Question

Well, I’m making a relatively simple platformer game with java and I have a method that generates the level, but the tiles won’t draw.

public void generateDungeon() {
    int y = 30;
    for(int x = 0; x < block[0].length; x++) {
        block[x][y] = new Block(new Rectangle(x * Tile.tileSize, y *      Tile.tileSize, Tile.tileSize, Tile.tileSize), Tile.basic);
    }
}

I want the Y to stay the same so that’s why it has a set value.

That is where I think the problem lies, but here’s the console message

Exception in thread "Thread-2" java.lang.NullPointerException
at mineandbuild.Player.isCollidingWithBlock(Player.java:82)
at mineandbuild.Player.tick(Player.java:22)
at mineandbuild.Component.tick(Component.java:89)
at mineandbuild.Component.run(Component.java:110)
at java.lang.Thread.run(Unknown Source)

The console says the problem is at this line of code:

public boolean isCollidingWithBlock(Point pt1, Point pt2) {     
    for(int x = (int) (this.x / Tile.tileSize); x < (int) (this.x / Tile.tileSize  + 3); x++) {
        for(int y = (int) (this.y / Tile.tileSize); y < (int) (this.y / Tile.tileSize  + 3); y++) {
            if(x >= 0 && y >= 0 && x < Component.dungeon.block.length && y < Component.dungeon.block[0].length)
This line --->  if(Component.dungeon.block[x][y].id != Tile.air) {
                if(Component.dungeon.block[x][y].contains(pt1) || Component.dungeon.block[x][y].contains(pt2)) {
                    return true;
                }
            }
        }
    }

    return false;
}

Thanks!

Answer 1

Try printing out the x and y values for

if(Component.dungeon.block[x][y].id != Tile.air) {

You say that in the code before the value of y should stay the same, which means for every other index of y in the 2-d array they’re set to null, but in the forloop you have this

for(int y = (int) (this.y / Tile.tileSize); y < (int) (this.y / Tile.tileSize  + 3); y++) {

which leads me to believe that you’re trying to access indices that are null, then trying to access the “id” field, except that that object doesn’t exist.