Yes, I definitely understand that. I were doing that as proof of concept. BTW, just after I send out my previous mail last night, I realized I forgot to set DSDRAW_BLEND flag to enable alpha blending in drawing operations. After I fixed that(just one more line:), it worked! But when I tried to send email again to this mailing list, it keeped being bounced back. :(
Thanks. On Wednesday 07 April 2004 23:04, Sven Neumann wrote: > Hi, > > Xiong Huan <[EMAIL PROTECTED]> writes: > > I am considering leverage DirectFB's RGBA support and exposing it on > > GDK/GTK level. I noticed gdk-directfb uses standard GdkColor > > definition and thus hides the underlying alpha-blending support. So > > I appended a new filed "guchar alpha" in GdkColor structure, and in > > gdk_directfb_setup_for_drawing() I assigned this value to "alpha" > > varialbe rather than used the original hardcoded one(0xFF). I think > > this is a simple way to pass alpha value from user to directfb and, > > at the same time, make as little change as possible. > > > > Then I modified gtk_style_real_realize() in gtkstyle.c trying to > > test my change. I hardcoded style->black.alpha to be 120, which is > > later passed to gc_values.foreground. Then I run a simple gtk button > > application, thinking its foregound color will be > > semi-transparent. However, there is no change at all. > > > > I added some debug information in gdk_directfb_draw_lines() function > > and notieced the alpha value(120 in my case) was really passed in > > it. But why it has no effect at all? > > > > Am I missing somthing here? Can anyone throw some light on it? > > Changing GTK+/GDK structures out of the directfb directory is not > possible since we want this port to be integrated with the GTK+ > mainline. So unless there's alpha transparency support in the > mainline, transparency on the gdk-directfb level will always be a > kludge. > > > Sven -- Info: To unsubscribe send a mail to [EMAIL PROTECTED] with "unsubscribe directfb-users" as subject.
