With Windows CE 2.0 and later, a display driver can use up to three levels of blit processing: the default blit emulation provided by the GPE, the software acceleration provided by the emulation library or by your own custom code, and the hardware acceleration supported by the display device hardware. The display driver can choose, based on the parameters of individual operations, which method to use for each blit that it performs.
The Platform Builder provides the GPE library, which is located under Public\Common\OAK\Lib. This class library, offered in binary form, serves as the foundation for Windows CE–based display drivers. The GPE supplies default processing for blits in its EmulatedBlt function.