add Display for Vec3, add SimulationSet, and add EntityChunkPos component

6 files changed, 142 insertions, 72 deletions

diff --git a/azalea-core/src/position.rs b/azalea-core/src/position.rs
index 369607c5..e2a9c4cc 100755
--- a/azalea-core/src/position.rs
+++ b/azalea-core/src/position.rs
@@ -564,6 +564,12 @@ impl fmt::Display for BlockPos {
         write!(f, "{} {} {}", self.x, self.y, self.z)
     }
 }
+impl fmt::Display for Vec3 {
+    /// Display a position as `x y z`.
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "{} {} {}", self.x, self.y, self.z)
+    }
+}
 
 const PACKED_X_LENGTH: u64 = 1 + 25; // minecraft does something a bit more complicated to get this 25
 const PACKED_Z_LENGTH: u64 = PACKED_X_LENGTH;
diff --git a/azalea-core/src/tick.rs b/azalea-core/src/tick.rs
index db10d80a..c6f02c12 100644
--- a/azalea-core/src/tick.rs
+++ b/azalea-core/src/tick.rs
@@ -1,4 +1,8 @@
 use bevy_ecs::schedule::ScheduleLabel;
 
+/// A Bevy schedule that runs every Minecraft game tick, i.e. every 50ms.
+///
+/// Many client systems run on this schedule, the most important one being
+/// physics.
 #[derive(ScheduleLabel, Hash, Copy, Clone, Debug, Default, Eq, PartialEq)]
 pub struct GameTick;
diff --git a/azalea-entity/src/lib.rs b/azalea-entity/src/lib.rs
index e08284a9..1b643e4a 100644
--- a/azalea-entity/src/lib.rs
+++ b/azalea-entity/src/lib.rs
@@ -23,6 +23,7 @@ use bevy_ecs::{bundle::Bundle, component::Component};
 pub use data::*;
 use derive_more::{Deref, DerefMut};
 pub use dimensions::EntityDimensions;
+use plugin::indexing::EntityChunkPos;
 use std::{
     fmt::Debug,
     hash::{Hash, Hasher},
@@ -347,6 +348,9 @@ pub struct EntityBundle {
     pub world_name: InstanceName,
     pub position: Position,
     pub last_sent_position: LastSentPosition,
+
+    pub chunk_pos: EntityChunkPos,
+
     pub physics: Physics,
     pub direction: LookDirection,
     pub eye_height: EyeHeight,
@@ -375,6 +379,7 @@ impl EntityBundle {
             uuid: EntityUuid(uuid),
             world_name: InstanceName(world_name),
             position: Position(pos),
+            chunk_pos: EntityChunkPos(ChunkPos::from(&pos)),
             last_sent_position: LastSentPosition(pos),
             physics: Physics::new(dimensions, &pos),
             eye_height: EyeHeight(eye_height),
diff --git a/azalea-entity/src/plugin/indexing.rs b/azalea-entity/src/plugin/indexing.rs
index 86e91ff2..c8aaffb0 100644
--- a/azalea-entity/src/plugin/indexing.rs
+++ b/azalea-entity/src/plugin/indexing.rs
@@ -8,12 +8,13 @@ use bevy_ecs::{
     query::Changed,
     system::{Commands, Query, Res, ResMut, Resource},
 };
+use derive_more::{Deref, DerefMut};
 use nohash_hasher::IntMap;
 use std::{collections::HashMap, fmt::Debug};
 use tracing::{debug, warn};
 use uuid::Uuid;
 
-use crate::{EntityUuid, LastSentPosition, Position};
+use crate::{EntityUuid, Position};
 
 use super::LoadedBy;
 
@@ -83,33 +84,37 @@ impl Debug for EntityUuidIndex {
     }
 }
 
-// TODO: this should keep track of chunk position changes in a better way
-// instead of relying on LastSentPosition
+/// The chunk position that an entity is currently in.
+#[derive(Component, Debug, Deref, DerefMut)]
+pub struct EntityChunkPos(pub ChunkPos);
 
 /// Update the chunk position indexes in [`Instance::entities_by_chunk`].
 ///
 /// [`Instance::entities_by_chunk`]: azalea_world::Instance::entities_by_chunk
 pub fn update_entity_chunk_positions(
-    mut query: Query<(Entity, &Position, &LastSentPosition, &InstanceName), Changed<Position>>,
+    mut query: Query<(Entity, &Position, &InstanceName, &mut EntityChunkPos), Changed<Position>>,
     instance_container: Res<InstanceContainer>,
 ) {
-    for (entity, pos, last_pos, world_name) in query.iter_mut() {
+    for (entity, pos, world_name, mut entity_chunk_pos) in query.iter_mut() {
         let instance_lock = instance_container.get(world_name).unwrap();
         let mut instance = instance_lock.write();
 
-        let old_chunk = ChunkPos::from(*last_pos);
+        let old_chunk = **entity_chunk_pos;
         let new_chunk = ChunkPos::from(*pos);
-
         if old_chunk != new_chunk {
-            // move the entity from the old chunk to the new one
-            if let Some(entities) = instance.entities_by_chunk.get_mut(&old_chunk) {
-                entities.remove(&entity);
+            **entity_chunk_pos = new_chunk;
+
+            if old_chunk != new_chunk {
+                // move the entity from the old chunk to the new one
+                if let Some(entities) = instance.entities_by_chunk.get_mut(&old_chunk) {
+                    entities.remove(&entity);
+                }
+                instance
+                    .entities_by_chunk
+                    .entry(new_chunk)
+                    .or_default()
+                    .insert(entity);
             }
-            instance
-                .entities_by_chunk
-                .entry(new_chunk)
-                .or_default()
-                .insert(entity);
         }
     }
 }
diff --git a/azalea/src/lib.rs b/azalea/src/lib.rs
index fd2cb83a..84c215d5 100644
--- a/azalea/src/lib.rs
+++ b/azalea/src/lib.rs
@@ -29,6 +29,7 @@ pub use azalea_core::{
     resource_location::ResourceLocation,
 };
 pub use azalea_entity as entity;
+pub use azalea_physics as physics;
 pub use azalea_protocol as protocol;
 pub use azalea_registry as registry;
 pub use azalea_world as world;
diff --git a/azalea/src/pathfinder/simulation.rs b/azalea/src/pathfinder/simulation.rs
index ab3b340e..bea99e93 100644
--- a/azalea/src/pathfinder/simulation.rs
+++ b/azalea/src/pathfinder/simulation.rs
@@ -7,7 +7,7 @@ use azalea_client::{
 };
 use azalea_core::{position::Vec3, resource_location::ResourceLocation, tick::GameTick};
 use azalea_entity::{
-    attributes::AttributeInstance, Attributes, EntityDimensions, Physics, Position,
+    attributes::AttributeInstance, Attributes, EntityDimensions, LookDirection, Physics, Position,
 };
 use azalea_world::{ChunkStorage, Instance, InstanceContainer, MinecraftEntityId, PartialInstance};
 use bevy_app::App;
@@ -20,6 +20,7 @@ pub struct SimulatedPlayerBundle {
     pub position: Position,
     pub physics: Physics,
     pub physics_state: PhysicsState,
+    pub look_direction: LookDirection,
     pub attributes: Attributes,
     pub inventory: InventoryComponent,
 }
@@ -35,6 +36,7 @@ impl SimulatedPlayerBundle {
             position: Position::new(position),
             physics: Physics::new(dimensions, &position),
             physics_state: PhysicsState::default(),
+            look_direction: LookDirection::new(0.0, 0.0),
             attributes: Attributes {
                 speed: AttributeInstance::new(0.1),
                 attack_speed: AttributeInstance::new(4.0),
@@ -44,6 +46,77 @@ impl SimulatedPlayerBundle {
     }
 }
 
+fn simulation_instance_name() -> ResourceLocation {
+    ResourceLocation::new("azalea:simulation")
+}
+
+fn create_simulation_instance(chunks: ChunkStorage) -> (App, Arc<RwLock<Instance>>) {
+    let instance_name = simulation_instance_name();
+
+    let instance = Arc::new(RwLock::new(Instance {
+        chunks,
+        ..Default::default()
+    }));
+
+    let mut app = App::new();
+    // we don't use all the default azalea plugins because we don't need all of them
+    app.add_plugins((
+        azalea_physics::PhysicsPlugin,
+        azalea_entity::EntityPlugin,
+        azalea_client::movement::PlayerMovePlugin,
+        super::PathfinderPlugin,
+        crate::BotPlugin,
+        azalea_client::task_pool::TaskPoolPlugin::default(),
+        // for mining
+        azalea_client::inventory::InventoryPlugin,
+        azalea_client::mining::MinePlugin,
+        azalea_client::interact::InteractPlugin,
+    ))
+    .insert_resource(InstanceContainer {
+        instances: [(instance_name.clone(), Arc::downgrade(&instance.clone()))]
+            .iter()
+            .cloned()
+            .collect(),
+    })
+    .add_event::<SendPacketEvent>();
+
+    app.edit_schedule(bevy_app::Main, |schedule| {
+        schedule.set_executor_kind(bevy_ecs::schedule::ExecutorKind::SingleThreaded);
+    });
+
+    (app, instance)
+}
+
+fn create_simulation_player(
+    ecs: &mut World,
+    instance: Arc<RwLock<Instance>>,
+    player: SimulatedPlayerBundle,
+) -> Entity {
+    let instance_name = simulation_instance_name();
+
+    let mut entity = ecs.spawn((
+        MinecraftEntityId(0),
+        azalea_entity::LocalEntity,
+        azalea_entity::metadata::PlayerMetadataBundle::default(),
+        azalea_entity::EntityBundle::new(
+            Uuid::nil(),
+            *player.position,
+            azalea_registry::EntityKind::Player,
+            instance_name,
+        ),
+        azalea_client::InstanceHolder {
+            // partial_instance is never actually used by the pathfinder so
+            partial_instance: Arc::new(RwLock::new(PartialInstance::default())),
+            instance: instance.clone(),
+        },
+        InventoryComponent::default(),
+    ));
+    entity.insert(player);
+
+    let entity_id = entity.id();
+    entity_id
+}
+
 /// Simulate the Minecraft world to see if certain movements would be possible.
 pub struct Simulation {
     pub app: App,
@@ -53,71 +126,47 @@ pub struct Simulation {
 
 impl Simulation {
     pub fn new(chunks: ChunkStorage, player: SimulatedPlayerBundle) -> Self {
-        let instance_name = ResourceLocation::new("azalea:simulation");
-
-        let instance = Arc::new(RwLock::new(Instance {
-            chunks,
-            ..Default::default()
-        }));
-
-        let mut app = App::new();
-        // we don't use all the default azalea plugins because we don't need all of them
-        app.add_plugins((
-            azalea_physics::PhysicsPlugin,
-            azalea_entity::EntityPlugin,
-            azalea_client::movement::PlayerMovePlugin,
-            super::PathfinderPlugin,
-            crate::BotPlugin,
-            azalea_client::task_pool::TaskPoolPlugin::default(),
-            // for mining
-            azalea_client::inventory::InventoryPlugin,
-            azalea_client::mining::MinePlugin,
-            azalea_client::interact::InteractPlugin,
-        ))
-        .insert_resource(InstanceContainer {
-            instances: [(instance_name.clone(), Arc::downgrade(&instance.clone()))]
-                .iter()
-                .cloned()
-                .collect(),
-        })
-        .add_event::<SendPacketEvent>();
-
-        app.edit_schedule(bevy_app::Main, |schedule| {
-            schedule.set_executor_kind(bevy_ecs::schedule::ExecutorKind::SingleThreaded);
-        });
-
-        let mut entity = app.world.spawn((
-            MinecraftEntityId(0),
-            azalea_entity::LocalEntity,
-            azalea_entity::metadata::PlayerMetadataBundle::default(),
-            azalea_entity::EntityBundle::new(
-                Uuid::nil(),
-                *player.position,
-                azalea_registry::EntityKind::Player,
-                instance_name,
-            ),
-            azalea_client::InstanceHolder {
-                // partial_instance is never actually used by the pathfinder so
-                partial_instance: Arc::new(RwLock::new(PartialInstance::default())),
-                instance: instance.clone(),
-            },
-            InventoryComponent::default(),
-        ));
-        entity.insert(player);
-
-        let entity_id = entity.id();
-
+        let (mut app, instance) = create_simulation_instance(chunks);
+        let entity = create_simulation_player(&mut app.world, instance.clone(), player);
         Self {
             app,
-            entity: entity_id,
+            entity,
             _instance: instance,
         }
     }
+
     pub fn tick(&mut self) {
-        self.app.world.run_schedule(GameTick);
         self.app.update();
+        self.app.world.run_schedule(GameTick);
     }
     pub fn position(&self) -> Vec3 {
         **self.app.world.get::<Position>(self.entity).unwrap()
     }
 }
+
+/// A set of simulations, useful for efficiently doing multiple simulations.
+pub struct SimulationSet {
+    pub app: App,
+    instance: Arc<RwLock<Instance>>,
+}
+impl SimulationSet {
+    pub fn new(chunks: ChunkStorage) -> Self {
+        let (app, instance) = create_simulation_instance(chunks);
+        Self { app, instance }
+    }
+    pub fn tick(&mut self) {
+        self.app.update();
+        self.app.world.run_schedule(GameTick);
+    }
+
+    pub fn spawn(&mut self, player: SimulatedPlayerBundle) -> Entity {
+        create_simulation_player(&mut self.app.world, self.instance.clone(), player)
+    }
+    pub fn despawn(&mut self, entity: Entity) {
+        self.app.world.despawn(entity);
+    }
+
+    pub fn position(&self, entity: Entity) -> Vec3 {
+        **self.app.world.get::<Position>(entity).unwrap()
+    }
+}