17. Dots as part of the labyrinth

In our last approach to the map of the labyrinth (the one which used an "array of strings", the position for the dots was represented as ".". We can now extract that information from the map, so that the dots are paced in their correct positions, instead of being at random positions.

Now, the amount of dots cannot be predefined. It must be calculated by counting how many dots are represented in the map:

// First: count how many dots are there
int amountOfDots = 0;
for (int row = 0; row < 15; row++)
{
    for (int column = 0; column < 17; column++)
    {
        if (map[row][column] == '.')
            amountOfDots++;
    }
}
int[] xDot = new int[amountOfDots];
int[] yDot = new int[amountOfDots];
bool[] visible = new bool[amountOfDots];
 

And then we would fill in the array with the calculated x and y for each dot (easy: the current column and row, multiplied by the size of each tile, which is 32):

// Now, we 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++;
        }
    }
}
 

So the full source might be:

/*
  First mini-graphics-game skeleton
  Version G: dots from map
*/
 
using System;
 
public class Game02g
{
    public static void Main()
    {
        bool fullScreen = false;
        SdlHardware.Init(800, 600, 24, fullScreen);
 
        Image dotImage = new Image("dot.bmp");
        Image enemyImage = new Image("ghostGreen.bmp");
        Image pacImage = new Image("pac01r.bmp");
        Image wallImage = new Image("wall.bmp");
 
        int x=32, y=32;
        int pacSpeed = 6;
 
        int amountOfEnemies = 4;
        float[] xEnemy = { 150, 400, 500, 600 };
        float[] yEnemy = { 100, 200, 300, 400 };
        float[] incrXEnemy = { 5f, 3f, 6f, 4.5f };
 
        string [] map = {
            "-----------------",
            "-.......-.......-",
            "-.--.--.-.--.--.-",
            "-...............-",
            "-.--.-.---.-.--.-",
            "-....-..-..-....-",
            "----.--...--.----",
            ".................",
            "----.-.-.-.-.----",
            "-....-.-.-.-....-",
            "-.--.-.---.-.--.-",
            "-...............-",
            "-.--.-.---.-.--.-",
            "-....-.....-....-",
            "-----------------"
        };
 
        // Data for the dots
        // First: count how many
        int amountOfDots = 0;
        for (int row = 0; row < 15; row++)
        {
            for (int column = 0; column < 17; column++)
            {
                if (map[row][column] == '.')
                    amountOfDots++;
            }
        }
        int[] xDot = new int[amountOfDots];
        int[] yDot = new int[amountOfDots];
        bool[] 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++;
                }
            }
        }
 
 
        int score = 0;
        bool gameFinished = false;
 
        // Game Loop
        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)) x += pacSpeed;
            if (SdlHardware.KeyPressed(SdlHardware.KEY_LEFT)) x -= pacSpeed;
            if (SdlHardware.KeyPressed(SdlHardware.KEY_DOWN)) y += pacSpeed;
            if (SdlHardware.KeyPressed(SdlHardware.KEY_UP)) 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);
        }
    }
}
 

Which would look like this:

We can still walk through the walls. We'll correct in the next version.