nixpkgs/nixos/modules/config/fonts/fontconfig.nix

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2016-07-16 21:11:42 +01:00
/*
NixOS support 2 fontconfig versions, "support" and "latest".
- "latest" refers to default fontconfig package (pkgs.fontconfig).
configuration files are linked to /etc/fonts/VERSION/conf.d/
- "support" refers to supportPkg (pkgs."fontconfig_${supportVersion}").
configuration files are linked to /etc/fonts/conf.d/
This module generates a package containing configuration files and link it in /etc/fonts.
Fontconfig reads files in folder name / file name order, so the number prepended to the configuration file name decide the order of parsing.
Low number means high priority.
*/
{ config, lib, pkgs, ... }:
with lib;
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let cfg = config.fonts.fontconfig;
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fcBool = x: "<bool>" + (boolToString x) + "</bool>";
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# back-supported fontconfig version and package
# version is used for font cache generation
supportVersion = "210";
supportPkg = pkgs."fontconfig_${supportVersion}";
# latest fontconfig version and package
# version is used for configuration folder name, /etc/fonts/VERSION/
# note: format differs from supportVersion and can not be used with makeCacheConf
latestVersion = pkgs.fontconfig.configVersion;
latestPkg = pkgs.fontconfig;
# supported version fonts.conf
supportFontsConf = pkgs.makeFontsConf { fontconfig = supportPkg; fontDirectories = config.fonts.fonts; };
# configuration file to read fontconfig cache
# version dependent
# priority 0
cacheConfSupport = makeCacheConf { version = supportVersion; };
cacheConfLatest = makeCacheConf {};
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# generate the font cache setting file for a fontconfig version
# use latest when no version is passed
makeCacheConf = { version ? null }:
let
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fcPackage = if builtins.isNull version
then "fontconfig"
else "fontconfig_${version}";
makeCache = fontconfig: pkgs.makeFontsCache { inherit fontconfig; fontDirectories = config.fonts.fonts; };
cache = makeCache pkgs."${fcPackage}";
cache32 = makeCache pkgs.pkgsi686Linux."${fcPackage}";
in
pkgs.writeText "fc-00-nixos-cache.conf" ''
<?xml version='1.0'?>
<!DOCTYPE fontconfig SYSTEM 'fonts.dtd'>
<fontconfig>
<!-- Font directories -->
${concatStringsSep "\n" (map (font: "<dir>${font}</dir>") config.fonts.fonts)}
<!-- Pre-generated font caches -->
<cachedir>${cache}</cachedir>
${optionalString (pkgs.stdenv.isx86_64 && cfg.cache32Bit) ''
<cachedir>${cache32}</cachedir>
''}
</fontconfig>
'';
# rendering settings configuration file
# priority 10
renderConf = pkgs.writeText "fc-10-nixos-rendering.conf" ''
<?xml version='1.0'?>
<!DOCTYPE fontconfig SYSTEM 'fonts.dtd'>
<fontconfig>
<!-- Default rendering settings -->
<match target="pattern">
<edit mode="append" name="hinting">
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${fcBool cfg.hinting.enable}
</edit>
<edit mode="append" name="autohint">
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${fcBool cfg.hinting.autohint}
</edit>
<edit mode="append" name="hintstyle">
freetype: 2.6.5 -> 2.7.1 The Infinality bytecode interpreter is removed in favor of the new v40 TrueType interpreter. In the past, the Infinality interpreter provided support for ClearType-style hinting instructions while the default interpreter (then v35) provided support only for original TrueType-style instructions. The v40 interpreter corrects this deficiency, so the Infinality interpreter is no longer necessary. To understand why the Infinality interpreter is no longer necessary, we should understand how ClearType differs from TrueType and how the v40 interpreter works. The following is a summary of information available on the FreeType website [1] mixed with my own editorializing. TrueType instructions use horizontal and vertical hints to improve glyph rendering. Before TrueType, fonts were only vertically hinted; horizontal hints improved rendering by snapping stems to pixel boundaries. Horizontal hinting is a risk because it can significantly distort glyph shapes and kerning. Extensive testing at different resolutions is needed to perfect the TrueType hints. Microsoft invested significant effort to do this with its "Core fonts for the Web" project, but few other typefaces have seen this level of attention. With the advent of subpixel rendering, the effective horizontal resolution of most displays increased significantly. ClearType eschews horizontal hinting in favor of horizontal supersampling. Most fonts are designed for the Microsoft bytecode interpreter, which implements a compatibility mode with TrueType-style (horizontal and vertical) instructions. However, applying the full horizontal hints to subpixel-rendered fonts leads to color fringes and inconsistent stem widths. The Infinality interpreter implements several techniques to mitigate these problems, going so far as to embed font- and glyph-specific hacks in the interpreter. On the other hand, the v40 interpreter ignores the horizontal hinting instructions so that glyphs render as they are intended to on the Microsoft interpreter. Without the horizontal hints, the problems of glyph and kerning distortion, color fringes, and inconsistent stem widths--the problems the Infinality interpreter was created to solve--simply don't occur in the first place. There are also security concerns which motivate removing the Infinality patches. Although there is an updated version of the Infinality interpreter for FreeType 2.7, the lack of a consistent upstream maintainer is a security concern. The interpreter is a Turing-complete virtual machine which has had security vulnerabilities in the past. While the default interpreter is used in billions of devices and is maintained by an active developer, the Infinality interpreter is neither scrutinized nor maintained. We will probably never know if there are defects in the Infinality interpreter, and if they were discovered they would likely never be fixed. I do not think that is an acceptable situtation for a core library like FreeType. Dropping the Infinality patches means that font rendering will be less customizable. I think this is an acceptable trade-off. The Infinality interpreter made many compromises to mitigate the problems with horizontal hinting; the main purpose of customization is to tailor these compromises to the user's preferences. The new interpreter does not have to make these compromises because it renders fonts as their designers intended, so this level of customization is not necessary. The Infinality-associated patches are also removed from cairo. These patches only set the default rendering options in case they aren't set though Fontconfig. On NixOS, the rendering options are always set in Fontconfig, so these patches never actually did anything for us! The Fontconfig test suite is patched to account for a quirk in the way PCF fonts are named. The fontconfig option `hintstyle` is no longer configurable in NixOS. This option selects the TrueType interpreter; the v40 interpreter is `hintslight` and the older v35 interpreter is `hintmedium` or `hintfull` (which have actually always been the same thing). The setting may still be changed through the `localConf` option or by creating a user Fontconfig file. Users with HiDPI displays should probably disable hinting and antialiasing: at best they have no visible effect. The fontconfig-ultimate settings are still available in NixOS, but they are no longer the default. They still work, but their main purpose is to set rendering quirks which are no longer necessary and may actually be detrimental (e.g. setting `hintfull` for some fonts). Also, the vast array of font substitutions provided is not an appropriate default; the default setting should be to give the user the font they asked for. [1]. https://www.freetype.org/freetype2/docs/subpixel-hinting.html
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<const>hintslight</const>
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</edit>
<edit mode="append" name="antialias">
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${fcBool cfg.antialias}
</edit>
<edit mode="append" name="rgba">
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<const>${cfg.subpixel.rgba}</const>
</edit>
<edit mode="append" name="lcdfilter">
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<const>lcd${cfg.subpixel.lcdfilter}</const>
</edit>
</match>
${optionalString (cfg.dpi != 0) ''
<match target="pattern">
<edit name="dpi" mode="assign">
<double>${toString cfg.dpi}</double>
</edit>
</match>
''}
</fontconfig>
'';
# local configuration file
# priority 51
localConf = pkgs.writeText "fc-local.conf" cfg.localConf;
# default fonts configuration file
# priority 52
defaultFontsConf =
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let genDefault = fonts: name:
optionalString (fonts != []) ''
<alias>
<family>${name}</family>
<prefer>
${concatStringsSep ""
(map (font: ''
<family>${font}</family>
'') fonts)}
</prefer>
</alias>
'';
in
pkgs.writeText "fc-52-nixos-default-fonts.conf" ''
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<?xml version='1.0'?>
<!DOCTYPE fontconfig SYSTEM 'fonts.dtd'>
<fontconfig>
<!-- Default fonts -->
${genDefault cfg.defaultFonts.sansSerif "sans-serif"}
${genDefault cfg.defaultFonts.serif "serif"}
${genDefault cfg.defaultFonts.monospace "monospace"}
</fontconfig>
'';
# bitmap font options
# priority 53
rejectBitmaps = pkgs.writeText "fc-53-nixos-bitmaps.conf" ''
<?xml version="1.0"?>
<!DOCTYPE fontconfig SYSTEM "fonts.dtd">
<fontconfig>
${optionalString (!cfg.allowBitmaps) ''
<!-- Reject bitmap fonts -->
<selectfont>
<rejectfont>
<pattern>
<patelt name="scalable"><bool>false</bool></patelt>
</pattern>
</rejectfont>
</selectfont>
''}
<!-- Use embedded bitmaps in fonts like Calibri? -->
<match target="font">
<edit name="embeddedbitmap" mode="assign">
${fcBool cfg.useEmbeddedBitmaps}
</edit>
</match>
</fontconfig>
'';
# reject Type 1 fonts
# priority 53
rejectType1 = pkgs.writeText "fc-53-nixos-reject-type1.conf" ''
<?xml version="1.0"?>
<!DOCTYPE fontconfig SYSTEM "fonts.dtd">
<fontconfig>
<!-- Reject Type 1 fonts -->
<selectfont>
<rejectfont>
<pattern>
<patelt name="fontformat"><string>Type 1</string></patelt>
</pattern>
</rejectfont>
</selectfont>
</fontconfig>
'';
# fontconfig configuration package
confPkg = pkgs.runCommand "fontconfig-conf" { preferLocalBuild = true; } ''
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support_folder=$out/etc/fonts
latest_folder=$out/etc/fonts/${latestVersion}
mkdir -p $support_folder/conf.d
mkdir -p $latest_folder/conf.d
# fonts.conf
ln -s ${supportFontsConf} $support_folder/fonts.conf
ln -s ${latestPkg.out}/etc/fonts/fonts.conf \
$latest_folder/fonts.conf
# fontconfig default config files
ln -s ${supportPkg.out}/etc/fonts/conf.d/*.conf \
$support_folder/conf.d/
ln -s ${latestPkg.out}/etc/fonts/conf.d/*.conf \
$latest_folder/conf.d/
# update latest 51-local.conf path to look at the latest local.conf
rm $latest_folder/conf.d/51-local.conf
substitute ${latestPkg.out}/etc/fonts/conf.d/51-local.conf \
$latest_folder/conf.d/51-local.conf \
--replace local.conf /etc/fonts/${latestVersion}/local.conf
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# 00-nixos-cache.conf
ln -s ${cacheConfSupport} \
$support_folder/conf.d/00-nixos-cache.conf
ln -s ${cacheConfLatest} $latest_folder/conf.d/00-nixos-cache.conf
# 10-nixos-rendering.conf
ln -s ${renderConf} $support_folder/conf.d/10-nixos-rendering.conf
ln -s ${renderConf} $latest_folder/conf.d/10-nixos-rendering.conf
# 50-user.conf
${optionalString (! cfg.includeUserConf) ''
rm $support_folder/conf.d/50-user.conf
rm $latest_folder/conf.d/50-user.conf
''}
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# local.conf (indirect priority 51)
${optionalString (cfg.localConf != "") ''
ln -s ${localConf} $support_folder/local.conf
ln -s ${localConf} $latest_folder/local.conf
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''}
# 52-nixos-default-fonts.conf
ln -s ${defaultFontsConf} $support_folder/conf.d/52-nixos-default-fonts.conf
ln -s ${defaultFontsConf} $latest_folder/conf.d/52-nixos-default-fonts.conf
# 53-nixos-bitmaps.conf
ln -s ${rejectBitmaps} $support_folder/conf.d/53-nixos-bitmaps.conf
ln -s ${rejectBitmaps} $latest_folder/conf.d/53-nixos-bitmaps.conf
${optionalString (! cfg.allowType1) ''
# 53-nixos-reject-type1.conf
ln -s ${rejectType1} $support_folder/conf.d/53-nixos-reject-type1.conf
ln -s ${rejectType1} $latest_folder/conf.d/53-nixos-reject-type1.conf
''}
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'';
# Package with configuration files
# this merge all the packages in the fonts.fontconfig.confPackages list
fontconfigEtc = pkgs.buildEnv {
name = "fontconfig-etc";
paths = cfg.confPackages;
ignoreCollisions = true;
};
in
{
options = {
fonts = {
Rewrite Fontconfig NixOS module Details: * The option `fonts.enableFontConfig` has (finally) been renamed `fonts.fontconfig.enable`. * Configurations are loaded in this order: first the Fontconfig-upstream configuration is loaded, then the NixOS-specific font directories are set, the system-wide default configuration is loaded, and finally the user configuration is loaded (if enabled). * The NixOS options `fonts.fontconfig.defaultFonts.monospace`, `fonts.fontconfig.defaultFonts.sansSerif` and `fonts.fontconfig.defaultFonts.serif` are added to allow setting the default system-wide font used for these generic faces. The defaults are the appropriate faces from the DejaVu collection because of their comprehensive Unicode coverage, clean rendering, and excellent legibility. * The NixOS option `fonts.fontconfig.antialias` can be used to disable antialiasing (it is enabled by default). * The options `fonts.fontconfig.subpixel.rgba` and `fonts.fontconfig.subpixel.lcdfilter` control the system-wide default settings for subpixel order and LCD filtering algorithm, respectively. * `fonts.fontconfig.hinting.enable` can be used to disable TrueType font hinting (it is enabled by default). `fonts.fontconfig.hinting.autohint` controls the FreeType autohinter. `fonts.fontconfig.hinting.style` controls the hint style; it is "full" by default. * User configurations can be disabled system-wide by setting `fonts.fontconfig.includeUserConf = false`. They are enabled by default so users can set Fontconfig options in the desktop environment of their choice.
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fontconfig = {
enable = mkOption {
type = types.bool;
default = true;
description = ''
If enabled, a Fontconfig configuration file will be built
pointing to a set of default fonts. If you don't care about
running X11 applications or any other program that uses
Fontconfig, you can turn this option off and prevent a
dependency on all those fonts.
'';
};
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confPackages = mkOption {
internal = true;
type = with types; listOf path;
default = [ ];
description = ''
Fontconfig configuration packages.
'';
};
Rewrite Fontconfig NixOS module Details: * The option `fonts.enableFontConfig` has (finally) been renamed `fonts.fontconfig.enable`. * Configurations are loaded in this order: first the Fontconfig-upstream configuration is loaded, then the NixOS-specific font directories are set, the system-wide default configuration is loaded, and finally the user configuration is loaded (if enabled). * The NixOS options `fonts.fontconfig.defaultFonts.monospace`, `fonts.fontconfig.defaultFonts.sansSerif` and `fonts.fontconfig.defaultFonts.serif` are added to allow setting the default system-wide font used for these generic faces. The defaults are the appropriate faces from the DejaVu collection because of their comprehensive Unicode coverage, clean rendering, and excellent legibility. * The NixOS option `fonts.fontconfig.antialias` can be used to disable antialiasing (it is enabled by default). * The options `fonts.fontconfig.subpixel.rgba` and `fonts.fontconfig.subpixel.lcdfilter` control the system-wide default settings for subpixel order and LCD filtering algorithm, respectively. * `fonts.fontconfig.hinting.enable` can be used to disable TrueType font hinting (it is enabled by default). `fonts.fontconfig.hinting.autohint` controls the FreeType autohinter. `fonts.fontconfig.hinting.style` controls the hint style; it is "full" by default. * User configurations can be disabled system-wide by setting `fonts.fontconfig.includeUserConf = false`. They are enabled by default so users can set Fontconfig options in the desktop environment of their choice.
2014-11-30 19:36:49 +00:00
antialias = mkOption {
type = types.bool;
default = true;
freetype: 2.6.5 -> 2.7.1 The Infinality bytecode interpreter is removed in favor of the new v40 TrueType interpreter. In the past, the Infinality interpreter provided support for ClearType-style hinting instructions while the default interpreter (then v35) provided support only for original TrueType-style instructions. The v40 interpreter corrects this deficiency, so the Infinality interpreter is no longer necessary. To understand why the Infinality interpreter is no longer necessary, we should understand how ClearType differs from TrueType and how the v40 interpreter works. The following is a summary of information available on the FreeType website [1] mixed with my own editorializing. TrueType instructions use horizontal and vertical hints to improve glyph rendering. Before TrueType, fonts were only vertically hinted; horizontal hints improved rendering by snapping stems to pixel boundaries. Horizontal hinting is a risk because it can significantly distort glyph shapes and kerning. Extensive testing at different resolutions is needed to perfect the TrueType hints. Microsoft invested significant effort to do this with its "Core fonts for the Web" project, but few other typefaces have seen this level of attention. With the advent of subpixel rendering, the effective horizontal resolution of most displays increased significantly. ClearType eschews horizontal hinting in favor of horizontal supersampling. Most fonts are designed for the Microsoft bytecode interpreter, which implements a compatibility mode with TrueType-style (horizontal and vertical) instructions. However, applying the full horizontal hints to subpixel-rendered fonts leads to color fringes and inconsistent stem widths. The Infinality interpreter implements several techniques to mitigate these problems, going so far as to embed font- and glyph-specific hacks in the interpreter. On the other hand, the v40 interpreter ignores the horizontal hinting instructions so that glyphs render as they are intended to on the Microsoft interpreter. Without the horizontal hints, the problems of glyph and kerning distortion, color fringes, and inconsistent stem widths--the problems the Infinality interpreter was created to solve--simply don't occur in the first place. There are also security concerns which motivate removing the Infinality patches. Although there is an updated version of the Infinality interpreter for FreeType 2.7, the lack of a consistent upstream maintainer is a security concern. The interpreter is a Turing-complete virtual machine which has had security vulnerabilities in the past. While the default interpreter is used in billions of devices and is maintained by an active developer, the Infinality interpreter is neither scrutinized nor maintained. We will probably never know if there are defects in the Infinality interpreter, and if they were discovered they would likely never be fixed. I do not think that is an acceptable situtation for a core library like FreeType. Dropping the Infinality patches means that font rendering will be less customizable. I think this is an acceptable trade-off. The Infinality interpreter made many compromises to mitigate the problems with horizontal hinting; the main purpose of customization is to tailor these compromises to the user's preferences. The new interpreter does not have to make these compromises because it renders fonts as their designers intended, so this level of customization is not necessary. The Infinality-associated patches are also removed from cairo. These patches only set the default rendering options in case they aren't set though Fontconfig. On NixOS, the rendering options are always set in Fontconfig, so these patches never actually did anything for us! The Fontconfig test suite is patched to account for a quirk in the way PCF fonts are named. The fontconfig option `hintstyle` is no longer configurable in NixOS. This option selects the TrueType interpreter; the v40 interpreter is `hintslight` and the older v35 interpreter is `hintmedium` or `hintfull` (which have actually always been the same thing). The setting may still be changed through the `localConf` option or by creating a user Fontconfig file. Users with HiDPI displays should probably disable hinting and antialiasing: at best they have no visible effect. The fontconfig-ultimate settings are still available in NixOS, but they are no longer the default. They still work, but their main purpose is to set rendering quirks which are no longer necessary and may actually be detrimental (e.g. setting `hintfull` for some fonts). Also, the vast array of font substitutions provided is not an appropriate default; the default setting should be to give the user the font they asked for. [1]. https://www.freetype.org/freetype2/docs/subpixel-hinting.html
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description = ''
Enable font antialiasing. At high resolution (> 200 DPI),
antialiasing has no visible effect; users of such displays may want
to disable this option.
'';
Rewrite Fontconfig NixOS module Details: * The option `fonts.enableFontConfig` has (finally) been renamed `fonts.fontconfig.enable`. * Configurations are loaded in this order: first the Fontconfig-upstream configuration is loaded, then the NixOS-specific font directories are set, the system-wide default configuration is loaded, and finally the user configuration is loaded (if enabled). * The NixOS options `fonts.fontconfig.defaultFonts.monospace`, `fonts.fontconfig.defaultFonts.sansSerif` and `fonts.fontconfig.defaultFonts.serif` are added to allow setting the default system-wide font used for these generic faces. The defaults are the appropriate faces from the DejaVu collection because of their comprehensive Unicode coverage, clean rendering, and excellent legibility. * The NixOS option `fonts.fontconfig.antialias` can be used to disable antialiasing (it is enabled by default). * The options `fonts.fontconfig.subpixel.rgba` and `fonts.fontconfig.subpixel.lcdfilter` control the system-wide default settings for subpixel order and LCD filtering algorithm, respectively. * `fonts.fontconfig.hinting.enable` can be used to disable TrueType font hinting (it is enabled by default). `fonts.fontconfig.hinting.autohint` controls the FreeType autohinter. `fonts.fontconfig.hinting.style` controls the hint style; it is "full" by default. * User configurations can be disabled system-wide by setting `fonts.fontconfig.includeUserConf = false`. They are enabled by default so users can set Fontconfig options in the desktop environment of their choice.
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};
dpi = mkOption {
type = types.int;
default = 0;
description = ''
Force DPI setting. Setting to <literal>0</literal> disables DPI
forcing; the DPI detected for the display will be used.
'';
};
localConf = mkOption {
type = types.lines;
default = "";
description = ''
freetype: 2.6.5 -> 2.7.1 The Infinality bytecode interpreter is removed in favor of the new v40 TrueType interpreter. In the past, the Infinality interpreter provided support for ClearType-style hinting instructions while the default interpreter (then v35) provided support only for original TrueType-style instructions. The v40 interpreter corrects this deficiency, so the Infinality interpreter is no longer necessary. To understand why the Infinality interpreter is no longer necessary, we should understand how ClearType differs from TrueType and how the v40 interpreter works. The following is a summary of information available on the FreeType website [1] mixed with my own editorializing. TrueType instructions use horizontal and vertical hints to improve glyph rendering. Before TrueType, fonts were only vertically hinted; horizontal hints improved rendering by snapping stems to pixel boundaries. Horizontal hinting is a risk because it can significantly distort glyph shapes and kerning. Extensive testing at different resolutions is needed to perfect the TrueType hints. Microsoft invested significant effort to do this with its "Core fonts for the Web" project, but few other typefaces have seen this level of attention. With the advent of subpixel rendering, the effective horizontal resolution of most displays increased significantly. ClearType eschews horizontal hinting in favor of horizontal supersampling. Most fonts are designed for the Microsoft bytecode interpreter, which implements a compatibility mode with TrueType-style (horizontal and vertical) instructions. However, applying the full horizontal hints to subpixel-rendered fonts leads to color fringes and inconsistent stem widths. The Infinality interpreter implements several techniques to mitigate these problems, going so far as to embed font- and glyph-specific hacks in the interpreter. On the other hand, the v40 interpreter ignores the horizontal hinting instructions so that glyphs render as they are intended to on the Microsoft interpreter. Without the horizontal hints, the problems of glyph and kerning distortion, color fringes, and inconsistent stem widths--the problems the Infinality interpreter was created to solve--simply don't occur in the first place. There are also security concerns which motivate removing the Infinality patches. Although there is an updated version of the Infinality interpreter for FreeType 2.7, the lack of a consistent upstream maintainer is a security concern. The interpreter is a Turing-complete virtual machine which has had security vulnerabilities in the past. While the default interpreter is used in billions of devices and is maintained by an active developer, the Infinality interpreter is neither scrutinized nor maintained. We will probably never know if there are defects in the Infinality interpreter, and if they were discovered they would likely never be fixed. I do not think that is an acceptable situtation for a core library like FreeType. Dropping the Infinality patches means that font rendering will be less customizable. I think this is an acceptable trade-off. The Infinality interpreter made many compromises to mitigate the problems with horizontal hinting; the main purpose of customization is to tailor these compromises to the user's preferences. The new interpreter does not have to make these compromises because it renders fonts as their designers intended, so this level of customization is not necessary. The Infinality-associated patches are also removed from cairo. These patches only set the default rendering options in case they aren't set though Fontconfig. On NixOS, the rendering options are always set in Fontconfig, so these patches never actually did anything for us! The Fontconfig test suite is patched to account for a quirk in the way PCF fonts are named. The fontconfig option `hintstyle` is no longer configurable in NixOS. This option selects the TrueType interpreter; the v40 interpreter is `hintslight` and the older v35 interpreter is `hintmedium` or `hintfull` (which have actually always been the same thing). The setting may still be changed through the `localConf` option or by creating a user Fontconfig file. Users with HiDPI displays should probably disable hinting and antialiasing: at best they have no visible effect. The fontconfig-ultimate settings are still available in NixOS, but they are no longer the default. They still work, but their main purpose is to set rendering quirks which are no longer necessary and may actually be detrimental (e.g. setting `hintfull` for some fonts). Also, the vast array of font substitutions provided is not an appropriate default; the default setting should be to give the user the font they asked for. [1]. https://www.freetype.org/freetype2/docs/subpixel-hinting.html
2017-03-05 23:39:38 +00:00
System-wide customization file contents, has higher priority than
<literal>defaultFonts</literal> settings.
'';
};
Rewrite Fontconfig NixOS module Details: * The option `fonts.enableFontConfig` has (finally) been renamed `fonts.fontconfig.enable`. * Configurations are loaded in this order: first the Fontconfig-upstream configuration is loaded, then the NixOS-specific font directories are set, the system-wide default configuration is loaded, and finally the user configuration is loaded (if enabled). * The NixOS options `fonts.fontconfig.defaultFonts.monospace`, `fonts.fontconfig.defaultFonts.sansSerif` and `fonts.fontconfig.defaultFonts.serif` are added to allow setting the default system-wide font used for these generic faces. The defaults are the appropriate faces from the DejaVu collection because of their comprehensive Unicode coverage, clean rendering, and excellent legibility. * The NixOS option `fonts.fontconfig.antialias` can be used to disable antialiasing (it is enabled by default). * The options `fonts.fontconfig.subpixel.rgba` and `fonts.fontconfig.subpixel.lcdfilter` control the system-wide default settings for subpixel order and LCD filtering algorithm, respectively. * `fonts.fontconfig.hinting.enable` can be used to disable TrueType font hinting (it is enabled by default). `fonts.fontconfig.hinting.autohint` controls the FreeType autohinter. `fonts.fontconfig.hinting.style` controls the hint style; it is "full" by default. * User configurations can be disabled system-wide by setting `fonts.fontconfig.includeUserConf = false`. They are enabled by default so users can set Fontconfig options in the desktop environment of their choice.
2014-11-30 19:36:49 +00:00
defaultFonts = {
monospace = mkOption {
type = types.listOf types.str;
default = ["DejaVu Sans Mono"];
Rewrite Fontconfig NixOS module Details: * The option `fonts.enableFontConfig` has (finally) been renamed `fonts.fontconfig.enable`. * Configurations are loaded in this order: first the Fontconfig-upstream configuration is loaded, then the NixOS-specific font directories are set, the system-wide default configuration is loaded, and finally the user configuration is loaded (if enabled). * The NixOS options `fonts.fontconfig.defaultFonts.monospace`, `fonts.fontconfig.defaultFonts.sansSerif` and `fonts.fontconfig.defaultFonts.serif` are added to allow setting the default system-wide font used for these generic faces. The defaults are the appropriate faces from the DejaVu collection because of their comprehensive Unicode coverage, clean rendering, and excellent legibility. * The NixOS option `fonts.fontconfig.antialias` can be used to disable antialiasing (it is enabled by default). * The options `fonts.fontconfig.subpixel.rgba` and `fonts.fontconfig.subpixel.lcdfilter` control the system-wide default settings for subpixel order and LCD filtering algorithm, respectively. * `fonts.fontconfig.hinting.enable` can be used to disable TrueType font hinting (it is enabled by default). `fonts.fontconfig.hinting.autohint` controls the FreeType autohinter. `fonts.fontconfig.hinting.style` controls the hint style; it is "full" by default. * User configurations can be disabled system-wide by setting `fonts.fontconfig.includeUserConf = false`. They are enabled by default so users can set Fontconfig options in the desktop environment of their choice.
2014-11-30 19:36:49 +00:00
description = ''
System-wide default monospace font(s). Multiple fonts may be
listed in case multiple languages must be supported.
Rewrite Fontconfig NixOS module Details: * The option `fonts.enableFontConfig` has (finally) been renamed `fonts.fontconfig.enable`. * Configurations are loaded in this order: first the Fontconfig-upstream configuration is loaded, then the NixOS-specific font directories are set, the system-wide default configuration is loaded, and finally the user configuration is loaded (if enabled). * The NixOS options `fonts.fontconfig.defaultFonts.monospace`, `fonts.fontconfig.defaultFonts.sansSerif` and `fonts.fontconfig.defaultFonts.serif` are added to allow setting the default system-wide font used for these generic faces. The defaults are the appropriate faces from the DejaVu collection because of their comprehensive Unicode coverage, clean rendering, and excellent legibility. * The NixOS option `fonts.fontconfig.antialias` can be used to disable antialiasing (it is enabled by default). * The options `fonts.fontconfig.subpixel.rgba` and `fonts.fontconfig.subpixel.lcdfilter` control the system-wide default settings for subpixel order and LCD filtering algorithm, respectively. * `fonts.fontconfig.hinting.enable` can be used to disable TrueType font hinting (it is enabled by default). `fonts.fontconfig.hinting.autohint` controls the FreeType autohinter. `fonts.fontconfig.hinting.style` controls the hint style; it is "full" by default. * User configurations can be disabled system-wide by setting `fonts.fontconfig.includeUserConf = false`. They are enabled by default so users can set Fontconfig options in the desktop environment of their choice.
2014-11-30 19:36:49 +00:00
'';
};
sansSerif = mkOption {
type = types.listOf types.str;
default = ["DejaVu Sans"];
Rewrite Fontconfig NixOS module Details: * The option `fonts.enableFontConfig` has (finally) been renamed `fonts.fontconfig.enable`. * Configurations are loaded in this order: first the Fontconfig-upstream configuration is loaded, then the NixOS-specific font directories are set, the system-wide default configuration is loaded, and finally the user configuration is loaded (if enabled). * The NixOS options `fonts.fontconfig.defaultFonts.monospace`, `fonts.fontconfig.defaultFonts.sansSerif` and `fonts.fontconfig.defaultFonts.serif` are added to allow setting the default system-wide font used for these generic faces. The defaults are the appropriate faces from the DejaVu collection because of their comprehensive Unicode coverage, clean rendering, and excellent legibility. * The NixOS option `fonts.fontconfig.antialias` can be used to disable antialiasing (it is enabled by default). * The options `fonts.fontconfig.subpixel.rgba` and `fonts.fontconfig.subpixel.lcdfilter` control the system-wide default settings for subpixel order and LCD filtering algorithm, respectively. * `fonts.fontconfig.hinting.enable` can be used to disable TrueType font hinting (it is enabled by default). `fonts.fontconfig.hinting.autohint` controls the FreeType autohinter. `fonts.fontconfig.hinting.style` controls the hint style; it is "full" by default. * User configurations can be disabled system-wide by setting `fonts.fontconfig.includeUserConf = false`. They are enabled by default so users can set Fontconfig options in the desktop environment of their choice.
2014-11-30 19:36:49 +00:00
description = ''
System-wide default sans serif font(s). Multiple fonts may be
listed in case multiple languages must be supported.
Rewrite Fontconfig NixOS module Details: * The option `fonts.enableFontConfig` has (finally) been renamed `fonts.fontconfig.enable`. * Configurations are loaded in this order: first the Fontconfig-upstream configuration is loaded, then the NixOS-specific font directories are set, the system-wide default configuration is loaded, and finally the user configuration is loaded (if enabled). * The NixOS options `fonts.fontconfig.defaultFonts.monospace`, `fonts.fontconfig.defaultFonts.sansSerif` and `fonts.fontconfig.defaultFonts.serif` are added to allow setting the default system-wide font used for these generic faces. The defaults are the appropriate faces from the DejaVu collection because of their comprehensive Unicode coverage, clean rendering, and excellent legibility. * The NixOS option `fonts.fontconfig.antialias` can be used to disable antialiasing (it is enabled by default). * The options `fonts.fontconfig.subpixel.rgba` and `fonts.fontconfig.subpixel.lcdfilter` control the system-wide default settings for subpixel order and LCD filtering algorithm, respectively. * `fonts.fontconfig.hinting.enable` can be used to disable TrueType font hinting (it is enabled by default). `fonts.fontconfig.hinting.autohint` controls the FreeType autohinter. `fonts.fontconfig.hinting.style` controls the hint style; it is "full" by default. * User configurations can be disabled system-wide by setting `fonts.fontconfig.includeUserConf = false`. They are enabled by default so users can set Fontconfig options in the desktop environment of their choice.
2014-11-30 19:36:49 +00:00
'';
};
serif = mkOption {
type = types.listOf types.str;
default = ["DejaVu Serif"];
Rewrite Fontconfig NixOS module Details: * The option `fonts.enableFontConfig` has (finally) been renamed `fonts.fontconfig.enable`. * Configurations are loaded in this order: first the Fontconfig-upstream configuration is loaded, then the NixOS-specific font directories are set, the system-wide default configuration is loaded, and finally the user configuration is loaded (if enabled). * The NixOS options `fonts.fontconfig.defaultFonts.monospace`, `fonts.fontconfig.defaultFonts.sansSerif` and `fonts.fontconfig.defaultFonts.serif` are added to allow setting the default system-wide font used for these generic faces. The defaults are the appropriate faces from the DejaVu collection because of their comprehensive Unicode coverage, clean rendering, and excellent legibility. * The NixOS option `fonts.fontconfig.antialias` can be used to disable antialiasing (it is enabled by default). * The options `fonts.fontconfig.subpixel.rgba` and `fonts.fontconfig.subpixel.lcdfilter` control the system-wide default settings for subpixel order and LCD filtering algorithm, respectively. * `fonts.fontconfig.hinting.enable` can be used to disable TrueType font hinting (it is enabled by default). `fonts.fontconfig.hinting.autohint` controls the FreeType autohinter. `fonts.fontconfig.hinting.style` controls the hint style; it is "full" by default. * User configurations can be disabled system-wide by setting `fonts.fontconfig.includeUserConf = false`. They are enabled by default so users can set Fontconfig options in the desktop environment of their choice.
2014-11-30 19:36:49 +00:00
description = ''
System-wide default serif font(s). Multiple fonts may be listed
in case multiple languages must be supported.
Rewrite Fontconfig NixOS module Details: * The option `fonts.enableFontConfig` has (finally) been renamed `fonts.fontconfig.enable`. * Configurations are loaded in this order: first the Fontconfig-upstream configuration is loaded, then the NixOS-specific font directories are set, the system-wide default configuration is loaded, and finally the user configuration is loaded (if enabled). * The NixOS options `fonts.fontconfig.defaultFonts.monospace`, `fonts.fontconfig.defaultFonts.sansSerif` and `fonts.fontconfig.defaultFonts.serif` are added to allow setting the default system-wide font used for these generic faces. The defaults are the appropriate faces from the DejaVu collection because of their comprehensive Unicode coverage, clean rendering, and excellent legibility. * The NixOS option `fonts.fontconfig.antialias` can be used to disable antialiasing (it is enabled by default). * The options `fonts.fontconfig.subpixel.rgba` and `fonts.fontconfig.subpixel.lcdfilter` control the system-wide default settings for subpixel order and LCD filtering algorithm, respectively. * `fonts.fontconfig.hinting.enable` can be used to disable TrueType font hinting (it is enabled by default). `fonts.fontconfig.hinting.autohint` controls the FreeType autohinter. `fonts.fontconfig.hinting.style` controls the hint style; it is "full" by default. * User configurations can be disabled system-wide by setting `fonts.fontconfig.includeUserConf = false`. They are enabled by default so users can set Fontconfig options in the desktop environment of their choice.
2014-11-30 19:36:49 +00:00
'';
};
};
hinting = {
enable = mkOption {
type = types.bool;
default = true;
freetype: 2.6.5 -> 2.7.1 The Infinality bytecode interpreter is removed in favor of the new v40 TrueType interpreter. In the past, the Infinality interpreter provided support for ClearType-style hinting instructions while the default interpreter (then v35) provided support only for original TrueType-style instructions. The v40 interpreter corrects this deficiency, so the Infinality interpreter is no longer necessary. To understand why the Infinality interpreter is no longer necessary, we should understand how ClearType differs from TrueType and how the v40 interpreter works. The following is a summary of information available on the FreeType website [1] mixed with my own editorializing. TrueType instructions use horizontal and vertical hints to improve glyph rendering. Before TrueType, fonts were only vertically hinted; horizontal hints improved rendering by snapping stems to pixel boundaries. Horizontal hinting is a risk because it can significantly distort glyph shapes and kerning. Extensive testing at different resolutions is needed to perfect the TrueType hints. Microsoft invested significant effort to do this with its "Core fonts for the Web" project, but few other typefaces have seen this level of attention. With the advent of subpixel rendering, the effective horizontal resolution of most displays increased significantly. ClearType eschews horizontal hinting in favor of horizontal supersampling. Most fonts are designed for the Microsoft bytecode interpreter, which implements a compatibility mode with TrueType-style (horizontal and vertical) instructions. However, applying the full horizontal hints to subpixel-rendered fonts leads to color fringes and inconsistent stem widths. The Infinality interpreter implements several techniques to mitigate these problems, going so far as to embed font- and glyph-specific hacks in the interpreter. On the other hand, the v40 interpreter ignores the horizontal hinting instructions so that glyphs render as they are intended to on the Microsoft interpreter. Without the horizontal hints, the problems of glyph and kerning distortion, color fringes, and inconsistent stem widths--the problems the Infinality interpreter was created to solve--simply don't occur in the first place. There are also security concerns which motivate removing the Infinality patches. Although there is an updated version of the Infinality interpreter for FreeType 2.7, the lack of a consistent upstream maintainer is a security concern. The interpreter is a Turing-complete virtual machine which has had security vulnerabilities in the past. While the default interpreter is used in billions of devices and is maintained by an active developer, the Infinality interpreter is neither scrutinized nor maintained. We will probably never know if there are defects in the Infinality interpreter, and if they were discovered they would likely never be fixed. I do not think that is an acceptable situtation for a core library like FreeType. Dropping the Infinality patches means that font rendering will be less customizable. I think this is an acceptable trade-off. The Infinality interpreter made many compromises to mitigate the problems with horizontal hinting; the main purpose of customization is to tailor these compromises to the user's preferences. The new interpreter does not have to make these compromises because it renders fonts as their designers intended, so this level of customization is not necessary. The Infinality-associated patches are also removed from cairo. These patches only set the default rendering options in case they aren't set though Fontconfig. On NixOS, the rendering options are always set in Fontconfig, so these patches never actually did anything for us! The Fontconfig test suite is patched to account for a quirk in the way PCF fonts are named. The fontconfig option `hintstyle` is no longer configurable in NixOS. This option selects the TrueType interpreter; the v40 interpreter is `hintslight` and the older v35 interpreter is `hintmedium` or `hintfull` (which have actually always been the same thing). The setting may still be changed through the `localConf` option or by creating a user Fontconfig file. Users with HiDPI displays should probably disable hinting and antialiasing: at best they have no visible effect. The fontconfig-ultimate settings are still available in NixOS, but they are no longer the default. They still work, but their main purpose is to set rendering quirks which are no longer necessary and may actually be detrimental (e.g. setting `hintfull` for some fonts). Also, the vast array of font substitutions provided is not an appropriate default; the default setting should be to give the user the font they asked for. [1]. https://www.freetype.org/freetype2/docs/subpixel-hinting.html
2017-03-05 23:39:38 +00:00
description = ''
Enable font hinting. Hinting aligns glyphs to pixel boundaries to
improve rendering sharpness at low resolution. At high resolution
(> 200 dpi) hinting will do nothing (at best); users of such
displays may want to disable this option.
'';
Rewrite Fontconfig NixOS module Details: * The option `fonts.enableFontConfig` has (finally) been renamed `fonts.fontconfig.enable`. * Configurations are loaded in this order: first the Fontconfig-upstream configuration is loaded, then the NixOS-specific font directories are set, the system-wide default configuration is loaded, and finally the user configuration is loaded (if enabled). * The NixOS options `fonts.fontconfig.defaultFonts.monospace`, `fonts.fontconfig.defaultFonts.sansSerif` and `fonts.fontconfig.defaultFonts.serif` are added to allow setting the default system-wide font used for these generic faces. The defaults are the appropriate faces from the DejaVu collection because of their comprehensive Unicode coverage, clean rendering, and excellent legibility. * The NixOS option `fonts.fontconfig.antialias` can be used to disable antialiasing (it is enabled by default). * The options `fonts.fontconfig.subpixel.rgba` and `fonts.fontconfig.subpixel.lcdfilter` control the system-wide default settings for subpixel order and LCD filtering algorithm, respectively. * `fonts.fontconfig.hinting.enable` can be used to disable TrueType font hinting (it is enabled by default). `fonts.fontconfig.hinting.autohint` controls the FreeType autohinter. `fonts.fontconfig.hinting.style` controls the hint style; it is "full" by default. * User configurations can be disabled system-wide by setting `fonts.fontconfig.includeUserConf = false`. They are enabled by default so users can set Fontconfig options in the desktop environment of their choice.
2014-11-30 19:36:49 +00:00
};
autohint = mkOption {
type = types.bool;
default = false;
Rewrite Fontconfig NixOS module Details: * The option `fonts.enableFontConfig` has (finally) been renamed `fonts.fontconfig.enable`. * Configurations are loaded in this order: first the Fontconfig-upstream configuration is loaded, then the NixOS-specific font directories are set, the system-wide default configuration is loaded, and finally the user configuration is loaded (if enabled). * The NixOS options `fonts.fontconfig.defaultFonts.monospace`, `fonts.fontconfig.defaultFonts.sansSerif` and `fonts.fontconfig.defaultFonts.serif` are added to allow setting the default system-wide font used for these generic faces. The defaults are the appropriate faces from the DejaVu collection because of their comprehensive Unicode coverage, clean rendering, and excellent legibility. * The NixOS option `fonts.fontconfig.antialias` can be used to disable antialiasing (it is enabled by default). * The options `fonts.fontconfig.subpixel.rgba` and `fonts.fontconfig.subpixel.lcdfilter` control the system-wide default settings for subpixel order and LCD filtering algorithm, respectively. * `fonts.fontconfig.hinting.enable` can be used to disable TrueType font hinting (it is enabled by default). `fonts.fontconfig.hinting.autohint` controls the FreeType autohinter. `fonts.fontconfig.hinting.style` controls the hint style; it is "full" by default. * User configurations can be disabled system-wide by setting `fonts.fontconfig.includeUserConf = false`. They are enabled by default so users can set Fontconfig options in the desktop environment of their choice.
2014-11-30 19:36:49 +00:00
description = ''
Enable the autohinter in place of the default interpreter.
The results are usually lower quality than correctly-hinted
fonts, but better than unhinted fonts.
Rewrite Fontconfig NixOS module Details: * The option `fonts.enableFontConfig` has (finally) been renamed `fonts.fontconfig.enable`. * Configurations are loaded in this order: first the Fontconfig-upstream configuration is loaded, then the NixOS-specific font directories are set, the system-wide default configuration is loaded, and finally the user configuration is loaded (if enabled). * The NixOS options `fonts.fontconfig.defaultFonts.monospace`, `fonts.fontconfig.defaultFonts.sansSerif` and `fonts.fontconfig.defaultFonts.serif` are added to allow setting the default system-wide font used for these generic faces. The defaults are the appropriate faces from the DejaVu collection because of their comprehensive Unicode coverage, clean rendering, and excellent legibility. * The NixOS option `fonts.fontconfig.antialias` can be used to disable antialiasing (it is enabled by default). * The options `fonts.fontconfig.subpixel.rgba` and `fonts.fontconfig.subpixel.lcdfilter` control the system-wide default settings for subpixel order and LCD filtering algorithm, respectively. * `fonts.fontconfig.hinting.enable` can be used to disable TrueType font hinting (it is enabled by default). `fonts.fontconfig.hinting.autohint` controls the FreeType autohinter. `fonts.fontconfig.hinting.style` controls the hint style; it is "full" by default. * User configurations can be disabled system-wide by setting `fonts.fontconfig.includeUserConf = false`. They are enabled by default so users can set Fontconfig options in the desktop environment of their choice.
2014-11-30 19:36:49 +00:00
'';
};
};
includeUserConf = mkOption {
type = types.bool;
default = true;
description = ''
Include the user configuration from
<filename>~/.config/fontconfig/fonts.conf</filename> or
<filename>~/.config/fontconfig/conf.d</filename>.
'';
};
subpixel = {
rgba = mkOption {
default = "rgb";
2015-08-17 18:52:45 +01:00
type = types.enum ["rgb" "bgr" "vrgb" "vbgr" "none"];
Rewrite Fontconfig NixOS module Details: * The option `fonts.enableFontConfig` has (finally) been renamed `fonts.fontconfig.enable`. * Configurations are loaded in this order: first the Fontconfig-upstream configuration is loaded, then the NixOS-specific font directories are set, the system-wide default configuration is loaded, and finally the user configuration is loaded (if enabled). * The NixOS options `fonts.fontconfig.defaultFonts.monospace`, `fonts.fontconfig.defaultFonts.sansSerif` and `fonts.fontconfig.defaultFonts.serif` are added to allow setting the default system-wide font used for these generic faces. The defaults are the appropriate faces from the DejaVu collection because of their comprehensive Unicode coverage, clean rendering, and excellent legibility. * The NixOS option `fonts.fontconfig.antialias` can be used to disable antialiasing (it is enabled by default). * The options `fonts.fontconfig.subpixel.rgba` and `fonts.fontconfig.subpixel.lcdfilter` control the system-wide default settings for subpixel order and LCD filtering algorithm, respectively. * `fonts.fontconfig.hinting.enable` can be used to disable TrueType font hinting (it is enabled by default). `fonts.fontconfig.hinting.autohint` controls the FreeType autohinter. `fonts.fontconfig.hinting.style` controls the hint style; it is "full" by default. * User configurations can be disabled system-wide by setting `fonts.fontconfig.includeUserConf = false`. They are enabled by default so users can set Fontconfig options in the desktop environment of their choice.
2014-11-30 19:36:49 +00:00
description = ''
freetype: 2.6.5 -> 2.7.1 The Infinality bytecode interpreter is removed in favor of the new v40 TrueType interpreter. In the past, the Infinality interpreter provided support for ClearType-style hinting instructions while the default interpreter (then v35) provided support only for original TrueType-style instructions. The v40 interpreter corrects this deficiency, so the Infinality interpreter is no longer necessary. To understand why the Infinality interpreter is no longer necessary, we should understand how ClearType differs from TrueType and how the v40 interpreter works. The following is a summary of information available on the FreeType website [1] mixed with my own editorializing. TrueType instructions use horizontal and vertical hints to improve glyph rendering. Before TrueType, fonts were only vertically hinted; horizontal hints improved rendering by snapping stems to pixel boundaries. Horizontal hinting is a risk because it can significantly distort glyph shapes and kerning. Extensive testing at different resolutions is needed to perfect the TrueType hints. Microsoft invested significant effort to do this with its "Core fonts for the Web" project, but few other typefaces have seen this level of attention. With the advent of subpixel rendering, the effective horizontal resolution of most displays increased significantly. ClearType eschews horizontal hinting in favor of horizontal supersampling. Most fonts are designed for the Microsoft bytecode interpreter, which implements a compatibility mode with TrueType-style (horizontal and vertical) instructions. However, applying the full horizontal hints to subpixel-rendered fonts leads to color fringes and inconsistent stem widths. The Infinality interpreter implements several techniques to mitigate these problems, going so far as to embed font- and glyph-specific hacks in the interpreter. On the other hand, the v40 interpreter ignores the horizontal hinting instructions so that glyphs render as they are intended to on the Microsoft interpreter. Without the horizontal hints, the problems of glyph and kerning distortion, color fringes, and inconsistent stem widths--the problems the Infinality interpreter was created to solve--simply don't occur in the first place. There are also security concerns which motivate removing the Infinality patches. Although there is an updated version of the Infinality interpreter for FreeType 2.7, the lack of a consistent upstream maintainer is a security concern. The interpreter is a Turing-complete virtual machine which has had security vulnerabilities in the past. While the default interpreter is used in billions of devices and is maintained by an active developer, the Infinality interpreter is neither scrutinized nor maintained. We will probably never know if there are defects in the Infinality interpreter, and if they were discovered they would likely never be fixed. I do not think that is an acceptable situtation for a core library like FreeType. Dropping the Infinality patches means that font rendering will be less customizable. I think this is an acceptable trade-off. The Infinality interpreter made many compromises to mitigate the problems with horizontal hinting; the main purpose of customization is to tailor these compromises to the user's preferences. The new interpreter does not have to make these compromises because it renders fonts as their designers intended, so this level of customization is not necessary. The Infinality-associated patches are also removed from cairo. These patches only set the default rendering options in case they aren't set though Fontconfig. On NixOS, the rendering options are always set in Fontconfig, so these patches never actually did anything for us! The Fontconfig test suite is patched to account for a quirk in the way PCF fonts are named. The fontconfig option `hintstyle` is no longer configurable in NixOS. This option selects the TrueType interpreter; the v40 interpreter is `hintslight` and the older v35 interpreter is `hintmedium` or `hintfull` (which have actually always been the same thing). The setting may still be changed through the `localConf` option or by creating a user Fontconfig file. Users with HiDPI displays should probably disable hinting and antialiasing: at best they have no visible effect. The fontconfig-ultimate settings are still available in NixOS, but they are no longer the default. They still work, but their main purpose is to set rendering quirks which are no longer necessary and may actually be detrimental (e.g. setting `hintfull` for some fonts). Also, the vast array of font substitutions provided is not an appropriate default; the default setting should be to give the user the font they asked for. [1]. https://www.freetype.org/freetype2/docs/subpixel-hinting.html
2017-03-05 23:39:38 +00:00
Subpixel order. The overwhelming majority of displays are
<literal>rgb</literal> in their normal orientation. Select
<literal>vrgb</literal> for mounting such a display 90 degrees
clockwise from its normal orientation or <literal>vbgr</literal>
for mounting 90 degrees counter-clockwise. Select
<literal>bgr</literal> in the unlikely event of mounting 180
degrees from the normal orientation. Reverse these directions in
the improbable event that the display's native subpixel order is
<literal>bgr</literal>.
Rewrite Fontconfig NixOS module Details: * The option `fonts.enableFontConfig` has (finally) been renamed `fonts.fontconfig.enable`. * Configurations are loaded in this order: first the Fontconfig-upstream configuration is loaded, then the NixOS-specific font directories are set, the system-wide default configuration is loaded, and finally the user configuration is loaded (if enabled). * The NixOS options `fonts.fontconfig.defaultFonts.monospace`, `fonts.fontconfig.defaultFonts.sansSerif` and `fonts.fontconfig.defaultFonts.serif` are added to allow setting the default system-wide font used for these generic faces. The defaults are the appropriate faces from the DejaVu collection because of their comprehensive Unicode coverage, clean rendering, and excellent legibility. * The NixOS option `fonts.fontconfig.antialias` can be used to disable antialiasing (it is enabled by default). * The options `fonts.fontconfig.subpixel.rgba` and `fonts.fontconfig.subpixel.lcdfilter` control the system-wide default settings for subpixel order and LCD filtering algorithm, respectively. * `fonts.fontconfig.hinting.enable` can be used to disable TrueType font hinting (it is enabled by default). `fonts.fontconfig.hinting.autohint` controls the FreeType autohinter. `fonts.fontconfig.hinting.style` controls the hint style; it is "full" by default. * User configurations can be disabled system-wide by setting `fonts.fontconfig.includeUserConf = false`. They are enabled by default so users can set Fontconfig options in the desktop environment of their choice.
2014-11-30 19:36:49 +00:00
'';
};
lcdfilter = mkOption {
default = "default";
2015-08-17 18:52:45 +01:00
type = types.enum ["none" "default" "light" "legacy"];
Rewrite Fontconfig NixOS module Details: * The option `fonts.enableFontConfig` has (finally) been renamed `fonts.fontconfig.enable`. * Configurations are loaded in this order: first the Fontconfig-upstream configuration is loaded, then the NixOS-specific font directories are set, the system-wide default configuration is loaded, and finally the user configuration is loaded (if enabled). * The NixOS options `fonts.fontconfig.defaultFonts.monospace`, `fonts.fontconfig.defaultFonts.sansSerif` and `fonts.fontconfig.defaultFonts.serif` are added to allow setting the default system-wide font used for these generic faces. The defaults are the appropriate faces from the DejaVu collection because of their comprehensive Unicode coverage, clean rendering, and excellent legibility. * The NixOS option `fonts.fontconfig.antialias` can be used to disable antialiasing (it is enabled by default). * The options `fonts.fontconfig.subpixel.rgba` and `fonts.fontconfig.subpixel.lcdfilter` control the system-wide default settings for subpixel order and LCD filtering algorithm, respectively. * `fonts.fontconfig.hinting.enable` can be used to disable TrueType font hinting (it is enabled by default). `fonts.fontconfig.hinting.autohint` controls the FreeType autohinter. `fonts.fontconfig.hinting.style` controls the hint style; it is "full" by default. * User configurations can be disabled system-wide by setting `fonts.fontconfig.includeUserConf = false`. They are enabled by default so users can set Fontconfig options in the desktop environment of their choice.
2014-11-30 19:36:49 +00:00
description = ''
freetype: 2.6.5 -> 2.7.1 The Infinality bytecode interpreter is removed in favor of the new v40 TrueType interpreter. In the past, the Infinality interpreter provided support for ClearType-style hinting instructions while the default interpreter (then v35) provided support only for original TrueType-style instructions. The v40 interpreter corrects this deficiency, so the Infinality interpreter is no longer necessary. To understand why the Infinality interpreter is no longer necessary, we should understand how ClearType differs from TrueType and how the v40 interpreter works. The following is a summary of information available on the FreeType website [1] mixed with my own editorializing. TrueType instructions use horizontal and vertical hints to improve glyph rendering. Before TrueType, fonts were only vertically hinted; horizontal hints improved rendering by snapping stems to pixel boundaries. Horizontal hinting is a risk because it can significantly distort glyph shapes and kerning. Extensive testing at different resolutions is needed to perfect the TrueType hints. Microsoft invested significant effort to do this with its "Core fonts for the Web" project, but few other typefaces have seen this level of attention. With the advent of subpixel rendering, the effective horizontal resolution of most displays increased significantly. ClearType eschews horizontal hinting in favor of horizontal supersampling. Most fonts are designed for the Microsoft bytecode interpreter, which implements a compatibility mode with TrueType-style (horizontal and vertical) instructions. However, applying the full horizontal hints to subpixel-rendered fonts leads to color fringes and inconsistent stem widths. The Infinality interpreter implements several techniques to mitigate these problems, going so far as to embed font- and glyph-specific hacks in the interpreter. On the other hand, the v40 interpreter ignores the horizontal hinting instructions so that glyphs render as they are intended to on the Microsoft interpreter. Without the horizontal hints, the problems of glyph and kerning distortion, color fringes, and inconsistent stem widths--the problems the Infinality interpreter was created to solve--simply don't occur in the first place. There are also security concerns which motivate removing the Infinality patches. Although there is an updated version of the Infinality interpreter for FreeType 2.7, the lack of a consistent upstream maintainer is a security concern. The interpreter is a Turing-complete virtual machine which has had security vulnerabilities in the past. While the default interpreter is used in billions of devices and is maintained by an active developer, the Infinality interpreter is neither scrutinized nor maintained. We will probably never know if there are defects in the Infinality interpreter, and if they were discovered they would likely never be fixed. I do not think that is an acceptable situtation for a core library like FreeType. Dropping the Infinality patches means that font rendering will be less customizable. I think this is an acceptable trade-off. The Infinality interpreter made many compromises to mitigate the problems with horizontal hinting; the main purpose of customization is to tailor these compromises to the user's preferences. The new interpreter does not have to make these compromises because it renders fonts as their designers intended, so this level of customization is not necessary. The Infinality-associated patches are also removed from cairo. These patches only set the default rendering options in case they aren't set though Fontconfig. On NixOS, the rendering options are always set in Fontconfig, so these patches never actually did anything for us! The Fontconfig test suite is patched to account for a quirk in the way PCF fonts are named. The fontconfig option `hintstyle` is no longer configurable in NixOS. This option selects the TrueType interpreter; the v40 interpreter is `hintslight` and the older v35 interpreter is `hintmedium` or `hintfull` (which have actually always been the same thing). The setting may still be changed through the `localConf` option or by creating a user Fontconfig file. Users with HiDPI displays should probably disable hinting and antialiasing: at best they have no visible effect. The fontconfig-ultimate settings are still available in NixOS, but they are no longer the default. They still work, but their main purpose is to set rendering quirks which are no longer necessary and may actually be detrimental (e.g. setting `hintfull` for some fonts). Also, the vast array of font substitutions provided is not an appropriate default; the default setting should be to give the user the font they asked for. [1]. https://www.freetype.org/freetype2/docs/subpixel-hinting.html
2017-03-05 23:39:38 +00:00
FreeType LCD filter. At high resolution (> 200 DPI), LCD filtering
has no visible effect; users of such displays may want to select
<literal>none</literal>.
Rewrite Fontconfig NixOS module Details: * The option `fonts.enableFontConfig` has (finally) been renamed `fonts.fontconfig.enable`. * Configurations are loaded in this order: first the Fontconfig-upstream configuration is loaded, then the NixOS-specific font directories are set, the system-wide default configuration is loaded, and finally the user configuration is loaded (if enabled). * The NixOS options `fonts.fontconfig.defaultFonts.monospace`, `fonts.fontconfig.defaultFonts.sansSerif` and `fonts.fontconfig.defaultFonts.serif` are added to allow setting the default system-wide font used for these generic faces. The defaults are the appropriate faces from the DejaVu collection because of their comprehensive Unicode coverage, clean rendering, and excellent legibility. * The NixOS option `fonts.fontconfig.antialias` can be used to disable antialiasing (it is enabled by default). * The options `fonts.fontconfig.subpixel.rgba` and `fonts.fontconfig.subpixel.lcdfilter` control the system-wide default settings for subpixel order and LCD filtering algorithm, respectively. * `fonts.fontconfig.hinting.enable` can be used to disable TrueType font hinting (it is enabled by default). `fonts.fontconfig.hinting.autohint` controls the FreeType autohinter. `fonts.fontconfig.hinting.style` controls the hint style; it is "full" by default. * User configurations can be disabled system-wide by setting `fonts.fontconfig.includeUserConf = false`. They are enabled by default so users can set Fontconfig options in the desktop environment of their choice.
2014-11-30 19:36:49 +00:00
'';
};
};
cache32Bit = mkOption {
default = false;
type = types.bool;
description = ''
Generate system fonts cache for 32-bit applications.
'';
};
allowBitmaps = mkOption {
type = types.bool;
default = true;
description = ''
Allow bitmap fonts. Set to <literal>false</literal> to ban all
bitmap fonts.
'';
};
allowType1 = mkOption {
type = types.bool;
default = false;
description = ''
Allow Type-1 fonts. Default is <literal>false</literal> because of
poor rendering.
'';
};
useEmbeddedBitmaps = mkOption {
type = types.bool;
default = false;
description = ''Use embedded bitmaps in fonts like Calibri.'';
};
};
};
};
2017-04-03 14:48:50 +01:00
config = mkMerge [
(mkIf cfg.enable {
environment.systemPackages = [ pkgs.fontconfig ];
environment.etc.fonts.source = "${fontconfigEtc}/etc/fonts/";
})
(mkIf (cfg.enable && !cfg.penultimate.enable) {
fonts.fontconfig.confPackages = [ confPkg ];
})
];
}