Android 如何在选定的底部导航的顶部边缘获得曲线？

我刚开始做一个项目，想把弯曲的bottomnavigationview放得更像是用户点击凹凸产生的波浪。 像这样

我几乎找到了一个库，在这个库中，开发人员通过向项目添加topedgetreatment完成了出色的工作。然而，我更感兴趣的是用贝塞尔曲线来做这个。我查了很多密码，但都没用

有人能帮我得到一个提示，关于如何画一个凹凸动画

下面是我试图做的，但那不是我想要实现的

public class CurvedBottomNavigationView extends BottomNavigationView {
 private Path mPath;
 private Paint mPaint;
/** the CURVE_CIRCLE_RADIUS represent the radius of the fab button */
 public final int CURVE_CIRCLE_RADIUS = 256 / 3;
 // the coordinates of the first curve
 public Point mFirstCurveStartPoint = new Point();
 public Point mFirstCurveEndPoint = new Point();
 public Point mFirstCurveControlPoint2 = new Point();
 public Point mFirstCurveControlPoint1 = new Point();
//the coordinates of the second curve
 @SuppressWarnings(“FieldCanBeLocal”)
 public Point mSecondCurveStartPoint = new Point();
 public Point mSecondCurveEndPoint = new Point();
 public Point mSecondCurveControlPoint1 = new Point();
 public Point mSecondCurveControlPoint2 = new Point();
 public int mNavigationBarWidth;
 public int mNavigationBarHeight;
public CurvedBottomNavigationView(Context context) {
 super(context);
 init();
 }
public CurvedBottomNavigationView(Context context, AttributeSet attrs) {
 super(context, attrs);
 init();
 }
public CurvedBottomNavigationView(Context context, AttributeSet attrs, int defStyleAttr) {
 super(context, attrs, defStyleAttr);
 init();
 }
private void init() {
 mPath = new Path();
 mPaint = new Paint();
 mPaint.setStyle(Paint.Style.FILL_AND_STROKE);
 mPaint.setColor(Color.WHITE);
 setBackgroundColor(Color.TRANSPARENT);
 }
@Override
 protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
 super.onLayout(changed, left, top, right, bottom);
}
@Override
 protected void onSizeChanged(int w, int h, int oldw, int oldh) {
 super.onSizeChanged(w, h, oldw, oldh);
 // get width and height of navigation bar
 // Navigation bar bounds (width & height)
 mNavigationBarWidth = getWidth();
 mNavigationBarHeight = getHeight();
 // the coordinates (x,y) of the start point before curve
 mFirstCurveStartPoint.set((mNavigationBarWidth / 2) — (CURVE_CIRCLE_RADIUS * 2) — (CURVE_CIRCLE_RADIUS / 3), 0);
 // the coordinates (x,y) of the end point after curve
 mFirstCurveEndPoint.set(mNavigationBarWidth / 2, CURVE_CIRCLE_RADIUS + (CURVE_CIRCLE_RADIUS / 4));
 // same thing for the second curve
 mSecondCurveStartPoint = mFirstCurveEndPoint;
 mSecondCurveEndPoint.set((mNavigationBarWidth / 2) + (CURVE_CIRCLE_RADIUS * 2) + (CURVE_CIRCLE_RADIUS / 3), 0);
// the coordinates (x,y) of the 1st control point on a cubic curve
 mFirstCurveControlPoint1.set(mFirstCurveStartPoint.x + CURVE_CIRCLE_RADIUS + (CURVE_CIRCLE_RADIUS / 4), mFirstCurveStartPoint.y);
 // the coordinates (x,y) of the 2nd control point on a cubic curve
 mFirstCurveControlPoint2.set(mFirstCurveEndPoint.x — (CURVE_CIRCLE_RADIUS * 2) + CURVE_CIRCLE_RADIUS, mFirstCurveEndPoint.y);
mSecondCurveControlPoint1.set(mSecondCurveStartPoint.x + (CURVE_CIRCLE_RADIUS * 2) — CURVE_CIRCLE_RADIUS, mSecondCurveStartPoint.y);
 mSecondCurveControlPoint2.set(mSecondCurveEndPoint.x — (CURVE_CIRCLE_RADIUS + (CURVE_CIRCLE_RADIUS / 4)), mSecondCurveEndPoint.y);
 }
@Override
 protected void onDraw(Canvas canvas) {
 super.onDraw(canvas);
 mPath.reset();
 mPath.moveTo(0, 0);
 mPath.lineTo(mFirstCurveStartPoint.x, mFirstCurveStartPoint.y);
mPath.cubicTo(mFirstCurveControlPoint1.x, mFirstCurveControlPoint1.y,
 mFirstCurveControlPoint2.x, mFirstCurveControlPoint2.y,
 mFirstCurveEndPoint.x, mFirstCurveEndPoint.y);
mPath.cubicTo(mSecondCurveControlPoint1.x, mSecondCurveControlPoint1.y,
 mSecondCurveControlPoint2.x, mSecondCurveControlPoint2.y,
 mSecondCurveEndPoint.x, mSecondCurveEndPoint.y);
mPath.lineTo(mNavigationBarWidth, 0);
 mPath.lineTo(mNavigationBarWidth, mNavigationBarHeight);
 mPath.lineTo(0, mNavigationBarHeight);
 mPath.close();
canvas.drawPath(mPath, mPaint);
 }
}