Benchmark DirectFB

Benchmarks
The DirectFB example suites include benchmark 'df_dok'. We have ran this benchmark on the following platform:

After enabling 2D acceleration in A* environment, the graphics benchmark score improves. It looks like even embedded processor like SH-4 can be used when DirectFB can use hardware acceleration. So a graphics library would be essential in a graphical system.

For G* (Intel CE2110) environment, just basic operations like opaque rectangle and blits are really optimized, some operations are much slower and we can notice rendering artifacts/bugs. So take care, possible you'll have to fallback to software rendering on such platform. Cyan-colored cells are supposed to be accelerated.