Chapter 11 Printer Minidrivers and RasDD

A printer minidriver is an executable data file that the raster printer device driver (RasDD) uses to print to a raster printing device. This GPC file describes the capabilities, commands, and resident fonts of a printer or class of printers.

RasDD is the Windows NT system-supplied device driver that, with a minidriver, provides printer support for raster printing devices. RasDD uses a GDI standard bitmap, allowing GDI to handle most of the rendering. So, instead of implementing all the DrvXxx functions that GDI requires, a driver writer need only create a minidriver that provides information about the printer. This greatly simplies the task of developing a Windows NT raster printer driver.

Other reasons for using minidrivers include:

• They achieve portability across CPU types.

• They provide improvements to the minidriver and printer driver software.

• They receive updates and changes to the graphics engine.

• They obtain high quality color rendering and halftoning.

• They support 1, 4, and 8 bits-per-pixel color.

This chapter provides design guidelines for those vendors who need to develop their own raster device drivers. For those vendors who need only develop a minidriver, this chapter provides a detailed description on how to use Unitool.