Background.java :  » Game » cloak » com » cloak » game » Android Open Source

/*
 * Copyright (C) 2009 Jason Tomlinson.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.cloak.game;

import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Paint;

/**
 * Provides a simple mechanism to draw custom backgrounds, these can be static or move in a north, south, east or west direction.
 */
public class Background {
  
  /** Background attributes **/
  private int mX;
  private int mY;
  private int mWidth;
  private int mHeight;
  //TODO should this be done in the same fashion as we animate sprites, movement doesn't appear to be fluid.
  private int mSpeed;
  
  /** Image displayed on-screen **/
  private Bitmap mImage;
  private Paint mPaint;
  
  /** Direction to scroll the background **/ 
  public final static int NONE  = -1;
  public final static int NORTH   = 1;
  public final static int EAST   = 2;
  public final static int SOUTH   = 3;
  public final static int WEST  = 4;
  private int mDirection = NONE;
  
  /** Buffer is used when an image goes off screen, this determines how long until we see the image again **/
  private int mBuffer = 0;
  
  /** Are we displaying a scrolling background **/
  private boolean mParallax;
  
  public Background (int x, int y, int speed, Bitmap img) {
    init(x, y, speed, img, false, NONE, 0);
  }
  
  public Background (int x, int y, int speed, Bitmap img, boolean parallax, int direction, int buffer) {
    init(x, y, speed, img, parallax, direction, buffer);
  }
  
  public void init(int x, int y, int speed, Bitmap img, boolean parallax, int direction, int buffer) {
    mX = x;
    mY = y;
    mSpeed = speed;
    mImage = Bitmap.createBitmap(img);
    mWidth = mImage.getWidth();
    mHeight = mImage.getHeight();
    
    mParallax = parallax;
    
    mDirection = direction;
    mBuffer = buffer;
    
    mPaint = new Paint();
    mPaint.setAntiAlias(true);
  }
  
  public void heartbeat() {
    //jmt: move the image based on direction
    if (mDirection > NONE) {
      if (mDirection == NORTH) {
        //TODO: implement north movement
      } else if (mDirection == EAST) {
        //TODO: implement east movement
      } else if (mDirection == SOUTH) {
        //TODO: implement south movement
      } else if (mDirection == WEST) {
        mX -= mSpeed;
      
        if (mX < -mWidth)
          mX = mWidth + mBuffer;
      }
    }
    
  }
  
  public void draw(Canvas canvas) {
    //jmt: draw the image
    canvas.drawBitmap(mImage, mX, mY, mPaint);
    
    //jmt: parallax backgrounds need to be drawn multiple times to produce the required effect of continual motion 
    if (mParallax) {
      if (mDirection == NORTH) {
        //TODO: implement north movement
      } else if (mDirection == EAST) {
        //TODO: implement east movement
      } else if (mDirection == SOUTH) {
        //TODO: implement south movement
      } else if (mDirection == WEST) {
        if (mX < 0)
          canvas.drawBitmap(mImage, mX + mWidth, mY, mPaint);
        else
          canvas.drawBitmap(mImage, mX - mWidth, mY, mPaint);
      }
    }
  }
}