Switch free flight mode to quaternion

src/bin/pumpkin.rs

@@ -32,6 +32,35 @@ where V: Into <Vec3>
 	))
 }
 
+struct EulerAngles {
+	pub azimuth: f32,
+	pub altitude: f32,
+}
+
+impl Default for EulerAngles {
+	fn default () -> Self {
+		Self {
+			azimuth: 0.0,
+			altitude: 0.0,
+		}
+	}
+}
+
+impl EulerAngles {
+	pub fn to_vec3 (&self) -> Vec3 {
+		let alt = self.altitude.to_radians ();
+		let azi = self.azimuth.to_radians ();
+		
+		let z = alt.sin ();
+		let xy_len = alt.cos ();
+		
+		let x = xy_len * -azi.sin ();
+		let y = xy_len * azi.cos ();
+		
+		(x, y, z).into ()
+	}
+}
+
 // TODO: Use iota macro
 const KEY_LEFT: usize = 0;
 const KEY_RIGHT: usize = KEY_LEFT + 1;
@@ -71,55 +100,60 @@ impl ControllerState {
 		
 		if self.is_pressed (KEY_LEFT) {
 			controlled_angle.azimuth += spin_f;
-			std::cmp::min (spin_speed + 1, SPIN_RAMP_TIME)
 		}
 		else if self.is_pressed (KEY_RIGHT) {
 			controlled_angle.azimuth -= spin_f;
-			std::cmp::min (spin_speed + 1, SPIN_RAMP_TIME)
 		}
 		else if self.is_pressed (KEY_UP) {
 			controlled_angle.altitude = f32::min (90.0, controlled_angle.altitude + spin_f);
-			std::cmp::min (spin_speed + 1, SPIN_RAMP_TIME)
 		}
 		else if self.is_pressed (KEY_DOWN) {
 			controlled_angle.altitude = f32::max (-90.0, controlled_angle.altitude - spin_f);
-			std::cmp::min (spin_speed + 1, SPIN_RAMP_TIME)
 		}
 		else {
+			return 0;
+		}
+		
+		std::cmp::min (spin_speed + 1, SPIN_RAMP_TIME)
+	}
+	
+	pub fn control_quat (
+		&self,
+		controlled_quat: &mut Quat,
+		spin_speed: i32
+	) -> i32
+	{
+		const SPIN_RAMP_TIME: i32 = 30;
+		let spin_f = 4.0 * (spin_speed + 1) as f32 / SPIN_RAMP_TIME as f32;
+		let spin_f = spin_f.to_radians ();
+		
+		let mut delta = Quat::default ();
+		
+		if self.is_pressed (KEY_LEFT) {
+			delta = delta.mul_quat (Quat::from_rotation_y (-spin_f));
+		}
+		if self.is_pressed (KEY_RIGHT) {
+			delta = delta.mul_quat (Quat::from_rotation_y (spin_f));
+		}
+		if self.is_pressed (KEY_UP) {
+			delta = delta.mul_quat (Quat::from_rotation_x (-spin_f));
+		}
+		if self.is_pressed (KEY_DOWN) {
+			delta = delta.mul_quat (Quat::from_rotation_x (spin_f));
+		}
+		
+		//println! ("spin_f {}, Quat {:?}", spin_f, delta);
+		
+		if delta == Quat::default () {
 			0
 		}
-	}
-}
-
-struct EulerAngles {
-	pub azimuth: f32,
-	pub altitude: f32,
-}
-
-impl Default for EulerAngles {
-	fn default () -> Self {
-		Self {
-			azimuth: 0.0,
-			altitude: 0.0,
+		else {
+			*controlled_quat = (controlled_quat.mul_quat (delta)).normalize ();
+			std::cmp::min (spin_speed + 1, SPIN_RAMP_TIME)
 		}
 	}
 }
 
-impl EulerAngles {
-	pub fn to_vec3 (&self) -> Vec3 {
-		let alt = self.altitude.to_radians ();
-		let azi = self.azimuth.to_radians ();
-		
-		let z = alt.sin ();
-		let xy_len = alt.cos ();
-		
-		let x = xy_len * -azi.sin ();
-		let y = xy_len * azi.cos ();
-		
-		(x, y, z).into ()
-	}
-}
-
 enum PlayMode {
 	WindTunnel,
 	FreeFlight,
@@ -143,8 +177,13 @@ struct WindTunnelState {
 	spin_speed: i32,
 }
 
+struct Airplane {
+	pos: Vec3,
+	ori: Quat,
+}
+
 struct FlightState {
-	airplane: EulerAngles,
+	airplane: Airplane,
 	spin_speed: i32,
 }
 
@@ -154,7 +193,7 @@ impl FlightState {
 	}
 	
 	pub fn step (&mut self, controller: &ControllerState) {
-		self.spin_speed = controller.control_eulers (&mut self.airplane, self.spin_speed);
+		self.spin_speed = controller.control_quat (&mut self.airplane.ori, self.spin_speed);
 	}
 }
 
@@ -214,7 +253,10 @@ impl WorldState {
 				spin_speed: 0,
 			},
 			flight: FlightState {
-				airplane: Default::default (),
+				airplane: Airplane {
+					pos: (0.0, 0.0, 1.35).into (),
+					ori: Default::default (),
+				},
 				spin_speed: 0,
 			},
 		}
@@ -986,10 +1028,9 @@ impl GameGraphics {
 				Mat4::from_rotation_x (euler.altitude.to_radians ())
 			},
 			PlayMode::FreeFlight => {
-				let euler = &state.flight.airplane;
-				Mat4::from_translation ((0.0, 0.0, 2.7 * 0.5).into ()) *
-				Mat4::from_rotation_z (euler.azimuth.to_radians ()) *
-				Mat4::from_rotation_x (euler.altitude.to_radians ())
+				let airplane = &state.flight.airplane;
+				Mat4::from_translation (airplane.pos) *
+				Mat4::from_quat (airplane.ori)
 			},
 		};
 		let inverse_airplane = airplane_model_mat.inverse ();