How to draw a Bitmap as a trapezoid?

Sub DrawTrapezoid(myBG As Canvas, BMP As Bitmap , X As Int, Y As Int, TopWidth As Int, BottomWidth As Int, Height As Int)
   Dim BottomLeft As Int
   If BottomWidth> TopWidth Then X = X + (BottomWidth-TopWidth)/2
   BottomLeft = X+ TopWidth/2 - BottomWidth/2
   mMatrix.setPolyToPoly( Array As Float(0,0,    BMP.Width,0,   BMP.Width, BMP.Height,   0,BMP.Height), 0,  Array As Float( X,Y, X+TopWidth,Y, BottomLeft+BottomWidth, Y+Height, BottomLeft, Y+Height   ), 0,4)
   ExDraw.drawBitmap4(myBG, BMP,  mMatrix, mPaint)
End Sub

Sub DrawTrapezoid(BG As Canvas, BMP As Bitmap ,SRC As Rect , X As Int, Y As Int, TopWidth As Int, BottomWidth As Int, Height As Int, Alpha As Int)
    Dim BottomLeft As Int
    ExDraw.save2(BG, LCAR.ExDraw.MATRIX_SAVE_FLAG)
    If TopWidth=0 Then TopWidth=BottomWidth
    If BottomWidth=0 Then BottomWidth=TopWidth
    If BottomWidth> TopWidth Then X = X + (BottomWidth-TopWidth)/2
    BottomLeft = X+ TopWidth/2 - BottomWidth/2
    If SRC=Null Then SRC.Initialize(0,0, BMP.Width, BMP.Height)
    mPaint.Initialize
    mPaint.SetAlpha(Alpha)
    mMatrix.setPolyToPoly( Array As Float(SRC.Left,SRC.Top,  SRC.Right,SRC.Top,  SRC.Right, SRC.Bottom,        SRC.Left,SRC.Bottom), 0,  Array As Float( X,Y, X+TopWidth,Y, BottomLeft+BottomWidth, Y+Height, BottomLeft, Y+Height  ), 0,4)
    ExDraw.drawBitmap4(BG, BMP,  mMatrix, mPaint)
    ExDraw.restore(BG) 'before Activity.Invalidate
End Sub