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

[Ivan Shmakov]

>>>>> Hamish  <hamish_b at yahoo.com> writes:

[...]

 >> 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
 > ...

	Thanks for the pointers!  Of the particular interest to me is
	[1], proposing almost the same additions to libgis to that I've
	posted recently.  Why these changes weren't applied?  Yes, I see
	Glynn's initial concerns, but it seems that they were due to
	some misconception, weren't they?

 > 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.

	I've dug through the code while preparing the patch, and I don't
	think of `struct color_rgb' to `struct RGBA_Color' to be a big
	change.  The diff is only 814 lines long, but it seemingly
	removes all of the references to `struct color_rgb' except for a
	couple of cases in lib/.

	(Surely, my patch will need a couple of `struct RGBA_Color' =>
	`RGB_Color' changes, as well as some testing.)

[1] nntp://news.gmane.org/gmane.comp.gis.grass.devel/11789
    (http://article.gmane.org/gmane.comp.gis.grass.devel/11789)