Bitmap位图渲染与操作
public class BitmapTest extends Activity{
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
this.getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(new BitmapView(this));
}
}
class BitmapView extends SurfaceView implements Callback,Runnable{
private Paint mPaint;
private Thread mThread;
private boolean mFlag;
private SurfaceHolder mSurfaceHolder;
private Canvas mCanvas;
private Bitmap mBitmap;
public BitmapView(Context context) {
super(context);
mSurfaceHolder=this.getHolder();
mSurfaceHolder.addCallback(this);
mPaint=new Paint();
mPaint.setColor(Color.WHITE);
mBitmap=BitmapFactory.decodeResource(getResources(), R.drawable.icon);
setFocusable(true);
}
@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width,
int height) {
// TODO Auto-generated method stub
}
@Override
public void surfaceCreated(SurfaceHolder holder) {
mFlag=true;
mThread=new Thread(this,"My Thread");
mThread.start();
}
@Override
public void surfaceDestroyed(SurfaceHolder holder) {
mFlag=false;
}
@Override
public void run() {
while (mFlag) {
long start=System.currentTimeMillis();
myDraw();
logic();
long end=System.currentTimeMillis();
try {
if((end-start)<50){
Thread.sleep(50-(end-start));
}
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
private void logic() {
// TODO Auto-generated method stub
}
private void myDraw() {
mCanvas=mSurfaceHolder.lockCanvas();
try {
if (mCanvas != null) {
mCanvas.drawColor(Color.WHITE);
//Drawing a bitmap
//mCanvas.drawBitmap(mBitmap, 0, 0, mPaint);
//Rotate bitmap method one
/*mCanvas.save();
mCanvas.rotate(30, mBitmap.getWidth() / 2, mBitmap.getHeight() / 2);
mCanvas.drawBitmap(mBitmap, 0, 0, mPaint);
mCanvas.restore();
mCanvas.drawBitmap(mBitmap, 100,0, mPaint);*/
//Rotate bitmap method two
/*Matrix matrix=new Matrix();
matrix.postRotate(30, mBitmap.getWidth()/2, mBitmap.getHeight()/2);
mCanvas.drawBitmap(mBitmap, matrix, mPaint);*/
//Translate bitmap method one
/*mCanvas.save();
mCanvas.translate( 10, 10);
mCanvas.drawBitmap(mBitmap, 0, 0, mPaint);
mCanvas.restore();*/
//Translate bitmap method two
/*Matrix matrix2=new Matrix();
matrix2.postTranslate(10, 10);
mCanvas.drawBitmap(mBitmap, matrix2, mPaint);*/
//Scale bitmap method one
/*mCanvas.save();
mCanvas.scale(2.0f, 2.0f, 50+mBitmap.getWidth()/2, 50+mBitmap.getHeight()/2);
// mCanvas.drawBitmap(mBitmap, 0, 0, mPaint);Only zoom to this point,rather than move to this point.
mCanvas.drawBitmap(mBitmap, 50, 50, mPaint);
mCanvas.restore();
mCanvas.drawBitmap(mBitmap, 50, 50, mPaint);*/
//Scale bitmap method two
/*Matrix matrix3=new Matrix();
matrix3.postScale(2.0f, 2.0f, 50+mBitmap.getWidth()/2, 50+mBitmap.getHeight()/2);
mCanvas.drawBitmap(mBitmap, matrix3, mPaint);
mCanvas.drawBitmap(mBitmap, 50,50, mPaint);*/
//Reverse bitmap image method one
//X reverse
/*mCanvas.drawBitmap(mBitmap ,0,0, mPaint);
mCanvas.save();
mCanvas.scale(-1, 1, 100+mBitmap.getWidth()/2, 100+mBitmap.getHeight()/2);
mCanvas.drawBitmap(mBitmap, 100, 100, mPaint);
mCanvas.restore();*/
//Y reverse
/*mCanvas.drawBitmap(mBitmap ,0,0, mPaint);
mCanvas.save();
mCanvas.scale(1, -1, 100+mBitmap.getWidth()/2, 100+mBitmap.getHeight()/2);
mCanvas.drawBitmap(mBitmap, 100, 100, mPaint);
mCanvas.restore();*/
//Reverse bitmap image methhod two
//X reverse
/*mCanvas.drawBitmap(mBitmap, 0,0, mPaint);
Matrix matrix4=new Matrix();
matrix4.postTranslate(100, 100);
matrix4.postScale(-1, 1, 100+mBitmap.getWidth()/2, 100+mBitmap.getHeight()/2);
mCanvas.drawBitmap(mBitmap, matrix4, mPaint);*/
//Y reverse
mCanvas.drawBitmap(mBitmap, 0,0, mPaint);
Matrix matrix5=new Matrix();
matrix5.postTranslate(100, 100);
matrix5.postScale(1, -1, 100+mBitmap.getWidth()/2, 100+mBitmap.getHeight()/2);
mCanvas.drawBitmap(mBitmap, matrix5, mPaint);
}
} catch (Exception e) {
// TODO: handle exception
}finally{
if(mCanvas != null){
mSurfaceHolder.unlockCanvasAndPost(mCanvas);
}
}
}
}
问题一
matrix5.postScale(1, -1, 100+mBitmap.getWidth()/2, 100+mBitmap.getHeight()/2);
postScale(theScaleFactorX,theScaleFactorY,myMidpointX,myMidpointY)
前面的两个参数分别表示x轴和y轴放锁定的比例，正负表示的是是否反转，后面两个参数表示的是以哪一点进行旋转和缩放
问题二
mCanvas.save();
mCanvas.scale(2.0f, 2.0f, 50+mBitmap.getWidth()/2, 50+mBitmap.getHeight()/2);
// mCanvas.drawBitmap(mBitmap, 0, 0, mPaint);Only zoom to this point,rather than move to this point.
mCanvas.drawBitmap(mBitmap, 50, 50, mPaint);
mCanvas.restore();