Implemented basic asteroid, moved ship drawing and updating into impl Ship block.

src/lib.rs

@@ -87,6 +87,70 @@ struct Ship {
     orientation: CGA,
 }
 
+impl Ship {
+    fn update(&mut self, dt_s: f64, keys: &HashSet<String>) {
+        let vel = self.vel.clone(); //Velocity at beginning of frame
+        let mut vel_2 = self.vel.clone();
+
+        let mut a_vec = - DRAG * &vel_2;
+
+        if keys.contains("w") {
+            let orient = &self.orientation; //Transforms body frame to local frame
+            let pos = &self.com_rotor; //Transforms local frame to world frame
+            let accel_body = ACCEL_STR * CGA::e15(); //The acceleration in the body frame.
+            let accel_local = orient * accel_body * orient.Reverse(); //The acceleration in the local frame.
+            let accel_world = pos * accel_local * pos.Reverse(); //The acceleration in the world frame.
+            a_vec = a_vec - accel_world; //Sum of drag and thrust.
+        }
+
+        if keys.contains("q") {
+            self.orientation = bivector_exponential(&(dt_s * CGA::e12())) * &self.orientation;
+        }
+
+        if keys.contains("e") {
+            self.orientation = bivector_exponential(&(-dt_s * CGA::e12())) * &self.orientation;
+        }
+
+
+        vel_2 = vel_2 + a_vec*dt_s; //Velocity at end of frame
+        let vel_3 = 0.5*(vel+&vel_2);
+        let delta = vel_3 * dt_s;
+        let pos = bivector_exponential(&delta)*&self.com_rotor; //Update position.
+        self.vel = vel_2;
+        self.com_rotor = pos;
+
+    }
+
+    fn draw(&self, context: &CanvasRenderingContext2d) {
+        let origin = gen_hyperbolic_point(&CGA::zero()); //Origin in the body frame.
+        let orient_rotor = &self.orientation; //Transforms body frame to local frame.
+        let com = &self.com_rotor; //Transforms local frame to world frame.
+        let v0_rotor = com*orient_rotor*bivector_exponential(&self.verts.0); //Combined transformation to locate a vertex of the ship in the world frame.
+        let v1_rotor = com*orient_rotor*bivector_exponential(&self.verts.1); //Combined transformation ...
+        let v2_rotor = com*orient_rotor*bivector_exponential(&self.verts.2); //Combined transformation ...
+        let p0 = &v0_rotor*&origin*&v0_rotor.Reverse(); //Produce a vertex of the ship in the world frame.
+        let p1 = &v1_rotor*&origin*&v1_rotor.Reverse(); //...
+        let p2 = &v2_rotor*&origin*&v2_rotor.Reverse(); //...
+
+        draw_point(context, &(com*&origin*com.Reverse()));
+        draw_point(context, &p0);
+        draw_point(context, &p1);
+        draw_point(context, &p2);
+        draw_line_between(context, &p0, &p1);
+        draw_line_between(context, &p1, &p2);
+        draw_line_between(context, &p2, &p0);
+
+        //Construct and draw line pointing straight ahead, to help orient the player.
+        let com_p = com * gen_hyperbolic_point(&CGA::zero()) * com.Reverse();
+        let delta_gen = com * orient_rotor * CGA::e14() * &orient_rotor.Reverse() * com.Reverse();
+        let dot = delta_gen | &com_p;
+        let line = CGA::e4() ^ com_p ^ dot ^ CGA::e3();
+        draw_line(context, &line);
+
+
+    }
+}
+
 enum Geometry {
     Circle(f64, f64, f64), //x,y,r
     Line(f64, f64, f64), //x,r,theta
@@ -94,7 +158,7 @@ enum Geometry {
 }
 
 /* Translation of a Euclidean Point. Need to use hyperbolic*/
-fn _point_to_cga(x: f64, y: f64) -> CGA {
+fn point_to_cga(x: f64, y: f64) -> CGA {
     let x_vec = CGA::e1();
     let y_vec = CGA::e2();
     let _z_vec =CGA::e3(); //This game assumes everything takes place in the plane.
@@ -327,14 +391,48 @@ fn bivector_exponential(bivector: &CGA) -> CGA {
     }
 }
 
-struct _Asteroid {
+struct Asteroid {
+    circle: CGA,
+    vel: CGA,
+}
+
+impl Asteroid {
+    fn new() -> Asteroid {
+        let v = 0.1;
+        let (v_x, v_y) = (v * 1.0_f64.cos(), v*1.0_f64.sin());
+        let vel = v_x*CGA::e15() + v_y*CGA::e25();
+        Self::new_from_coords(0.0_f64, 0.0_f64, 0.1_f64, vel)
+    }
+
+    fn new_from_coords(x: f64, y: f64, r: f64, vel: CGA) -> Asteroid {
+        let (a_x, a_y) = (x + r * 0.0_f64.cos(), y + r * 0.0_f64.sin());
+        let (b_x, b_y) = (x + r * 1.0_f64.cos(), y + r * 1.0_f64.sin());
+        let (c_x, c_y) = (x + r * 2.0_f64.cos(), y + r * 2.0_f64.sin());
+        let a = point_to_cga(a_x, a_y);
+        let b = point_to_cga(b_x, b_y);
+        let c = point_to_cga(c_x, c_y);
+        let circle = a^b^c^CGA::e3();
+        Asteroid { circle, vel }
+    }
+
+    fn update(&mut self, dt_s: f64) {
+        let vel = &self.vel;
+        let delta = vel * dt_s;
+        let vel_rotor = bivector_exponential(&delta);
+        let circle = &vel_rotor*&self.circle*&vel_rotor.Reverse();
+        self.circle = circle;
+    }
+
+    fn draw(&self, context: &CanvasRenderingContext2d) {
+        draw_line(context, &self.circle);
+    }
 }
 
 #[wasm_bindgen]
 pub struct Game {
     context: CanvasRenderingContext2d,
     ship: Ship,
-    //asteroids: Vec::<Asteroid>,
+    asteroids: Vec::<Asteroid>,
     keys: HashSet<String>,
 }
 
@@ -368,6 +466,7 @@ impl Game {
         Game { 
             context: context,
             ship,
+            asteroids: vec![Asteroid::new()],
             keys: HashSet::new(),
         }
     }
@@ -380,31 +479,10 @@ impl Game {
         self.context.set_stroke_style_str(BLACK);
         self.context.arc(CENTER_X, CENTER_Y, RADIUS, 0., TWO_PI).unwrap();
         self.context.stroke();
-
+        self.ship.draw(&self.context);
-        let origin = gen_hyperbolic_point(&CGA::zero()); //Origin in the body frame.
+        for asteroid in &self.asteroids {
-        let orient_rotor = &self.ship.orientation; //Transforms body frame to local frame.
+            asteroid.draw(&self.context);
-        let com = &self.ship.com_rotor; //Transforms local frame to world frame.
+        }
-        let v0_rotor = com*orient_rotor*bivector_exponential(&self.ship.verts.0); //Combined transformation to locate a vertex of the ship in the world frame.
-        let v1_rotor = com*orient_rotor*bivector_exponential(&self.ship.verts.1); //Combined transformation ...
-        let v2_rotor = com*orient_rotor*bivector_exponential(&self.ship.verts.2); //Combined transformation ...
-        let p0 = &v0_rotor*&origin*&v0_rotor.Reverse(); //Produce a vertex of the ship in the world frame.
-        let p1 = &v1_rotor*&origin*&v1_rotor.Reverse(); //...
-        let p2 = &v2_rotor*&origin*&v2_rotor.Reverse(); //...
-
-        draw_point(&self.context, &(com*&origin*com.Reverse()));
-        draw_point(&self.context, &p0);
-        draw_point(&self.context, &p1);
-        draw_point(&self.context, &p2);
-        draw_line_between(&self.context, &p0, &p1);
-        draw_line_between(&self.context, &p1, &p2);
-        draw_line_between(&self.context, &p2, &p0);
-
-        //Construct and draw line pointing straight ahead, to help orient the player.
-        let com_p = com * gen_hyperbolic_point(&CGA::zero()) * com.Reverse();
-        let delta_gen = com * orient_rotor * CGA::e14() * &orient_rotor.Reverse() * com.Reverse();
-        let dot = delta_gen | &com_p;
-        let line = CGA::e4() ^ com_p ^ dot ^ CGA::e3();
-        draw_line(&self.context, &line);
     }
 
     pub fn update(&mut self, dt_m: f64) {
@@ -413,35 +491,12 @@ impl Game {
         } else {
             dt_m / 1000.
         };
-        let vel = self.ship.vel.clone(); //Velocity at beginning of frame
-        let mut vel_2 = self.ship.vel.clone();
 
-        let mut a_vec = - DRAG * &vel_2;
+        for asteroid in &mut self.asteroids {
-
+            asteroid.update(dt_s);
-        if self.keys.contains("w") {
-            let orient = &self.ship.orientation; //Transforms body frame to local frame
-            let pos = &self.ship.com_rotor; //Transforms local frame to world frame
-            let accel_body = ACCEL_STR * CGA::e15(); //The acceleration in the body frame.
-            let accel_local = orient * accel_body * orient.Reverse(); //The acceleration in the local frame.
-            let accel_world = pos * accel_local * pos.Reverse(); //The acceleration in the world frame.
-            a_vec = a_vec - accel_world; //Sum of drag and thrust.
         }
 
-        if self.keys.contains("q") {
+        self.ship.update(dt_s, &self.keys);
-            self.ship.orientation = bivector_exponential(&(dt_s * CGA::e12())) * &self.ship.orientation;
-        }
-
-        if self.keys.contains("e") {
-            self.ship.orientation = bivector_exponential(&(-dt_s * CGA::e12())) * &self.ship.orientation;
-        }
-
-
-        vel_2 = vel_2 + a_vec*dt_s; //Velocity at end of frame
-        let vel_3 = 0.5*(vel+&vel_2);
-        let delta = vel_3 * dt_s;
-        let pos = bivector_exponential(&delta)*&self.ship.com_rotor; //Update position.
-        self.ship.vel = vel_2;
-        self.ship.com_rotor = pos;
     }
 
     pub fn key_down(&mut self, key: String) {