Hi,

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?

Thanks.


-- 
Info: To unsubscribe send a mail to [EMAIL PROTECTED] with 
"unsubscribe directfb-users" as subject.

Reply via email to