Tile engine Texture not updating when numbers in array change

Question

I draw my map from a txt file. I am using java with slick2d library. When I print the array the number changes in the array, but the texture doesn't change.

public class Tiles {

public Image[] tiles = new Image[5];

public int[][] map = new int[64][64];

public Image grass, dirt, fence, mound;

private SpriteSheet tileSheet;

public int tileWidth = 32;
public int tileHeight = 32;

public void init() throws IOException, SlickException {
    tileSheet = new SpriteSheet("assets/tiles.png", tileWidth, tileHeight);

    grass = tileSheet.getSprite(0, 0);
    dirt = tileSheet.getSprite(7, 7);
    fence = tileSheet.getSprite(2, 0);
    mound = tileSheet.getSprite(2, 6);
    tiles[0] = grass;
    tiles[1] = dirt; 
    tiles[2] = fence;
    tiles[3] = mound;

    int x=0, y=0;
BufferedReader in = new BufferedReader(new FileReader("assets/map.dat"));
String line;
while ((line = in.readLine()) != null) {
        String[] values = line.split(",");
        x = 0;
    for (String str : values) {
            int str_int = Integer.parseInt(str);
            map[x][y]=str_int;
            //System.out.print(map[x][y] + " ");
            x++;
        }
//System.out.println("");
y++;
}
    in.close();
}

public void update(GameContainer gc) {

}

public void render(GameContainer gc) {
    for(int y = 0; y < map.length; y++) {
        for(int x = 0; x < map[0].length; x ++) {
            int textureIndex = map[x][y];
            Image texture = tiles[textureIndex];
            texture.draw(x*tileWidth,y*tileHeight);
        }
    }
}

}

Mouse Picking Where I change the number in the array

Input input = gc.getInput();

    gc.getInput().setOffset(cameraX-400, cameraY-300);
    float mouseX = input.getMouseX();
    float mouseY = input.getMouseY();

    double mousetileX = Math.floor((double)mouseX/tiles.tileWidth);
    double mousetileY = Math.floor((double)mouseY/tiles.tileHeight);

    double playertileX = Math.floor(playerX/tiles.tileWidth);
    double playertileY = Math.floor(playerY/tiles.tileHeight);

    double lengthX = Math.abs((float)playertileX - mousetileX); 
    double lengthY = Math.abs((float)playertileY - mousetileY);
    double distance = Math.sqrt((lengthX*lengthX)+(lengthY*lengthY)); 

    if(input.isMousePressed(Input.MOUSE_LEFT_BUTTON) && distance < 4) {
        System.out.println("Clicked");  
        if(tiles.map[(int)mousetileX][(int)mousetileY] == 1) {
            tiles.map[(int)mousetileX][(int)mousetileY] = 0;
        }
    } 

I don't know what is wrong: all my textures work when I render them, it just doesn't update when the number in the array changes. I am obviously debugging when I say that I was printing the array and the number is changing like it should, so it's not a problem with my mouse picking code. It is a problem with my textures, but I don't know what because they all render correctly.

Answer 1

The problem could be in your render logic you have hardcoded to look at map[0]

Change to

    for(int y = 0; y < map.length; y++) {
        for(int x = 0; x < map[y].length; x ++) {
            int textureIndex = map[x][y];
            Image texture = tiles[textureIndex];
            texture.draw(x*tileWidth,y*tileHeight);
        }
    }

EDIT I as the comment below suggests map[0].length would be fine if the map is guaranteed to be same width each row. (this is what I for posting before morning coffee)

EDIT 2

It dawned on me that you have no option to update back to 1 if 0 in your click handler so you could never change a 0 to a 1 in the first place, so the number never changed

if(tiles.map[(int)mousetileX][(int)mousetileY] == 1) {
  tiles.map[(int)mousetileX][(int)mousetileY] = 0;
}

you could add an else statement like so

if(tiles.map[(int)mousetileX][(int)mousetileY] == 1) {
  tiles.map[(int)mousetileX][(int)mousetileY] = 0;
}
else {
   tiles.map[(int)mousetileX][(int)mousetileY] = 1;
}