Java Slick2D Texture Issue

Question

I was working on my game today and I found that the top of my trees have a weird texture problem where they overlap each other with a black box. It is only the top of the trees and the tops are split up into 9 blocks all with their own image. The 9 images are transparent, each is 32x32, and I've tried it a bunch of different ways with no luck. Does anyone know what the problem with the texture is? This isn't a generation question but an OpenGL/Slick2D question about textures. Here's a screenshot of the problem: Screenshot

EDIT: Here's a piece of the rendering code.

for (int x = (int) (World.instance.camera.getX() / Block.WIDTH); x < width; x++)
    {
        for (int y = (int) (World.instance.camera.getY() / Block.HEIGHT); y < height; y++)
        {
            try
            {
                if (blocks[x][y] != Block.AIR.getId())
                {
                    g.drawImage(textureCache.get(blocks[x][y]), x * Block.WIDTH, y * Block.HEIGHT);
                }
            }
            catch(Exception ex)
            {

            }
        }
    }

Answer 1

Looking at your code, it seems that you are only drawing a single image at each 32x32 square. So if tree A is in front of tree B, but tree A only partly fills a square, then tree A is the one listed in your blocks array and therefore retrieved from your "texture cache"; and not tree B. So tree A is all that is drawn.

To resolve this, your blocks structure would need to be three dimensional - basically, for each 32x32 square, you'd need some kind of "stack" of references to all the images whose corresponding object is found in that square. Then when you draw that square, draw all of the images in order, from the back to the front.