drawImage not working

Newbie & Debugging Questions
#1

Hello there, Java-Gaming people. I’m new to the forum, so maybe a little introduction is in order. So I’m this guy from the Netherlands, I have programmed in Gamemaker quite extensively, with which I started at a young age. Mind you I didn’t do the Drag and Drop stuff, but “proper” coding, and I have in gamemaker constructed some stuff that I think is pretty nifty, I have for example at a point programmed an online top down shooter from scratch (as far as that goes in gamemaker). However, this year at university (First year Software Science), I was introduced to Java, and after some tests I found out that it is an insane amount faster then Gamemaker, so I decided to move to Java, and I have succeeded(sp?) in creating a simple mario platformer, with image animations, a particle system and some gibberish, but I have now moved on to a new more structured project (An isometric RTS), BUT somewhere something must be going wrong because it does not draw images.

Tl;dr:
This is an extract from my script, this is the image initialization:

public class Tile extends GameImage
{
  int x,y;
  int type;
  TileGrid grid;
  Image image=Toolkit.getDefaultToolkit().getImage("Grass.png");

And this is the “draw” script, which I know to work, since it does draw the lines, but it does not draw the image, and I have no idea why.

  public void draw(Graphics2D g)
  {
    int dx,dy;
    dx=grid.X(x);
    dy=grid.Y(y);
    g.drawImage(image,dx-16,dy-8,null);    
    g.drawLine(dx-16,dy,dx,dy-8);
    g.drawLine(dx,dy-8,dx+16,dy);    
    g.drawLine(dx-16,dy,dx,dy+8);
    g.drawLine(dx,dy+8,dx+16,dy);        
  }

Help would be appreciated (:, in the meanwhile this forum has quite some resources and information to absorb.

#2

What are the image’s width and height? If they are both -1, then that means your image was not found and an empty Image object was returned.

#3

Dimensions are 32x16, but that is not stated anywhere in the code, should the program somehow know these values?

EDIT:
I added System.out.println(image.getWidth(null));to test what you said, and it returns -1, so you seem to have nailed the problem. Also that was a pretty fast response :P. So how would I fix it loading an empty image?

#4

You get the Image’s width and height by doing:


System.out.println(image.getWidth(null) + " " + image.getHeight(null));
#5

I fixed the problem by replacing the getImage URL with this:
Image image=Toolkit.getDefaultToolkit().getImage(“C:/Users/Bob/Desktop/Java game engine/Skeleton/Grass.png”);

How would I go about loading Grass.png from my current path? Because it is a bit silly to do it like this.

#6

It is best to use the Class.getResource(String) method. Using “grass.png” will look for the file inside the package (folder) of that Class. Using a forward slash ("/") at the beginning will look from the root of your package hierarchy.

So let’s say I have a class called MyClass inside package com.ra4king.mypackage, then MyClass.class.getResource(“grass.png”) or myClassInstance.getClass().getResource(“grass.png”) will look for that file inside the mypackage folder. The same file will be found if I do MyClass.class.getResource("/com/ra4king/mypackage/grass.png") or the getClass() way.

#7

All’s working smooth now, thanks for your quick and usefull responses!

#8

Glad to help :slight_smile:

Don’t forget to Appreciate (click the Appreciate button to the right of the Quote button) anyone that helps you on this forum. Keeps moods up ;D

#9

ra4king, you’re a gratuitous medal whore! :stuck_out_tongue:

;D

#10

Where is this appreciate button you speak of?

http://img197.imageshack.us/img197/7690/nobutton.png

EDIT: it just appeared, maybe you need 5 posts to be able to appreciate?

#11

There’s a reason he ranks #1 in awkwardness!
http://www.java-gaming.org/index.php?action=social
Oh how I love my closed source queries.

#12

I may be loud, but you can’t ignore me ;D

#13

ra4king -> Post visibility -> Hide all posts :stuck_out_tongue:

#14

But I know you won’t do that because you <3 me :persecutioncomplex: