Bit Block Transfer Acceleration (Windows CE 5.0)
A display driver can use 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
- The hardware acceleration, supported by the display device hardware
Based on the parameters of individual operations, the display driver can choose which method to use for each blit it performs.
The GPE library is in the %_WINCEROOT%\Public\Common\OAK\Lib directory. This class library, shown in binary form, is the foundation for display drivers.
The GPE supplies default processing for blits in its EmulatedBlt function. It provides a generic software implementation of BitBlt and line drawings.
Emulation library for software-accelerated blits
The emulation library contains emulated blit functions with destination pixel depths of 2, 8, and 16 bits per pixel.
You can use emulated blits to improve performance over the default blit processing provided in the GPE.
The source code can serve as a template for writing additional software-accelerated blits that are tailored to the display hardware. This is especially valuable to embedded system developers.
You can find the code samples for creating an emulation library for software-accelerated blits in the %_WINCEROOT%\Public\Common\OAK\Drivers\Display\Emul directory.
See Also
Bit Block Transfers and Line Drawing Acceleration | Line Drawing Acceleration | Accelerated Line Segment Function | Display Driver Development Concepts | Display Driver Extensions | Display Driver Samples
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