source: 2011/23/hniemi/Pallospeli/Pallospeli/Pallospeli/Peli.cs @ 1861

using System;
using System.Collections.Generic;
using Jypeli;
using Jypeli.Assets;
using Jypeli.Controls;
using Jypeli.Effects;
using Jypeli.Widgets;
using AdvanceMath;

namespace Pallospeli
{
    public class Peli : PhysicsGame
    {
        const int LEVELWIDTH = 500;
        const int WIDTH = 10;
        const int DIAMETER = LEVELWIDTH / WIDTH;
        const int HEIGHT = 7;

        GameObject launchpad;
        Vector start;

        Playfield playfield;

        public override void Begin()
        {
            SetLevel();
            SetControls();
        }

        /// <summary>
        /// Level setup
        /// </summary>
        public void SetLevel()
        {
            this.Level.Width = LEVELWIDTH;
            this.Level.Height = 800;
            this.Level.CreateBorders(true);
            
            playfield = new Playfield(WIDTH, HEIGHT);
            playfield.FillColorset(3);
            playfield.Balls = null;
            playfield.RepairBallLocations();

            launchpad = new GameObject(DIAMETER, DIAMETER, Shape.Circle);
            launchpad.Move(new Vector(this.Level.Center.X, this.Level.Bottom + (DIAMETER / 2)));
            launchpad.Color = playfield.Colorset[RandomGen.NextInt(playfield.Colorset.Length)];
            this.Add(launchpad);
            MessageDisplay.TextColor = Color.White;

            CreateBalls();
        }
        
        /// <summary>
        /// Creates balls from playfield.Balls.
        /// 
        /// Adds PhysicsObject to Balls.
        /// </summary>
        public void CreateBalls()
        {
            for (int i = 0; i < playfield.Balls.Length; i++)
            {
                for (int j = 0; j < playfield.Balls[i].Length; j++)
                {
                    if (playfield.Balls[i][j] != null)
                    {
                        //Luo PhysicsObjectin vastaamaan palloa
                        PhysicsObject ball = new PhysicsObject(DIAMETER, DIAMETER, Shape.Circle, CollisionShapeQuality.Best);
                        ball.IgnoresCollisionResponse = true;
                        ball.Position = new Vector((j * DIAMETER - Level.Width / 2 + (DIAMETER / 2)) + (i % 2) * (DIAMETER / 2), -(i * DIAMETER) + (Level.Height / 2) - (DIAMETER / 2));
                        ball.Color = playfield.Balls[i][j].Color;
                        ball.Tag = playfield.Balls[i][j].Location;
                        Add(ball);
                        playfield.Balls[i][j].Presentation = ball;
                    }
                }
            }
        }

        /// <summary>
        /// Binds controls
        /// </summary>
        public void SetControls()
        {
            Mouse.Listen(MouseButton.Left, ButtonState.Pressed, StartAim, "Ampuu");
            Mouse.Listen(MouseButton.Left, ButtonState.Released, Shoot, null);

            Keyboard.Listen(Key.F1, ButtonState.Pressed, ShowControlHelp, "Näytä ohjeet");
            Keyboard.Listen(Key.Escape, ButtonState.Pressed, Exit, "Poistu");

            IsMouseVisible = true;
        }

        private void StartAim()
        {
            start = Mouse.PositionOnWorld;
        }

        /// <summary>
        /// Changes color of launchpad
        /// </summary>
        public void NextBall()
        {
            launchpad.Color = playfield.Colorset[RandomGen.NextInt(playfield.Colorset.Length)];
        }

        /// <summary>
        /// Shoots the ball
        /// 
        /// Color of the bullet/ball is the same as color of the launchpad
        /// 
        /// Also calls NextBall
        /// </summary>
        public void Shoot()
        {
            PhysicsObject ammus = new PhysicsObject(DIAMETER, DIAMETER, Shape.Circle);
            ammus.Position = launchpad.Position + new Vector(0, 40);
            ammus.Color = launchpad.Color;
            NextBall();
            this.Add(ammus);
            this.AddCollisionHandler(ammus, Collision);
            ammus.Hit(Mouse.PositionOnWorld - start);
        }

        private void Collision(PhysicsObject obj, PhysicsObject obj2)
        {
            obj.Destroy();
            if (obj2.Tag is Location)
            {
                if (obj.Color == obj2.Color)
                {
                    playfield.Destroy((Location)obj2.Tag);
                    obj.Destroy();
                    playfield.StabilityCheck();

                }
            }
            else { /*obj.Destroy();*/ }
        }
    }

}