IkuradonGame

IkuradonGame.cs

using System.Diagnostics;

namespace IkuradonGame
{
    public partial class MainForm : Form
    {
        private const int MAX_BALL = 30;
        private Rectangle riceRect = new Rectangle();
        private Rectangle[] ballRects = new Rectangle[MAX_BALL];
        private Point[] diffs = new Point[MAX_BALL];
        private int[] xDirections = new int[MAX_BALL];
        private int[] yDirections = new int[MAX_BALL];
        private int[] ballSpeeds = new int[MAX_BALL];
        private bool[] hits = new bool[MAX_BALL];

        private Image rice = Image.FromFile("./img/rice.png");
        private Image ball = Image.FromFile("./img/ball.png");
        private Random random = new Random();

        private int riceRadius = 10;
        private int riceMaxRadius = 240;
        private int ballDiameter = 30;
        private int riceSpeed = 30;

        private Stopwatch stopwatch = new Stopwatch();

        public MainForm()
        {
            InitializeComponent();

            this.riceRect.X = (this.Width / 2) - (this.rice.Width / 2);
            this.riceRect.Y = (this.Width / 2) - (this.rice.Height / 2);
            this.riceRect.Width = this.riceMaxRadius;
            this.riceRect.Height = this.riceMaxRadius;

            for (int ii = 0; ii < this.ballRects.Count(); ii++)
            {
                this.ballRects[ii] = new Rectangle(
                    (this.Width / 2) - (this.ballDiameter / 2),
                    (this.Height / 2) - (this.ballDiameter / 2),
                    this.ballDiameter,
                    this.ballDiameter
                );

                this.ballSpeeds[ii] = DecisionBallSpeed();
                this.xDirections[ii] = DecisionDirection();
                this.yDirections[ii] = DecisionDirection();
                this.hits[ii] = false;
                this.diffs[ii] = new Point(0, 0);
            }
        }

        private void MainForm_Shown(object sender, EventArgs e)
        {
            this.LblStopWatch.Text = this.stopwatch.Elapsed.ToString();
            this.LblIkura.Text = "Ikura:0/" + MAX_BALL.ToString();
        }

        protected override void OnPaint(PaintEventArgs e)
        {
            Graphics g = e.Graphics;

            g.DrawImage(this.rice, this.riceRect);
            for (int ii = 0; ii < this.ballRects.Count(); ii++)
            {
                var rect = this.ballRects[ii];
                g.DrawImage(this.ball, rect);
            }

            g.Dispose();
        }

        private void DrawTimer_Tick(object sender, EventArgs e)
        {
            if (GetHitCount() != MAX_BALL)
            {
                this.LblStopWatch.Text = this.stopwatch.Elapsed.ToString();
            }

            for (int ii = 0; ii < this.ballRects.Count(); ii++)
            {
                ref var ballRect = ref this.ballRects[ii];
                ref var diff = ref this.diffs[ii];
                ref var ballSpeed = ref this.ballSpeeds[ii];
                ref var xDirection = ref this.xDirections[ii];
                ref var yDirection = ref this.yDirections[ii];
                ref var hit = ref this.hits[ii];

                if (hits[ii])
                {
                    ballRect.X = this.riceRect.X + diff.X;
                    ballRect.Y = this.riceRect.Y + diff.Y;
                    continue;
                }

                ballRect.X += xDirection * ballSpeed;
                if (
                    ballRect.X < ballRect.Width ||
                    ballRect.X > this.Width - ballRect.Width
                )
                {
                    xDirection = -xDirection;
                    ballSpeed = DecisionBallSpeed();
                }

                ballRect.Y += yDirection * ballSpeed;
                if (
                    ballRect.Y < ballRect.Height ||
                    ballRect.Y > this.Height - ballRect.Height
                )
                {
                    yDirection = -yDirection;
                    ballSpeed = DecisionBallSpeed();
                }

                var ballX = ballRect.X + (ballRect.Width / 2);
                var ballY = ballRect.Y + (ballRect.Height / 2);
                var ballRadius = (ballRect.Width / 2);

                // rice center point
                var riceX = this.riceRect.X + (this.riceRect.Width / 2);
                var riceY = this.riceRect.Y + (this.riceRect.Height / 2) - 30;

                var a = ballX - riceX;
                var b = ballY - riceY;
                var c = Math.Sqrt(a * a + b * b);

                if (c <= ballRadius + this.riceRadius / 2)
                {
                    this.riceRadius += 1;
                    hit = true;
                    diff.X = ballRect.X - this.riceRect.X;
                    diff.Y = ballRect.Y - this.riceRect.Y;
                }
            }

            this.LblIkura.Text = 
                "Ikura:" + GetHitCount().ToString() + 
                "/" +
                MAX_BALL.ToString();
            this.Refresh();
        }

        private void MainForm_KeyDown(object sender, KeyEventArgs e)
        {
            switch (e.KeyCode)
            {
                case Keys.H:
                    riceRect.X -= this.riceSpeed;
                    break;
                case Keys.J:
                    riceRect.Y += this.riceSpeed;
                    break;
                case Keys.K:
                    riceRect.Y -= this.riceSpeed;
                    break;
                case Keys.L:
                    riceRect.X += this.riceSpeed;
                    break;
            }
        }

        private int DecisionBallSpeed()
        {
            return this.random.Next(2, 40);
        }

        private int DecisionDirection()
        {
            return (this.random.NextDouble() >= 0.5) ? (1) : (-1);
        }

        private void BtnStart_Click(object sender, EventArgs e)
        {
            this.DrawTimer.Enabled = true;
            this.BtnStart.Visible = false;
            this.Focus();
            this.stopwatch.Start();
        }

        private int GetHitCount()
        {
            int count = 0;
            foreach (var hit in this.hits)
            {
                if (hit) count++;
            }

            return count;
        }
    }
}