Binaryworld - AreaFill - Fill an area with a solid color ... [ VB -> Graphics ]

Private Declare Function ExtFloodFill Lib "GDI32" (ByVal hDC As Long, _
  ByVal X As Long, ByVal Y As Long, ByVal colorCode As Long, _
  ByVal fillType As Long) As Long
Const FLOODFILLBORDER = 0
Const FLOODFILLSURFACE = 1

' Fill a region using the current color or brush
' OBJ can be a form or a control that exposes
'    a device context (eg a picture box)
' X,Y are given in the current system coordinates
'
' If BORDERCOLOR is specified, fills the area
' enclosed by a border of that color
' If BORDERCOLOR is omitted, the area is filled with
' the color now at coordinates (x,y), and any
' different color is considered to a the border

Sub AreaFill(obj As Object, ByVal X As Long, ByVal Y As Long, _
  ByVal colorCode As Long, Optional borderColor As Variant)

  Dim x2 As Long, y2 As Long
  Dim saveFillStyle As Long
  Dim saveFillColor As Long

  With obj
    ' convert into pixel coordinates
    x2 = .ScaleX(X, .ScaleMode, vbPixels)
    y2 = .ScaleY(Y, .ScaleMode, vbPixels)

    ' save FillStyle and FillColor properties
    saveFillStyle = .FillStyle
    saveFillColor = .FillColor
    ' enforce new properties
    .FillStyle = 0
    .FillColor = colorCode

    If IsMissing(borderColor) Then
      ' get color at given coordinates
      borderColor = .Point(X, Y)
      ' change all the pixels with that color
      ExtFloodFill .hDC, x2, y2, borderColor, FLOODFILLSURFACE
    Else
      ExtFloodFill .hDC, x2, y2, borderColor, FLOODFILLBORDER
    End If

    ' restore properties
    .FillStyle = saveFillStyle
    .FillColor = saveFillColor
  End With

End Sub