android imageview手势旋转导致边缘质量下降

Question

我正在使用下面的代码来拖动，在图像视图内缩放旋转图像，并且当旋转图像边缘变得模糊而图像本身保持相同的质量时，它只能正常工作，这不会发生在缩放，请建议解决方案，坦克，代码： -

private void dragZoomRotate(ImageView view, MotionEvent event){ 

    view.setScaleType(ImageView.ScaleType.MATRIX);  

    // Handle touch events here...

    switch (event.getAction() & MotionEvent.ACTION_MASK)   
    {
    case MotionEvent.ACTION_DOWN:
        savedMatrix.set(matrix);
        start.set(event.getX() , event.getY() );
        mode = DRAG;
        lastEvent = null;
        break;
    case MotionEvent.ACTION_POINTER_DOWN:   // first and second finger down
        oldDist = spacing(event);         
        savedMatrix.set(matrix);
        midPoint(mid, event);
        mode = ZOOM;

        lastEvent = new float[4];
        lastEvent[0] = event.getX(0);
        lastEvent[1] = event.getX(1);
        lastEvent[2] = event.getY(0);
        lastEvent[3] = event.getY(1);
        degrees = rotation(event);
        break;
    case MotionEvent.ACTION_UP: // first finger lifted
    case MotionEvent.ACTION_POINTER_UP:   // second finger lifted
        mode = NONE;
        lastEvent = null;

        break;
    case MotionEvent.ACTION_MOVE:    
        if (mode == DRAG) { 
            // ...
            matrix.set(savedMatrix);

            matrix.postTranslate(event.getX() - start.x , event.getY() - start.y );

        }
        else if (mode == ZOOM && event.getPointerCount()==2) {
            float newDist = spacing(event);
            matrix.set(savedMatrix);
            if (newDist > 10f) {              
                float scale = newDist / oldDist;
             //   matrix.postScale(scale, scale, mid.x, mid.y);
            } 
            if (lastEvent!=null){
                newRot = rotation(event); 
                float r = newRot-degrees;
                matrix.postRotate(r, view.getMeasuredWidth()/2, view.getMeasuredHeight()/2);  
            }
        }
        // 
        break;
    }   

    view.setImageMatrix(matrix);
}

private float rotation(MotionEvent event) 
{
    double delta_x = (event.getX(0) - event.getX(1));
    double delta_y = (event.getY(0) - event.getY(1)); 
    double radians = Math.atan2(delta_y, delta_x);
    return (float) Math.toDegrees(radians);         
} 




/*     
 * --------------------------------------------------------------------------
 * Method: spacing Parameters: MotionEvent Returns: float Description:
 * 
 * checks the spacing between the two fingers on touch
 * ----------------------------------------------------
 */

private float spacing(MotionEvent event) 
{
    float x = event.getX(0) - event.getX(1);
    float y = event.getY(0) - event.getY(1);
    return FloatMath.sqrt(x * x + y * y);
}

/*
 * --------------------------------------------------------------------------
 * Method: midPoint Parameters: PointF object, MotionEvent Returns: void
 * Description: calculates the midpoint between the two fingers
 * ------------------------------------------------------------
 */   

private void midPoint(PointF point, MotionEvent event) 
{
    float x = event.getX(0) + event.getX(1);
    float y = event.getY(0) + event.getY(1);
    point.set(x / 2, y / 2);
}