C# & Game Programming - A…er's Guide (2nd Edition)/Buono 2nd Ed.iso/Chapter3/AsteroidMiner/AsteroidMiner Forms/AsteroidMinerGDI+.cs

Text File | 2004-09-02 | 25KB | 634 lines

/* AsteroidMiner v2.0 - by Salvatore A. Buono */
using System;
using System.Drawing;
using System.Windows.Forms;
using System.IO; // for file read/write

using GameClasses; // Our common utility class

namespace Games {
    public class AsteroidMiner : System.Windows.Forms.Form {
        // Constants
        const int SCALE = 25;
        const string MEDIA_ROOT = @".\media\";
        const int TIMER_BASE = 40;    // in millis.
        const int MAX_STARS = 20;     // # of stars
        const int MAX_ASTEROIDS = 4;  // # of asteroids (if on)
        const int MAX_MISSILES = 2;   // # of missiles/ship
        const int MISSILE_LIFE = 50;  // 40 ticks
        const int THRUSTER_LIFE = 10; // 10 ticks
        const int ASTEROID_SPEED = 10;// how much they move
        const int GRAVITY_SPEED = 75; // how often gravity affects you
        const int GRAVITY_EFFECT = 5; // how much it effects you
        const int DEFAULT_SPEED = 5;  // default game speed
        const int NUM_LIVES = 5;      // determines when the game is over
        const int SCORE_ASTEROID = 10; // 10 points for hitting an asteroid

        // Image buffer to prevent screen-flicker
        Bitmap offScreenBuffer;

        // Member fields -- UI elements
        private System.Windows.Forms.MainMenu mainMenu1;
        private System.Windows.Forms.MenuItem menuItem1;

        // Member fields
        GameState gameState;  // Holds state information
        PlayerImageArray player;

        AnimatedImage[] exhaustImages;
        AnimatedImage[] playerMissiles;
        AnimatedImage[] asteroids;

        Point[] stars;  // background star field
        Image imgStar;

        GameTimer timer;    // Event timer to control all animation
        TimedEvent p1Event; // The player event, for easy reference

        int HighScore = 0;
        private System.Windows.Forms.MenuItem menuItem2;        // Game's top score loads from file
        int p1LastDirection = 0;

        // Main entry-point function
        [STAThread] static void Main() {
            Application.Run(new AsteroidMiner());
        }

    #region Set-up & Initialization
        // Default constructor
        public AsteroidMiner() {
            InitializeComponent();

            gameState = new GameState();

            // Set up timer & timed events
            timer = new GameTimer(TIMER_BASE);
            TimedEvent newEvent;

            // Initialize the two player objects
            player = new PlayerImageArray(9);
            player.constraintBox = this.ClientRectangle;

            // Load images into PlayerImageArrays
            player.LoadImage(MEDIA_ROOT + "FireBall.JPG", 0);
            player.LoadImages(MEDIA_ROOT + "Ship1-%%.JPG", 1, 8);
            player.RescaleImage(SCALE, SCALE);

            // player thruster event
            newEvent = new TimedEvent(THRUSTER_LIFE,
                new TickHandler(PlayerThrust));
            newEvent.payload = player;
            timer.addEvent(newEvent, 1, "player");
            p1Event = newEvent;

            // Initialize exhaust images
            exhaustImages = new AnimatedImage[9];
            for (int i = 0; i < 9; i ++) {
                exhaustImages[i] = new AnimatedImage(0, 0);
                exhaustImages[i].imageData = Utils.LoadImage(MEDIA_ROOT +
                    "Exhaust" + i + ".JPG");
                exhaustImages[i].RescaleImage(SCALE / 2, SCALE / 2);
            }
            // Set correct image offsets
            exhaustImages[1].imageOffsetX = 14;
            exhaustImages[1].imageOffsetY = -5;
            exhaustImages[2].imageOffsetX = 9;
            exhaustImages[2].imageOffsetY = -9;
            exhaustImages[3].imageOffsetX = 0;
            exhaustImages[3].imageOffsetY = -6;
            exhaustImages[4].imageOffsetX = -8;
            exhaustImages[4].imageOffsetY = 6;
            exhaustImages[5].imageOffsetX = 1;
            exhaustImages[5].imageOffsetY = 17;
            exhaustImages[6].imageOffsetX = 8;
            exhaustImages[6].imageOffsetY = 20;
            exhaustImages[7].imageOffsetX = 11;
            exhaustImages[7].imageOffsetY = 17;
            exhaustImages[8].imageOffsetX = 20;
            exhaustImages[8].imageOffsetY = 6;

            // Initialize the background stars
            Random rnd = new Random();
            stars = new Point[MAX_STARS];
            for (int i = 0; i < MAX_STARS; i++)
                stars[i] = new Point(rnd.Next(ClientSize.Width), rnd.Next(ClientSize.Height));

            imgStar = Utils.LoadImage(MEDIA_ROOT + "FireBall.JPG");

            // Initialize player's missiles
            playerMissiles = new AnimatedImage[MAX_MISSILES];
            for (int i = 0; i < MAX_MISSILES; i++) {
                playerMissiles[i] = new AnimatedImage(0, 0);
                playerMissiles[i].owner = player;
                playerMissiles[i].constraintBox = this.ClientRectangle;
                playerMissiles[i].imageData = Utils.LoadImage(MEDIA_ROOT +
                    "Weapon1.JPG");
                playerMissiles[i].RescaleImage(SCALE / 5, SCALE / 5);

                // Set up timer & events
                newEvent = new TimedEvent(MISSILE_LIFE,
                    new TickHandler(MoveMissile));
                newEvent.payload = playerMissiles[i];
                timer.addEvent(newEvent, 1, "playerMissile" + i);
            }

            // Initialize the asteroids
            asteroids = new AnimatedImage[MAX_ASTEROIDS];
            for (int i = 0; i < MAX_ASTEROIDS; i++) {
                // Note, there are only 4 image positions so strange
                // things happen when MAX_ASTEROIDS > 4
                asteroids[i] = new AnimatedImage((i % 2 == 1) ? 3 * SCALE :
                    20 * SCALE, (i < 2 ? 3 * SCALE : 12 * SCALE));
                asteroids[i].direction = rnd.Next(1, 8);
                asteroids[i].constraintBox = this.ClientRectangle;
                asteroids[i].imageData = Utils.LoadImage(MEDIA_ROOT +
                    "Asteroid" + i + ".JPG");
                asteroids[i].RescaleImage(2 * SCALE, 2 * SCALE);

                newEvent = new TimedEvent(new TickHandler(MoveAsteroids));
                newEvent.payload = asteroids[i];
                timer.addEvent(newEvent, ASTEROID_SPEED, "asteroid" + i);
                newEvent.isActive = true;
            }

            newEvent = new TimedEvent(new TickHandler(Gravity));
            newEvent.isActive = true;
            timer.addEvent(newEvent, GRAVITY_SPEED, "");

            // Call Invalidate() every tick
            newEvent = new TimedEvent(new TickHandler(ScreenRefresh));
            timer.addEvent(newEvent, 1, "invalidate");
            newEvent.isActive = true;



        }

        // (re) Sets positional data, scores, and other game data
        public void Setup() {
            gameState.currentState = GameState.State.Started;
            gameState.currentSpeed = DEFAULT_SPEED;

            player.imagePosX = 12 * SCALE - (player.imageWidth >> 1);
            player.imagePosY = 8 * SCALE;

            if (player.score > HighScore)
                SaveHighScore(player.score);
            HighScore = LoadHighScore();
            if(HighScore < player.score) {
        HighScore = player.score;}
            player.score = 0;


            player.deaths = 0;
            player.isActive = true;
            player.direction = AnimatedImage.NORTH;

            for (int i = 0; i < MAX_MISSILES; i++) {
                playerMissiles[i].isActive = false;
            }

            for (int i = 0; i < MAX_ASTEROIDS; i++) {
                asteroids[i].RescaleImage(2 * SCALE, 2 * SCALE);
                asteroids[i].isActive = true;
            }

            timer.Start();
        }

        // Form's initialize method - we initialize all form related items
        private void InitializeComponent() {
            this.mainMenu1 = new System.Windows.Forms.MainMenu();
            this.menuItem1 = new System.Windows.Forms.MenuItem();
            this.menuItem2 = new System.Windows.Forms.MenuItem();
            //
            // mainMenu1
            //
            this.mainMenu1.MenuItems.AddRange(new System.Windows.Forms.MenuItem[] {
                                                                                      this.menuItem1,
                                                                                      this.menuItem2});
            //
            // menuItem1
            //
            this.menuItem1.Index = 0;
            this.menuItem1.Text = "Asteroid Miner";
            this.menuItem1.Click += new System.EventHandler(this.SinglePlayer_Click);
            //
            // menuItem2
            //
            this.menuItem2.Index = 1;
            this.menuItem2.Text = "";
            //
            // AsteroidMiner
            //
            this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
            this.BackColor = System.Drawing.Color.Black;
            this.ClientSize = new System.Drawing.Size(600, 400);
            this.Menu = this.mainMenu1;
            this.Name = "AsteroidMiner";
            this.Text = "Asteroid Miner";
            this.Load += new System.EventHandler(this.AsteroidMiner_Load);

        }
    #endregion

    #region Game-play functions
        // Start up the player's thrusters
        public void EngageThrusters(Player player) {
            if (player.isActive) {
                if (player == player)
                    p1Event.Reset(); // reset the timer from now

                Utils.PlaySound(MEDIA_ROOT + "Thrust.wav");
            }

            return;
        }

        // Fire a missile (if any available) from the given player
        public void FireMissile(Player player, AnimatedImage[] missiles) {
            if (!player.isActive)
                return;

            for (int i = 0; i < MAX_MISSILES; i++) {
                // shoot the first missile that's not already out there!
                if (!missiles[i].isActive) {
                    // set missiles properties so that it will get
                    // properly animated
                    missiles[i].isActive = true;
                    missiles[i].direction = player.direction;
                    missiles[i].imagePosX = player.imagePosX;
                    missiles[i].imagePosY = player.imagePosY;

                    TimedEvent missileEvent = timer.getEvent
                        ("playerMissile" + i);
                    missileEvent.Reset();

                    Utils.PlaySound(MEDIA_ROOT + "Fire.wav");
                    break;
                }
            }
        }

        public void ExertGravitationalPull(Player player) {
            if (player.imagePosX != ClientSize.Width >> 1)
                player.imagePosX += (player.imagePosX >
                    (ClientSize.Width >> 1)) ? -GRAVITY_EFFECT : GRAVITY_EFFECT;
            if (player.imagePosY != ClientSize.Height >> 1)
                player.imagePosY += (player.imagePosY >
                    (ClientSize.Height >> 1)) ? -GRAVITY_EFFECT : GRAVITY_EFFECT;
        }
    #endregion

    #region Collision Detection Routines
        // Ships can run into the asteroids and missiles.
        // We'll assume that the missiles will detect their collisions
        // so we only have to worry about the others.
        public bool CheckShipCollision(Player player) {
            Player opponent = player;

            // Asteroid collision?
            for (int i = 0; i < MAX_ASTEROIDS; i++) {
                if (asteroids[i].isActive) {
                    if (asteroids[i].Intersects(player)) {
                        ShipCollided(player);
                        return true;
                    }
                }
            }

            return false;
        }

        // Asteroids can run into ships & missiles. We'll assume that
        // missiles will detect their collisions themselves since they
        // update frequently.
        public bool CheckAsteroidCollision() {
            for (int i = 0; i < MAX_ASTEROIDS; i++) {
                if (asteroids[i].isActive) {
                    if (asteroids[i].Intersects(player)) {
                        ShipCollided(player);
                        return true;
                    }
                }
            }

            return false;
        }

        // Missiles can only run into asteroids.
        public bool CheckMissileCollision(AnimatedImage missile) {
            if (missile.isActive) {
                for (int i = 0; i < MAX_ASTEROIDS; i++) {
                    if (missile.Intersects(asteroids[i])) {
                        AsteroidCollided(asteroids[i]);
                        missile.isActive = false;
                        Utils.PlaySound(MEDIA_ROOT + "Hit.wav");
                        return true;
                    }
                }
            }

            return false;  // Must not have hit anything!
        }

        // The ship ran into something! Add to the death count and
        // end the game if we're out of lives.
        public void ShipCollided(Player victim) {
            if (!victim.isActive)
                return; // He's already dead!

            victim.isActive = false;
            victim.direction = 0; // index of our explosion image
            Utils.PlaySound(MEDIA_ROOT + "Hit.wav");

            victim.deaths++;

            if(victim.deaths >= NUM_LIVES) {
                gameState.currentState = GameState.State.Stopped;

                if (victim.score > HighScore) {
                    SaveHighScore(victim.score);
                }
            }
        }

        // The asteroid was hit! Cycle through its different scaled
        // display & increment the player's score.
        public void AsteroidCollided(AnimatedImage victim) {
            int scaleFactor = (victim.imageWidth <= (SCALE / 2)) ?
                SCALE * 2 : victim.imageWidth / 2;
            victim.RescaleImage(scaleFactor, scaleFactor);

            player.score += SCORE_ASTEROID;
        }
    #endregion

    #region OnPaint
        protected override void OnPaint(PaintEventArgs e) {
            Graphics gOffScreen;     // Graphics context for offscreen buffer
            Graphics g = e.Graphics; // Screen's graphics object

            // If the size of the window has changed, we need a new buffer
            if (offScreenBuffer == null ||
                offScreenBuffer.Width != this.ClientSize.Width ||
                offScreenBuffer.Height != this.ClientSize.Height) {
                if (ClientSize.Width == 0 || ClientSize.Height == 0)
                    return;
                offScreenBuffer = new Bitmap(this.ClientSize.Width,
                    this.ClientSize.Height);
            }

            // We paint just as if it were the screen. The function need not
            // know it is being buffered.
            gOffScreen = Graphics.FromImage(offScreenBuffer);
            DoPaint(gOffScreen);   // Call normal paint method
            gOffScreen.Dispose();  // Free up resources right away

            // We draw our buffered image onto the screen in one operation.
            // This could be improved further still by using clip regions.
            g.DrawImage(offScreenBuffer, 0, 0);
        }

        public void DoPaint(Graphics g) {
            // Redraw the background
            g.FillRectangle(Brushes.Black, 0, 0,
                this.Size.Width, this.Size.Height);

            // Write start-up text if game is stopped
            if (gameState.currentState == GameState.State.Stopped) {
                Brush YellowBrush = Brushes.Yellow;
                Font LargeAlgerianFont = new Font("Algerian", 24);
                Font MidAlgerianFont = new Font("Algerian", 18);

                g.DrawString("C# and Game Programming", LargeAlgerianFont, YellowBrush, 2 * SCALE, SCALE);
                g.DrawString("A Beginner's Guide", LargeAlgerianFont, YellowBrush, 9 * SCALE, 5 * SCALE);
                g.DrawString("By Salvatore A. Buono", MidAlgerianFont, YellowBrush, 2 * SCALE, 14 * SCALE);
            }    else {
                // Draw the scores
                Font normal = new Font("Time New Roman", 14, FontStyle.Bold);
                if(player.score < HighScore) {
          g.DrawString(HighScore.ToString(), normal, Brushes.Blue,
              4 * SCALE, SCALE);}
                else {
                    g.DrawString(player.score.ToString(), normal,  Brushes.Blue,
                        4 * SCALE, SCALE);}
                g.DrawString(player.score.ToString(), normal,  Brushes.Blue,
                    16 * SCALE, SCALE);

                // Draw the stars
                for(int i = 0; i < MAX_STARS; i++)
                    g.DrawImage(imgStar, stars[i].X, stars[i].Y, 10, 10);

                // Draw player 1 & its appropriate exhaust
                player.Display(g);
                if (p1Event.isActive) {
                    exhaustImages[player.direction].imagePosX = player.imagePosX;
                    exhaustImages[player.direction].imagePosY = player.imagePosY;
                    exhaustImages[player.direction].Display(g);
                }

                // Draw missiles
                for (int i = 0; i < MAX_MISSILES; i ++) {
                    if (playerMissiles[i].isActive)
                        playerMissiles[i].Display(g);
                }

                // Draw asteroids
                for (int i = 0; i < MAX_ASTEROIDS; i++) {
                    asteroids[i].Display(g);
                }
            }
        }
    #endregion

    #region OnKey
        protected override void OnKeyDown(KeyEventArgs e) {
            if (gameState.currentState != GameState.State.Started)
                return;

            // Player controls
            switch(e.KeyCode) {
                case Keys.Up:
                    p1LastDirection = player.direction;
                    EngageThrusters(player);
                    break;
                case Keys.Left:
                    if (player.isActive)
                        player.RotateDirection(1);
                    break;
                case Keys.Right:
                    if (player.isActive)
                        player.RotateDirection(-1);
                    break;
                case Keys.Down:
                    if (!player.isActive)
                        player.isActive = true;
                    player.RandomizePosition();
                    break;
                case Keys.NumPad0:
                case Keys.Space:
                    FireMissile(player, playerMissiles);
                    break;

                    // Exit game
                case Keys.Escape:
                    ExitApplication();
                    break;
            }
            base.OnKeyDown(e);
        }
    #endregion

    #region TimedEvent Tick Handlers
        // Implements the player's thruster push. Called repetitively until
        // the timer counts down to 0.
        public void PlayerThrust(TimedEvent e, Object obj) {
            if (gameState.currentState == GameState.State.Stopped) {
                e.isActive = false;
                return;
            }

            Player player = (Player) obj;
            int tempDir = player.direction;

            player.direction = p1LastDirection;
            player.Animate();
            player.Animate();
            player.direction = tempDir;
            player.WrapInBox();

            CheckShipCollision(player);
        }

        // Implements the missile's movement. Called automatically until
        // the timer counts down to 0.
        public void MoveMissile(TimedEvent e, Object obj) {
            if (gameState.currentState == GameState.State.Stopped) {
                e.isActive = false;
                return;
            }

            // Get a proper missile object from the event
            AnimatedImage missile = (AnimatedImage) obj;
            for(int i = 0; i < gameState.currentSpeed; i++) {
                missile.Animate();
                missile.WrapInBox();

                // See if we hit anything!
                CheckMissileCollision(missile);
            }

            // disable the missile so it can be fired again
            if (e.tickCounter <= 1)
                missile.isActive = false;
        }

        // Implements the asteroid's random movement. This is called
        // continously throughout the game.
        public void MoveAsteroids(TimedEvent e, Object obj) {
            if (gameState.currentState == GameState.State.Stopped) {
                e.isActive = false;
                return;
            }

            Random rnd = new Random();
            for(int i = 0; i < MAX_ASTEROIDS; i++) {
                if (rnd.Next(10) > 7) // Change the direction ~70% of the time
                    asteroids[i].direction = rnd.Next(1, 8);
                asteroids[i].Animate();
                asteroids[i].WrapInBox();
                CheckAsteroidCollision();
            }
        }

        // Implements the gravity (from an unseen field -- that only
        // affects ships -- located at the center of the screen).
        public void Gravity(TimedEvent e, Object obj) {
            if (gameState.currentState == GameState.State.Stopped) {
                e.isActive = false;
                return;
            }

            if (player.isActive){ // Doesn't pull "dead" ships
                ExertGravitationalPull(player);
                CheckShipCollision(player);
            }

            Utils.PlaySound(MEDIA_ROOT + "Gravity.wav");
        }

        // Regular refresh function. The screen will redraw every tick.
        public void ScreenRefresh(TimedEvent e, Object obj) {Invalidate();}
    #endregion

    #region Menu Click Handler
        private void SinglePlayer_Click(object sender, System.EventArgs e) {
            gameState.currentMode = GameState.Mode.SinglePlayer;
            Setup();
        }
    #endregion

    #region File Read/Write
        // Utility function to read the high score from a file
        public int LoadHighScore() {
            StreamReader file;
            string strTemp = "";
            int score = 0;

            try {
                file = new StreamReader(@".\HighScore.txt");
                for (int i = 0; i < 4; i++)
                    strTemp = file.ReadLine();
                score = int.Parse(strTemp.Substring(0, strTemp.IndexOf("\t")));
                file.Close();
            } catch (Exception e) {Console.WriteLine(e);}

            return score;
        }

        // Utility function to write the high score from a file
        public void SaveHighScore(int score) {
            StreamWriter file;

            try {
                file = new StreamWriter(@".\HighScore.txt");
                file.WriteLine("Asteroid Miner High Scores");
                file.WriteLine("--------------------------");
                file.WriteLine();
                file.WriteLine(score + "\t" + DateTime.Now);
                file.Flush();
                file.Close();
            } catch (Exception e) {Console.WriteLine(e);}
        }
    #endregion

        // Clean exit function
        public void ExitApplication() {
            if (MessageBox.Show ("Are you sure you want to quit?", "End Game",
                MessageBoxButtons.YesNo) == DialogResult.Yes)
                Application.Exit();
        }

        // The default Invalidate clears the entire screen creating a very
        // undesireable flicker. This override allows the paint method to
        // control it's redraw.
        public new void Invalidate() {
            OnPaint(new PaintEventArgs(Graphics.FromHwnd(this.Handle),
                new Rectangle(new Point(0, 0), this.Size)));
        }

        // The system occasionally also calls OnPaintBackground which will
        // mean the screen will be cleared, painted with the background
        // color, then repainted. This is another cause of flicker, so we
        // just override it and tell it not to do anything!
        protected override void OnPaintBackground(PaintEventArgs e) {
            // Do nothing!
        }

        private void AsteroidMiner_Load(object sender, System.EventArgs e) {

        }
    }
}