processing-minecraft/BlockTextures.pde

public class BlockTextures {
  private PImage terrain;
  private HashMap<Integer, PImage> sprites;

  public BlockTextures() {
    terrain = loadImage("terrain.png");

    sprites = new HashMap<Integer, PImage>();
    for (int row = 0; row < 16; row++) {
      for (int column = 0; column < 16; column++) {
        sprites.put((16*row)+column, terrain.get(column*16, row*16, 16, 16));
      }
    }
  }

  public PImage get(int id) {
    return sprites.get(id);
  }
}