This chapter describes the DrvSplXxx functions that comprise the user-mode printer driver. User-mode printer driver function declarations can be found in winddiui.h, which is provided with this DDK.
A printer driver writer can optionally implement a user-mode printer driver to provide rendering functionality in user mode. If you do implement this module, see the Comments section of each reference page to determine whether a DrvSplXxx function is required or optional.