Imports System.Runtime.InteropServices

Public NotInheritable Class Win32Helper
    Public Structure TRIVERTEX
        Public x As Integer
        Public y As Integer
        Public Red As UShort
        Public Green As UShort
        Public Blue As UShort
        Public Alpha As UShort
        Public Sub New(ByVal x As Integer, ByVal y As Integer, ByVal color As Color)
            Me.New(x, y, color.R, color.G, color.B, color.A)
        End Sub
        Public Sub New(ByVal x As Integer, ByVal y As Integer, ByVal red As UShort, ByVal green As UShort, ByVal blue As UShort, ByVal alpha As UShort)
            Me.x = x
            Me.y = y
            Me.Red = CUShort((red << 8))
            Me.Green = CUShort((green << 8))
            Me.Blue = CUShort((blue << 8))
            Me.Alpha = CUShort((alpha << 8))
        End Sub
    End Structure

    Public Structure GRADIENT_RECT
        Public UpperLeft As UInteger
        Public LowerRight As UInteger
        Public Sub New(ByVal ul As UInteger, ByVal lr As UInteger)
            Me.UpperLeft = ul
            Me.LowerRight = lr
        End Sub
    End Structure


    <DllImport("coredll.dll", SetLastError:=True, EntryPoint:="GradientFill")> _
    Public Shared Function GradientFill(ByVal hdc As IntPtr, ByVal pVertex As TRIVERTEX(), ByVal dwNumVertex As UInteger, ByVal pMesh As GRADIENT_RECT(), ByVal dwNumMesh As UInteger, ByVal dwMode As UInteger) As Boolean
    End Function

    Public Const GRADIENT_FILL_RECT_H As Integer = 0
    Public Const GRADIENT_FILL_RECT_V As Integer = 1

End Class