Frame stats

src/main.rs

@@ -62,9 +62,29 @@ impl<'a> DrawContext<'a> {
 	}
 }
 
+// Frame timing:
+// <start>
+//	Input
+//	Draw
+// <draw>
+//	Physics
+// <phys>
+//	Wait
+// <wait>
+//	Apply input
+// <total>
+#[derive(Debug, Default)]
+struct PerformanceStats {
+	last_frame_draw: f64,
+	last_frame_phys: f64,
+	last_frame_wait: f64,
+	last_frame_total: f64,
+}
+
 fn main() -> Result<(), String> {
 	let sdl_context = sdl2::init()?;
 	let video_subsystem = sdl_context.video()?;
+	let mut stats = PerformanceStats::default();
 
 	let window = video_subsystem
 		.window("SDL2", 640, 480)
@@ -82,20 +102,15 @@ fn main() -> Result<(), String> {
 
 	let sa = SpriteAtlas::new(&texture_creator)?;
 	let mut event_pump = sdl_context.event_pump()?;
-
-	let mut system = System::new();
-
+	let mut dc = DrawContext::new(&mut canvas, Camera::new());
 	let mut i = InputStatus::new();
 
+	let mut system = System::new();
 	let mut s = Ship::new(ShipKind::Gypsum, Cartesian::new(0.0, 0.0));
 
-	//let mut last_frame_time = 0f64;
 	let mut frame_start;
-
 	let mut running = true;
 
-	let mut dc = DrawContext::new(&mut canvas, Camera::new());
-
 	while running {
 		frame_start = Instant::now();
 		dc.update();
@@ -120,19 +135,22 @@ fn main() -> Result<(), String> {
 		system.draw(&mut dc, &sa)?;
 		s.draw(&mut dc, &sa)?;
 		dc.canvas.present();
+		stats.last_frame_draw = frame_start.elapsed().as_secs_f64();
+
+		// Physics goes here
 
 		let frame_time = frame_start.elapsed().as_secs_f64();
+		stats.last_frame_phys = frame_time;
 
 		// Wait
 		// (limit frame rate)
 		if frame_time < FTL {
 			std::thread::sleep(Duration::from_secs_f64(FTL - frame_time));
 		}
+		stats.last_frame_wait = frame_start.elapsed().as_secs_f64();
 
 		// Apply input
-
 		let frame_time = frame_start.elapsed().as_secs_f64();
-		//last_frame_time = frame_time;
 
 		s.body.tick(frame_time);
 		system.tick(frame_time);
@@ -148,6 +166,8 @@ fn main() -> Result<(), String> {
 		if i.key_left {
 			s.body.rot(1.0 * frame_time);
 		}
+
+		stats.last_frame_total = frame_start.elapsed().as_secs_f64();
 	}
 
 	Ok(())