A printer driver that exploits all the Windows 95 functionality meet the requirements described in the following sections. These requirements are listed below in the order of importance:
If your printer driver expects Windows 95 to provide Image Color Matching for a color printer, then the driver must support the new DEVMODE structure.
Other benefits that any printer driver gains by supporting the new DEVMODE structure are:
Any driver that supports the new Windows 95 DEVMODE structure and reports DEVMODE.dmSpecVersion = 0x0400 must support the new DrvSetPrinterData and DrvGetPrinterData DDIs, which are described below.
The new DrvSetPrinterData DDI enables 16-bit printer drivers to store DEVMODE structure data in the registry, where it is easy for 32-bit system component to access. If a printer driver caches DEVMODE data by calling DrvSetPrinterData, then Windows 95 print subsystem components can return DEVMODE data to Win32 APIs without having to call the device driver to get the data.
The DrvGetPrinterData DDI retrieves the DEVMODE data from the registry.
Note that any driver that supports the new Windows 95 DEVMODE structure and reports DEVMODE.dmSpecVersion = 0x0400 must also support the new DrvSetPrinterData and DrvGetPrinterData DDIs.
Windows 95, unlike Windows 3.x, supports TrueType fonts that contain more than 256 characters. Windows 95 enumerates multiple character sets from a single TrueType font to applications. Windows 95 does this based on the contents of an individual TrueType font that has been installed.
In order to render these fonts on output devices, a printer device driver must report the capability to understand and support TrueType glyph indices, which are two-byte values, in addition to Windows ANSI characters, which are one-byte values. Device drivers which understand and support TrueType glyph indices will be able to automatically support TrueType fonts with multiple character sets, without having special knowledge of each of these character sets. This is a key requirement in products distributed in Europe and the Far East, where multi-lingual character issues are common.
Windows 95 provides a new Property Sheet dialog box style for controlling the attributes of many system objects, including printers.
(To look at the property sheets for an installed printer in the Windows 95 user interface, do the following: Click the Start button; select Settings; select Printers; right-click on the installed printer icon; and then select Properties.)
Printer property sheets are used for configuring attributes of printer objects managed by the print subsystem (attributes such as spool settings, port settings, and peer-to-peer sharing). A print driver that supports the ExtDeviceModePropSheet DDI can provide additional property sheets displayed at the same level and will visually appear as better integrated into the system.
Drivers that do not support the ExtDeviceModePropSheet DDI have to support the Windows 3.x ExtDeviceMode DDI and the user will access the driver-controlled settings by pressing a button on one of the system-supplied property sheets.
For more information about the DeviceCapabilities function, see the Windows® 3.1 DDK.
For information about the benefits of using EMF spooling as well as implementation details, see About the Print Spooler.
Printer drivers can use the services offered by the DIB Engine, which is a new Windows 95 component, to operate on DIB files. This saves writing and testing code in the device driver to perform these operations.
For more information about the services offered by the DIB engine, see About Display Minidrivers.
Printer drivers for devices that draw Bezier curves and that support the new Bezier curve style as part of their Output DDI will enable GDI to call the driver to render a Bezier curve with one call instead of a series of Output calls with the OS_POLYLINE flag set in the wStyle parameter.
Drivers that support the OS_POLYBEZIER flag in the Output DDI wStyle parameter must report this capability by setting the CC_POLYBEZIER bit in GDIINFO.dpCurves.