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

[Ivan Shmakov]

>>>>> Glynn Clements <glynn at gclements.plus.com> writes:

 >>> AFAIK, GRASS itself never sets errno.

 >> But, IIUC, it doesn't prevent `errno' from being set by the standard
 >> library functions it calls?

 >> Setting `errno' would make sense should there be a demand to use the
 >> standard C means of error reporting in the GRASS code.  And I can
 >> see a point in it.

 > I would rather have a separate grass_errno function (PROJ has
 > pj_errno), so that failures originating at the OS level (e.g. ENOSPC
 > or EPERM) can have the underlying cause determined.

	Surely.  I'd just ask not to ``if (errno == FOO) {
	set_grass_errno_for_this_thread (BAR); }'', but rather just pass
	`errno' to the caller untouched.

	Iff the problem could be described completely by the `errno'
	value, then the value of grass_errno () shouldn't be touched.

[...]

 >> As for a generic color facility, I'd suggest looking at the
 >> following for the inspiration:

 >> http://www-swiss.ai.mit.edu/~jaffer/slib_5#Color
 >> http://www-swiss.ai.mit.edu/~jaffer/Color/Color-Scheme

 > I'm inclined to think that supporting explicit colour spaces is
 > overkill for GRASS.

[...]

	I'm going to agree for just now.