package {
	import flash.display.Sprite;
	import flash.events.Event;
	public class as3circle extends Sprite {
		public var keyboard_input:keys;
		public var circle_hero = new circle;
		public var level_wall = new wall;
		public var number_of_coins = 4;
		public function as3circle() {
			for (var i=1; i<=number_of_coins; i++) {
				var ingame_coin = new coin;
				addChild(ingame_coin);
			}
			addChild(circle_hero);
			var keyboard_sprite = new Sprite();
			keyboard_input = new keys(this);
			addChild(level_wall);
			stage.addEventListener(Event.ENTER_FRAME,on_enter_frame);
		}
		public function on_enter_frame(event:Event) {
			if (keyboard_input.is_left()) {
				circle_hero.apply_force(-1,0);
			}
			if (keyboard_input.is_right()) {
				circle_hero.apply_force(1,0);
			}
			if (keyboard_input.is_up()) {
				circle_hero.apply_force(0,-1);
			}
			if (keyboard_input.is_down()) {
				circle_hero.apply_force(0,1);
			}
		}
	}
}

package {
	import flash.display.Sprite;
	import flash.events.Event;
	public class wall extends Sprite {
		// variables used in this class
		private var point_x:int;
		private var point_y:int;
		// precision is the number of points I am going to calculate
		// on hero's circumference
		private var precision:int = 36;
		// calculating once for all 2*PI
		private var twopi: Number = Math.PI*2;
		// main function
		public function wall() {
			place_wall();
			// checking for collisions at every frame
			addEventListener(Event.ENTER_FRAME, check_collisions);
		}
		private function check_collisions(e:Event) {
			for (var i=0; i<precision; i++) {
				// checking for collisions between the hero and the wall
				point_x = as3circle(root).circle_hero.x + 25 * Math.cos(twopi*i/precision);
				point_y = as3circle(root).circle_hero.y - 25 * Math.sin(twopi*i/precision);
				if (this.hitTestPoint(point_x, point_y, true)) {
					// in case of collision, reset the hero
					as3circle(root).circle_hero.init();
				}
			}
		}
		private function place_wall() {
			x=0;
			y=175;
		}
	}
}