Dx = ((Lx - WOx) * VEx / WEx) + VOx
Dx x value in device units
Lx x value in logical units (also known as page space units)
WOx window x origin
VOx viewport x origin
WEx window x-extent
VEx viewport x-extent
трансляции координат
Код:
http://msdn2.microsoft.com/en-us/library/ms533160.aspx - взято отсюда