Don't know all answers but will give you a few. Shachar Kaufman wrote: > Hi all, > > I'm revisiting DFB after a long while. Nice to see the advancement > made, congratulations on the progress made so far. > > A couple of quick questions: I'm referring to the 1.3 release. > > General: > 1. Are there example applications to play with making use of the newer > features such as multiple composited planes? > 2. In that respect, where can I find a list of projects using DFB? There is a (growing) list of devices which are using DirectFB on the wiki. http://www.directfb.org/wiki/index.php/Embedded_DirectFB_Hardware However, the wiki is not operational right now, upgrading. There is also a limited list of Projects on the homepage www.directfb.org. > 3. I'd like to understand the rationale behind running X over DFB - > what's in it for users in terms of performance? I am using this solely to test stuff on my PC; so I can use GDB comfortably. If you have a proper X-plugin for your gfx card there is no benefit in using DFB. It is satisfyingly easy to port the stuff after it has stood the PC-test.
> 4. Is there a sane way of searching through the archives of the DFB lists? The main mailing lists are duplicated on Gmane, that might be searchable. check http://dir.gmane.org/search.php?match=directfb > 5. Against what does df_dok measure performance? what is the baseline? If you mean the percentage at the end, this is the processor load. If you don't have hardware acceleration expect this to be close to 100%. Over 100% is measuring inaccuracy.. ;) > 6. I can't seem to be able to use neither my serial keyboard nor USB > keyboard, nor USB mouse (they work fine in X, serial console and > network terminal). I don't have Linux input support yet. Any idea what > I'm missing? maybe it's a directfbrc issue? It would help if you specify what you are using. system (x11/fbdev/devmem), graphics card, what you mean with 'no linux input support yet', you can try df_input, or provide the output of dfbinfo. > > Driver development: > 1. I'm having trouble with the concepts of surface, layer and region. > I'd appreciate an explanation or a link to one. This one has been asked before - you might try the mailing list or check http://www.directfb.org/index.php?path=Documentation%2FOther+Documents > 2. My platform has special requirements for visible buffers (lets say > the front and back main color buffer, which may be outputted to the > compositor and/or for display) while it gives more freedom when it > comes to off-screen buffers. How do I make DFB aware of this? I'll explain the common usecase. If your device has a mixer, all the 'visual' layers are normally modeled as 'layers'. In DirectFB, each layer can have up to 3 buffers (which are abstracted as 1 surface coupled to the layer) and flipping is done by the graphics driver on demand. Offscreen buffers are modeled as surfaces (not coupled to layers), which can hold icons, fonts, bitmaps, anything drawable. What you would do is define the layer restrictions, e.g. pixelformat restrictions, in the driver, DirectFB will call TestConfiguration to find this out, and provide necessary conversion routines if the offscreen buffers are of different type than what is supported by your layers. > 3. Most examples (at least from 1.2 examples release) seem to use > update region (with a new offset) as means of double buffering. Why > not simply use a double buffer and flip with Flip? or am I missing the > meaning of Flip and Update? > You can specify if your layer is single or double buffered in configuration. Your application is unaware of this, so there is a single function which can do both (either copy an updated region, or flip the buffers). At least, I think that's what you mean.. > That's it for now :) > > Thanks. > hth, Niels > ------------------------------------------------------------------------ > > _______________________________________________ > directfb-users mailing list > directfb-users@directfb.org > http://mail.directfb.org/cgi-bin/mailman/listinfo/directfb-users > -- .------------------------------------------. | DirectFB - Hardware accelerated graphics | | http://www.directfb.org/ | "------------------------------------------" _______________________________________________ directfb-users mailing list directfb-users@directfb.org http://mail.directfb.org/cgi-bin/mailman/listinfo/directfb-users
