Add Asteroid game

CM2030 Graphics Programming/Topic 3/3.4.1/asteroidSystem.js

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+class AsteroidSystem {
+
+  //creates arrays to store each asteroid's data
+  constructor(){
+    this.locations = [];
+    this.velocities = [];
+    this.accelerations = [];
+    this.diams = [];
+  }
+
+  run(multiplier){
+      this.spawn(multiplier);
+      this.move();
+      this.draw();
+  }
+
+  // spawns asteroid at random intervals
+  spawn(multiplier){
+    if (random(1) < 0.01 * multiplier){
+      this.accelerations.push(new createVector(0,random(0.1,1)));
+      this.velocities.push(new createVector(0, 0));
+      this.locations.push(new createVector(random(width), 0));
+      this.diams.push(random(30,50));
+    }
+  }
+
+  //moves all asteroids
+  move(){
+    for (var i=0; i<this.locations.length; i++){
+      this.velocities[i].add(this.accelerations[i]);
+      this.locations[i].add(this.velocities[i]);
+      this.accelerations[i].mult(0);
+    }
+  }
+
+  applyForce(f){
+    for (var i=0; i<this.locations.length; i++){
+      this.accelerations[i].add(f);
+    }
+  }
+
+  //draws all asteroids
+  draw(){
+    noStroke();
+    fill(200);
+    for (var i=0; i<this.locations.length; i++){
+      ellipse(this.locations[i].x, this.locations[i].y, this.diams[i], this.diams[i]);
+    }
+  }
+
+  //function that calculates effect of gravity on each asteroid and accelerates it
+  calcGravity(centerOfMass){
+    for (var i=0; i<this.locations.length; i++){
+      var gravity = p5.Vector.sub(centerOfMass, this.locations[i]);
+      gravity.normalize();
+      gravity.mult(.001);
+      this.applyForce(gravity);
+    }
+  }
+
+  //destroys all data associated with each asteroid
+  destroy(index){
+    this.locations.splice(index,1);
+    this.velocities.splice(index,1);
+    this.accelerations.splice(index,1);
+    this.diams.splice(index,1);
+  }
+}