[SDL] Re: slooow

Mattias.Blomqvist at nokia.com Mattias.Blomqvist at nokia.com
Thu Apr 13 08:29:59 PDT 2000


Yepp. But that wasnt at all what we discussed. Using 32 bits per pixel is
faster than using 24. Although only 24 of the bits are used for
colorinformation since this is the way that the X-server does. Anyway, it
was still much slower than expected.

/Mattias

> -----Original Message-----
> From: EXT Pierre Phaneuf [mailto:pp at ludusdesign.com]
> Sent: 13. April 2000 15:54
> To: sdl at lokigames.com
> Subject: [SDL] Re: slooow
> 
> 
> Mattias.Blomqvist at nokia.com wrote:
> 
> > > That seems very wrong.  What depth is your display set to?
> > > SDL_BlitSurface() shouldn't take 50 ms for even a 
> 1024x768 blit, since
> > > it's using inline assembly version of memcpy(), unless 
> it's doing a
> > > complicated unoptimized conversion blit (which almost 
> never happens)
> > 
> > Depth is 32.
> 
> Just FYI, as this is a programming forum and this is an often confused
> thing: in this case, the color depth is 24 (the number of 
> bits actually
> used) and the bits per pixel is 32 (the number of bits a single pixel
> occupies in the frame buffer memory).
> 
> Color depth <= bits per pixel, all the time. There are some uncommon
> video boards that can do a 30 bits color depth, apparently 
> (according to
> Dirk Hohndel).
 



More information about the SDL mailing list