[haiku-development] Re: Offscreen and onscreen views

  • From: "François Revol" <revol@xxxxxxx>
  • To: haiku-development@xxxxxxxxxxxxx
  • Date: Mon, 20 Oct 2008 20:22:42 +0200 CEST

> Hello,
>
> In the clock app, amongst others, we have an 'offscreen' view and an
> 'onscreen' view.  The offscreen view performs the actual drawing
> while
> the onscreen view composites the offscreen view into a BBitmap and
> then draws the bitmap.  I assume this is done to ensure that the
> drawing is flicker-free.
>
> Is it planned to rework the compositing engine so that this is no
> longer necessary?  Something like B_BUFFERED as a view flag?  Also,
> is

BeOS R5.1d0 (aka Dano) had an API to specify which views should be
double buffered... but it didn't always work the way you'd think it
would.
Maybe it could be useful, however I think most of Haiku app_server
drawing are actually double-buffered already, to help with speed in
VESA mode. IIRC

> it planned to add alpha transparency to the windowing system?  (Not
> for R1, obviously, but in the future.)

There is no compelling reason appart eye candy, and that's not
something we really push for. Possibly a rendering backend using
accelerated OpenGL would allow that in the future...
Feel free to send a diff.

François.

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