Le jeudi 26 juin 2008 à 15:22 -0700, Bill Spitzak a écrit :
> Fltk2.0 did add a way to create a window with an arbitrary visual and 
> colormap, but it did not store them. Any attempt to draw would assume 
> you are using the default visual and colormap. But you could create a 
> Window object and if you overrode draw() you could draw it using your 
> own X code.
> 

In fact it's the flush() method that must be overrode, because this
method creates a backbuffer with the default visual / default depth
(either a window or a pixmap), and copy it to the window using a gc
created with the default visual and this generate BadMatch error, and
doesn't fill the window on the screen.

> Making this more general is probalby ok as long as anything about X is 
> kept out of the public interface (ie no methods on Window).
> 
> I'm not clear how this fixed your composite extension issues. It lets 
> you specify the visual, but isn't the real problem that the defualt 
> visual is wrong?
> 

I doesn't really fix my problem, but this patch was made to workaround
the real problem: FLTK write some value in the fourth byte of a pixel,
this value is not used in 24bits visual, but in 32bits visual, it's the
ALPHA channel (RGBA). So all drawing made by FLTK are more or less
transparent with a 32bits visual. One would excepted it to be either
fully opaque (what I want) or fully transparent (which is easy to fix),
not something in the middle. 

It seems the fourth value is related to brightness: black color is fully
transparent and white color fully opaque.

Regards

-- 
Yann Droneaud <[EMAIL PROTECTED]> +33 (0) 1 40 41 17 59
Ingénieur conseil
Mandriva 



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