WindowsScreensavers/GameOfLife/MainForm.cs

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace GameOfLife
{
    public partial class MainForm : Form
    {
        private Point mouseLocation;

        private bool[,] newCells;
        private bool[,] toggleCells;
        private bool[,] oldCells;

        private Random random;

        private int gridSize = 4;

        private int magicCells = 0;

        private double density = 0.45;

        public MainForm(Rectangle bounds)
        {
            InitializeComponent();
            random = new Random();
            Bounds = bounds;
            newCells = new bool[bounds.Width / gridSize, bounds.Height / gridSize];
            toggleCells = new bool[bounds.Width / gridSize, bounds.Height / gridSize];
            oldCells = new bool[bounds.Width / gridSize, bounds.Height / gridSize];

            for (var x = 0; x < newCells.GetLength(0); x++) {
                for (var y = 0; y < newCells.GetLength(1); y++) {
                    newCells[x, y] = random.NextDouble() <= density;
                    oldCells[x, y] = false;
                    toggleCells[x, y] = true;
                }
            }
        }

        private void MainForm_Load(object sender, EventArgs e)
        {
            Cursor.Hide();
            TopMost = true;

            timer.Interval = 50;
            timer.Tick += new EventHandler(timer_Tick);
            timer.Start();
        }

        private void MainForm_MouseMove(object sender, MouseEventArgs e)
        {
            if (!mouseLocation.IsEmpty)
            {
                // Terminate if mouse is moved a significant distance
                if (Math.Abs(mouseLocation.X - e.X) > 5 ||
                    Math.Abs(mouseLocation.Y - e.Y) > 5)
                    Application.Exit();
            }

            // Update current mouse location
            mouseLocation = e.Location;

        }

        private void MainForm_MouseClick(object sender, MouseEventArgs e)
        {
            Application.Exit();
        }

        private void MainForm_KeyPress(object sender, KeyPressEventArgs e)
        {
            Application.Exit();
        }

        private int GetAliveNeighbors(bool[,] cells, int x, int y) {
            int prevX = x == cells.GetLowerBound(0) ? cells.GetUpperBound(0) : x - 1;
            int nextX = x == cells.GetUpperBound(0) ? cells.GetLowerBound(0) : x + 1;
            int prevY = y == cells.GetLowerBound(1) ? cells.GetUpperBound(1) : y - 1;
            int nextY = y == cells.GetUpperBound(1) ? cells.GetLowerBound(1) : y + 1;

            int aliveNeighbors = 0;
            if (cells[prevX, prevY]) {
                aliveNeighbors += 1;
            }
            if (cells[x, prevY])
            {
                aliveNeighbors += 1;
            }
            if (cells[nextX, prevY])
            {
                aliveNeighbors += 1;
            }
            if (cells[prevX, y])
            {
                aliveNeighbors += 1;
            }
            if (cells[nextX, y])
            {
                aliveNeighbors += 1;
            }
            if (cells[prevX, nextY])
            {
                aliveNeighbors += 1;
            }
            if (cells[x, nextY])
            {
                aliveNeighbors += 1;
            }
            if (cells[nextX, nextY])
            {
                aliveNeighbors += 1;
            }
            return aliveNeighbors;
        }

        private void timer_Tick(object sender, EventArgs e) {
            for (var x = 0; x < newCells.GetLength(0); x++)
            {
                for (var y = 0; y < newCells.GetLength(1); y++)
                {
                    oldCells[x, y] = newCells[x, y];
                }
            }

            for (var x = 0; x < newCells.GetLength(0); x++)
            {
                for (var y = 0; y < newCells.GetLength(1); y++)
                {
                    int neighbors = GetAliveNeighbors(oldCells, x, y);
                    bool shouldLive = false;
                    if (oldCells[x, y] && neighbors == 2)
                    {
                        shouldLive = true;
                    } else if (!oldCells[x, y] && neighbors == 3) {
                        shouldLive = true;
                    }

                    newCells[x, y] = shouldLive;
                    toggleCells[x, y] = oldCells[x, y] == newCells[x, y];
                }
            }

            for (var i = 0; i < magicCells; i++) {
                int magicX = random.Next(0, newCells.GetUpperBound(0));
                int magicY = random.Next(0, newCells.GetUpperBound(1));

                newCells[magicX, magicY] = true;
                toggleCells[magicX, magicY] = oldCells[magicX, magicY] == newCells[magicX, magicY];
            }

            Redraw(CreateGraphics());
        }

        private void Redraw(Graphics graphics) {
            graphics.FillRectangle(Brushes.Black, Bounds);
            for (var x = 0; x < newCells.GetLength(0); x++)
            {
                for (var y = 0; y < newCells.GetLength(1); y++)
                {
                    if (newCells[x, y])
                    {
                        graphics.FillRectangle(Brushes.White, x * gridSize, y * gridSize, gridSize, gridSize);
                    }
                    //else if (!newCells[x, y]) {
                    //    graphics.FillRectangle(Brushes.Black, x * gridSize, y * gridSize, gridSize, gridSize);
                    //}
                }
            }
        }

        private void MainForm_Paint(object sender, PaintEventArgs e)
        {
            Redraw(e.Graphics);
        }
    }
}