Issue 5164: Doc: Add usage of OpenType font feature

[lilypond.git] / Documentation / notation / text.itely

diff --git a/Documentation/notation/text.itely b/Documentation/notation/text.itely
index 8d9c8fcc899aee783684b5813a2b05d2bf16d017..fabee1a937628909748f2d94d01e25dd157cb045 100644 (file)
--- a/Documentation/notation/text.itely
+++ b/Documentation/notation/text.itely
@@ -1387,17 +1387,53 @@ left braces; right braces may be obtained by rotation, see
 @ref{Rotating objects}.
 
 Three families of text fonts are made available:
 @ref{Rotating objects}.
 
 Three families of text fonts are made available:

-@itemize
-@item
-The @emph{roman} (serif) font,
-which defaults to LilyPond Serif (an alias of TeX Gyre Schola).
-@item
-The @emph{sans} font,
-which defaults to LilyPond Sans Serif (an alias of TeX Gyre Heros).
-@item
-The @emph{typewriter} (monospaced) font,
-which defaults to LilyPond Monospace (an alias of TeX Gyre Cursor).
-@end itemize
+the @emph{roman} (serif) font,
+the @emph{sans} font, and the @emph{typewriter} font.
+
+For @code{svg} backend:
+@multitable @columnfractions .15 .30
+@headitem Family @tab Default font
+@item @emph{roman} @tab @code{serif}
+@item @emph{sans} @tab @code{sans-serif}
+@item @emph{typewriter} @tab @code{monospace}
+@end multitable
+
+@code{serif}, @code{sans-serif}, and @code{monospace} are
+@code{generic-family} in SVG and CSS specifications.
+
+For other backends:
+@multitable @columnfractions .15 .30 .55
+@headitem Family @tab Default font (alias) @tab Alias definition lists
+@item @emph{roman}
+@tab @code{LilyPond Serif}
+@tab
+TeX Gyre Schola,
+C059, Century SchoolBook URW, Century Schoolbook L,
+DejaVu Serif,
+..., serif
+@item @emph{sans}
+@tab @code{LilyPond Sans Serif}
+@tab
+TeX Gyre Heros,
+Nimbus Sans, Nimbus Sans L, DejaVu Sans,
+..., sans-serif
+@item @emph{typewriter}
+@tab @code{LilyPond Monospace}
+@tab
+TeX Gyre Cursor,
+Nimbus Mono PS, Nimbus Mono, Nimbus Mono L,
+DejaVu Sans Mono,
+..., monospace
+@end multitable
+
+@code{LilyPond Serif}, @code{LilyPond Sans Serif},
+and @code{LilyPond Monospace} are font aliases defined
+in the LilyPond dedicated FontConfig configuration file
+@code{00-lilypond-fonts.conf}.
+Where a character dosen't exist in the first font listed,
+the next font listed will be used instead for that character.
+For details of alias definitions, please see
+to @code{00-lilypond-fonts.conf} under the installed directory.

 
 Each family may include different shapes and series.  The following
 example demonstrates the ability to select alternate families, shapes,
 
 Each family may include different shapes and series.  The following
 example demonstrates the ability to select alternate families, shapes,


@@ -1441,6 +1477,42 @@ is preferable to use the simpler syntax explained in
 }
 @end lilypond
 
 }
 @end lilypond
 

+@noindent
+When using OpenType fonts, font features can be used.
+OpenType font scripts and languages can not be specified.
+Note: Not all OpenType fonts have all functions.
+If you request a feature that doesn't exist in the chosen font,
+then the feature is simply ignored.
+
+@lilypond[quote,verbatim]
+% True small caps
+\markup { Normal Style: Hello HELLO }
+\markup { \caps { Small Caps: Hello } }
+\markup { \override #'(font-features . ("smcp"))
+          { True Small Caps: Hello } }
+
+% Number styles
+\markup { Normal Number Style: 0123456789 }
+\markup { \override #'(font-features . ("onum"))
+          { Old Number Style: 0123456789 } }
+
+% Stylistic Alternates
+\markup { \override #'(font-features . ("salt 0"))
+          { Stylistic Alternates 0: εφπρθ } }
+\markup { \override #'(font-features . ("salt 1"))
+          { Stylistic Alternates 1: εφπρθ } }
+
+% Multiple features
+\markup { \override #'(font-features . ("onum" "smcp" "salt 1"))
+          { Multiple features: Hello 0123456789 εφπρθ } }
+@end lilypond
+
+@noindent For the full OpenType font feature list please see:
+@uref{https://www.microsoft.com/typography/otspec/featurelist.htm}
+
+@noindent For identifying features of OpenType fonts please see:
+@uref{http://lists.gnu.org/archive/html/lilypond-devel/2017-08/msg00004.html}
+

 Although it is easy to switch between preconfigured fonts, it is also
 possible to use other fonts, as explained in the following sections:
 @ref{Single entry fonts} and @ref{Entire document fonts}.
 Although it is easy to switch between preconfigured fonts, it is also
 possible to use other fonts, as explained in the following sections:
 @ref{Single entry fonts} and @ref{Entire document fonts}.