[GRASS-dev] lib fn to convert int color number to RGB values?

[Hamish]

Ivan Shmakov wrote:
> $ nl -ba include/gis.h 
> ...
>    336	typedef struct
>    337	{
>    338	    unsigned char r, g, b, a;  /* red, green, blue, and alpha
> */
>    339	} RGBA_Color ;
>    340	
>    341	typedef RGBA_Color RGB_Color;
> ...
> $ 
> 
> 	s/RGB_Color/RGBA_Color/ ?

no, the idea there was to be a shortcut for those who wanted to use the
struct but didn't care about alpha and didn't want to cause confusion
in the variable namespace. In those cases the alpha channel is ignored
and treated as an unused superfluous appendage. Perhaps it is of
dubious use, but I don't think anything actually uses it...

you can read some earlier history of RGBA_Color here:
 http://article.gmane.org/gmane.comp.gis.grass.devel/12185/
 http://thread.gmane.org/gmane.comp.gis.grass.devel/20463/focus=20488
 http://thread.gmane.org/gmane.comp.gis.grass.devel/11789/focus=11983
 ...


As we should be beginning to focus on stabilizing the grass 6 source, 
I would prefer to wait for the upcoming start of grass7 before
retooling the color handling subsystem much more. It may be crusty &
old, but it works and known. Then we can do it once, right, instead of
just bolting new ideas onto the legacy system.


Hamish



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