faster life

using System;
using System.Drawing;
using System.Drawing.Imaging;
using System.Windows.Forms;

namespace colorlife {
    public unsafe partial class frmDavesLife : Form {
        Bitmap canvas;
        Graphics g;
        Rectangle bmpRect;
        BitmapData bmpData;
        uint* currPos;
        bool fadeColors = true,
            cycleColors = true;

        System.Windows.Forms.Timer tmrFrames = new System.Windows.Forms.Timer(); //mah frame counter
        byte[] field; //the game state array
        bool gameRunning = true, altFrame = false; //gameRunning so the Game loop terminates properly, altFrame is flipped every frame
        uint w, //width
             h, //height
             w1, //width - 1
             wp1, //width + 1
             w2,
             w3,
             l,  //length
             lw, //l - w
             x, //x coord
             outerL,
             i, //index
             FPS = 0, //fps
             FPSTotal = 0, //total fps, for average calculation
             frameCount = 0, //number of frames, to determine the average
             timerCount = 0;
        byte* t, //start address of the active half of the field array
              a; //start of the inactive half
        byte n;
        //color cycling stuff
        Color[] colorList = { Color.Purple, Color.Blue, Color.Green, Color.Yellow, Color.Orange, Color.Red };
        uint cycleLength = 80, //frames between each full color
            currCycleFrame = 0, currCycleItem = 0, //counters
            col, //current frame's computed color
            colDecVal = 1, //RGB value decrement each frame
            colLimit = 31; //RGB value lower limit

        byte rVal, gVal, bVal; //current color values

        public frmDavesLife() {
            Initialize();
            Random R = new Random(0);
            for (x = 1; x <= w; x++) {
                for (int y = 1; y <= h; y++) {
                    field[(y * (w + 2)) + x] = (byte)(R.Next(100) <= 15 ? 1 : 0);
                }
            }
            altFrame = false;
            tmrFrames.Enabled = true;
            Game();
        }

        public frmDavesLife(string path) {
            Initialize();
            for (x = 0; x < outerL * 2; x++) field[x] = 0;
            altFrame = false;
            string[] pattern = System.IO.File.ReadAllLines(path);
            for (int x = 0; x < (pattern[0].Length <= this.ClientSize.Width ? pattern[0].Length : this.ClientSize.Width); x++) {
                for (int y = 0; y <= pattern.GetUpperBound(0); y++) {
                    field[x + (y * w)] = byte.Parse(pattern[y][x].ToString());
                }
            }
            tmrFrames.Enabled = true;
            Game();
        }

        void Initialize() {
            this.ClientSize = new Size(800, 600);
            this.FormBorderStyle = FormBorderStyle.Fixed3D;
            this.MinimizeBox = false;
            this.MaximizeBox = false;
            this.DoubleBuffered = true;
            this.Text = "Dave's Game of Life";
            this.Deactivate += new EventHandler(Form1_Deactivate);
            this.Activated += new EventHandler(frmDavesLife_Activated);
            this.Paint += new PaintEventHandler(Form1_Paint);
            tmrFrames.Tick += new EventHandler(tmrFrames_Tick);
            canvas = new Bitmap(this.ClientSize.Width, this.ClientSize.Height);
            w = (uint)canvas.Width;
            h = (uint)canvas.Height;
            bmpRect = new Rectangle(0, 0, (int)w, (int)h);
            l = w * h;
            w1 = (w + 2) - 1;
            wp1 = (w + 2) + 1;
            //lw = l - w;
            w2 = w + 2;
            w3 = w + 3;
            outerL = (w + 2) * (h + 2);
            g = Graphics.FromImage(canvas);
            g.Clear(Color.Black);
            field = new byte[outerL * 2];
            tmrFrames.Interval = 1000;
            if (cycleColors) {
                rVal = colorList[0].R;
                gVal = colorList[0].G;
                bVal = colorList[0].B;
            }
            else
                col = 0xffffffff;
            this.Show();
            Application.DoEvents();
        }

        void frmDavesLife_Activated(object sender, EventArgs e) {
            if (!gameRunning) {
                gameRunning = true;
                Game();
            }
        }

        void tmrFrames_Tick(object sender, EventArgs e) {
            timerCount++;
            if (gameRunning) {
                FPSTotal += FPS;
                frameCount++;
            }
            this.Text = string.Format(
                "{0} ({1}) - {2}",
                FPS.ToString(),
                FPSTotal / frameCount,
                timerCount);
            FPS = 0;
        }

        void Form1_Paint(object sender, PaintEventArgs e) {
            e.Graphics.DrawImageUnscaled(canvas, 0, 0);
        }

        void Form1_Deactivate(object sender, EventArgs e) {
            gameRunning = false;
        }

        void Game() {
            while (gameRunning) {
                FPS++;
                //if (cycleColors)
                //    CycleColors();
                ComputeFrame();
                this.Refresh();
                Application.DoEvents();
                altFrame = !altFrame;
            }
        }

        void CycleColors() { //this method could be optimized, but it's such a small hit on performance that it frankly doesn't matter
            Color col1 = colorList[currCycleItem];
            Color col2 = currCycleItem < (colorList.Length - 1) ? colorList[currCycleItem + 1] : colorList[0];
            rVal = (byte)((((col2.R - col1.R) / (double)cycleLength) * currCycleFrame) + col1.R);
            gVal = (byte)((((col2.G - col1.G) / (double)cycleLength) * currCycleFrame) + col1.G);
            bVal = (byte)((((col2.B - col1.B) / (double)cycleLength) * currCycleFrame) + col1.B);
            if (++currCycleFrame == cycleLength) {
                currCycleFrame = 0;
                currCycleItem = (currCycleItem + 1) % (uint)colorList.Length;
            }
            col = 0xff000000 | (uint)((rVal << 16) | (gVal << 8) | bVal);
        }

        void ComputeFrame() {
            i = 0;
            x = 0;

            //lock the canvas, because i haven't delved into actual bitmap pointer drawing to the screen itself
            bmpData = canvas.LockBits(bmpRect, ImageLockMode.ReadWrite, PixelFormat.Format32bppPArgb);
            currPos = (uint*)bmpData.Scan0;

            fixed (byte* f = field) { //field contains the entire grid plus swap
                t = f + w3; //starting point of the current generation
                a = t; //starting point of the next generation

                //determine which is which
                if (altFrame) t += outerL;
                else a += outerL;

                while (i++ < l) {
                    //sum living neighbors
                    n = (byte)(*(t - 1) + *(t + 1) + *(t - w2) + *(t + w2) + *(t - w1) + *(t + w1) + *(t - wp1) + *(t + wp1));

                    if (*t == 1) { //current cell is alive
                        *a = (byte)((n != 2 && n != 3) ? 0 : 1);
                        *currPos = 0xffffffff; // col;
                    }
                    else { //he's dead, jim
                        *a = (byte)(n == 3 ? 1 : 0);
                        //if (fadeColors) { //fancy color cycling and fading, looks cool, but is slow
                        //    if ((*currPos & 0x00ff0000) > (uint)(colLimit << 16)) *currPos -= (uint)(colDecVal << 16);
                        //    if ((*currPos & 0x0000ff00) > (uint)(colLimit << 8)) *currPos -= (uint)(colDecVal << 8);
                        //    if ((*currPos & 0x000000ff) > (uint)(colLimit)) *currPos -= (uint)(colDecVal);
                        //}
                        //else
                        *currPos = 0xff000000;
                    }

                    ++currPos;
                    if (++x == w) {
                        x = 0;
                        a += 3;
                        t += 3;
                    }
                    else {
                        ++a;
                        ++t;
                    }
                }
            }
            canvas.UnlockBits(bmpData);
        }
    }

    static class Program {
        [STAThread]
        static void Main(string[] arg) {
            try {
                if (arg.Length > 0 && System.IO.File.Exists(arg[0]))
                    Application.Run(new frmDavesLife(arg[0]));
                else
                    Application.Run(new frmDavesLife());
            }
            catch { }
        }
    }
}