Misc technical notes
--------------------

Targeting OS X SDK to compile for older versions

	See environment variables:

	SDKROOT
	MACOSX_DEPLOYMENT_TARGET

	See <https://developer.apple.com/library/archive/documentation/DeveloperTools/Conceptual/cross_development/Configuring/configuring.html>
	<https://firefox-source-docs.mozilla.org/widget/cocoa/sdks.html>
	


Things I'd like to standardise
------------------------------

ICC:
	Tag for TAC. Should include all combination of colorant
	summs limits. Should be min and max ?
	Option for LUT for abitrary limit (similar to gamut LUT).

	Tag for 3D gamut Hull using triangles.

	Standard rendering intent encodings, to be used as basis
	of extra per color component attribute. Backward compatible
	with current ICC rendering intents ?
	Use "schemes" too, to allow for future changes.

	Spectral sub-tag for spectrum encoding.

	New named color using spectral.

	New colorant tag using spectral.

Other:
	Add rendering intent plane support to TIFF etc.


ICC profile locations in various operating systems.
---------------------------------------------------

Someone emailed me about a standard Linux location for ICC profiles,
and I decided to research this a little more than has been done in
the past, so though others might be interested in the results.

> I was wondering if you are aware of any standard location in the Linux
> filesystem to put ICC profiles?

There was some discussion about this on the OpenICC mailing list a while
back:

Stefan Klein wrote:
> Marti Maria, developer of littlecms (www.littlecms.com), suggested
> /usr/share/color/icc and ~/.color/icc as intuitive paths. We decided to
> go along with this.

Kai-Uwe Behrmann wrote:
> I followed the suggestions of using
>  /usr/share/color           for global configuration data and
>  /usr/share/color/icc       for global ICC profiles
>  ~/.color and ~/.color/icc  as user pendant.

Googling for "common Linux ICC profile directory" brings up other references.

For instance Scribus puts its profiles in

    /usr/local/share/Scribus/profiles


SUN has been implementing CMM's on its Solaris system
for a long while (using Kodaks KCMS), and have already
established other conventions in its part of the the Unix world:
> 1. The current directory
> 2. Directories listed by the KCMS_PROFILES environment variable, which is a
> colon-separated list of directories
> 3. /etc/openwin/devdata/profiles
> 4. /usr/openwin/etc/devdata/profiles
as well as having extensive support for ICC profiles in Java, on multiple
platforms (again using KCMS and the native platform CMM's it seems).


SGI has a CMM called Coloratura on their IRIX Unix system, and uses
yet another convention:
> The Coloratura CMS searches for a file sequentially in the directories specified
> by the environment variable CMS_DEFAULT_PATH, which is a colon-separated list of
> pathnames similar to that used in the environment variable MANPATH.
> The value of CMS_DEFAULT_PATH defined in cms.h is
> /var/cms/profiles/local:/var/cms/profiles:.,
> which allows you to place profiles you prefer in /var/cms/profiles/local,
> and generic profiles, which might have the same names, in
> /var/cms/profiles or your working directory.


Apple in OSX (another Unix based system) chooses

    /Library/ColorSync/Profile
    /System/Library/Colorsync/Profiles
    /Network/Library/ColorSync/Profiles
    ~/Library/ColorSync/Profiles

and individual drivers store relevant profiles in their application
resources: eg.

    /Library/Image Capture/Devices/EPSON SScanner.app/Contents/Resources/
and
    /Library/Printers/Canon/BJPrinter/PMs/BJC8200PM.plugin/Contents/Resources/
and
    /Library/Printers/hp/Profiles
and many other places.

Microsoft Windows chooses:

\WINDOWS\SYSTEM\COLOR
\WINNT\SYSTEM32\COLOR
\WINNT\SYSTEM32\SPOOL\DRIVERS\COLOR

depending on the operating system version.
Photoshop on MSWindows seems to use its own location:

\Program Files\Common Files\Adobe\Color\Profiles

Note that Apple ColorSync, Microsoft ICM2.0 and KCMS as implemented
by SUN are all existing CMM's with detailed technical documentation
available via the web (as examples of how it has been done, and the variety
of facilities a CMM may make available.)


============================================================================
Autotools and some Linux systems expect env vars:

CFLAGS: C flags, passed during compile AND link (e.g., -O2 -std=c99)
CXXFLAGS: C++ flags, passed during compile AND link (e.g., -O2 -std=c++98)
CPPFLAGS: pre-processor flags, passed ONLY during compile (e.g., -DNDEBUG=1 -Iadditional/include)
LDFLAGS: linker flags, passed ONLY during link (e.g., -export_dynamic -Ladditional/libdir -llib)

to have effect.
