21. More detailed initialization

In the last two versions of our game, an "Init" function existed, but it did almost nothing. It is time for it to really initialize most of the variables in our program. We want it to be something like:

public static void Init()
{
    bool fullScreen = false;
    SdlHardware.Init(800, 600, 24, fullScreen);
 
    dotImage = new Image("dot.bmp");
    enemyImage = new Image("ghostGreen.bmp");
    pacImage = new Image("pac01r.bmp");
    wallImage = new Image("wall.bmp");
 
    x = 32;
    y = 32;
    pacSpeed = 4;
 
    amountOfEnemies = 4;
 
    // Data for the dots
    // First: count how many dots are there
    amountOfDots = 0;
    for (int row = 0; row < 15; row++)
    {
        for (int column = 0; column < 17; column++)
        {
            ...
 

So that our Main looks like:

public static void Main()
{
    Init();
    Intro();
 
    // Game Loop
    bool gameFinished = false;
    while (!gameFinished)
    {
        ...
 

But that also means another change: most of our variables, which previously were declared inside Main, must now we declared out of it, to be shared by different functions. Also, as they are out ouf Main, and because of reasons whihc we will not detail (nor avoid) yet, they must be declared as "static":

public class Game02k
{
    static int x, y;
    static int pacSpeed;
    static int amountOfEnemies;
 
    static int[] xDot;
    static int[] yDot;
    static bool[] visible;
    static int amountOfDots;
 
    ...
 
 

And the final source code for this version would be:

/*
  First mini-graphics-game skeleton
  Version K: more detailed "Init", most variables become static attributes
*/
 
using System;
 
public class Game02k
{
    static int x, y;
    static int pacSpeed;
    static int amountOfEnemies;
 
    static float[] xEnemy = { 150, 400, 500, 600 };
    static float[] yEnemy = { 100, 200, 300, 400 };
    static float[] incrXEnemy = { 5f, 3f, 6f, 4.5f };
 
    static int[] xDot;
    static int[] yDot;
    static bool[] visible;
    static int amountOfDots;
 
    static Image dotImage;
    static Image enemyImage;
    static Image pacImage;
    static Image wallImage;
 
    static string[] map = {
            "-----------------",
            "-.......-.......-",
            "-.--.--.-.--.--.-",
            "-...............-",
            "-.--.-.---.-.--.-",
            "-....-..-..-....-",
            "----.--...--.----",
            ".................",
            "----.-.-.-.-.----",
            "-....-.-.-.-....-",
            "-.--.-.---.-.--.-",
            "-...............-",
            "-.--.-.---.-.--.-",
            "-....-.....-....-",
            "-----------------"
    };
    static int score;
 
    public static void Init()
    {
        bool fullScreen = false;
        SdlHardware.Init(800, 600, 24, fullScreen);
 
        dotImage = new Image("dot.bmp");
        enemyImage = new Image("ghostGreen.bmp");
        pacImage = new Image("pac01r.bmp");
        wallImage = new Image("wall.bmp");
 
        x = 32;
        y = 32;
        pacSpeed = 4;
 
        amountOfEnemies = 4;
 
        // Data for the dots
        // First: count how many dots are there
        amountOfDots = 0;
        for (int row = 0; row < 15; row++)
        {
            for (int column = 0; column < 17; column++)
            {
                if (map[row][column] == '.')
                    amountOfDots++;
            }
        }
        xDot = new int[amountOfDots];
        yDot = new int[amountOfDots];
        visible = new bool[amountOfDots];
        // Now, assign their coordinates
        int currentDot = 0;
        for (int row = 0; row < 15; row++)
        {
            for (int column = 0; column < 17; column++)
            {
                if (map[row][column] == '.')
                {
                    xDot[currentDot] = column * 32;
                    yDot[currentDot] = row * 32;
                    visible[currentDot] = true;
                    currentDot++;
                }
            }
        }
        score = 0;
    }
 
 
    public static void Intro()
    {
        Image pac = new Image("pac01r.bmp");
        Image ghost = new Image("ghostGreen.bmp");
        int x = -40;
        do
        {
            SdlHardware.ClearScreen();
            SdlHardware.DrawHiddenImage(ghost, x - 50, 300);
            SdlHardware.DrawHiddenImage(pac, x, 300);
            SdlHardware.ShowHiddenScreen();
            x += 8;
            if (x > 850) x = -40;
            SdlHardware.Pause(20);
        }
        while (!SdlHardware.KeyPressed(SdlHardware.KEY_SPC));
 
    }
 
    public static bool CanMoveTo(int x, int y, string[] map)
    {
        bool canMove = true;
        for (int row = 0; row < 15; row++)
        {
            for (int column = 0; column < 17; column++)
            {
                if (map[row][column] == '-')
                    if ((x > column * 32 - 32) &&
                        (x < column * 32 + 32) &&
                        (y > row * 32 - 32) &&
                        (y < row * 32 + 32)
                        )
                    {
                        canMove = false;
                    }
            }
        }
        return canMove;
    }
 
    public static void Main()
    {
        Init();
        Intro();
 
        // Game Loop
        bool gameFinished = false;
        while (!gameFinished)
        {
            // Draw
            SdlHardware.ClearScreen();
            //Console.Write("Score: {0}",score);
 
            // Background map
            for (int row = 0; row < 15; row++)
            {
                for (int column = 0; column < 17; column++)
                {
                    if (map[row][column] == '-')
                        SdlHardware.DrawHiddenImage(wallImage, column * 32, row * 32);
                }
            }
 
            for (int i = 0; i < amountOfDots; i++)
            {
                if (visible[i])
                    SdlHardware.DrawHiddenImage(dotImage, xDot[i], yDot[i]);
            }
 
            SdlHardware.DrawHiddenImage(pacImage, x, y);
 
            for (int i = 0; i < amountOfEnemies; i++)
                SdlHardware.DrawHiddenImage(enemyImage,
                    (int)xEnemy[i], (int)yEnemy[i]);
 
            SdlHardware.ShowHiddenScreen();
 
            // Read keys and calculate new position
            if (SdlHardware.KeyPressed(SdlHardware.KEY_RIGHT)
                    && CanMoveTo(x + pacSpeed, y, map))
                x += pacSpeed;
 
            if (SdlHardware.KeyPressed(SdlHardware.KEY_LEFT)
                    && CanMoveTo(x - pacSpeed, y, map))
                x -= pacSpeed;
 
            if (SdlHardware.KeyPressed(SdlHardware.KEY_DOWN)
                    && CanMoveTo(x, y + pacSpeed, map))
                y += pacSpeed;
 
            if (SdlHardware.KeyPressed(SdlHardware.KEY_UP)
                    && CanMoveTo(x, y - pacSpeed, map))
                y -= pacSpeed;
 
            if (SdlHardware.KeyPressed(SdlHardware.KEY_ESC))
                gameFinished = true;
 
            // Move enemies and environment
            for (int i = 0; i < amountOfEnemies; i++)
            {
                xEnemy[i] += incrXEnemy[i];
                if ((xEnemy[i] < 1) || (xEnemy[i] > 760))
                    incrXEnemy[i] = -incrXEnemy[i];
            }
 
            // Collisions, lose energy or lives, etc
            for (int i = 0; i < amountOfDots; i++)
                if (visible[i] &&
                    (x > xDot[i] - 32) &&
                    (x < xDot[i] + 32) &&
                    (y > yDot[i] - 32) &&
                    (y < yDot[i] + 32)
                    )
                {
                    score += 10;
                    visible[i] = false;
                }
 
            // Pause till next fotogram
            SdlHardware.Pause(40);
        }
    }
}