Android Question Clip Path ... I need Help on this one...

    r = (a * a + b * b) / (b + b)

Private Sub drawMask
    Dim cnv As B4XCanvas
    cnv.Initialize(pnlTarget)
    cnv.DrawPath(makeMask(pnlTarget), xui.Color_Red, True, 0)
End Sub

Private Sub makeMask(target As Pane) As B4XPath
    Dim a As Float = target.Height / 2
    Dim b As Float = target.Width / 3
    Dim r As Float = (a * a + b * b) / (b + b)
    Dim angle As Float = ASin(a / r)
    Dim d As Float = angle / 20
    Dim p As B4XPath
    p.Initialize(b + b, 0)
    For i = 1 To 40
        angle = angle - d
        p.LineTo(3 * b - r + r * Cos(angle), a - r * Sin(angle))
    Next
    p.LineTo(0, a + a)
    p.LineTo(0, 0)
    Return p   
End Sub

Public Sub drawMask
    Dim p As B4XView = xui.CreatePanel("")
    p.SetLayoutAnimated(0, 0, 0, B4XImageView1.mBase.Width, B4XImageView1.mBase.Height)
    Dim cnv As B4XCanvas
    cnv.Initialize(p)
    cnv.DrawPath(makeMask(p), xui.Color_Red, True, 0)
    Dim MaskBmp As B4XBitmap = cnv.CreateBitmap
    cnv.Invalidate
    cnv.Release

    B4XImageView1.mBackgroundColor = xui.Color_Transparent
    B4XImageView1.ResizeMode = "FILL"
    B4XImageView1.Update

    Dim ImageBmp As B4XBitmap = xui.LoadBitmapResize(File.DirAssets, "1.png", MaskBmp.Width, MaskBmp.Height, False)
    Dim BitmapCreatorEffects1 As BitmapCreatorEffects
    BitmapCreatorEffects1.Initialize
    B4XImageView1.Bitmap = BitmapCreatorEffects1.DrawThroughMask(ImageBmp, MaskBmp)
 
End Sub
Private Sub makeMask(target As B4XView) As B4XPath
    Dim a As Float = target.Height / 2
    Dim b As Float = target.Width / 3
    Dim r As Float = (a * a + b * b) / (b + b)
    Dim angle As Float = ASin(a / r)
    Dim d As Float = angle / 20
    Dim p As B4XPath
    p.Initialize(b + b, 0)
    For i = 1 To 40
        angle = angle - d
        p.LineTo(3 * b - r + r * Cos(angle), a - r * Sin(angle))
    Next
    p.LineTo(0, a + a)
    p.LineTo(0, 0)
    Return p
End Sub