backgroundlayer.java

来自「J2ME手机游戏开发技术详解随书光盘」· Java 代码 · 共 57 行

import javax.microedition.lcdui.*;
import javax.microedition.lcdui.game.*;


public class BackgroundLayer extends TiledLayer{
    private int horizontalMove;
    private int totalPixelLength;
    
    public BackgroundLayer(int columns, int rows, Image image, int tileWidth, int tileHeight){
        super(columns, rows, image, tileWidth, tileHeight);
        totalPixelLength = (columns * tileWidth);
    }
    
    /**
     * Sets the number of pixels to move  the layer each 
     * time move() is called
     */
    public void setHorizontalMove(int aHorizontalMove){
        horizontalMove = aHorizontalMove;
    }
    
    /**
     * Moves the background the number of pixels specified with
     * setHorizontalMove()
     */
    public void move(){
        super.move(horizontalMove,0);       
        totalPixelLength += horizontalMove;
    }
    
    /**
     * Sets the Background's cells according to the information in the passed
     * parameter int[] aCellMap.
     * nbrfRows and nbrOfCols refers to the Background's layout
     */
    public void setCells(int[] aCellMap, int nbrOfRows, int nbrOfCols){
        for (int i = 0; i < aCellMap.length; i++) {
            int column = i % nbrOfCols;
            int row = (i - column) / nbrOfCols;
            setCell(column, row, aCellMap[i]);
            
        }
    }
    
    /**
     * Returns true if the Background has reached it's end,
     * false otherwise.
     */
    public boolean endOfBackground(int aScreenWidth){
        if (totalPixelLength-aScreenWidth>0){
            return false;
        }else{
            return true;
        }
    }
}