Ground.java

import java.io.File;
import java.awt.image.BufferedImage;
import javax.imageio.ImageIO;
import java.util.ArrayList;
import java.awt.*;

/**
Draws the ground in the game
@author Jack Humphries
@version 5/16/2014
*/

public class Ground
{
   /** the distance by which the ground moves */
   public static final int GROUND_MOVE = 1;
   
   /** the height of the ground */
   public static final int HEIGHT = 12;

   /** the y coordinate of the top of the ground */
   private int y;
   
   /** the width of the ground */
   private int width;
   
   /** the image tiles that make up the ground */
   private ArrayList<BufferedImage> groundTiles;
   
   /** the x coordinates for the image tiles that make up the ground */
   private ArrayList<Integer> groundTileXCoords;
   
   /**
   generates the graphics for the ground
   */   
   private void generateGround()
   {
      groundTiles = new ArrayList<BufferedImage>();
      groundTileXCoords = new ArrayList<Integer>();
      
      File groundPath = new File("images/ground.png");
      
      BufferedImage groundTile = new BufferedImage(1, 1, 
         BufferedImage.TYPE_INT_RGB);
   
      try
      {
         groundTile = ImageIO.read(groundPath);
      }
      catch (Exception exception)
      {
      
      }
      
      int tempWidth = 0;
      
      //add enough tiles to the array so that there is an extra tile
      while (tempWidth < width + groundTile.getWidth())
      {
         groundTiles.add(groundTile);
         groundTileXCoords.add(tempWidth);
         tempWidth += groundTile.getWidth();
      }
   }
   
   /**
   redraws the ground
   @param g2 the graphics object
   */
   public void redrawGround(Graphics2D g2)
   {
      for (int tile = 0; tile < groundTiles.size(); tile++)
      {
         BufferedImage groundTile = groundTiles.get(tile);
         int groundTileXCoord = groundTileXCoords.get(tile);
                           
         g2.drawImage(groundTile, groundTileXCoord, y, null);
      }
   }
   
   /**
   moves the ground
   */
   public void moveGround()
   {
      int tileWidth = groundTiles.get(0).getWidth();
      
      //the first tile has moved completely off the screen
      //add it back to the end of the array
      if (groundTileXCoords.get(0) - 1 <= -tileWidth)
      {
         BufferedImage firstGroundTile = groundTiles.get(0);
         int firstGroundTileXCoord = groundTileXCoords.get(0);
         
         BufferedImage lastGroundTile 
            = groundTiles.get(groundTiles.size() -1);
         int lastGroundTileXCoord
            = groundTileXCoords.get(groundTileXCoords.size() - 1);
            
         int newXCoord = lastGroundTileXCoord + lastGroundTile.getWidth();
         
         groundTiles.add(firstGroundTile);
         groundTileXCoords.add(newXCoord);
         
         groundTiles.remove(0);
         groundTileXCoords.remove(0);
      }
   
      for (int tile = 0; tile < groundTiles.size(); tile++)
      {
         BufferedImage groundTile = groundTiles.get(tile);
         int groundTileXCoord = groundTileXCoords.get(tile);
         
         groundTileXCoord -= GROUND_MOVE;
                           
         groundTileXCoords.set(tile, groundTileXCoord);
      }
   }
   
   public Ground(int theWidth, int theY)
   {
      y = theY;
      width = theWidth;
      
      generateGround();
   }  
}