Java Animating using drawImage [closed]

Question

Hi I have a tile based game and I would like to know how to animate the grass image this is what I have so far:

public class dirt extends block{


    float frame = 0;
    public dirt(int x,int y){
        this.x = x;
        this.y = y;
        r = new Rectangle(x - (int)tilemap.camx,y - (int)tilemap.camy,20,20);
        solid = false;

    }

    public void tick(){
        createCollisionRect();

        int tester = (int)(frame +.1);

        if(tester < 3){
            frame+=.1;
        }else{
            frame = 0;
        }


    }

    public void render(Graphics g){
        ImageIcon i62 = new ImageIcon("res/grasssheet.png");
        img = i62.getImage();
        g.drawImage(img, x - (int)tilemap.camx,y-(int)tilemap.camy,x+20,y+60/***/,0,20*(int)frame,60,20*(int)frame + 20,null);
        //g.drawImage(img, x- (int)tilemap.camx,y-(int)tilemap.camy, null);

    }
}

This kinda works but I don't why all the images glitch out.

I think I need an image observer but I don't understand that so if that's the problem explain what I have to please.

Answer 1

It looks like you are drawing directly to the graphics objects instead of buffering. Have you seen the documentation?

Java has a BufferStrategy class that might help you. You should do your drawing off-screen, then switch the view using the BufferStrategy object, removing all flickering.

You might want to look at some Java game engines though: They already do a lot of the heavy lifting for you, letting you focus on the game logic and play.

Answer 2

Your question is too vague.
What do you mean by "glitch out"?

From the look of the drawImage I assume that you want to draw a single 'frame' (20px*20px) from the spritesheet? That's not what I see there.
Try:

g.drawImage(img.getSubimage((frame*20),0,20,20), x - (int)tilemap.camx, y-(int)tilemap.camy, null);

Also, you shouldn't be reloading the images on every render call. Load it once and, for example, pass it in the constructor, or, better yet, create a tile 'Type', load the image once there and give each tile a reference to a tile type.
(And is there a reason you are loading it as an ImageIcon as opposed to, say, a BufferedImage?)