walkero
/
harfbuzz
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

[manual] Fix font functions section 

Fixes https://github.com/harfbuzz/harfbuzz/issues/2731
This commit is contained in:
Khaled Hosny 2021-01-01 01:31:19 +02:00
parent 3583fce86d
commit 319e5b3200
1 changed files with 20 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

27
docs/usermanual-fonts-and-faces.xml
View File

@ -260,18 +260,18 @@
</listitem>
</itemizedlist>
<para>
You can fetch the font-functions configuration for a font object
by calling <function>hb_font_get_font_funcs()</function>:
You can create new font-functions by calling
<function>hb_font_funcs_create()</function>:
</para>
<programlisting language="C">
hb_font_funcs_t *ffunctions;
ffunctions = hb_font_get_font_funcs (font);
hb_font_funcs_t *ffunctions = hb_font_funcs_create ();
hb_font_set_funcs (font, ffunctions, font_data, destroy);
</programlisting>
<para>
The individual methods can each be replaced with their own setter
The individual methods can each be set with their own setter
function, such as
<function>hb_font_funcs_set_nominal_glyph_func(*ffunctions,
func, *user_data, destroy)</function>.
<function>hb_font_funcs_set_nominal_glyph_func(ffunctions,
func, user_data, destroy)</function>.
</para>
<para>
Font-functions structures can be reused for multiple font
@ -291,6 +291,19 @@
programs from changing the configuration and introducing
inconsistencies and errors downstream.
</para>
<para>
To override only some functions while using the default implementation
for the others, you will need to create a sub-font. By default, the
sub-font uses the font functions of its parent except for the functions
that were explicitly set. The following code will override only the
<function>hb_font_get_nominal_glyph_func_t</function> for the sub-font:
</para>
<programlisting language="C">
hb_font_t *subfont = hb_font_create_sub_font (font)
hb_font_funcs_t *ffunctions = hb_font_funcs_create ();
hb_font_funcs_set_nominal_glyph_func(ffunctions, func, user_data, destroy);
hb_font_set_funcs (subfont, ffunctions, font_data, destroy);
</programlisting>
</section>
<section id="fonts-and-faces-native-opentype">