Add runner and timer

src/main.rs

@@ -1,4 +1,5 @@
 use std::io::stdout;
+use std::time::Duration;
 use anyhow::Error;
 use clap::Parser;
 use clap::ArgEnum;
@@ -11,8 +12,10 @@ use crate::fill::circle::CircleFillMode;
 use crate::fill::FillMode;
 use crate::fill::level::LevelFillMode;
 use crate::render::{Renderer, SamplerRenderer};
+use crate::runner::Runner;
 use crate::sampler::ComposedSampler;
 use crate::surface::WriteSurface;
+use crate::timer::SimpleTimer;
 use crate::vec::Vector;
 
 mod color;
@@ -24,6 +27,8 @@ mod surface;
 mod animation;
 mod sampler;
 mod render;
+mod timer;
+mod runner;
 
 #[derive(Copy, Clone, ArgEnum)]
 enum AnimationType {
@@ -81,12 +86,11 @@ fn main() -> Result<(), Error> {
     let sampler = Box::new(ComposedSampler::new(animation, fill, color, char));
     let surface = Box::new(WriteSurface::new(stdout(), width, height));
 
-    let mut renderer = Box::new(SamplerRenderer::new(surface, sampler));
+    let renderer = Box::new(SamplerRenderer::new(surface, sampler));
+    let timer = Box::new(SimpleTimer::new(Duration::from_millis(1000 / 60)));
+    let runner = Runner::new(Duration::from_secs(2), timer, renderer);
 
-    renderer.render(0.5);
-    renderer.present()?;
-
-    Ok(())
+    runner.run()
 }
 
 fn create_animation(animation: AnimationType, size: Vector) -> Box<dyn Animation> {

src/runner.rs

@@ -0,0 +1,31 @@
+use std::time::Duration;
+use anyhow::Error;
+use crate::Renderer;
+use crate::timer::Timer;
+
+pub struct Runner {
+    timer: Box<dyn Timer>,
+    ticks: u128,
+    renderer: Box<dyn Renderer>,
+}
+
+impl Runner {
+    pub fn new(duration: Duration,
+               timer: Box<dyn Timer>,
+               renderer: Box<dyn Renderer>) -> Self {
+        let ticks = duration.as_nanos() / timer.delay().as_nanos();
+
+        Self { timer, ticks, renderer }
+    }
+
+    pub fn run(mut self) -> Result<(), Error> {
+        for i in 0..self.ticks {
+            let step = i as f32 / self.ticks as f32;
+
+            self.renderer.render(step);
+            self.renderer.present()?;
+            self.timer.sleep();
+        }
+        self.renderer.finish()
+    }
+}

src/timer.rs

@@ -0,0 +1,39 @@
+use std::thread::sleep;
+use std::time::{Duration, Instant};
+use mockall::automock;
+
+#[automock]
+pub trait Timer {
+    fn sleep(&mut self);
+
+    fn delay(&self) -> Duration;
+}
+
+pub struct SimpleTimer {
+    delay: Duration,
+    last: Instant
+}
+
+impl SimpleTimer {
+    pub fn new(delay: Duration) -> Self {
+        Self {
+            last: Instant::now(),
+            delay,
+        }
+    }
+}
+
+impl Timer for SimpleTimer {
+    fn sleep(&mut self) {
+        let now = Instant::now();
+
+        if self.last + self.delay > now {
+            sleep(self.delay - (now - self.last));
+        }
+        self.last = Instant::now();
+    }
+
+    fn delay(&self) -> Duration {
+        self.delay
+    }
+}