'This example requires the Windows API
NoMainWin
WindowWidth = 267.5
WindowHeight = 292.5
UpperLeftX=int((DisplayWidth-WindowWidth)/2)
UpperLeftY=int((DisplayHeight-WindowHeight)/2)

Global hDC : hDC = GetDC(0)
Struct point, x As long, y As long
Struct RGB, Red As long, Green As long, Blue As long
Struct rect, left As long, top As long, right As long, bottom As long

StyleBits #main.gbox, 0, _WS_BORDER, 0, 0
GraphicBox #main.gbox, 2.5, 2.5, 253, 252

Open "Flood Fill - Click a Color" For Window As #main
Print #main, "TrapClose quit"
Print #main.gbox, "Down; Fill Black; Place 125 125; BackColor White; " _
                  + "CircleFilled 115; Place 105 105; BackColor Black; CircleFilled 50; Flush"
Print #main.gbox, "When leftButtonUp gBoxClick"
Print #main.gbox, "Size 1"
Wait

    Sub quit handle$
        Call ReleaseDC 0, hDC
        Close #main
        End
    End Sub


    Sub gBoxClick handle$, MouseX, MouseY
        result = GetCursorPos()
        targetRGB = GetPixel(hDC, point.x.struct, point.y.struct)
        ColorDialog "", replacementColor$
        If replacementColor$ = "" Then Exit Sub
        Print #main.gbox, "Color " + Word$(replacementColor$, 1) + " " + Word$(replacementColor$, 2) + " " + Word$(replacementColor$, 3)
        result = FloodFill(MouseX, MouseY, targetRGB)
        Print #main.gbox, "DelSegment FloodFill"
        Print #main.gbox, "GetBMP FloodFill 0 0 500 500; CLS; DrawBMP FloodFill 0 0; Flush FloodFill"
        Notice "Complete!"
        UnLoadBMP "FloodFill"
    End Sub

    Sub ReleaseDC hWnd, hDC
        CallDLL #user32,"ReleaseDC", hWnd As uLong, hDC As uLong, ret As Long
    End Sub

    Function GetDC(hWnd)
        CallDLL #user32, "GetDC", hWnd As uLong, GetDC As uLong
    End Function

    Function GetCursorPos()
        CallDLL #user32, "GetCursorPos", point As struct, GetCursorPos As uLong
    End Function

    Function GetPixel(hDC, x, y)
        CallDLL #gdi32, "GetPixel", hDC As uLong, x As long, y As long, GetPixel As long
    End Function

    Function getLongRGB(RGB.Blue)
        getLongRGB = (RGB.Blue * (256 * 256))
    End Function

    Function GetWindowRect(hWnd)
        'Get ClientRectangle
        CallDLL #user32, "GetWindowRect", hWnd As ulong, rect As struct, GetWindowRect As ulong
    End Function

    Function FloodFill(mouseXX, mouseYY, targetColor)
        Scan
        result = GetWindowRect(Hwnd(#main.gbox))
        X = Int(mouseXX + rect.left.struct)
        Y = Int(mouseYY + rect.top.struct)
        If (GetPixel(hDC, X, Y) <> targetColor) Then
            Exit Function
        Else
            CLS
            Print str$(mouseXX) + "   " + str$(mouseYY)
            Print #main.gbox, "Set " + str$(mouseXX) + " " + str$(mouseYY)
        End If
        If (mouseXX > 0) And (mouseXX < 253) Then
            result = FloodFill((mouseXX - 1), mouseYY, targetColor)
            result = FloodFill((mouseXX + 1), mouseYY, targetColor)
        End If
        If (mouseYY > 0) And (mouseYY < 252) Then
            result = FloodFill(mouseXX, (mouseYY + 1), targetColor)
            result = FloodFill(mouseXX, (mouseYY - 1), targetColor)
        End If
    End Function