Trying to get the flight physics to feel right

src/bin/pumpkin.rs

@@ -68,19 +68,41 @@ const KEY_DOWN: usize = KEY_UP + 1;
 
 struct ControllerState {
 	keys: Vec <bool>,
+	
+	trigger_left: i16,
+	trigger_right: i16,
 }
 
 impl ControllerState {
-	pub fn from_sdl_keyboard (k: &sdl2::keyboard::KeyboardState) -> Self {
+	pub fn new (
-		let f = |c| k.is_scancode_pressed (c);
+		k: &sdl2::keyboard::KeyboardState,
+		c: &Option <sdl2::controller::GameController>
+	) -> Self {
+		use sdl2::controller::*;
+		
+		let f = |code| k.is_scancode_pressed (code);
+		let b = |code| match c {
+			None => false,
+			Some (c) => c.button (code),
+		};
+		
+		let key_or_gamepad = |key, button| f (key) || b (button);
 		
 		Self {
 			keys: vec! [
-				f (Scancode::Left),
+				key_or_gamepad (Scancode::Left, Button::DPadLeft),
-				f (Scancode::Right),
+				key_or_gamepad (Scancode::Right, Button::DPadRight),
-				f (Scancode::Up),
+				key_or_gamepad (Scancode::Up, Button::DPadUp),
-				f (Scancode::Down),
+				key_or_gamepad (Scancode::Down, Button::DPadDown),
 			],
+			trigger_left: match c {
+				None => 0,
+				Some (c) => c.axis (Axis::TriggerLeft),
+			},
+			trigger_right: match c {
+				None => 0,
+				Some (c) => c.axis (Axis::TriggerRight),
+			},
 		}
 	}
 	
@@ -187,6 +209,19 @@ struct FlightState {
 	spin_speed: i32,
 }
 
+impl Default for FlightState {
+	fn default () -> Self {
+		Self {
+			airplane: Airplane {
+				pos: (0.0, -10.0, 20.0).into (),
+				vel: (0.0, 0.0, 0.0).into (),
+				ori: Default::default (),
+			},
+			spin_speed: 0,
+		}
+	}
+}
+
 impl FlightState {
 	pub fn handle_event (&mut self, _event: &sdl2::event::Event) {
 		
@@ -209,10 +244,12 @@ impl FlightState {
 		
 		let object_space_dir = airplane.ori.conjugate ().mul_vec3 (direction);
 		
+		let throttle = 1.0 + (controller.trigger_right as f32 - controller.trigger_left as f32) / 32767.0;
+		
 		// Forces
 		let gravity = Vec3::from ((0.0, 0.0, -0.25));
-		let thrust = nose;
+		let thrust = nose * throttle;
-		let laminar_drag = 0.5 * speed * -object_space_dir.y () * nose;
+		let laminar_drag = 0.25 * speed * -object_space_dir.y () * nose;
 		
 		let turbulent_dir = Vec3::from ((0.5 * object_space_dir.x (), 0.0, object_space_dir.z ()));
 		let turbulent_drag = -speed * speed * airplane.ori.mul_vec3 (turbulent_dir);
@@ -231,11 +268,15 @@ impl FlightState {
 		
 		// Gauges
 		let alti = airplane.pos.z () * 100.0;
-		let airspeed = speed * 100.0;
+		let air_speed = speed * 100.0;
+		let ground_vel = Vec3::from ((airplane.vel.x (), airplane.vel.y (), 0.0));
+		let ground_speed = ground_vel.length () * 100.0;
 		
-		println! ("Alti: {}, Airspeed: {}", 
+		println! ("Alti: {}, Airspeed: {}, Groundspeed: {}, Throttle: {}", 
 		alti as i32,
-		airspeed as i32
+		air_speed as i32,
+		ground_speed as i32,
+		(throttle * 100.0) as i32
 		);
 	}
 }
@@ -295,14 +336,7 @@ impl WorldState {
 				},
 				spin_speed: 0,
 			},
-			flight: FlightState {
+			flight: Default::default (),
-				airplane: Airplane {
-					pos: (0.0, -0.5, 0.125).into (),
-					vel: (0.0, 0.0, 0.0).into (),
-					ori: Default::default (),
-				},
-				spin_speed: 0,
-			},
 		}
 	}
 	
@@ -898,8 +932,8 @@ impl GameGraphics {
 
 fn main () {
 	let sdl_context = sdl2::init ().unwrap ();
-	let video_subsystem = sdl_context.video ().unwrap ();
 	
+	let video_subsystem = sdl_context.video ().unwrap ();
 	let window = video_subsystem.window ("OpenGL? In my Rust?", 1280, 720)
 		.position_centered ()
 		.opengl ()
@@ -924,6 +958,9 @@ fn main () {
 	
 	let mut graphics_frames = 0;
 	
+	let controller_subsystem = sdl_context.game_controller ().unwrap ();
+	let controller = controller_subsystem.open (0).ok ();
+	
 	let mut event_pump = sdl_context.event_pump ().unwrap ();
 	'running: loop {
 		let frames_to_do = time_step.step ();
@@ -940,7 +977,10 @@ fn main () {
 			}
 		}
 		
-		let controller = ControllerState::from_sdl_keyboard (&event_pump.keyboard_state ());
+		let controller = ControllerState::new (
+			&event_pump.keyboard_state (),
+			&controller
+		);
 		
 		for _ in 0..frames_to_do {
 			state.step (&controller);