ID Number: Q74994
3.00 3.10
WINDOWS
Summary:
In the Microsoft Windows graphical environment, a display driver must
support all of its declared capabilities at all times, regardless of
the current video mode of the adapter. For example, when Windows is
running in enhanced mode, a display driver can be called to perform
graphics operations on a memory bitmap while a full-screen MS-DOS
(non-Windows) application is running in the foreground. This may occur
if an application developed for Windows is printing in the background,
and the graphics device interface (GDI) calls the display driver to
perform some imaging for the current page.
If the display driver relies on adapter hardware for certain graphics
operations, but cannot access this hardware due to the current video
mode of the adapter, then the driver must include "host side" drawing
to handle this case.
The 8514/A display driver provides an example of hardware operations
emulated in host code when drawing to main memory bitmaps. This source
code is available in the Windows Device Development Kit (DDK) versions
3.0 and 3.1.
Additional reference words: 3.00 3.10 DDKDISPLAY