SDL and alpha

hi`

I guess I could look at the source to fiddle this out, but how dows SDL
handle a bitmap that only uses alpha in some places (like alpha being
used only very little in a surface that has an alpha channel)? Is there
any optimization for those cases?–
Daniel Vogel My opinions may have changed,
666 @ http://grafzahl.de but not the fact that I am right

hi`

I guess I could look at the source to fiddle this out, but how dows SDL
handle a bitmap that only uses alpha in some places (like alpha being
used only very little in a surface that has an alpha channel)? Is there
any optimization for those cases?

Nope. :slight_smile:
Not yet… :slight_smile:

-Sam Lantinga				(slouken at devolution.com)

Lead Programmer, Loki Entertainment Software–
“Any sufficiently advanced bug is indistinguishable from a feature”
– Rich Kulawiec

Sam Lantinga wrote:

hi`

I guess I could look at the source to fiddle this out, but how dows SDL
handle a bitmap that only uses alpha in some places (like alpha being
used only very little in a surface that has an alpha channel)? Is there
any optimization for those cases?

Nope. :slight_smile:
Not yet… :slight_smile:

There could be something like that RLE stuff for transparency - you
split up the surface in two parts. One using transparency and opaque
using the RLE acceleration and then one using RLE alpha acceleration.
This has proven to be a big performance gain on an average ‘not too much
alpha’ surface. I guess once I am in a real good mood I might have a
look at SDL (somewhen in April) ;)–
Daniel Vogel My opinions may have changed,
666 @ http://grafzahl.de but not the fact that I am right