when window's opacity is 255,setBlittingFlags to MMSFB_BLIT_BLEND_ALPHACHANNEL.directfb will call blend function.that is not require.
So should setBlittingFlags to MMSFB_BLIT_NOFX. set to MMSFB_BLIT_NOFX will improve efficiency.isn't it?

Hi wood.zhang,

yes thats right, in this case it would be efficent to use NOFX. We shall correct this soon.

What kind of device you are using, that requires DirectFB? If there is no hardware acceleration involved, you might get better results using the Disko fbdev backend.

kind regards
Stefan

we are using ti' davinci.we will use disko on C2 Microsystems's CC1100/1200 from today.
using the Disko fbdev backend?How do I configure?

Hi wood.zhang,

we are currently finishing the framebuffer backend for the DavinciFB. The final commits will occur some time this week.

I created a small howto for configuration of the disko framebuffer backend, which can be found here.

The C2 Microsystems CC1100 seems to be a very sophisticated board, which will be poorly supported by the generic framebuffer backend. It seems feasible to add specific support for that board to Disko.

kind regards
Stefan

Hi wood.zhang,

no, there is no problem.

Disko is internally working with alpha channel pixelformats (ARGB,AYUV,...).

So MMSMainWindow, MMSChildWindow and MMSPopupWindow have an alpha channel.

The MMSRootWindow has no alpha channel, because the disko gui knows, that root windows are in the background and therefore the alphachannel is not required.

So Main, Child and Popup Windows have to blit with the MMSFB_BLIT_BLEND_ALPHACHANNEL blitting flag.

Additionally we can decrease the opacity (default is 255). If the opacity is lower than 255 we use the MMSFB_BLIT_BLEND_COLORALPHA blitting flags.

We can speak about a Disko extension (new xml parameter) to explicitly switch off the alphachannel support for a single window. In that case we can use MMSFB_BLIT_NOFX.

Regards
Jens