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[directfb-dev] Re: ANNOUNCE: DirectFB 0.9.12
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[directfb-dev] Re: ANNOUNCE: DirectFB 0.9.12

Quoting Ville Syrj?l? (
> On Thu, Jun 20, 2002 at 12:00:30AM +0200, Sven Neumann wrote:
> >   - Implemented missing BES flipping in matrox driver.
> What about the WAITFORSYNC problem? With the current approach the BES flip
> happens one vsync too late. Might not be a real problem with high refresh
> rates but what about TV output? Nobody commented on my idea about calling
> dfb_fbdev_wait_vsync() after dfb_layer_flip_buffers().

The IDirectFBSurface::Flip() method for display layers waits for the vsync
before calling the driver if WAITFORSYNC is specified. Waiting for the vsync
in the driver after flipping would cause a double waiting.

The vsync stuff needs to be cleaned up so that the application doesn't need
to know whether flipping takes effect on vsync or if it should wait before
or after flipping. Btw, the BES can be programmed to flip immediately,
which would be a hot fix as applications could use WAITFORSYNC then.

The current state of the flip/vsync stuff is definitely unsatisfying.
Expect a reasonable behaviour for the next release, any input on application
needs would be helpful.

Best regards,
  Denis Oliver Kropp

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