Hi,
I have a question and a suggestion for the fontconfig config priority in the font packaging policy.
I'm writing a small script to validate the fontconfig config in packages to not mess up. the goal is to check if the priority is set accurately and the config files are following our templates. it roughly started working. but I'm not quite sure what "Latin" in LGC really covers. is it similar to what Latin-[1-10] covers? or more strictly applied?
The suggestion is, about improving the policy to set the priority more strictly. I have two ideas:
1) have variety of the priorities for non-LGC fonts as well like for default, main and low perhaps. even though LGC fonts has a priority for default font, but not for non-LGC fonts. it may messes up their default font if multiple fonts with the same priority such as 65 are installed. this priority things could avoids this issue. it may be something like:
65-69 ... High priority non-LGC fonts 70 ... Main non-LGC font list 71-64 ... Low priority non-LGC fonts
2) describes what exactly "default", "Main" and "Low" priority means. during developing and testing this script, I see some packages is possibly wrongly set the priority to their fontconfig config files, for example, some font is set the priority to 57 that is supposed to be the default font, but not marked as mandatory in comps. so I'd suggest to update comps or change the priority like:
- mandatory for higher priority - default for main priority - optional for low priority
and update the policy with it as well.
Any thoughts or comments are welcome.
TIA, -- Akira TAGOH
Le jeudi 17 décembre 2009 à 23:06 +0900, Akira TAGOH a écrit :
Hi,
Hi,
I have a question and a suggestion for the fontconfig config priority in the font packaging policy.
I'm writing a small script to validate the fontconfig config in packages to not mess up.
Wondeful! If you want commit access to fontpackages to have it integrated with our other tools, just ask (if the licensing is OK with you)
the goal is to check if the priority is set accurately and the config files are following our templates. it roughly started working. but I'm not quite sure what "Latin" in LGC really covers. is it similar to what Latin-[1-10] covers? or more strictly applied?
LGC roughtly means latin-like alphabetical scripts that are written linearly with few ligatures, and those that exist optional (not indic, not arabic, not cjk…) Also an unofficial requirement for those scripts is to be from regions where people are familiar enough with latin letters not to butcher them when they include them in fonts
A more professional description would be welcome :)
The suggestion is, about improving the policy to set the priority more strictly. I have two ideas:
- have variety of the priorities for non-LGC fonts as well
like for default, main and low perhaps. even though LGC fonts has a priority for default font, but not for non-LGC fonts. it may messes up their default font if multiple fonts with the same priority such as 65 are installed. this priority things could avoids this issue. it may be something like:
65-69 ... High priority non-LGC fonts 70 ... Main non-LGC font list 71-64 ... Low priority non-LGC fonts
Those ranges are inherited from the fontconfig master file split that occured a few years ago upstream. I'm not so sure that nowadays they are the most appropriate. We've certainly started pushing a lot more fontconfig files that upstream thought at the time, and are hitting many limitations (layout that was supposed to be flexible enough to allow customization, but is not really because of the files that have kept long font lists). If you try to split the non-latin file, for example, you quickly hit prefix starvation. However, that's just MHO. Other people may not share it. But please keep an open mind and do propose another file naming convention if you find a better one. I think that the main requirements would be to
1. clearly define the ranges a local sysadmin, a distro, and fontconfig upstream fallbacks should use 2. try to separate classes of fonts to minimize risks of conflicts (like the current lgc/non lgc split) 3. make locale appear when it is relevant 4. make the font names appear in filenames so people do not need grepping to locate where the rules associated with their font are
It is possible in fontconfig to use something longer that the current 2-digit prefixes to order files
- describes what exactly "default", "Main" and "Low"
priority means. during developing and testing this script, I see some packages is possibly wrongly set the priority to their fontconfig config files, for example, some font is set the priority to 57 that is supposed to be the default font, but not marked as mandatory in comps. so I'd suggest to update comps or change the priority like:
- mandatory for higher priority
- default for main priority
- optional for low priority
and update the policy with it as well.
I don't think using comps brutally will work :
1. currently we do not have separate comps groups for every fontconfig/css generic, fontconfig and apps really want a separate font stack for each generic (though this could be fixed by splitting the master fonts comps group)
2. sometimes our requirements are a lot more subtle than mandatory/default : dejavu and liberation are both default, but their ordering is not random
However I can only applaud trying to improve our fontconfig packaging, and writing qa tests: this is sorely needed, if we want to continue improving Fedora font support.
Best regards,
On Wed, 23 Dec 2009 00:14:26 +0100, "NM" == Nicolas Mailhot nicolas.mailhot@laposte.net wrote:
NM> Wondeful! If you want commit access to fontpackages to have it NM> integrated with our other tools, just ask (if the licensing is OK with NM> you)
Sure. that sounds nice :)
NM> LGC roughtly means latin-like alphabetical scripts that are written NM> linearly with few ligatures, and those that exist optional (not indic, NM> not arabic, not cjk…) Also an unofficial requirement for those scripts NM> is to be from regions where people are familiar enough with latin NM> letters not to butcher them when they include them in fonts
So I guess the language coverages of ISO-8859-{1-5,7,9,10,13-16} may works similarly right?
NM> Those ranges are inherited from the fontconfig master file split that NM> occured a few years ago upstream. I'm not so sure that nowadays they are NM> the most appropriate.
I see. I don't mind which ranges should be used. my point here is to have a bit more strict prioirty-sets to apply the fontconfig config files efficiently.
NM> We've certainly started pushing a lot more NM> fontconfig files that upstream thought at the time, and are hitting many NM> limitations (layout that was supposed to be flexible enough to allow NM> customization, but is not really because of the files that have kept NM> long font lists). If you try to split the non-latin file, for example, NM> you quickly hit prefix starvation.
Correct if it's spent randomly. I didn't mean that though. and that's also why I'm suggesting to have more clearer definition in the policy to not make more breakage. at least to avoid it in Fedora.
I'm at the position where to have minimum-sets of the configuration in upstream. which doesn't mean to have a starter kit nor all-in-one. but just leave to each fonts packages to have one. generally speaking, ideally if a kind of the font installer can create/install the certain fontconfig configuration file into the system, that would be really nice. once we have more strict policy we could have that feature perhaps.
NM> you quickly hit prefix starvation. However, that's just MHO. Other NM> people may not share it. But please keep an open mind and do propose NM> another file naming convention if you find a better one. I think that NM> the main requirements would be to
NM> 1. clearly define the ranges a local sysadmin, a distro, and fontconfig NM> upstream fallbacks should use NM> 2. try to separate classes of fonts to minimize risks of conflicts (like NM> the current lgc/non lgc split) NM> 3. make locale appear when it is relevant NM> 4. make the font names appear in filenames so people do not need NM> grepping to locate where the rules associated with their font are
Sure. that looks sane.
NM> I don't think using comps brutally will work :
NM> 1. currently we do not have separate comps groups for every NM> fontconfig/css generic, fontconfig and apps really want a separate font NM> stack for each generic (though this could be fixed by splitting the NM> master fonts comps group)
NM> 2. sometimes our requirements are a lot more subtle than NM> mandatory/default : dejavu and liberation are both default, but their NM> ordering is not random
I see. so what's the _default font_ means in the policy then? I was assuming if it's available at the system. thus, focusing attention on comps then though.
Anyway, if we have obvious definition for that, I'm fine then. possibly everything goes into the higher priority will messes up you know. this is the main reason why I'm trying to make the font packages better, making the fontconfig configuration files machine-auditable to reduce the check-cost.
NM> However I can only applaud trying to improve our fontconfig packaging, NM> and writing qa tests: this is sorely needed, if we want to continue NM> improving Fedora font support.
NM> Best regards,
NM> -- NM> Nicolas Mailhot
-- Akira TAGOH
-
Akira TAGOH -
Nicolas Mailhot