by Richard Russell, November 2006
Normally you would write to the screen using BBC BASIC's built-in text and graphics statements; see the main help documentation (particularly Graphics and Colours and VDU Emulation). However there may be circumstances when you need to use the Windows API instead, for example when the built-in statements do not provide the required features, or when you need to ensure that the screen and printer outputs are as similar as possible (e.g. a Print Preview facility).
There are two principal ways of outputting to the screen via the Windows API, one using the Graphics Device Interface (GDI) and the other using the GDI Plus interface (GDI+).
For information on writing to the screen using the Windows Graphics Device Interface see the article Writing graphics to the printer, and particularly the note at the end entitled Writing to the screen. All the Windows GDI functions described in that article are equally applicable to writing to the screen.
For information on writing to the screen using the Windows GDI Plus interface see the section in the main help documentation entitled Antialiased graphics.