[Scummvm-devel] 'gob' engine & 8bpp

[Johannes Schickel]

On Wed, Apr 1, 2015 at 12:18 AM, Miro Kropáček <miro.kropacek at gmail.com>
wrote:

> during my experiments with SDL and ScummVM I've noticed that Gobliiins
> (both EGA and VGA versions) for some strange reason asks SDL for
> 320x240x16bpp resolution. This is nothing on current PCs but on our
> platform it has fatal consequences because palette updates have to be done
> via full framebuffer refresh and it's really slow.
>
>
It is always beneficial to mention what platform you talk about with "our
platform". I can't figure out what you mean by "our platform" to be
honest...

But anyway: that's actually expected. ScummVM asks for a 16bpp output mode
with SDL. We always output 16bpp and do any CLUT8 to 16bpp conversion on
our own. This is mostly because our overlay (i.e. our GUI) does not render
at 8bpp modes but only 16bpp. Thus our whole backend simply uses 16bpp
internally.


> I tried to set VGA and EGA as the rendering engine but no change. Is there
> a reason for that? Or some global switch which would force Gobliiins to
> render in 8bit?
>

Gobliiins renders internally as CLUT8 AFAIK. But, as mentioned earlier,
ScummVM always requests a 16bpp output. That means the gob engine is
completely innocent here. It also means: you are out of luck, you can't
make ScummVM output 8bpp without substantial code changes.


> Btw, even in a version compiled with --disable-16bit I could observe that,
> really unexpected.
>
>
The --disable-16bit options is only to disallow the engines to use a 16bpp
graphics mode on their own (or to be precise to disallow them from using
anything but CLUT8).

// Johannes
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