Hi, Denis Thanks for your comments. On Sat, Oct 18, 2008 at 12:23 PM, Denis Oliver Kropp <[EMAIL PROTECTED]>wrote:
> 冯要文 wrote: > >> Hi, All >> >> I'm developing applications based on directfb with HW acceleration. >> > > Which hardware and DirectFB version? The hardware is in FPGA and not released to the market yet. I use DirectFB-1.2.6. > > > I'm using a single buffer. >> > > I assume that you do this because you're not rendering directly into the > displayed memory portion anyhow and require a Flip() even with a single > buffer (exclusive layer). I use examples from DirectFB site to test the driver. I'm really a newbie to DirectFB. I render on the display memory directly. From your comments, I think the Flip is redundant. > > What's your way of setting up the output surface (primary)? > > My application look like this: >> >> ... >> CreateSurface >> Drawing/Blitting >> Flip >> WaitIdle >> > > Why not first WaitIdle() and then Flip()? Sorry. The Filp is after the WaitIdle in the fact. I made a mistake. > > > Maybe in your case the Flip() is performed asynchronously, a bit later? > > I guess that's why you wait afterwards, but it's most likely a coincidence > that the WaitIdle() is about the right time to wait... > > I assume, but are you running this in a loop? Otherwise it would be even > more > strange, like some commands not being flushed... > > Are you missing the last pieces that were drawn, or do you see the the > first > piece overwriting the rendered frame already? No. I miss some portion of a single drawing/blitting primitive. e.g. I lost a corner when I fill a rectangle. I know it is the cache data not flushed by hardware. So I need to flush the cache and wait the hardware for idle. > My questions are: >> 1. Is WaitIdle the synchronization primitive for directfb? >> I use WaitIdle to make sure the HW has been finished the drawing/blitting. >> Otherwise the pictures on the screen are incomplete - lost a corner, etc. >> > > Yes, WaitIdle() is the global synchronization method for the one > accelerator. > > 2. Are the synchronizations automatically done by Flip if I use >> double/triple buffer? >> > > Yes, but they are also done with single buffering. > > Have a look at dfb_layer_region_flip_update() in src/core/layer_region.c. > > -- > Best regards, > Denis Oliver Kropp > > .------------------------------------------. > | DirectFB - Hardware accelerated graphics | > | http://www.directfb.org/ | > "------------------------------------------" > -- Thanks, Yaowen.Feng
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