Does "Alpha" channel blend blitting work on ALL platforms?

Does “Alpha” channel blend blitting work on ALL platforms ???

Hi,

I wish to have screens in my next game that:

  1. fade from black to rendered screen
  2. fade from rendered screen to black

I figure that Alpha channel blend blitting is the best method to do
these operations.
Blitting a black sprite the size of the screen over the pre rendered screen
with varying levels of alpha enabled should do the trick.

My question to the S.D.L.® game making experts is:
does “Alpha” channel blend blitting work on ALL platforms?

I really am only interested now in the P.C. Windows® platforms:
P.C. Windows® 98/98SE/2000/Me/XP/MediaCenter/2003/Vista

Will above technique work on ALL above Windows® versions?

Another question is are would the above technique be C.P.U. intensive
and very expensive?
I try to create game software that can run good on older machines.

Thanks in advance for your expert answers!

P.S. - “S.D.L.® Rocks!”

Jesse
SLNTHERO at AOL.com
http://www.SilentHeroProductions.com

I wish to have screens in my next game that:

  1. fade from black to rendered screen
  2. fade from rendered screen to black

Blitting a black sprite the size of the screen over the pre rendered screen
with varying levels of alpha enabled should do the trick.

My question to the S.D.L.® game making experts is:
does “Alpha” channel blend blitting work on ALL platforms?

Yes, it does.

Another question is are would the above technique be C.P.U. intensive
and very expensive?

Yes, it is.

You might also try gamma fading, which is faster when supported, but isn’t
supported on all platforms and drivers.

P.S. - “S.D.L.® Rocks!”

Thanks! :slight_smile:

See ya,
-Sam Lantinga, Lead Software Engineer, Blizzard Entertainment

Thanks Sam

Looking forward to the new StarCraft when it is ready!

Jesse
SLNTHERO at AOL.com
http://www.SilentHeroProductions.com

Sam Lantinga wrote:>> I wish to have screens in my next game that:

  1. fade from black to rendered screen
  2. fade from rendered screen to black

Blitting a black sprite the size of the screen over the pre rendered screen
with varying levels of alpha enabled should do the trick.

My question to the S.D.L.® game making experts is:
does “Alpha” channel blend blitting work on ALL platforms?

Yes, it does.

Another question is are would the above technique be C.P.U. intensive
and very expensive?

Yes, it is.

You might also try gamma fading, which is faster when supported, but isn’t
supported on all platforms and drivers.

P.S. - “S.D.L.® Rocks!”

Thanks! :slight_smile:

See ya,
-Sam Lantinga, Lead Software Engineer, Blizzard Entertainment


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