Reporting Multisample Support
A driver reports the multisample capabilities of its associated hardware by specifying the number of samples per pixel for each surface format it reports. The DDPIXELFORMAT structure has been extended to include a structure called MultiSampleCaps. This structure has members that let the driver express the number of samples per pixel for both flip (fullscreen) and blt (windowed) multisampling. Each of these members is a WORD type in which each bit of the WORD value indicates support for a given number of samples per pixel. Hence, the driver can express support for several different sample counts with a single surface format entry.