qb64-include/solarize.bm

$if Solarize = undefined then
$let Solarize = defined
Sub Solarize (image As Long, threshold)
    Dim oldDest As Long
    Dim oldSource As Long
    Dim y As Long
    Dim x As Long
    Dim orgc As _Unsigned Long
    Dim r As Integer
    Dim g As Integer
    Dim b As Integer
    oldDest = _Dest
    oldSource = _Source
    _Dest image
    _Source image
    For y = 0 To _Height(image) - 1
        For x = 0 To _Width(image) - 1
            orgc = Point(x, y)
            If _Red(orgc) > threshold Then r = 255 - _Red(orgc) Else r = _Red(orgc)
            If _Green(orgc) > threshold Then g = 255 - _Green(orgc) Else g = _Green(orgc)
            If _Blue(orgc) > threshold Then b = 255 - _Blue(orgc) Else b = _Blue(orgc)
            PSet (x, y), _RGB32(r, g, b)
        Next
    Next
    _Dest oldDest
    _Source oldSource
End Sub
$end if