type_info(&self) -> Vec<TypeInfo> {
-        self.components.clone()
-    }
-
-    unsafe fn put(self, mut f: impl FnMut(*mut u8, ComponentId, usize) -> bool) {
-        for (mut data, info) in self.data.into_iter().zip(self.components.into_iter()) {
-            debug_assert_eq!(data.len(), info.layout().size());
-
-            if f(data.as_mut_ptr(), info.id(), info.layout().size()) {
-                std::mem::forget(data);
-            }
-        }
-    }
-}
-
 /// A statically typed collection of components
 pub trait Bundle: DynamicBundle {
     #[doc(hidden)]
diff --git a/crates/bevy_ecs/hecs/src/entity_builder.rs b/crates/bevy_ecs/hecs/src/entity_builder.rs
@@ -25,11 +25,8 @@ use crate::{
 };
 
 use bevy_utils::HashSet;
-use core::{
-    any::TypeId,
-    mem::{self, MaybeUninit},
-    ptr,
-};
+use core::{intrinsics::copy_nonoverlapping, mem::MaybeUninit, ptr};
+use ptr::slice_from_raw_parts;
 
 use crate::{archetype::TypeInfo, Component, DynamicBundle};
 
@@ -68,24 +65,40 @@ impl EntityBuilder {
 
     /// Add `component` to the entity
     pub fn add<T: Component>(&mut self, component: T) -> &mut Self {
-        if !self.id_set.insert(TypeId::of::<T>().into()) {
+        self.add_dynamic(TypeInfo::of::<T>(), unsafe {
+            &*slice_from_raw_parts(
+                &component as *const T as *const u8,
+                std::mem::size_of::<T>(),
+            )
+        });
+        std::mem::forget(component);
+        self
+    }
+
+    /// Add a dynamic component to the entity
+    ///
+    /// You must provide the type info and a slice containing the component data
+    pub fn add_dynamic(&mut self, type_info: TypeInfo, data: &[u8]) -> &mut Self {
+        debug_assert_eq!(type_info.layout().size(), data.len());
+
+        if !self.id_set.insert(type_info.id) {
             return self;
         }
-        let end = self.cursor + mem::size_of::<T>();
+        let end = self.cursor + type_info.layout.size();
         if end > self.storage.len() {
             self.grow(end);
         }
-        if mem::size_of::<T>() != 0 {
+        if type_info.layout.size() != 0 {
             unsafe {
-                self.storage
-                    .as_mut_ptr()
-                    .add(self.cursor)
-                    .cast::<T>()
-                    .write_unaligned(component);
+                copy_nonoverlapping(
+                    data.as_ptr(),
+                    self.storage.as_mut_ptr().add(self.cursor) as *mut u8,
+                    data.len(),
+                );
             }
         }
-        self.info.push((TypeInfo::of::<T>(), self.cursor));
-        self.cursor += mem::size_of::<T>();
+        self.info.push((type_info, self.cursor));
+        self.cursor += type_info.layout().size();
         self
     }
 
diff --git a/crates/bevy_ecs/hecs/src/lib.rs b/crates/bevy_ecs/hecs/src/lib.rs
@@ -77,7 +77,7 @@ mod world;
 
 pub use archetype::{Archetype, TypeState};
 pub use borrow::{AtomicBorrow, Ref, RefMut};
-pub use bundle::{Bundle, DynamicBundle, MissingComponent, RuntimeBundle};
+pub use bundle::{Bundle, DynamicBundle, MissingComponent};
 pub use entities::{Entity, EntityReserver, Location, NoSuchEntity};
 pub use entity_builder::{BuiltEntity, EntityBuilder};
 pub use query::{
diff --git a/examples/ecs/dynamic_components.rs b/examples/ecs/dynamic_components.rs
@@ -11,7 +11,7 @@ use std::{alloc::Layout, time::Duration};
 use bevy::prelude::*;
 use bevy_app::ScheduleRunnerPlugin;
 use bevy_ecs::{
-    ComponentId, DynamicComponentInfo, DynamicComponentQuery, DynamicSystemSettings, RuntimeBundle,
+    ComponentId, DynamicComponentInfo, DynamicComponentQuery, DynamicSystemSettings, EntityBuilder,
     TypeInfo,
 };
 
@@ -24,11 +24,12 @@ fn spawn_scene(world: &mut World, _resources: &mut Resources) {
     // representing a Position and one representing a Velocity. Each of these will be made up of two
     // bytes for simplicity, one representing the x and y position/velocity.
 
-    // We create our first component bundle
-    let components1 = RuntimeBundle {
-        // we must define our components' type information
-        components: vec![
-            // First we define our "Position" component
+    // We create our first entity
+    let mut builder = EntityBuilder::new();
+    // Then we add our "Position component"
+    let entity1 = builder
+        .add_dynamic(
+            // We need to describe our component's information
             TypeInfo {
                 // We must provide a unique id for the compoonent
                 id: ComponentId::ExternalId(0),
@@ -37,53 +38,62 @@ fn spawn_scene(world: &mut World, _resources: &mut Resources) {
                 // And we must specify a drop function for our component
                 drop: |_| (),
             },
-            // Next we define our "Velocity" component
+            // And provide the raw byte data data for the component
+            vec![
+                0, // X position byte
+                0, // Y position byte
+            ]
+            // And cast the data to a pointer
+            .as_slice(),
+        )
+        // Next we add our "Velocity component"
+        .add_dynamic(
             TypeInfo {
-                // We must specify a different ID for the velocity component
+                // This component needs its own unique ID
                 id: ComponentId::ExternalId(1),
-                // We specify the layout which happens to be the same as "Position"
-                layout: Layout::from_size_align(2, 1).unwrap(),
-                // And the drop function
+                layout: Layout::from_size_align(2 /* size */, 1 /* alignment */).unwrap(),
                 drop: |_| (),
             },
-        ],
-
-        // Data must be a Vector of Vectors of bytes and must contain the raw byte data for
-        // each of the components we want to add
-        data: vec![
-            // This will be the raw byte data for our position component
             vec![
                 0, // X position byte
-                0, // Y position byte
-            ],
-            // This will be the raw byte data for our velocity component
-            vec![
-                1, // X velocity byte
-                0, // Y velocity byte
-            ],
-        ],
-    };
-
-    // Now we create another bundle for our next entity
-    let components2 = RuntimeBundle {
-        components: vec![
+                1, // Y position byte
+            ]
+            .as_slice(),
+        )
+        .build();
+
+    // And let's create another entity
+    let mut builder = EntityBuilder::new();
+    let entity2 = builder
+        .add_dynamic(
             TypeInfo {
                 id: ComponentId::ExternalId(0),
-                layout: Layout::from_size_align(2 /* size */, 1 /* alignment */).unwrap(),
+                layout: Layout::from_size_align(2, 1).unwrap(),
                 drop: |_| (),
             },
+            vec![
+                0, // X position byte
+                0, // Y position byte
+            ]
+            .as_slice(),
+        )
+        .add_dynamic(
             TypeInfo {
                 id: ComponentId::ExternalId(1),
                 layout: Layout::from_size_align(2, 1).unwrap(),
                 drop: |_| (),
             },
-        ],
-        data: vec![vec![0, 0], vec![0, 2]],
-    };
+            vec![
+                2, // X position byte
+                0, // Y position byte
+            ]
+            .as_slice(),
+        )
+        .build();
 
     // Now we can spawn our entities
-    world.spawn(components1);
-    world.spawn(components2);
+    world.spawn(entity1);
+    world.spawn(entity2);
 }
 
 fn main() {
