Re: GtkDrawingArea

[John Cupitt ng-london org uk]

Jean-Yves Lamoureux wrote:
> Le Jeudi 18 Avril 2002 12:43, John Cupitt ng-london org uk a écrit :
> 
> 
>>It will be dithered if you connect (eg.) to a 15bpp display. If your
>>display is 24 or 32, it's passed through untouched. It also uses Xshm if
>>it's available.
>>
> 
> So what I said is right ?  If I display an rgb_image, it will be a 24bpp 
> display. I want to draw a 15bpp image, so if what you say is right, I need
to 
> convert it to 24bpp, then gdk will convert it to 15bpp back again. It is a

> bit idiot, I think there must be another way to do that, no ?
> thanks

There's gdk_draw_image() which just boinks a GdkImage to the display. 
You need to build a GdkImage which exactly matches the X server display 
in depth and colour map.

It can be a pain to use: it means your code needs to be able to generate 
an image in any format an X server might ask for. This can be a lot of work.

The gdk_draw_rgb_image() functions hide all this by only taking a 24 
bits image, and then converting for you with dither.

John



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Aelbert Cuyp 13 February - 12 May 2002 

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