[SDL] HOWTO color cycling

Dan moos at pt.lu
Wed Aug 29 04:17:01 PDT 2001


just an idea: save the image 3 times: 1time only with the r component,
second the g component, third with the b component! then cycle it with the
alpha value? is just an idea and i did no thinking about it!



----- Original Message -----
From: "Jo" <IoDream at ifrance.com>
To: <sdl at libsdl.org>
Sent: Tuesday, August 28, 2001 11:08 PM
Subject: RE: [SDL] HOWTO color cycling


> -----Message d'origine-----
> De : sdl-admin at libsdl.org [mailto:sdl-admin at libsdl.org]De la part de
> David Olofson
> Envoyé : lundi 27 août 2001 14:47
> À : sdl at libsdl.org
> Objet : Re: [SDL] HOWTO color cycling
>
> (snipped)
> > Cool idea! :-)
>
> Thanks ;)
>
> >It should work, but it's probably faster to use a specifically optimized
> >pixel level real time animation instead. If you don't convert the
> >graphics to the display format, SDL will have to do the palette lookup in
> >real time every time you blit the surface. This is usually not (never?)
> >hardware accelerated on mainstream consumer hardware. (IIRC, some 3D
> >cards support indexed color textures, though... Would that be usable?)
> >
> >Then again, SDL's 256 color emulation seems to be pretty darn fast (*),
> >so I wouldn't think it's a big deal, at least not for low resolutions
> >(like 320x240) on "normal" computers.
> >
> >(*) Fast enough that I still haven't bothered to port my GUI +
> >    visualization toolkit to non-256 modes, despite using it on X
> >    in 32 bit mode most of the time. Resolutions used are 640x480
> >    and up, with nearly full screen oscilloscope displays and the
> >    like, and it's not exactly sluggish.
>
> I agree with that, but I've noticed that palette effect (like fade-in/out)
> don't work with GDI display (look at testwin in SDL test programs). This
> should be emulated by the SDL, I think.
>
> (snipped)
> >//David Olofson --- Programmer, Reologica Instruments AB
> >
> >.- M A I A -------------------------------------------------.
> >|      Multimedia Application Integration Architecture      |
> >| A Free/Open Source Plugin API for Professional Multimedia |
> >`----------------------------> http://www.linuxdj.com/maia -'
> >.- David Olofson -------------------------------------------.
> >| Audio Hacker - Open Source Advocate - Singer - Songwriter |
> >`--------------------------------------> david at linuxdj.com -'
>
>
>
____________________________________________________________________________
__
> ifrance.com, l'email gratuit le plus complet de l'Internet !
> vos emails depuis un navigateur, en POP3, sur Minitel, sur le WAP...
> http://www.ifrance.com/_reloc/email.emailif
>
>
>
> _______________________________________________
> SDL mailing list
> SDL at libsdl.org
> http://www.libsdl.org/mailman/listinfo/sdl
>





More information about the SDL mailing list