如何在Java代码中随机生成图块

Question

I have question about random generation of sprite sheet tiles in java. Whenever I try to use a for loop the random generation changes every millisecond or faster. I am very confused and have no idea where to start from here. If anyone can come up with some easy code for a begginer to grasp the concept of random generation!

Here is the code I am working with for generating a flat map /

public class Map {

    Random random = new Random();

    public static int mapxDirection;
    public static int mapx = 1;
    public static int bgSpeed = 20;
    public static int grass = 16;
    public static int dirt = 0;
    public static int stone = 1;
    public static int waterup = 2;
    public static int waterside = 18;
    public static int glass = 17;
    public static int chicken = 32;
    public static int steak = 33;
    public static int mapSpeed = 3;

    public static BufferedImage[] sprites;

    public void renderMap(Graphics g) {

        final int width = 32;
        final int height = 32;
        final int rows = 16;
        final int cols = 16;

        sprites = new BufferedImage[rows * cols];

        BufferedImage spritesheet = null;
        try {
            spritesheet = ImageIO.read(new File("res/SpriteSheet.png"));
        } catch (IOException e) {

            e.printStackTrace();
        }

        for (int i = 0; i < rows; i++) {
            for (int j = 0; j < cols; j++) {
                sprites[(i * cols) + j] = spritesheet.getSubimage(i * width, j
                        * height, width, height);
            }
        }

        for (int i = 0; i < 2000; i += 32) {
            g.drawImage(sprites[grass], Map.mapx + i, 259, null);
        }

        for (int i = 0; i < 2000; i += 32) {
            for (int j = 291; j <= 508; j += 32) {
                g.drawImage(sprites[dirt], Map.mapx + i, j, null);
            }
        }
        for (int i = 0; i < 2000; i += 32) {
            for (int j = 508; j <= 540; j += 32) {
                g.drawImage(sprites[stone], Map.mapx + i, j - 3, null);
            }
        }
    }
}

Answer 1

There are multiple ways this can be done, it also depends on what type on random generation you want to achieve for example, do you what to completely randomize every tile or do you what to load random chunks. The popular game Minecraft uses the method of random chuck generation.

If your new to game programming, i recommend checking out RealTutsGML Game Programming Tutorials . He teaches you a easy and good way of loading in sprite sheets and also teaches you how to load in and create a level in paint. All though he is making a platformer, you can easily convert the same method into a top down game.

Here is how i would go about creating a random generation map. First i would create a abstract class called GameObject. Every object you make will extend this class.

public abstract class GameObject {

    protected float x, y;
    protected ObjectId id;
    protected float velX= 0, velY = 0;

    protected boolean falling = true;
    protected boolean jumping = false;

    public GameObject(float x, float y, ObjectId id) {
        this.x = x;
        this.y = y;
        this.id = id;
    }

    public abstract void tick(LinkedList<GameObject> object);
    public abstract void render(Graphics g);
    public abstract Rectangle getBounds();

    public float getX() { return x; }
    public float getY() { return y; }
    public float getVelX() { return velX; }
    public float getVelY() { return velY; }
    public boolean isFalling() { return falling; }
    public boolean isJumping() { return jumping; }

    public void setX(float x) { this.x = x; }
    public void setY(float y) { this.y = y; }
    public void setVelX(float velX) { this.velX = velX; }
    public void setVelY(float velY) { this.velY = velY; }
    public void setFalling(boolean falling) { this.falling = falling; }
    public void setJumping(boolean jumping) { this.jumping = jumping; }

    public ObjectId getId() { return id; }
}

For example if i want to make a object called Block, i would create a class called Block and extends GameObject like this.

public class Block extends GameObject {

    private boolean animate = true;

    Texture tex = Game.getInstance();
    private int type;

    public Block(float x, float y, int type, ObjectId id) {
        super(x, y, id);
        this.type = type;
    }

    public void tick(LinkedList<GameObject> object) {
        bAnimate.runAnimation();
    }

    public void render(Graphics g) {
        if (type == 0) g.drawImage(tex.red_block[0], (int)x, (int)y, null); // Red Block
        if (type == 1) g.drawImage(tex.green_block[0], (int)x, (int)y, null); // Blue Block
        if (type == 2) g.drawImage(tex.blue_block[0], (int)x, (int)y, null); // Green Block
        if (type == 3) g.drawImage(tex.yellow_block[0], (int)x, (int)y, null); // Yellow Block
        if (type == 4) g.drawImage(tex.orange_block[0], (int)x, (int)y, null); // Orange Block
        if (type == 5) g.drawImage(tex.pink_block[0], (int)x, (int)y, null); // Pink Block
    }

    public Rectangle getBounds() {
        return new Rectangle((int)x, (int)y, 32, 32);
    }

}

I then create a LinkedList like this. An also create 2 methods for adding and removing objects for the list.

protected LinkedList<GameObject> object = new LinkedList<GameObject>();

public void addObject(GameObject object) {
    this.object.add(object);
}

public void remove(GameObject object) {
    this.object.remove(object);
}

I would then simply add objects to the list like this.

addObject(new Block(x * 32, y * 32, random.nextInt(6), ObjectId.Block)); 

Sense this post is getting kinda big i will leave the rest to you, if you like i can see you the source code of the project i am using. This is also the same method that "RealTutsGML" uses in his tutorials.

I see that you and using Map.mapx instead of that just write the variable mapx no need for the Map . Also your data should always be private or protected. I also recommend making a variable that holds your map size like this.

private static int mapSize = 2000;

It is just so that if you want to change the map size you don't have to replace more than one number.

I hope this helps you out.

Here is a list of java programming books .