DirectDraw Application & Driver for WinCE

The content of this article includes:

1. Display System Integration 2. DirectDraw utility 3. GPE class 4. DDGPE class

1. Display System Integration

 

2. DirectDraw utility

Why DirectDraw?

 

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The hardware abstraction layer (HAL) provides a consistent interface through which to work directly with the display hardware, getting maximum performance.

DirectDraw assesses the video hardware's capabilities, making use of special hardware functionality 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 functionality when the hardware does not.

DirectDraw makes it easy for you to implement page flipping with multiple back buffers in full-screen applications.

Support for clipping in windowed or full-screen applications.

Support for hardware-assisted overlays with z-ordering.

Access to image-stretching hardware.

Simultaneous access to standard and enhanced display-device memory areas.

DirectDraw features:

Bit-block transfers (blits)

Page flipping and multiple back buffers

Overlays, which is placing one image surface over another on the video display

Alpha source over destination blending, which is blending two surfaces using the source alpha image component

Video YUV pixel formats and color conversion

Direct video access to the frame buffer

 

DirectDraw and screen rotation are mutually exclusive features. The Rflat driver does not have any DirectDraw entry points. (CE6 does not have this limitation)

Flipping Surfaces

Overlay Surface

2.  GPE based driver

To be continued ...........