From: "Michael Stewart" <mike AT reggin DOT freeserve DOT co DOT uk>
Newsgroups: comp.os.msdos.djgpp
Subject: Re: Fades
Date: Thu, 18 Mar 1999 19:31:29 -0000
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The Beyonder wrote in message <36ED4D0B DOT 78A2B9ED AT geocities DOT com>...
>IIRC That's sorta harder because each individual pixel on the screen has
>to be changed to the next colour... but all you really have to do is go
>through the SVGA virtual frame buffer and start changing the pixels FI:
>
><START CODE>
>RGB pixValue;
>
>while (!allFade) {
> for (int i=0;i<l*w;i++) {
> pixValue = getPixel24( x,y );
> FadeStep ( &pixValue );
> putPixel24( x,y, pixValue );
> }
>}
></END CODE>
>
>or some such.  But I believe that there has to be a better method
>availabe...
>
>John Carbrey wrote:
>>
>> All the fade functions that I have seen so far only allow for 256 colors.
Is
>> there a way I can fade in 16,24,or 32 bit color?
>>
>> Yt,
>>
>> John Carbrey
>
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I asked Shawn Hargreaves a similar question, this is a copy of the message:
>
> >I'm of two minds as to include colour fading in my routines.
> >Now, palette fading is easy and relatively efficient to do in indexed
> colour
> >modes. But is there a efficient way (without hardware support) to perform
> >the same effect in 15/16/24/32 bit direct colour modes ?
>
> Not that I have ever come across.
>
> >I cannot think of any methods of performing it well. The only way of
> doing
> >it, that I can think of, is to perform a colour fade on a per pixel
> level.
>
> Yeah, it is a pain in the arse but I think that is what you have to do.
> One easy way to implement this is just to repeatedly draw a black
> translucent rectangle covering the entire screen, which will gradually
> darken it down. But this is painfully slow: I think that is one of the
> biggest disadvantages of switching from a 256 color to truecolor mode.
>
> --
> Shawn Hargreaves - shawn AT talula DOT demon DOT co DOT uk -
> http://www.talula.demon.co.uk/
> "Without music to decorate it, time is just a bunch of boring production
> deadlines or dates by which bills must be paid." - Frank Zappa
>


--
Michael Stewart
mike AT reggin DOT freeserve DOT co DOT uk
"Just because you're paraniod doesn't mean they aren't after you..."