[SDL] How to make libsdl support 18bpp?

[Bob Pendleton]

On Sat, 2008-01-05 at 14:50 +0800, Mxdyd wrote:
> Hello,
> I'm trying to port the libsdl onto  arm-linux,but my  LCD is
> 18bpp.How can I make it  support  18bpp?Which  file should  I
> modify? 

You are talking about a pretty big project. But, to get started down
load the SDL source and grep -iR bpp * to find all the files that
mention bpp (bits per pixel). Read all the ones in the include directory
and take a look at all the ones in src, especially those under
src/video.

That should get you started.

You might just want to find out if your display can be set to a 16 or 15
bit mode and use it in that mode. Or, you might be being fooled by an 18
bit display where the 6 bits of color are allocated in 8 bit bytes with
the low 2 bits ignored, in which case you can use the 24 bit modes with
much less modification.

18 bits per pixel is a very weird format. It almost always means that
the pixels are really mapped to memory on 8 bit boundaries with 2 bits
physically missing. So, read the hardware specifications very carefully
before you do any other work. 

Bob Pendleton

> 
> 
> ______________________________________________________________________
> 雅虎邮箱传递新年祝福，个性贺卡送亲朋！ 
> _______________________________________________
> SDL mailing list
> SDL at lists.libsdl.org
> http://lists.libsdl.org/listinfo.cgi/sdl-libsdl.org
-- 
+--------------------------------------+
+ Bob Pendleton: writer and programmer +
+ email: Bob at Pendleton.com             +
+ web: www.GameProgrammer.com          +
+ www.Wise2Food.com                    +
+ nutrient info on 7,000+ common foods +
+--------------------------------------+