changed logic of how to run the loop to allow for external event loops

Cargo.toml

@@ -11,3 +11,6 @@ include = ["/src", "LICENSE", "/examples"]
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+
+[dev-dependencies]
+winit = "0.25.0"

README.md

@@ -18,21 +18,26 @@ fn main() {
     let mut x: f32 = 0.0;
 
     // create a closure containing your update logic
-    let update_logic = |state: &mut State| {    
+    let mut update_logic = move |state: &mut State| {    
         // access loop metadata via the State object    
         x += state.get_timescale();
         print!("x: {} | ", x);
 
         // print information about the current tick's timings
-        state.debug_tick();
+        state.debug_time();
     };
     
     // create a closure containing your display logic
-    let display_logic = |state: &State| {
+    let display_logic = move |state: &State| {
         //
     };
 
     // run the simulation with your user-defined update and display logic
-    sim.run(update_logic, display_logic);
+    // initialize the sim (cleans internal clocks, etc.)
+    sim.init();
+    loop {
+        // "step" the sim forward
+        sim.step(&mut update_logic, &display_logic);
+    }
 }
 ```

examples/basics.rs

@@ -8,20 +8,25 @@ fn main() {
     let mut x: f32 = 0.0;
 
     // create a closure containing your update logic
-    let update_logic = |state: &mut State| {    
+    let mut update_logic = move |state: &mut State| {    
         // access loop metadata via the State object    
         x += state.get_timescale();
         print!("x: {} | ", x);
 
         // print information about the current tick's timings
-        state.debug_tick();
+        state.debug_time();
     };
     
     // create a closure containing your display logic
-    let display_logic = |state: &State| {
+    let display_logic = move |state: &State| {
         //
     };
 
     // run the simulation with your user-defined update and display logic
-    sim.run(update_logic, display_logic);
+    // initialize the sim (cleans internal clocks, etc.)
+    sim.init();
+    loop {
+        // "step" the sim forward
+        sim.step(&mut update_logic, &display_logic);
+    }
 }

examples/windowing.rs

@@ -0,0 +1,46 @@
+use hypoloop::core::{State, Loop};
+use winit::{
+    event::{ElementState, Event, KeyboardInput, WindowEvent},
+    event_loop::{ControlFlow, EventLoop},
+    window::{CursorIcon, WindowBuilder},
+};
+
+fn main() {
+    // create sim with default configuration
+    let mut sim = Loop::new();
+
+    // test variable
+    let mut x: f32 = 0.0;
+    
+    // create a winit event loop
+    let event_loop = EventLoop::new();
+    
+    // create a winit window
+    let window = WindowBuilder::new().build(&event_loop).unwrap();
+    window.set_title("Windowing test with hypoloop");
+
+    // create a closure containing your update logic
+    let mut update_logic = move |state: &mut State| {    
+        // access loop metadata via the State object    
+        x += state.get_timescale();
+        print!("x: {} | ", x);
+
+        // print information about the current tick's timings
+        state.debug_time();
+    };
+    
+    // create a closure containing your display logic
+    let display_logic = move |state: &State| {
+        // redraw the winit window
+        window.request_redraw();
+    };
+    
+    // initialize the sim (cleans internal clocks, etc.)
+    sim.init();
+
+    // run the winit event loop with embedded hypoloop sim
+    event_loop.run(move |event, _, control_flow| {
+        // "step" the sim forward
+        sim.step(&mut update_logic, &display_logic);
+    });
+}

src/lib.rs

@@ -7,10 +7,11 @@ pub mod core {
         update_interval: u32,
         timescale: f32,
         simulate: bool,
+        clock_start: Instant,
+        last_tick: Instant,
         delta_time: u32,
         irl_time: Duration,
-        sim_time: Duration,
+        sim_time: Duration
-        last_tick: Instant
     }
 
     impl State {
@@ -21,10 +22,11 @@ pub mod core {
                 update_interval: 40,
                 timescale: 1.0,
                 simulate: true,
+                clock_start: Instant::now(),
+                last_tick: Instant::now(),
                 delta_time: 0,
                 irl_time: Duration::new(0,0),
-                sim_time: Duration::new(0,0),
+                sim_time: Duration::new(0,0)
-                last_tick: Instant::now()
             };
 
             // Make sure that delta_time always starts the same as update_interval
@@ -59,12 +61,12 @@ pub mod core {
             self.last_tick
         }
 
-        /// Pauses the simulation
+        /// Pauses the simulation from within update logic
         pub fn pause(&mut self) {
             self.simulate = false;
         }
 
-        /// Resumes the simulation
+        /// Resumes the simulation from within update logic
         pub fn resume(&mut self) {
             self.simulate = true;
         }
@@ -74,12 +76,15 @@ pub mod core {
             self.timescale = timescale;
         }
 
-        /// Prints a string of information about the current tick
+        /// Prints a string of information about the current time (IRL time, Sim time, Delta time (tick), Delta time (step))
-        pub fn debug_tick(self) {
+        /// IRL time: Real time (in ms) elapsed since the start of the loop
+        /// Sim time: Virtual time (in ms) elapsed since the start of the loop
+        /// Delta time (tick): Real time (in ms) elapsed between the last tick and the previous tick
+        /// Delta time (step): Real time (in ms with nanosecond accuracy) elapsed since the last update tick
+        pub fn debug_time(self) {
             let elapsed_time = Instant::now().duration_since(self.last_tick);
             let loop_delay_ms = elapsed_time.as_nanos() as f32 / 1_000_000.0;
-            let loop_rate_hz = 1000.0 / loop_delay_ms;
+            println!("IRL time: {}ms | Sim time: {}ms | Delta time (tick): {}ms | Delta time (step): {}ms", self.irl_time.as_millis(), self.sim_time.as_millis(), self.delta_time, loop_delay_ms);
-            println!("IRL time: {}ms | Sim time: {}ms | Tick delay/rate: {}ms/{}hz", self.irl_time.as_millis(), self.sim_time.as_millis(), loop_delay_ms, loop_rate_hz);
         }
     }
 
@@ -99,15 +104,21 @@ pub mod core {
             }
         }
     
-        /// Initializes and runs the simulation using a user-supplied callback as the update logic
+        /// Initializes or re-initializes the simulation
-        pub fn run(&mut self, mut update_callback: impl FnMut(&mut State), mut display_callback: impl FnMut(&State)) {
+        pub fn init(&mut self) {
             // Make sure the simulation will run
             self.state.simulate = true;
 
-            // start the clock to keep track of real time
+            // reset the internal clocks
-            let clock_start = Instant::now();
+            self.state.clock_start = Instant::now();
+            self.state.irl_time = Duration::new(0,0);
+            self.state.sim_time = Duration::new(0,0);
+        }
 
-            while self.state.simulate {
+        /// Executes the per-loop logic (can be triggered manually so that hypoloop can be tied into external event loops)
+        pub fn step(&mut self, mut update_callback: impl FnMut(&mut State), display_callback: impl Fn(&State)) {
+            // don't run if the simulation is paused
+            if self.state.simulate {
                 // TODO - support frameskips
                 if !self.realtime || delta_time(self.state.last_tick) >= self.state.update_interval {
                     // mutable delta time and timescale for flexibility
@@ -121,7 +132,7 @@ pub mod core {
                     } else {
                         self.state.delta_time = self.state.update_interval;
                         self.state.sim_time += Duration::from_millis(self.state.update_interval as u64);
-                        self.state.irl_time = Instant::now().duration_since(clock_start);
+                        self.state.irl_time = Instant::now().duration_since(self.state.clock_start);
                     }
         
                     // update
@@ -144,34 +155,8 @@ pub mod core {
         }
     }
     
-    
-    // update function
-    // this is where all your per-tick logic should go
-    fn update(user_function: fn(), delta_time: u32, timescale: f32) {
-        // use timestep to scale per-tick calculations appropriately
-        let timestep: f32 = delta_time as f32 / 1000.0 * timescale;
-    
-        // call user update function
-        user_function();
-    }
-    
-    // display function
-    // this is where you should call a render function
-    fn display(delta_time: u32, timescale: f32, update_interval: u32) {
-        // use interpolation to smooth display values between ticks
-        let interpolation: f32 = delta_time as f32 / update_interval as f32 * timescale;
-    }
-    
     // gets the time in milliseconds that's elapsed since the earlier Instant
     fn delta_time(earlier: Instant) -> u32 {
         Instant::now().duration_since(earlier).as_millis() as u32
     }
-    
-    // default update function (does nothing)
-    fn default_update() {
-    }
-    
-    // default display function (does nothing)
-    fn default_display() {
-    }
 }