The DirectDraw component brings many powerful features to you, the Windows graphics programmer:
·The Hardware Abstraction Layer (HAL) of DirectDraw provides a consistent interface through which to work directly with the display and video memory, getting maximum performance from the system hardware.
·DirectDraw assesses the video hardware's capabilities, making use of special hardware features whenever possible. For example, if your video card supports hardware blitting, DirectDraw delegates blits to the video card, greatly increasing performance. Additionally, DirectDraw provides a Hardware Emulation Layer (HEL) to support features when the hardware does not.
·DirectDraw exists over Windows 95, gaining the advantage of 32-bit memory addressing and a flat memory model that the operating system provides. DirectDraw presents video and system memory as large blocks of storage, not as small segments. If you've ever used segment:offset addressing, you will quickly begin to appreciate this "flat" memory model.
·DirectDraw makes it easy for you to implement page flipping with multiple back buffers in full-screen applications. For more information, see Page Flipping and Back Buffering.
·Support for clipping in windowed or full-screen applications.
·Support for 3-D z-buffers.
·Support for hardware-assisted overlays with z-ordering.
·Access to image-stretching hardware.
·Simultaneous access to standard and enhanced display-device memory areas.
·Other features include custom and dynamic palettes, exclusive hardware access, and resolution switching.
These features combine to make it possible for you to write applications that easily out-perform standard Windows GDI-based applications and even MS-DOS applications.