Added a fps counter

src/fps_counter.rs

@@ -0,0 +1,28 @@
+pub struct FpsCounter {
+    last_frame_time: std::time::Instant,
+    frame_count: u32,
+    fps: u32
+}
+
+impl FpsCounter {
+    pub fn new() -> Self {
+        Self {
+            last_frame_time: std::time::Instant::now(),
+            frame_count: 0,
+            fps: 0,
+        }
+    }
+
+    pub fn fps(&self) -> u32 {
+        self.fps
+    }
+
+    pub fn tick(&mut self) {
+        self.frame_count += 1;
+        if self.last_frame_time.elapsed() > std::time::Duration::from_secs(1) {
+            self.fps = self.frame_count;
+            self.frame_count = 0;
+            self.last_frame_time = std::time::Instant::now();
+        }
+    }
+}

src/main.rs

@@ -2,8 +2,11 @@ mod color;
 mod emitter;
 mod particle;
 mod renderer;
+mod fps_counter;
+
 use emitter::{EmitShape, Emitter, EmitterOptions};
 use particle::Particle;
+use fps_counter::FpsCounter;
 
 use fontdue::{Font, FontSettings};
 use glam::Vec2;
@@ -75,6 +78,7 @@ fn main() {
     let mut particles: Vec<Particle> = Vec::with_capacity(1000);
     let mut emitters: Vec<Emitter> = Vec::with_capacity(10);
     let mut renderer: Renderer = Renderer::new(WIDTH, HEIGHT);
+    let mut fps_counter: FpsCounter = FpsCounter::new();
 
     let mut last_win_size: (usize, usize) = window.get_size();
     let mut last_start_time: std::time::Instant = std::time::Instant::now();
@@ -89,6 +93,8 @@ fn main() {
         let frame_delta: std::time::Duration = last_start_time.elapsed();
         last_start_time = std::time::Instant::now();
 
+        fps_counter.tick();
+
         let win_size: (usize, usize) = window.get_size();
         if win_size != last_win_size {
             last_win_size = win_size;
@@ -121,7 +127,7 @@ fn main() {
 
         renderer.draw_text(
             &font,
-            format!("fps: {}\nparticles: {}", (1.0 / frame_delta.as_secs_f32()) as u32, particles.len()).as_str(),
+            format!("fps: {}\nparticles: {}", fps_counter.fps(), particles.len()).as_str(),
             Vec2::ZERO,
             8.0,
             0xffffff,

src/particle.rs

@@ -44,6 +44,7 @@ impl Particle {
 
     // Returns true if alive
     pub fn update(&mut self, frame_delta: std::time::Duration, renderer: &mut Renderer) -> bool {
+        // Delete itself if it's out of bounds, TODO: Size should be used
         if self.position.y < 0.0 || self.position.y > renderer.height() as f32 || self.position.x < 0.0 || self.position.x > renderer.width() as f32 {
             return false;
         }