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Every display driver has a GDIINFO structure that specifies the display's
capabilities and characteristics. GDI uses this information to determine
what the display driver can do and what GDI must simulate. The GDI
information can be classified as follows:
 
♦  Driver management
 
♦  Driver capabilities
 
♦  Device dimensions
 
The driver-management information specifies the version of Windows for which
the driver was written, and the type of technology the display uses to
generate output. Additionally, the driver-management information also
specifies the size in bytes of the PDEVICE structure, and number of device
contexts the driver can manage at the same time. The version number
specifies a Windows version (not the display driver version). For example, a
display driver written for Windows 3.1 should set the dpVersion member to
0x30A.
 
The driver-capabilities information specifies the capabilities of the
display device, such as whether the display hardware can draw polygons and
ellipses, scale text, or clip output. Driver capabilities also specify the
number of brushes, pens, fonts, and colors available on the display and
whether the display can handle bitmaps and color palettes.
 
The device-dimension information specifies the maximum width and height of
the screen in both millimeters and device units, the number of color bits or
planes, the aspect ratio, the minimum length of a dot in a styled line, and
the number of device units (or pixels per inch).
 
The subsequent sections of this topic describe the GDIINFO structure more
fully. Each section describes the capabilities associated with given members
and explains how to determine what capabilities a display driver can
support.
 
 
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