Add system criteria

examples/testbed/src/free_fly_camera.rs

@@ -39,9 +39,9 @@ impl FreeFlyCamera {
     }
 }
 
-pub struct FreeFlyCameraController;
+pub struct FreeFlyCameraPlugin;
 
-impl SimpleSystem for FreeFlyCameraController {
+impl SimpleSystem for FreeFlyCameraPlugin {
     fn execute_mut(&mut self, world: &mut World) -> anyhow::Result<()> {
         let mut camera_rot = Vec3::default();
 
@@ -147,8 +147,8 @@ impl SimpleSystem for FreeFlyCameraController {
     }
 }
 
-impl Plugin for FreeFlyCameraController {
+impl Plugin for FreeFlyCameraPlugin {
     fn setup(&self, game: &mut Game) {
-        game.with_system("free_fly_camera_controller", FreeFlyCameraController, &[]);
+        game.with_system("free_fly_camera_system", FreeFlyCameraPlugin, &[]);
     }
 }

examples/testbed/src/main.rs

@@ -1,24 +1,60 @@
-use lyra_engine::{math::{self, Vec3}, ecs::{World, components::{transform::TransformComponent, camera::CameraComponent, model::ModelComponent}, EventQueue, SimpleSystem, Component}, math::Transform, input::{KeyCode, InputButtons, MouseMotion}, game::Game, plugin::Plugin, render::window::{CursorGrabMode, WindowOptions}, change_tracker::Ct};
+use lyra_engine::{math::{self, Vec3}, ecs::{World, components::{transform::TransformComponent, camera::CameraComponent, model::ModelComponent, DeltaTime}, EventQueue, SimpleSystem, Component, Criteria, CriteriaSchedule, BatchedSystem}, math::Transform, input::{KeyCode, InputButtons, MouseMotion}, game::Game, plugin::Plugin, render::window::{CursorGrabMode, WindowOptions}, change_tracker::Ct};
 use lyra_engine::assets::{ResourceManager, Model};
 
-use tracing::debug;
-
 mod free_fly_camera;
-use free_fly_camera::{FreeFlyCameraController, FreeFlyCamera};
+use free_fly_camera::{FreeFlyCameraPlugin, FreeFlyCamera};
 
-/* pub const VERTICES: &[Vertex] = &[
-    Vertex { position: [-0.0868241, 0.49240386, 0.0], tex_coords: [0.4131759, 0.00759614], }, // A
-    Vertex { position: [-0.49513406, 0.06958647, 0.0], tex_coords: [0.0048659444, 0.43041354], }, // B
-    Vertex { position: [-0.21918549, -0.44939706, 0.0], tex_coords: [0.28081453, 0.949397], }, // C
-    Vertex { position: [0.35966998, -0.3473291, 0.0], tex_coords: [0.85967, 0.84732914], }, // D
-    Vertex { position: [0.44147372, 0.2347359, 0.0], tex_coords: [0.9414737, 0.2652641], }, // E
-]; */
+struct FixedTimestep {
+    max_tps: u32,
+    fixed_time: f32,
+    accumulator: f32,
+}
 
-pub const INDICES: &[u16] = &[
-    0, 1, 4,
-    1, 2, 4,
-    2, 3, 4,
-];
+impl FixedTimestep {
+    pub fn new(max_tps: u32) -> Self {
+        Self {
+            max_tps,
+            fixed_time: Self::calc_fixed_time(max_tps),
+            accumulator: 0.0,
+        }
+    }
+
+    fn calc_fixed_time(max_tps: u32) -> f32 {
+        1.0 / max_tps as f32
+    }
+
+    fn set_tps(&mut self, tps: u32) {
+        self.max_tps = tps;
+        self.fixed_time = Self::calc_fixed_time(tps);
+    }
+
+    fn tps(&self) -> u32 {
+        self.max_tps
+    }
+
+    fn fixed_time(&self) -> f32 {
+        self.fixed_time
+    }
+}
+
+impl Criteria for FixedTimestep {
+    fn can_run(&mut self, world: &mut edict::World, check_count: u32) -> CriteriaSchedule {
+        if check_count == 0 {
+            let delta_time = world.get_resource::<DeltaTime>().unwrap();
+            self.accumulator += **delta_time;
+        }
+
+        if self.accumulator >= self.fixed_time {
+            self.accumulator -= self.fixed_time;
+            return CriteriaSchedule::YesAndLoop;
+        }
+
+        CriteriaSchedule::No
+    }
+}
+
+#[derive(Clone)]
+struct TpsAccumulator(f32);
 
 #[async_std::main]
 async fn main() {
@@ -54,111 +90,42 @@ async fn main() {
         Ok(())
     };
 
-    /* let fps_system = |world: &mut World| -> anyhow::Result<()> {
-        let mut counter: RefMut<fps_counter::FPSCounter> = world.get_resource_mut().unwrap();
+    let fps_system = |world: &mut World| -> anyhow::Result<()> {
+        let mut counter = world.get_resource_mut::<fps_counter::FPSCounter>().unwrap();
 
         let fps = counter.tick();
 
-        debug!("FPS: {fps}");
+        println!("FPS: {fps}");
 
         Ok(())
     };
     let fps_plugin = move |game: &mut Game| {
         let world = game.world();
         world.insert_resource(fps_counter::FPSCounter::new());
+    };
 
-        game.with_system("fps", fps_system, &["input"]);
-    }; */
-
-    let jiggle_system = |world: &mut World| -> anyhow::Result<()> {
-        let keys = world.get_resource::<InputButtons<KeyCode>>();
-        if keys.is_none() {
-            return Ok(());
-        }
-        let keys = keys.unwrap();
-
-        let speed = 0.01;
-        let rot_speed = 1.0;
-
-        let mut dir_x = 0.0;
-        let mut dir_y = 0.0;
-        let mut dir_z = 0.0;
-
-        let mut rot_x = 0.0;
-        let mut rot_y = 0.0;
-
-        if keys.is_pressed(KeyCode::A) {
-            dir_x += speed;
-        }
-        
-        if keys.is_pressed(KeyCode::D) {
-            dir_x -= speed;
-        }
-        
-        if keys.is_pressed(KeyCode::S) {
-            dir_y += speed;
-        }
-        
-        if keys.is_pressed(KeyCode::W) {
-            dir_y -= speed;
-        }
-
-        if keys.is_pressed(KeyCode::E) {
-            dir_z += speed;
-        }
-        
-        if keys.is_pressed(KeyCode::Q) {
-            dir_z -= speed;
-        }
-
-        if keys.is_pressed(KeyCode::Left) {
-            rot_y -= rot_speed;
-        }
-
-        if keys.is_pressed(KeyCode::Right) {
-            rot_y += rot_speed;
-        }
-
-        if keys.is_pressed(KeyCode::Up) {
-            rot_x -= rot_speed;
-        }
-
-        if keys.is_pressed(KeyCode::Down) {
-            rot_x += rot_speed;
-        }
-
-        drop(keys);
-
-        if dir_x == 0.0 && dir_y == 0.0 && dir_z == 0.0 && rot_x == 0.0 && rot_y == 0.0 {
-            return Ok(());
-        }
-
-        //debug!("moving by ({}, {})", dir_x, dir_y);
+    let spin_system = |world: &mut World| -> anyhow::Result<()> {
+        const SPEED: f32 = 5.0;
+        let delta_time = **world.get_resource::<DeltaTime>().unwrap();
 
         for transform in world.query_mut::<(&mut TransformComponent,)>().iter_mut() {
             let t = &mut transform.transform;
-            //debug!("Translation: {}", t.translation);
-            //debug!("Rotation: {}", t.rotation);
-
-            /* t.translation += glam::Vec3::new(0.0, 0.001, 0.0);
-            t.translation.x *= -1.0; */
-            t.translation.x += dir_x;
-            t.translation.y += dir_y;
-            t.translation.z += dir_z;
-            t.rotate_x(math::Angle::Degrees(rot_x));
-            t.rotate_y(math::Angle::Degrees(rot_y));
-        }
-
-        let events = world.get_resource_mut::<EventQueue>().unwrap();
-        if let Some(mm) = events.read_events::<MouseMotion>() {
-            debug!("Mouse motion: {:?}", mm);
+            t.rotate_y(math::Angle::Degrees(SPEED * delta_time));
         }
 
         Ok(())
     };
 
     let jiggle_plugin = move |game: &mut Game| {
-        //game.with_system("jiggle", jiggle_system, &["input"]);
+        game.world().insert_resource(TpsAccumulator(0.0));
+        
+        let mut sys = BatchedSystem::new();
+        sys.with_criteria(FixedTimestep::new(60));
+        sys.with_system(spin_system);
+        sys.with_system(fps_system);
+
+        game.with_system("fixed", sys, &[]);
+        fps_plugin(game);
     };
     
     Game::initialize().await
@@ -166,6 +133,6 @@ async fn main() {
         .with_startup_system(setup_sys)
         //.with_plugin(fps_plugin)
         .with_plugin(jiggle_plugin)
-        .with_plugin(FreeFlyCameraController)
+        .with_plugin(FreeFlyCameraPlugin)
         .run().await;
 }

src/ecs/components/delta_time.rs

@@ -6,7 +6,7 @@ use instant::Instant;
 use crate::plugin::Plugin;
 
 #[derive(Clone, Component)]
-pub struct DeltaTime(f32, Instant);
+pub struct DeltaTime(f32, Option<Instant>);
 
 impl std::ops::Deref for DeltaTime {
     type Target = f32;
@@ -25,8 +25,10 @@ impl std::ops::DerefMut for DeltaTime {
 fn delta_time_system(world: &mut World) -> anyhow::Result<()> {
     let now = Instant::now();
     let mut delta = world.get_resource_mut::<DeltaTime>().unwrap();
-    delta.0 = delta.1.elapsed().as_secs_f32();
-    delta.1 = now;
+    delta.0 = delta.1.unwrap_or(now).elapsed().as_secs_f32();
+    delta.1 = Some(now);
+
+    //println!("delta: {}", delta.0);
 
     Ok(())
 }
@@ -35,7 +37,7 @@ pub struct DeltaTimePlugin;
 
 impl Plugin for DeltaTimePlugin {
     fn setup(&self, game: &mut crate::game::Game) {
-        game.world().insert_resource(DeltaTime(0.0, Instant::now()));
+        game.world().insert_resource(DeltaTime(0.0, None));
         game.with_system("delta_time", delta_time_system, &[]);
     }
 }

src/ecs/mod.rs

@@ -1,151 +1,9 @@
 pub use edict::*;
 
 pub mod components;
+
 pub mod events;
 pub use events::*;
 
-use std::collections::HashMap;
-
-use petgraph::{stable_graph::{StableDiGraph, NodeIndex}, visit::Topo};
-use tracing::warn;
-
-/// A trait that represents a simple system
-pub trait SimpleSystem {
-    fn setup(&mut self, _world: &mut World) -> anyhow::Result<()> {
-        Ok(())
-    }
-
-    // todo: make async?
-    fn execute_mut(&mut self, world: &mut World) -> anyhow::Result<()>;
-}
-
-impl<S> SimpleSystem for S
-    where S: FnMut(&mut edict::World) -> anyhow::Result<()>
-{
-    fn execute_mut(&mut self, world: &mut World) -> anyhow::Result<()> {
-        self(world)
-    }
-}
-
-/// A system that executes a batch of systems in order that they were given.
-pub struct BatchedSystem {
-    systems: Vec<Box<dyn SimpleSystem>>,
-}
-
-impl BatchedSystem {
-    /// Create a new BatchedSystems. The systems will be executed in the order given.
-    pub fn new(systems: Vec<Box<dyn SimpleSystem>>) -> Self {
-        Self {
-            systems
-        }
-    }
-}
-
-impl SimpleSystem for BatchedSystem {
-    fn execute_mut(&mut self, world: &mut World) -> anyhow::Result<()> {
-        for system in self.systems.iter_mut() {
-            system.execute_mut(world)?;
-        }
-
-        Ok(())
-    }
-}
-
-struct SystemGraphNode {
-    name: String,
-    #[allow(dead_code)]
-    dependent_on: Vec<String>, // TODO
-    system: Box<dyn SimpleSystem>,
-}
-
-struct SystemGraphEdge {
-    
-}
-
-/// Dispatcher for multiple systems.
-/// 
-/// This struct uses a graph for finding executing systems with dependencies.
-/// At some point this will be multithreaded.
-pub struct SystemDispatcher {
-    graph: StableDiGraph<SystemGraphNode, SystemGraphEdge>,
-    node_refs: HashMap<String, NodeIndex>,
-}
-
-impl Default for SystemDispatcher {
-    fn default() -> Self {
-        Self {
-            graph: StableDiGraph::new(),
-            node_refs: HashMap::new(),
-        }
-    }
-}
-
-impl SystemDispatcher {
-    pub fn new() -> Self {
-        Self::default()
-    }
-
-    /// Adds a SimpleSystem to the SystemGraph.
-    ///  
-    /// WARN: Ensure that no cycles are created, this will cause the systems graph to not be sortable by topological sort,
-    /// and will cause a panic later on in the engine.
-    /// 
-    /// TODO: Return false if a cycle was created, making it impossible to know when to dispatch them. This will mean that the System would not of had been added.
-    pub fn add_system<S>(&mut self, name: &str, system: S, dependencies: &[&str]) -> bool
-    where
-        S: SimpleSystem + 'static
-    {
-        let name = name.to_string();
-        let dependencies: Vec<String> = dependencies.iter().map(|s| s.to_string()).collect();
-        let system = Box::new(system) as Box<dyn SimpleSystem>;
-
-        let added_index =
-            self.graph.add_node(SystemGraphNode {
-                name: name.to_string(),
-                dependent_on: dependencies.clone(),
-                system,
-            });
-
-        // store name ref to the graph node
-        self.node_refs.insert(name, added_index);
-
-        // find the dependencies in node_refs and add edges directed towards the new node
-        for depend in dependencies.into_iter() {
-            let idx = self.node_refs
-                .get(&depend)
-                .expect("Dependency not found!");
-
-            self.graph.add_edge(*idx, added_index, SystemGraphEdge { });
-        }
-
-        true
-    }
-
-    pub(crate) fn execute_systems(&mut self, world: &mut World) {
-        let mut topo = Topo::new(&self.graph);
-
-        while let Some(nx) = topo.next(&self.graph) {
-            let node = self.graph.node_weight_mut(nx).unwrap();
-
-            match node.system.execute_mut(world) {
-                Ok(()) => {},
-                Err(e) => {
-                    warn!("System execution of {} resulted in an error! '{}'.", node.name, e);
-
-                    // TODO: Find some way to stop traversing down a topopath in the graph executor and continue down a different one.
-                    // This might require a custom topopath implementation (preferably iterative). It would have to ensure that it
-                    // doesn't run other systems that are dependent on that failed system.
-                    return;
-                }
-            }
-        }
-    }
-}
-
-impl SimpleSystem for SystemDispatcher {
-    fn execute_mut(&mut self, world: &mut World) -> anyhow::Result<()> {
-        self.execute_systems(world);
-
-        Ok(())
-    }
-}
+pub mod system;
+pub use system::*;

src/ecs/system/batched.rs

@@ -0,0 +1,75 @@
+use super::{SimpleSystem, Criteria};
+use edict::World;
+
+/// A system that executes a batch of systems in order that they were given.
+/// You can optionally add criteria that must pass before the systems are
+/// executed.
+pub struct BatchedSystem {
+    systems: Vec<Box<dyn SimpleSystem>>,
+    criteria: Vec<Box<dyn Criteria>>,
+    criteria_checks: u32,
+}
+
+impl BatchedSystem {
+    /// Create a new BatchedSystem
+    pub fn new() -> Self {
+        Self {
+            systems: Vec::new(),
+            criteria: Vec::new(),
+            criteria_checks: 0,
+        }
+    }
+
+    pub fn with_system<S>(&mut self, system: S) -> &mut Self
+    where
+        S: SimpleSystem + 'static
+    {
+        self.systems.push(Box::new(system));
+        self
+    }
+
+    pub fn with_criteria<C>(&mut self, criteria: C) -> &mut Self
+    where
+        C: Criteria + 'static
+    {
+        self.criteria.push(Box::new(criteria));
+        self
+    }
+}
+
+impl SimpleSystem for BatchedSystem {
+    fn execute_mut(&mut self, world: &mut World) -> anyhow::Result<()> {
+        let mut can_run = true;
+        let mut check_again = false;
+
+        for criteria in self.criteria.iter_mut() {
+            match criteria.can_run(world, self.criteria_checks) {
+                super::CriteriaSchedule::Yes => can_run = can_run && true,
+                super::CriteriaSchedule::No => can_run = false,
+                super::CriteriaSchedule::YesAndLoop => {
+                    can_run = can_run && true;
+                    check_again = can_run && true;
+                },
+                super::CriteriaSchedule::NoAndLoop => {
+                    can_run = false;
+                    check_again = true;
+                },
+            }
+        }
+
+        if can_run {
+            for system in self.systems.iter_mut() {
+                system.execute_mut(world)?;
+            }
+        }
+
+        if check_again {
+            self.criteria_checks += 1;
+            self.execute_mut(world)?;
+        }
+
+        self.criteria_checks = 0;
+
+        Ok(())
+    }
+}

src/ecs/system/criteria.rs

@@ -0,0 +1,23 @@
+pub enum CriteriaSchedule {
+    Yes,
+    No,
+    YesAndLoop,
+    NoAndLoop,
+}
+
+pub trait Criteria {
+    /// Checks if this Criteria can run, and if it should check it again.
+    /// 
+    /// Parameters:
+    /// * `world` - The ecs world.
+    /// * `check_count` - The amount of times the Criteria has been checked this tick.
+    fn can_run(&mut self, world: &mut edict::World, check_count: u32) -> CriteriaSchedule;
+}
+
+impl<F> Criteria for F
+    where F: FnMut(&mut edict::World, u32) -> CriteriaSchedule
+{
+    fn can_run(&mut self, world: &mut edict::World, check_count: u32) -> CriteriaSchedule {
+        self(world, check_count)
+    }
+}

src/ecs/system/mod.rs

@@ -0,0 +1,127 @@
+pub mod batched;
+pub use batched::*;
+
+pub mod criteria;
+pub use criteria::*;
+
+use std::collections::HashMap;
+use edict::World;
+use petgraph::{stable_graph::{StableDiGraph, NodeIndex}, visit::Topo};
+use tracing::warn;
+
+/// A trait that represents a simple system
+pub trait SimpleSystem {
+    fn setup(&mut self, _world: &mut World) -> anyhow::Result<()> {
+        Ok(())
+    }
+
+    // todo: make async?
+    fn execute_mut(&mut self, world: &mut World) -> anyhow::Result<()>;
+}
+
+impl<S> SimpleSystem for S
+    where S: FnMut(&mut edict::World) -> anyhow::Result<()>
+{
+    fn execute_mut(&mut self, world: &mut World) -> anyhow::Result<()> {
+        self(world)
+    }
+}
+
+struct SystemGraphNode {
+    name: String,
+    #[allow(dead_code)]
+    dependent_on: Vec<String>, // TODO
+    system: Box<dyn SimpleSystem>,
+}
+
+struct SystemGraphEdge {
+    
+}
+
+/// Dispatcher for multiple systems.
+/// 
+/// This struct uses a graph for finding executing systems with dependencies.
+/// At some point this will be multithreaded.
+pub struct SystemDispatcher {
+    graph: StableDiGraph<SystemGraphNode, SystemGraphEdge>,
+    node_refs: HashMap<String, NodeIndex>,
+}
+
+impl Default for SystemDispatcher {
+    fn default() -> Self {
+        Self {
+            graph: StableDiGraph::new(),
+            node_refs: HashMap::new(),
+        }
+    }
+}
+
+impl SystemDispatcher {
+    pub fn new() -> Self {
+        Self::default()
+    }
+
+    /// Adds a SimpleSystem to the SystemGraph.
+    ///  
+    /// WARN: Ensure that no cycles are created, this will cause the systems graph to not be sortable by topological sort,
+    /// and will cause a panic later on in the engine.
+    /// 
+    /// TODO: Return false if a cycle was created, making it impossible to know when to dispatch them. This will mean that the System would not of had been added.
+    pub fn add_system<S>(&mut self, name: &str, system: S, dependencies: &[&str]) -> bool
+    where
+        S: SimpleSystem + 'static
+    {
+        let name = name.to_string();
+        let dependencies: Vec<String> = dependencies.iter().map(|s| s.to_string()).collect();
+        let system = Box::new(system) as Box<dyn SimpleSystem>;
+
+        let added_index =
+            self.graph.add_node(SystemGraphNode {
+                name: name.to_string(),
+                dependent_on: dependencies.clone(),
+                system,
+            });
+
+        // store name ref to the graph node
+        self.node_refs.insert(name, added_index);
+
+        // find the dependencies in node_refs and add edges directed towards the new node
+        for depend in dependencies.into_iter() {
+            let idx = self.node_refs
+                .get(&depend)
+                .expect("Dependency not found!");
+
+            self.graph.add_edge(*idx, added_index, SystemGraphEdge { });
+        }
+
+        true
+    }
+
+    pub(crate) fn execute_systems(&mut self, world: &mut World) {
+        let mut topo = Topo::new(&self.graph);
+
+        while let Some(nx) = topo.next(&self.graph) {
+            let node = self.graph.node_weight_mut(nx).unwrap();
+
+            match node.system.execute_mut(world) {
+                Ok(()) => {},
+                Err(e) => {
+                    warn!("System execution of {} resulted in an error! '{}'.", node.name, e);
+
+                    // TODO: Find some way to stop traversing down a topopath in the graph executor and continue down a different one.
+                    // This might require a custom topopath implementation (preferably iterative). It would have to ensure that it
+                    // doesn't run other systems that are dependent on that failed system.
+                    return;
+                }
+            }
+        }
+    }
+}
+
+impl SimpleSystem for SystemDispatcher {
+    fn execute_mut(&mut self, world: &mut World) -> anyhow::Result<()> {
+        self.execute_systems(world);
+
+        Ok(())
+    }
+}