(mgp-users 00600) Re: Transparency

[Yoshifumi Nishida <nishida@csl.sony.co.jp>]

From: Christopher Drexler <drexler@informatik.uni-erlangen.de>
Subject: (mgp-users 00590) Re: Transparency
Date: Wed, 30 May 2001 15:11:53 +0900
Message-ID: <>

>> On Wed, May 30, 2001 at 05:59:28AM +0900, Dalmiro Jorge Filipe Maia wrote:
>> > I have used transparency in mgp with solid
>> > backgrounds. It works ok, but when I try to 
>> > use transparent png images with a background
>> > set by %bgrad or %bimage it doesn't work. 
>> > Now if I use a black and white eps file
>> > transparency works just fine (white is transparent,
>> > black turns into foreground color), so the possibility
>> > to use the alpha channel with %bgrad and %bimage
>> > is there.
>> 
>> I encountered the same problems, especially with bw/grayscale png's (c.f.
>> mgp-users request 560). I'm now using 'imlib' support but some problems
>> remain. Maybe a bug in the libpng ?

I think it's not a bug in the libpng. 
In native mgp's png support(without imlib), mgp simply blends alpha channel 
with background color. I will try to fix this in future version.

Cheers,
--
Yoshifumi Nishida <nishida@csl.sony.co.jp>
Sony Computer Science Laboratories, Inc.