[SDL] PNG and transparency

Sam Lantinga slouken at devolution.com
Mon Apr 24 11:39:13 PDT 2000

> I just downloaded the latest SDL_Image library.  From what I could tell
> before when PNG files loaded I had natural transparency preserved.

It was probably using alpha, not real transparency.  I just updated the
image library to support transparent GIF images so that I don't have to
explicitly set the colorkey for them.  The alpha blend driver has been
updated so that it doesn't perform blending on all opaque or all transparent
pixels, but it's still faster to use a colorkey blit.

> Also when will the configure script from the CVS go into the stable and
> development distributions?  That last question is the #1 question on this
> list.

Very soon.  Let me think...  I can't think of any serious reason not to
release SDL 1.1.3 any day now.  I'm just waiting for the new YUV surface
and thread synchronization code to be fully exercised.  I can't get the
DirectDraw YUV code to actually create a YUV surface - I get "Invalid
pixel format" for some reason, even though the hardware supports the
FOURCC format I'm using.  Any suggestions?

See ya,
	-Sam Lantinga, Lead Programmer, Loki Entertainment Software

More information about the SDL mailing list