how to antialiasing in the canvas and path

i meet a trouble when i use canvas.clipPath,it show sawtooth,it looks not smooth,i know if i used a Paint,i can use mPaint.setFlags(Paint.ANTI_ALIAS_FLAG) ,this can antialiasing ,but in my code ,i cannot use paint.

public static void drawCurrentPageArea(Canvas canvas, Bitmap bitmap) {
    //cebakhja


    canvas.save();
    canvas.clipPath(getPath5(), Region.Op.XOR);
    canvas.drawBitmap(bitmap, 0, 0, null);
    canvas.restore();
}

public static Path getPath5()
{
    Path mPath5 = new Path();

    mPath5.moveTo(ptc.x, ptc.y);
    mPath5.quadTo(pte.x, pte.y, ptb.x,ptb.y);
    mPath5.lineTo(pta.x, pta.y);
    mPath5.lineTo(ptk.x, p开发者_如何学编程tk.y);
    mPath5.quadTo(pth.x, pth.y, ptj.x,ptj.y);
    mPath5.lineTo(ptf.x, ptf.y);
    mPath5.close();
    return mPath5;
}

you can see i use canvas.drawBitmap(bitmap, 0, 0, null); paint is null.if i need add a paint ,can you have some advice? the pic is as http://i.6.cn/cvbnm/36/5c/20/5d8d20e3bafe432d792793509f99131e.jpg

edit:i set the paint that is null ,but not effect

---

Try this.

private Paint mBitmapPaint = new Paint() {
    {
        setAntiAlias(true);
        setFilterBitmap(true);
    }
};

public static void drawCurrentPageArea(Canvas canvas, Bitmap bitmap) {
    // cebakhja
    canvas.save();
    canvas.clipPath(getPath5(), Region.Op.XOR);
    canvas.drawBitmap(bitmap, 0, 0, mBitmapPaint);
    canvas.restore();
}