[SDL] Blitting speeds

Prasanth Kumar kumar1 at home.com
Wed Aug 25 23:19:02 PDT 1999

John Garrison wrote:
> > I'm kind of new to SDL but did you do a 'DisplayFormat' operation
> > before you
> > do blitting? If the pixel format differs between the two surfaces,
> > SDL will
> > do a conversion while it is blitting.
> >
> Well, I when I added this code as well as closed down some apps to
> free up memory the framerate jumped from 13 to 24, but no other
> programs benefited, could the free memory make a 13-24 difference (I
> never tested this program but once so I don't know how it runs with
> full memory available.  It doesn't really make sense that the other
> programs didn't improve any, this should have made a difference
> shouldn't it?

The other thing to consider is whether you are running the best suited
SDL video mode? If not, then every time it is blitted to the screen
it need to do the pixel format conversion? They documentation suggest
convert the bitmaps (sprites) to match the best video mode and blit

Prasanth Kumar
kumar1 at home.com

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