nanogui: nano-X and alha blending
Subject:
Re: [nanogui] nano-X and alha blending
From:
"Greg Haerr" ####@####.####
Date:
30 Sep 2005 16:22:13 +0100
Message-Id: <0f6f01c5c5d0$73e034b0$6401a8c0@winXP>
: when the window appears, rather than just "popping up" it wants to fade
: in and fade out when closeing. I hoped to do this with alpha blending by
: having the window in a pixmap and starting out with a high transparency
: copying it into the window, and then with a timer, keep recopying it
: with less and less transparency until soild. Then reverse for "fade out".
:
:
: Is this possible?
Yes, its possible, but getting the window drawing to alpha
blend is going to be alot of work, since the only alpha blending
is image support, and none of the window drawing uses that.
All driver entry points would have to have to be modified to
use the alpha channel in the color passed to alpha blend,
which would be very slow without hardware support, or
the whole window drawn offscreen first and then blitted.
Both options currently would require big changes internally.
If your application draws the entire "window" including
faked borders and title bar, then you might easily display
a borderless window's contents using just blit, and
only the internal GdBlit routine would need to be modified.
All the nanowm window code would have to be included
in your application, though.
Regards,
Greg
