Re: [Bug-freedink] Screen or Sprites Flickering

[Eric Duhamel]

Thank you for following up. I did not get anywhere with compiling from the 
repository; seems I'd need to patch SDL2 and I'm not sure where to start with 
that.

On March 16, 2017 12:44:33 PM PDT, address@hidden wrote:
>
>OK so I reflashed my RPI with its stock Raspbian Wheezy.
>
>I think I had already witnessed this issue and at the time I figured
>there was nothing to do, since the framebuffer backend had never
>really worked for me in my previous setups.
>
>Indeed FreeDink/SDL requests a hardware-accelerated surface with
>double-buffering, and according to freedink --debug, it gets it.
>
>However it does not fulfill the contract, it seems we get a
>single-buffer surface, which causes the flickering.
>(incidentally you were right, this is flickering and not tearing)
>

If I'm not mistaken, this sounds like a bug in whatever GPU blob is included in 
Raspbian.

>You should be able to get the exact same issue in kobodl by selecting
>Options > Video > Software Shadow Buffer > No
>(thanks for reminding me about kobodl btw, nice memories :))
>

Sweet game!

>Currently FreeDink 108.4 does not support single-buffered graphics
>(in particular when it advertises itself as double-buffered ;)).
>

:-P

>Technical note: I should be possible to write a local patch to the
>flip_it() function so as to introduce an extra buffer.  That would
>hurt performances in general, but would fix the flickering on
>RPI/framebuffer.  Of course the other option is to run FreeDink under
>X11 where it works.  Would either be an option for you?
>

I'm currently collecting games for a Retropie-like system incorporating libre 
games instead. The setup tends to run without using X, but I suppose a "startx 
-- /usr/games/freedink" wouldn't be out of the question if it just works.

But I'd be more interested in a local patch to flip-it(), if one were 
available. If I compile a slightly patched version of legacy Freedink for this 
purpose I would maintain the fork on Gitlab and packages on Archive.org so 
others would have access to it. Hoping performance wouldn't take *too* much of 
a hit.

>With SDL2 I believe the framebuffer is not directly supported anymore,
>(http://forums.libsdl.org/viewtopic.php?t=9661)
>it will be either X11/software, or OpenGL.  Does the RPI still require
>proprietary drivers (cf. /opt/vc/) for OpenGL, or did the situation
>improve?
>

I don't think it has. At least I haven't heard anything. Would this mean future 
SDL2-based releases of Freedink are unlikely to work on the Pi?

--
Eric Duhamel
http://www.noxbanners.net/