Newbie blit question

SDL Development
1

Hi all,

I’ve been trying to make head or tail of the blit code in
the library … complex stuff isn’t it ?

So I have a question instead… Can the blit engines scale
the output on demand ? My gut feeling is that they will
(otherwise why have source and dest rectangles?) but it’s
not obvious…

If this is how it works, do the MMX routines cope with it as
well ?

I have an existing general scaling algorithm which works
reasonably well (in fact it’s almost as fast as simply
doubling pixels in X & Y) but I imagine any hardware/MMX
solution would be much faster…

I’m trying to write a cross-platform video player, and
decoding 30 fps jpegs leaves very little time for the image
display routines… Since I’m stuck with the image format,
I’m hoping for really fast blitting/scaling routines :-)))

ATB,
Simon.

2

hi`

in your particular case the easiest solution would be to let OpenGL do
the blitting and scaling. You would have to cope with texture size
limits and splitups, but you would get bilinear filtering on most cards
without a performance hit (and alpha blending, but I guess you won’t
need that ;-)). AFAIK smpeg has a GL viewer.

Simon Gornall wrote:>

I’m trying to write a cross-platform video player, and
decoding 30 fps jpegs leaves very little time for the image
display routines… Since I’m stuck with the image format,
I’m hoping for really fast blitting/scaling routines :-)))

ATB,
Simon.

–
Daniel Vogel

666 @ http://grafzahl.de