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diff --git a/libs/cairo-1.16.0/doc/public/xml/cairo-user-fonts.xml b/libs/cairo-1.16.0/doc/public/xml/cairo-user-fonts.xml new file mode 100644 index 0000000..894fd7a --- /dev/null +++ b/libs/cairo-1.16.0/doc/public/xml/cairo-user-fonts.xml @@ -0,0 +1,626 @@ +<?xml version='1.0' encoding='UTF-8'?> +<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" + "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd" [ +<!ENTITY version SYSTEM "version.xml"> +]> +<refentry id="cairo-User-Fonts"> +<refmeta> +<refentrytitle role="top_of_page" id="cairo-User-Fonts.top_of_page">User Fonts</refentrytitle> +<manvolnum>3</manvolnum> +<refmiscinfo>CAIRO Library</refmiscinfo> +</refmeta> +<refnamediv> +<refname>User Fonts</refname> +<refpurpose>Font support with font data provided by the user</refpurpose> +</refnamediv> + +<refsect1 id="cairo-User-Fonts.functions" role="functions_proto"> +<title role="functions_proto.title">Functions</title> +<informaltable pgwide="1" frame="none"> +<tgroup cols="2"> +<colspec colname="functions_return" colwidth="150px"/> +<colspec colname="functions_name"/> +<tbody> +<row><entry role="function_type"><link linkend="cairo-status-t"><returnvalue>cairo_status_t</returnvalue></link> +</entry><entry role="function_name"><phrase role="c_punctuation">(</phrase><link linkend="cairo-user-scaled-font-init-func-t">*cairo_user_scaled_font_init_func_t</link><phrase role="c_punctuation">)</phrase> <phrase role="c_punctuation">()</phrase></entry></row> +<row><entry role="function_type"><link linkend="cairo-status-t"><returnvalue>cairo_status_t</returnvalue></link> +</entry><entry role="function_name"><phrase role="c_punctuation">(</phrase><link linkend="cairo-user-scaled-font-render-glyph-func-t">*cairo_user_scaled_font_render_glyph_func_t</link><phrase role="c_punctuation">)</phrase> <phrase role="c_punctuation">()</phrase></entry></row> +<row><entry role="function_type"><link linkend="cairo-status-t"><returnvalue>cairo_status_t</returnvalue></link> +</entry><entry role="function_name"><phrase role="c_punctuation">(</phrase><link linkend="cairo-user-scaled-font-text-to-glyphs-func-t">*cairo_user_scaled_font_text_to_glyphs_func_t</link><phrase role="c_punctuation">)</phrase> <phrase role="c_punctuation">()</phrase></entry></row> +<row><entry role="function_type"><link linkend="cairo-status-t"><returnvalue>cairo_status_t</returnvalue></link> +</entry><entry role="function_name"><phrase role="c_punctuation">(</phrase><link linkend="cairo-user-scaled-font-unicode-to-glyph-func-t">*cairo_user_scaled_font_unicode_to_glyph_func_t</link><phrase role="c_punctuation">)</phrase> <phrase role="c_punctuation">()</phrase></entry></row> +<row><entry role="function_type"><link linkend="cairo-font-face-t"><returnvalue>cairo_font_face_t</returnvalue></link> * +</entry><entry role="function_name"><link linkend="cairo-user-font-face-create">cairo_user_font_face_create</link> <phrase role="c_punctuation">()</phrase></entry></row> +<row><entry role="function_type"><link linkend="void"><returnvalue>void</returnvalue></link> +</entry><entry role="function_name"><link linkend="cairo-user-font-face-set-init-func">cairo_user_font_face_set_init_func</link> <phrase role="c_punctuation">()</phrase></entry></row> +<row><entry role="function_type"><link linkend="cairo-user-scaled-font-init-func-t"><returnvalue>cairo_user_scaled_font_init_func_t</returnvalue></link> +</entry><entry role="function_name"><link linkend="cairo-user-font-face-get-init-func">cairo_user_font_face_get_init_func</link> <phrase role="c_punctuation">()</phrase></entry></row> +<row><entry role="function_type"><link linkend="void"><returnvalue>void</returnvalue></link> +</entry><entry role="function_name"><link linkend="cairo-user-font-face-set-render-glyph-func">cairo_user_font_face_set_render_glyph_func</link> <phrase role="c_punctuation">()</phrase></entry></row> +<row><entry role="function_type"><link linkend="cairo-user-scaled-font-render-glyph-func-t"><returnvalue>cairo_user_scaled_font_render_glyph_func_t</returnvalue></link> +</entry><entry role="function_name"><link linkend="cairo-user-font-face-get-render-glyph-func">cairo_user_font_face_get_render_glyph_func</link> <phrase role="c_punctuation">()</phrase></entry></row> +<row><entry role="function_type"><link linkend="void"><returnvalue>void</returnvalue></link> +</entry><entry role="function_name"><link linkend="cairo-user-font-face-set-unicode-to-glyph-func">cairo_user_font_face_set_unicode_to_glyph_func</link> <phrase role="c_punctuation">()</phrase></entry></row> +<row><entry role="function_type"><link linkend="cairo-user-scaled-font-unicode-to-glyph-func-t"><returnvalue>cairo_user_scaled_font_unicode_to_glyph_func_t</returnvalue></link> +</entry><entry role="function_name"><link linkend="cairo-user-font-face-get-unicode-to-glyph-func">cairo_user_font_face_get_unicode_to_glyph_func</link> <phrase role="c_punctuation">()</phrase></entry></row> +<row><entry role="function_type"><link linkend="void"><returnvalue>void</returnvalue></link> +</entry><entry role="function_name"><link linkend="cairo-user-font-face-set-text-to-glyphs-func">cairo_user_font_face_set_text_to_glyphs_func</link> <phrase role="c_punctuation">()</phrase></entry></row> +<row><entry role="function_type"><link linkend="cairo-user-scaled-font-text-to-glyphs-func-t"><returnvalue>cairo_user_scaled_font_text_to_glyphs_func_t</returnvalue></link> +</entry><entry role="function_name"><link linkend="cairo-user-font-face-get-text-to-glyphs-func">cairo_user_font_face_get_text_to_glyphs_func</link> <phrase role="c_punctuation">()</phrase></entry></row> + +</tbody> +</tgroup> +</informaltable> +</refsect1> +<refsect1 id="cairo-User-Fonts.other" role="other_proto"> +<title role="other_proto.title">Types and Values</title> +<informaltable role="enum_members_table" pgwide="1" frame="none"> +<tgroup cols="2"> +<colspec colname="name" colwidth="150px"/> +<colspec colname="description"/> +<tbody> +<row><entry role="define_keyword">#define</entry><entry role="function_name"><link linkend="CAIRO-HAS-USER-FONT:CAPS">CAIRO_HAS_USER_FONT</link></entry></row> + +</tbody> +</tgroup> +</informaltable> +</refsect1> + + +<refsect1 id="cairo-User-Fonts.description" role="desc"> +<title role="desc.title">Description</title> +<para>The user-font feature allows the cairo user to provide drawings for glyphs +in a font. This is most useful in implementing fonts in non-standard +formats, like SVG fonts and Flash fonts, but can also be used by games and +other application to draw "funky" fonts.</para> + +</refsect1> +<refsect1 id="cairo-User-Fonts.functions_details" role="details"> +<title role="details.title">Functions</title> +<refsect2 id="cairo-user-scaled-font-init-func-t" role="function" condition="since:1.8"> +<title>cairo_user_scaled_font_init_func_t ()</title> +<indexterm zone="cairo-user-scaled-font-init-func-t" role="1.8"><primary sortas="user_scaled_font_init_func_t">cairo_user_scaled_font_init_func_t</primary></indexterm> +<programlisting language="C"><link linkend="cairo-status-t"><returnvalue>cairo_status_t</returnvalue></link> +<phrase role="c_punctuation">(</phrase>*cairo_user_scaled_font_init_func_t<phrase role="c_punctuation">)</phrase> (<parameter><link linkend="cairo-scaled-font-t"><type>cairo_scaled_font_t</type></link> *scaled_font</parameter>, + <parameter><link linkend="cairo-t"><type>cairo_t</type></link> *cr</parameter>, + <parameter><link linkend="cairo-font-extents-t"><type>cairo_font_extents_t</type></link> *extents</parameter>);</programlisting> +<para><link linkend="cairo-user-scaled-font-init-func-t"><type>cairo_user_scaled_font_init_func_t</type></link> is the type of function which is +called when a scaled-font needs to be created for a user font-face.</para> +<para>The cairo context <parameter>cr</parameter> + is not used by the caller, but is prepared in font +space, similar to what the cairo contexts passed to the render_glyph +method will look like. The callback can use this context for extents +computation for example. After the callback is called, <parameter>cr</parameter> + is checked +for any error status.</para> +<para>The <parameter>extents</parameter> + argument is where the user font sets the font extents for +<parameter>scaled_font</parameter> +. It is in font space, which means that for most cases its +ascent and descent members should add to 1.0. <parameter>extents</parameter> + is preset to +hold a value of 1.0 for ascent, height, and max_x_advance, and 0.0 for +descent and max_y_advance members.</para> +<para>The callback is optional. If not set, default font extents as described +in the previous paragraph will be used.</para> +<para>Note that <parameter>scaled_font</parameter> + is not fully initialized at this +point and trying to use it for text operations in the callback will result +in deadlock.</para> +<refsect3 id="cairo-user-scaled-font-init-func-t.parameters" role="parameters"> +<title>Parameters</title> +<informaltable role="parameters_table" pgwide="1" frame="none"> +<tgroup cols="3"> +<colspec colname="parameters_name" colwidth="150px"/> +<colspec colname="parameters_description"/> +<colspec colname="parameters_annotations" colwidth="200px"/> +<tbody> +<row><entry role="parameter_name"><para>scaled_font</para></entry> +<entry role="parameter_description"><para>the scaled-font being created</para></entry> +<entry role="parameter_annotations"></entry></row> +<row><entry role="parameter_name"><para>cr</para></entry> +<entry role="parameter_description"><para>a cairo context, in font space</para></entry> +<entry role="parameter_annotations"></entry></row> +<row><entry role="parameter_name"><para>extents</para></entry> +<entry role="parameter_description"><para>font extents to fill in, in font space</para></entry> +<entry role="parameter_annotations"></entry></row> +</tbody></tgroup></informaltable> +</refsect3><refsect3 id="cairo-user-scaled-font-init-func-t.returns" role="returns"> +<title>Returns</title> +<para> <link linkend="CAIRO-STATUS-SUCCESS:CAPS"><literal>CAIRO_STATUS_SUCCESS</literal></link> upon success, or an error status on error.</para> +</refsect3><para role="since">Since: <link linkend="api-index-1.8">1.8</link></para></refsect2> +<refsect2 id="cairo-user-scaled-font-render-glyph-func-t" role="function" condition="since:1.8"> +<title>cairo_user_scaled_font_render_glyph_func_t ()</title> +<indexterm zone="cairo-user-scaled-font-render-glyph-func-t" role="1.8"><primary sortas="user_scaled_font_render_glyph_func_t">cairo_user_scaled_font_render_glyph_func_t</primary></indexterm> +<programlisting language="C"><link linkend="cairo-status-t"><returnvalue>cairo_status_t</returnvalue></link> +<phrase role="c_punctuation">(</phrase>*cairo_user_scaled_font_render_glyph_func_t<phrase role="c_punctuation">)</phrase> + (<parameter><link linkend="cairo-scaled-font-t"><type>cairo_scaled_font_t</type></link> *scaled_font</parameter>, + <parameter><type>unsigned long </type> glyph</parameter>, + <parameter><link linkend="cairo-t"><type>cairo_t</type></link> *cr</parameter>, + <parameter><link linkend="cairo-text-extents-t"><type>cairo_text_extents_t</type></link> *extents</parameter>);</programlisting> +<para><link linkend="cairo-user-scaled-font-render-glyph-func-t"><type>cairo_user_scaled_font_render_glyph_func_t</type></link> is the type of function which +is called when a user scaled-font needs to render a glyph.</para> +<para>The callback is mandatory, and expected to draw the glyph with code <parameter>glyph</parameter> + to +the cairo context <parameter>cr</parameter> +. <parameter>cr</parameter> + is prepared such that the glyph drawing is done in +font space. That is, the matrix set on <parameter>cr</parameter> + is the scale matrix of <parameter>scaled_font</parameter> +, +The <parameter>extents</parameter> + argument is where the user font sets the font extents for +<parameter>scaled_font</parameter> +. However, if user prefers to draw in user space, they can +achieve that by changing the matrix on <parameter>cr</parameter> +. All cairo rendering operations +to <parameter>cr</parameter> + are permitted, however, the result is undefined if any source other +than the default source on <parameter>cr</parameter> + is used. That means, glyph bitmaps should +be rendered using <link linkend="cairo-mask"><function>cairo_mask()</function></link> instead of <link linkend="cairo-paint"><function>cairo_paint()</function></link>.</para> +<para>Other non-default settings on <parameter>cr</parameter> + include a font size of 1.0 (given that +it is set up to be in font space), and font options corresponding to +<parameter>scaled_font</parameter> +.</para> +<para>The <parameter>extents</parameter> + argument is preset to have <literal>x_bearing</literal>, +<literal>width</literal>, and <literal>y_advance</literal> of zero, +<literal>y_bearing</literal> set to <literal>-font_extents.ascent</literal>, +<literal>height</literal> to <literal>font_extents.ascent+font_extents.descent</literal>, +and <literal>x_advance</literal> to <literal>font_extents.max_x_advance</literal>. +The only field user needs to set in majority of cases is +<literal>x_advance</literal>. +If the <literal>width</literal> field is zero upon the callback returning +(which is its preset value), the glyph extents are automatically computed +based on the drawings done to <parameter>cr</parameter> +. This is in most cases exactly what the +desired behavior is. However, if for any reason the callback sets the +extents, it must be ink extents, and include the extents of all drawing +done to <parameter>cr</parameter> + in the callback.</para> +<refsect3 id="cairo-user-scaled-font-render-glyph-func-t.parameters" role="parameters"> +<title>Parameters</title> +<informaltable role="parameters_table" pgwide="1" frame="none"> +<tgroup cols="3"> +<colspec colname="parameters_name" colwidth="150px"/> +<colspec colname="parameters_description"/> +<colspec colname="parameters_annotations" colwidth="200px"/> +<tbody> +<row><entry role="parameter_name"><para>scaled_font</para></entry> +<entry role="parameter_description"><para>user scaled-font</para></entry> +<entry role="parameter_annotations"></entry></row> +<row><entry role="parameter_name"><para>glyph</para></entry> +<entry role="parameter_description"><para>glyph code to render</para></entry> +<entry role="parameter_annotations"></entry></row> +<row><entry role="parameter_name"><para>cr</para></entry> +<entry role="parameter_description"><para>cairo context to draw to, in font space</para></entry> +<entry role="parameter_annotations"></entry></row> +<row><entry role="parameter_name"><para>extents</para></entry> +<entry role="parameter_description"><para>glyph extents to fill in, in font space</para></entry> +<entry role="parameter_annotations"></entry></row> +</tbody></tgroup></informaltable> +</refsect3><refsect3 id="cairo-user-scaled-font-render-glyph-func-t.returns" role="returns"> +<title>Returns</title> +<para> <link linkend="CAIRO-STATUS-SUCCESS:CAPS"><literal>CAIRO_STATUS_SUCCESS</literal></link> upon success, or +<link linkend="CAIRO-STATUS-USER-FONT-ERROR:CAPS"><literal>CAIRO_STATUS_USER_FONT_ERROR</literal></link> or any other error status on error.</para> +</refsect3><para role="since">Since: <link linkend="api-index-1.8">1.8</link></para></refsect2> +<refsect2 id="cairo-user-scaled-font-text-to-glyphs-func-t" role="function" condition="since:1.8"> +<title>cairo_user_scaled_font_text_to_glyphs_func_t ()</title> +<indexterm zone="cairo-user-scaled-font-text-to-glyphs-func-t" role="1.8"><primary sortas="user_scaled_font_text_to_glyphs_func_t">cairo_user_scaled_font_text_to_glyphs_func_t</primary></indexterm> +<programlisting language="C"><link linkend="cairo-status-t"><returnvalue>cairo_status_t</returnvalue></link> +<phrase role="c_punctuation">(</phrase>*cairo_user_scaled_font_text_to_glyphs_func_t<phrase role="c_punctuation">)</phrase> + (<parameter><link linkend="cairo-scaled-font-t"><type>cairo_scaled_font_t</type></link> *scaled_font</parameter>, + <parameter>const <link linkend="char"><type>char</type></link> *utf8</parameter>, + <parameter><link linkend="int"><type>int</type></link> utf8_len</parameter>, + <parameter><link linkend="cairo-glyph-t"><type>cairo_glyph_t</type></link> **glyphs</parameter>, + <parameter><link linkend="int"><type>int</type></link> *num_glyphs</parameter>, + <parameter><link linkend="cairo-text-cluster-t"><type>cairo_text_cluster_t</type></link> **clusters</parameter>, + <parameter><link linkend="int"><type>int</type></link> *num_clusters</parameter>, + <parameter><link linkend="cairo-text-cluster-flags-t"><type>cairo_text_cluster_flags_t</type></link> *cluster_flags</parameter>);</programlisting> +<para><link linkend="cairo-user-scaled-font-text-to-glyphs-func-t"><type>cairo_user_scaled_font_text_to_glyphs_func_t</type></link> is the type of function which +is called to convert input text to an array of glyphs. This is used by the +<link linkend="cairo-show-text"><function>cairo_show_text()</function></link> operation.</para> +<para>Using this callback the user-font has full control on glyphs and their +positions. That means, it allows for features like ligatures and kerning, +as well as complex <firstterm>shaping</firstterm> required for scripts like +Arabic and Indic.</para> +<para>The <parameter>num_glyphs</parameter> + argument is preset to the number of glyph entries available +in the <parameter>glyphs</parameter> + buffer. If the <parameter>glyphs</parameter> + buffer is <link linkend="NULL:CAPS"><literal>NULL</literal></link>, the value of +<parameter>num_glyphs</parameter> + will be zero. If the provided glyph array is too short for +the conversion (or for convenience), a new glyph array may be allocated +using <link linkend="cairo-glyph-allocate"><function>cairo_glyph_allocate()</function></link> and placed in <parameter>glyphs</parameter> +. Upon return, +<parameter>num_glyphs</parameter> + should contain the number of generated glyphs. If the value +<parameter>glyphs</parameter> + points at has changed after the call, the caller will free the +allocated glyph array using <link linkend="cairo-glyph-free"><function>cairo_glyph_free()</function></link>. The caller will also free +the original value of <parameter>glyphs</parameter> +, so the callback shouldn't do so. +The callback should populate the glyph indices and positions (in font space) +assuming that the text is to be shown at the origin.</para> +<para>If <parameter>clusters</parameter> + is not <link linkend="NULL:CAPS"><literal>NULL</literal></link>, <parameter>num_clusters</parameter> + and <parameter>cluster_flags</parameter> + are also +non-<link linkend="NULL:CAPS"><literal>NULL</literal></link>, and cluster mapping should be computed. The semantics of how +cluster array allocation works is similar to the glyph array. That is, +if <parameter>clusters</parameter> + initially points to a non-<link linkend="NULL:CAPS"><literal>NULL</literal></link> value, that array may be used +as a cluster buffer, and <parameter>num_clusters</parameter> + points to the number of cluster +entries available there. If the provided cluster array is too short for +the conversion (or for convenience), a new cluster array may be allocated +using <link linkend="cairo-text-cluster-allocate"><function>cairo_text_cluster_allocate()</function></link> and placed in <parameter>clusters</parameter> +. In this case, +the original value of <parameter>clusters</parameter> + will still be freed by the caller. Upon +return, <parameter>num_clusters</parameter> + should contain the number of generated clusters. +If the value <parameter>clusters</parameter> + points at has changed after the call, the caller +will free the allocated cluster array using <link linkend="cairo-text-cluster-free"><function>cairo_text_cluster_free()</function></link>.</para> +<para>The callback is optional. If <parameter>num_glyphs</parameter> + is negative upon +the callback returning or if the return value +is <link linkend="CAIRO-STATUS-USER-FONT-NOT-IMPLEMENTED:CAPS"><literal>CAIRO_STATUS_USER_FONT_NOT_IMPLEMENTED</literal></link>, the unicode_to_glyph callback +is tried. See <link linkend="cairo-user-scaled-font-unicode-to-glyph-func-t"><type>cairo_user_scaled_font_unicode_to_glyph_func_t</type></link>.</para> +<para>Note: While cairo does not impose any limitation on glyph indices, +some applications may assume that a glyph index fits in a 16-bit +unsigned integer. As such, it is advised that user-fonts keep their +glyphs in the 0 to 65535 range. Furthermore, some applications may +assume that glyph 0 is a special glyph-not-found glyph. User-fonts +are advised to use glyph 0 for such purposes and do not use that +glyph value for other purposes.</para> +<refsect3 id="cairo-user-scaled-font-text-to-glyphs-func-t.parameters" role="parameters"> +<title>Parameters</title> +<informaltable role="parameters_table" pgwide="1" frame="none"> +<tgroup cols="3"> +<colspec colname="parameters_name" colwidth="150px"/> +<colspec colname="parameters_description"/> +<colspec colname="parameters_annotations" colwidth="200px"/> +<tbody> +<row><entry role="parameter_name"><para>scaled_font</para></entry> +<entry role="parameter_description"><para>the scaled-font being created</para></entry> +<entry role="parameter_annotations"></entry></row> +<row><entry role="parameter_name"><para>utf8</para></entry> +<entry role="parameter_description"><para>a string of text encoded in UTF-8</para></entry> +<entry role="parameter_annotations"></entry></row> +<row><entry role="parameter_name"><para>utf8_len</para></entry> +<entry role="parameter_description"><para>length of <parameter>utf8</parameter> +in bytes</para></entry> +<entry role="parameter_annotations"></entry></row> +<row><entry role="parameter_name"><para>glyphs</para></entry> +<entry role="parameter_description"><para>pointer to array of glyphs to fill, in font space</para></entry> +<entry role="parameter_annotations"></entry></row> +<row><entry role="parameter_name"><para>num_glyphs</para></entry> +<entry role="parameter_description"><para>pointer to number of glyphs</para></entry> +<entry role="parameter_annotations"></entry></row> +<row><entry role="parameter_name"><para>clusters</para></entry> +<entry role="parameter_description"><para>pointer to array of cluster mapping information to fill, or <link linkend="NULL:CAPS"><literal>NULL</literal></link></para></entry> +<entry role="parameter_annotations"></entry></row> +<row><entry role="parameter_name"><para>num_clusters</para></entry> +<entry role="parameter_description"><para>pointer to number of clusters</para></entry> +<entry role="parameter_annotations"></entry></row> +<row><entry role="parameter_name"><para>cluster_flags</para></entry> +<entry role="parameter_description"><para>pointer to location to store cluster flags corresponding to the +output <parameter>clusters</parameter> +</para></entry> +<entry role="parameter_annotations"></entry></row> +</tbody></tgroup></informaltable> +</refsect3><refsect3 id="cairo-user-scaled-font-text-to-glyphs-func-t.returns" role="returns"> +<title>Returns</title> +<para> <link linkend="CAIRO-STATUS-SUCCESS:CAPS"><literal>CAIRO_STATUS_SUCCESS</literal></link> upon success, +<link linkend="CAIRO-STATUS-USER-FONT-NOT-IMPLEMENTED:CAPS"><literal>CAIRO_STATUS_USER_FONT_NOT_IMPLEMENTED</literal></link> if fallback options should be tried, +or <link linkend="CAIRO-STATUS-USER-FONT-ERROR:CAPS"><literal>CAIRO_STATUS_USER_FONT_ERROR</literal></link> or any other error status on error.</para> +</refsect3><para role="since">Since: <link linkend="api-index-1.8">1.8</link></para></refsect2> +<refsect2 id="cairo-user-scaled-font-unicode-to-glyph-func-t" role="function" condition="since:1.8"> +<title>cairo_user_scaled_font_unicode_to_glyph_func_t ()</title> +<indexterm zone="cairo-user-scaled-font-unicode-to-glyph-func-t" role="1.8"><primary sortas="user_scaled_font_unicode_to_glyph_func_t">cairo_user_scaled_font_unicode_to_glyph_func_t</primary></indexterm> +<programlisting language="C"><link linkend="cairo-status-t"><returnvalue>cairo_status_t</returnvalue></link> +<phrase role="c_punctuation">(</phrase>*cairo_user_scaled_font_unicode_to_glyph_func_t<phrase role="c_punctuation">)</phrase> + (<parameter><link linkend="cairo-scaled-font-t"><type>cairo_scaled_font_t</type></link> *scaled_font</parameter>, + <parameter><type>unsigned long </type> unicode</parameter>, + <parameter>unsigned <link linkend="long"><type>long</type></link> *glyph_index</parameter>);</programlisting> +<para><link linkend="cairo-user-scaled-font-unicode-to-glyph-func-t"><type>cairo_user_scaled_font_unicode_to_glyph_func_t</type></link> is the type of function which +is called to convert an input Unicode character to a single glyph. +This is used by the <link linkend="cairo-show-text"><function>cairo_show_text()</function></link> operation.</para> +<para>This callback is used to provide the same functionality as the +text_to_glyphs callback does (see <link linkend="cairo-user-scaled-font-text-to-glyphs-func-t"><type>cairo_user_scaled_font_text_to_glyphs_func_t</type></link>) +but has much less control on the output, +in exchange for increased ease of use. The inherent assumption to using +this callback is that each character maps to one glyph, and that the +mapping is context independent. It also assumes that glyphs are positioned +according to their advance width. These mean no ligatures, kerning, or +complex scripts can be implemented using this callback.</para> +<para>The callback is optional, and only used if text_to_glyphs callback is not +set or fails to return glyphs. If this callback is not set or if it returns +<link linkend="CAIRO-STATUS-USER-FONT-NOT-IMPLEMENTED:CAPS"><literal>CAIRO_STATUS_USER_FONT_NOT_IMPLEMENTED</literal></link>, an identity mapping from Unicode +code-points to glyph indices is assumed.</para> +<para>Note: While cairo does not impose any limitation on glyph indices, +some applications may assume that a glyph index fits in a 16-bit +unsigned integer. As such, it is advised that user-fonts keep their +glyphs in the 0 to 65535 range. Furthermore, some applications may +assume that glyph 0 is a special glyph-not-found glyph. User-fonts +are advised to use glyph 0 for such purposes and do not use that +glyph value for other purposes.</para> +<refsect3 id="cairo-user-scaled-font-unicode-to-glyph-func-t.parameters" role="parameters"> +<title>Parameters</title> +<informaltable role="parameters_table" pgwide="1" frame="none"> +<tgroup cols="3"> +<colspec colname="parameters_name" colwidth="150px"/> +<colspec colname="parameters_description"/> +<colspec colname="parameters_annotations" colwidth="200px"/> +<tbody> +<row><entry role="parameter_name"><para>scaled_font</para></entry> +<entry role="parameter_description"><para>the scaled-font being created</para></entry> +<entry role="parameter_annotations"></entry></row> +<row><entry role="parameter_name"><para>unicode</para></entry> +<entry role="parameter_description"><para>input unicode character code-point</para></entry> +<entry role="parameter_annotations"></entry></row> +<row><entry role="parameter_name"><para>glyph_index</para></entry> +<entry role="parameter_description"><para>output glyph index</para></entry> +<entry role="parameter_annotations"></entry></row> +</tbody></tgroup></informaltable> +</refsect3><refsect3 id="cairo-user-scaled-font-unicode-to-glyph-func-t.returns" role="returns"> +<title>Returns</title> +<para> <link linkend="CAIRO-STATUS-SUCCESS:CAPS"><literal>CAIRO_STATUS_SUCCESS</literal></link> upon success, +<link linkend="CAIRO-STATUS-USER-FONT-NOT-IMPLEMENTED:CAPS"><literal>CAIRO_STATUS_USER_FONT_NOT_IMPLEMENTED</literal></link> if fallback options should be tried, +or <link linkend="CAIRO-STATUS-USER-FONT-ERROR:CAPS"><literal>CAIRO_STATUS_USER_FONT_ERROR</literal></link> or any other error status on error.</para> +</refsect3><para role="since">Since: <link linkend="api-index-1.8">1.8</link></para></refsect2> +<refsect2 id="cairo-user-font-face-create" role="function" condition="since:1.8"> +<title>cairo_user_font_face_create ()</title> +<indexterm zone="cairo-user-font-face-create" role="1.8"><primary sortas="user_font_face_create">cairo_user_font_face_create</primary></indexterm> +<programlisting language="C"><link linkend="cairo-font-face-t"><returnvalue>cairo_font_face_t</returnvalue></link> * +cairo_user_font_face_create (<parameter><type>void</type></parameter>);</programlisting> +<para>Creates a new user font-face.</para> +<para>Use the setter functions to associate callbacks with the returned +user font. The only mandatory callback is render_glyph.</para> +<para>After the font-face is created, the user can attach arbitrary data +(the actual font data) to it using <link linkend="cairo-font-face-set-user-data"><function>cairo_font_face_set_user_data()</function></link> +and access it from the user-font callbacks by using +<link linkend="cairo-scaled-font-get-font-face"><function>cairo_scaled_font_get_font_face()</function></link> followed by +<link linkend="cairo-font-face-get-user-data"><function>cairo_font_face_get_user_data()</function></link>.</para> +<refsect3 id="cairo-user-font-face-create.returns" role="returns"> +<title>Returns</title> +<para> a newly created <link linkend="cairo-font-face-t"><type>cairo_font_face_t</type></link>. Free with +<link linkend="cairo-font-face-destroy"><function>cairo_font_face_destroy()</function></link> when you are done using it.</para> +</refsect3><para role="since">Since: <link linkend="api-index-1.8">1.8</link></para></refsect2> +<refsect2 id="cairo-user-font-face-set-init-func" role="function" condition="since:1.8"> +<title>cairo_user_font_face_set_init_func ()</title> +<indexterm zone="cairo-user-font-face-set-init-func" role="1.8"><primary sortas="user_font_face_set_init_func">cairo_user_font_face_set_init_func</primary></indexterm> +<programlisting language="C"><link linkend="void"><returnvalue>void</returnvalue></link> +cairo_user_font_face_set_init_func (<parameter><link linkend="cairo-font-face-t"><type>cairo_font_face_t</type></link> *font_face</parameter>, + <parameter><link linkend="cairo-user-scaled-font-init-func-t"><type>cairo_user_scaled_font_init_func_t</type></link> init_func</parameter>);</programlisting> +<para>Sets the scaled-font initialization function of a user-font. +See <link linkend="cairo-user-scaled-font-init-func-t"><type>cairo_user_scaled_font_init_func_t</type></link> for details of how the callback +works.</para> +<para>The font-face should not be immutable or a <link linkend="CAIRO-STATUS-USER-FONT-IMMUTABLE:CAPS"><literal>CAIRO_STATUS_USER_FONT_IMMUTABLE</literal></link> +error will occur. A user font-face is immutable as soon as a scaled-font +is created from it.</para> +<refsect3 id="cairo-user-font-face-set-init-func.parameters" role="parameters"> +<title>Parameters</title> +<informaltable role="parameters_table" pgwide="1" frame="none"> +<tgroup cols="3"> +<colspec colname="parameters_name" colwidth="150px"/> +<colspec colname="parameters_description"/> +<colspec colname="parameters_annotations" colwidth="200px"/> +<tbody> +<row><entry role="parameter_name"><para>font_face</para></entry> +<entry role="parameter_description"><para>A user font face</para></entry> +<entry role="parameter_annotations"></entry></row> +<row><entry role="parameter_name"><para>init_func</para></entry> +<entry role="parameter_description"><para>The init callback, or <link linkend="NULL:CAPS"><literal>NULL</literal></link></para></entry> +<entry role="parameter_annotations"></entry></row> +</tbody></tgroup></informaltable> +</refsect3><para role="since">Since: <link linkend="api-index-1.8">1.8</link></para></refsect2> +<refsect2 id="cairo-user-font-face-get-init-func" role="function" condition="since:1.8"> +<title>cairo_user_font_face_get_init_func ()</title> +<indexterm zone="cairo-user-font-face-get-init-func" role="1.8"><primary sortas="user_font_face_get_init_func">cairo_user_font_face_get_init_func</primary></indexterm> +<programlisting language="C"><link linkend="cairo-user-scaled-font-init-func-t"><returnvalue>cairo_user_scaled_font_init_func_t</returnvalue></link> +cairo_user_font_face_get_init_func (<parameter><link linkend="cairo-font-face-t"><type>cairo_font_face_t</type></link> *font_face</parameter>);</programlisting> +<para>Gets the scaled-font initialization function of a user-font.</para> +<refsect3 id="cairo-user-font-face-get-init-func.parameters" role="parameters"> +<title>Parameters</title> +<informaltable role="parameters_table" pgwide="1" frame="none"> +<tgroup cols="3"> +<colspec colname="parameters_name" colwidth="150px"/> +<colspec colname="parameters_description"/> +<colspec colname="parameters_annotations" colwidth="200px"/> +<tbody> +<row><entry role="parameter_name"><para>font_face</para></entry> +<entry role="parameter_description"><para>A user font face</para></entry> +<entry role="parameter_annotations"></entry></row> +</tbody></tgroup></informaltable> +</refsect3><refsect3 id="cairo-user-font-face-get-init-func.returns" role="returns"> +<title>Returns</title> +<para> The init callback of <parameter>font_face</parameter> +or <link linkend="NULL:CAPS"><literal>NULL</literal></link> if none set or an error has occurred.</para> +</refsect3><para role="since">Since: <link linkend="api-index-1.8">1.8</link></para></refsect2> +<refsect2 id="cairo-user-font-face-set-render-glyph-func" role="function" condition="since:1.8"> +<title>cairo_user_font_face_set_render_glyph_func ()</title> +<indexterm zone="cairo-user-font-face-set-render-glyph-func" role="1.8"><primary sortas="user_font_face_set_render_glyph_func">cairo_user_font_face_set_render_glyph_func</primary></indexterm> +<programlisting language="C"><link linkend="void"><returnvalue>void</returnvalue></link> +cairo_user_font_face_set_render_glyph_func + (<parameter><link linkend="cairo-font-face-t"><type>cairo_font_face_t</type></link> *font_face</parameter>, + <parameter><link linkend="cairo-user-scaled-font-render-glyph-func-t"><type>cairo_user_scaled_font_render_glyph_func_t</type></link> render_glyph_func</parameter>);</programlisting> +<para>Sets the glyph rendering function of a user-font. +See <link linkend="cairo-user-scaled-font-render-glyph-func-t"><type>cairo_user_scaled_font_render_glyph_func_t</type></link> for details of how the callback +works.</para> +<para>The font-face should not be immutable or a <link linkend="CAIRO-STATUS-USER-FONT-IMMUTABLE:CAPS"><literal>CAIRO_STATUS_USER_FONT_IMMUTABLE</literal></link> +error will occur. A user font-face is immutable as soon as a scaled-font +is created from it.</para> +<para>The render_glyph callback is the only mandatory callback of a user-font. +If the callback is <link linkend="NULL:CAPS"><literal>NULL</literal></link> and a glyph is tried to be rendered using +<parameter>font_face</parameter> +, a <link linkend="CAIRO-STATUS-USER-FONT-ERROR:CAPS"><literal>CAIRO_STATUS_USER_FONT_ERROR</literal></link> will occur.</para> +<refsect3 id="cairo-user-font-face-set-render-glyph-func.parameters" role="parameters"> +<title>Parameters</title> +<informaltable role="parameters_table" pgwide="1" frame="none"> +<tgroup cols="3"> +<colspec colname="parameters_name" colwidth="150px"/> +<colspec colname="parameters_description"/> +<colspec colname="parameters_annotations" colwidth="200px"/> +<tbody> +<row><entry role="parameter_name"><para>font_face</para></entry> +<entry role="parameter_description"><para>A user font face</para></entry> +<entry role="parameter_annotations"></entry></row> +<row><entry role="parameter_name"><para>render_glyph_func</para></entry> +<entry role="parameter_description"><para>The render_glyph callback, or <link linkend="NULL:CAPS"><literal>NULL</literal></link></para></entry> +<entry role="parameter_annotations"></entry></row> +</tbody></tgroup></informaltable> +</refsect3><para role="since">Since: <link linkend="api-index-1.8">1.8</link></para></refsect2> +<refsect2 id="cairo-user-font-face-get-render-glyph-func" role="function" condition="since:1.8"> +<title>cairo_user_font_face_get_render_glyph_func ()</title> +<indexterm zone="cairo-user-font-face-get-render-glyph-func" role="1.8"><primary sortas="user_font_face_get_render_glyph_func">cairo_user_font_face_get_render_glyph_func</primary></indexterm> +<programlisting language="C"><link linkend="cairo-user-scaled-font-render-glyph-func-t"><returnvalue>cairo_user_scaled_font_render_glyph_func_t</returnvalue></link> +cairo_user_font_face_get_render_glyph_func + (<parameter><link linkend="cairo-font-face-t"><type>cairo_font_face_t</type></link> *font_face</parameter>);</programlisting> +<para>Gets the glyph rendering function of a user-font.</para> +<refsect3 id="cairo-user-font-face-get-render-glyph-func.parameters" role="parameters"> +<title>Parameters</title> +<informaltable role="parameters_table" pgwide="1" frame="none"> +<tgroup cols="3"> +<colspec colname="parameters_name" colwidth="150px"/> +<colspec colname="parameters_description"/> +<colspec colname="parameters_annotations" colwidth="200px"/> +<tbody> +<row><entry role="parameter_name"><para>font_face</para></entry> +<entry role="parameter_description"><para>A user font face</para></entry> +<entry role="parameter_annotations"></entry></row> +</tbody></tgroup></informaltable> +</refsect3><refsect3 id="cairo-user-font-face-get-render-glyph-func.returns" role="returns"> +<title>Returns</title> +<para> The render_glyph callback of <parameter>font_face</parameter> +or <link linkend="NULL:CAPS"><literal>NULL</literal></link> if none set or an error has occurred.</para> +</refsect3><para role="since">Since: <link linkend="api-index-1.8">1.8</link></para></refsect2> +<refsect2 id="cairo-user-font-face-set-unicode-to-glyph-func" role="function" condition="since:1.8"> +<title>cairo_user_font_face_set_unicode_to_glyph_func ()</title> +<indexterm zone="cairo-user-font-face-set-unicode-to-glyph-func" role="1.8"><primary sortas="user_font_face_set_unicode_to_glyph_func">cairo_user_font_face_set_unicode_to_glyph_func</primary></indexterm> +<programlisting language="C"><link linkend="void"><returnvalue>void</returnvalue></link> +cairo_user_font_face_set_unicode_to_glyph_func + (<parameter><link linkend="cairo-font-face-t"><type>cairo_font_face_t</type></link> *font_face</parameter>, + <parameter><link linkend="cairo-user-scaled-font-unicode-to-glyph-func-t"><type>cairo_user_scaled_font_unicode_to_glyph_func_t</type></link> unicode_to_glyph_func</parameter>);</programlisting> +<para>Sets the unicode-to-glyph conversion function of a user-font. +See <link linkend="cairo-user-scaled-font-unicode-to-glyph-func-t"><type>cairo_user_scaled_font_unicode_to_glyph_func_t</type></link> for details of how the callback +works.</para> +<para>The font-face should not be immutable or a <link linkend="CAIRO-STATUS-USER-FONT-IMMUTABLE:CAPS"><literal>CAIRO_STATUS_USER_FONT_IMMUTABLE</literal></link> +error will occur. A user font-face is immutable as soon as a scaled-font +is created from it.</para> +<refsect3 id="cairo-user-font-face-set-unicode-to-glyph-func.parameters" role="parameters"> +<title>Parameters</title> +<informaltable role="parameters_table" pgwide="1" frame="none"> +<tgroup cols="3"> +<colspec colname="parameters_name" colwidth="150px"/> +<colspec colname="parameters_description"/> +<colspec colname="parameters_annotations" colwidth="200px"/> +<tbody> +<row><entry role="parameter_name"><para>font_face</para></entry> +<entry role="parameter_description"><para>A user font face</para></entry> +<entry role="parameter_annotations"></entry></row> +<row><entry role="parameter_name"><para>unicode_to_glyph_func</para></entry> +<entry role="parameter_description"><para>The unicode_to_glyph callback, or <link linkend="NULL:CAPS"><literal>NULL</literal></link></para></entry> +<entry role="parameter_annotations"></entry></row> +</tbody></tgroup></informaltable> +</refsect3><para role="since">Since: <link linkend="api-index-1.8">1.8</link></para></refsect2> +<refsect2 id="cairo-user-font-face-get-unicode-to-glyph-func" role="function" condition="since:1.8"> +<title>cairo_user_font_face_get_unicode_to_glyph_func ()</title> +<indexterm zone="cairo-user-font-face-get-unicode-to-glyph-func" role="1.8"><primary sortas="user_font_face_get_unicode_to_glyph_func">cairo_user_font_face_get_unicode_to_glyph_func</primary></indexterm> +<programlisting language="C"><link linkend="cairo-user-scaled-font-unicode-to-glyph-func-t"><returnvalue>cairo_user_scaled_font_unicode_to_glyph_func_t</returnvalue></link> +cairo_user_font_face_get_unicode_to_glyph_func + (<parameter><link linkend="cairo-font-face-t"><type>cairo_font_face_t</type></link> *font_face</parameter>);</programlisting> +<para>Gets the unicode-to-glyph conversion function of a user-font.</para> +<refsect3 id="cairo-user-font-face-get-unicode-to-glyph-func.parameters" role="parameters"> +<title>Parameters</title> +<informaltable role="parameters_table" pgwide="1" frame="none"> +<tgroup cols="3"> +<colspec colname="parameters_name" colwidth="150px"/> +<colspec colname="parameters_description"/> +<colspec colname="parameters_annotations" colwidth="200px"/> +<tbody> +<row><entry role="parameter_name"><para>font_face</para></entry> +<entry role="parameter_description"><para>A user font face</para></entry> +<entry role="parameter_annotations"></entry></row> +</tbody></tgroup></informaltable> +</refsect3><refsect3 id="cairo-user-font-face-get-unicode-to-glyph-func.returns" role="returns"> +<title>Returns</title> +<para> The unicode_to_glyph callback of <parameter>font_face</parameter> +or <link linkend="NULL:CAPS"><literal>NULL</literal></link> if none set or an error occurred.</para> +</refsect3><para role="since">Since: <link linkend="api-index-1.8">1.8</link></para></refsect2> +<refsect2 id="cairo-user-font-face-set-text-to-glyphs-func" role="function" condition="since:1.8"> +<title>cairo_user_font_face_set_text_to_glyphs_func ()</title> +<indexterm zone="cairo-user-font-face-set-text-to-glyphs-func" role="1.8"><primary sortas="user_font_face_set_text_to_glyphs_func">cairo_user_font_face_set_text_to_glyphs_func</primary></indexterm> +<programlisting language="C"><link linkend="void"><returnvalue>void</returnvalue></link> +cairo_user_font_face_set_text_to_glyphs_func + (<parameter><link linkend="cairo-font-face-t"><type>cairo_font_face_t</type></link> *font_face</parameter>, + <parameter><link linkend="cairo-user-scaled-font-text-to-glyphs-func-t"><type>cairo_user_scaled_font_text_to_glyphs_func_t</type></link> text_to_glyphs_func</parameter>);</programlisting> +<para>Sets th text-to-glyphs conversion function of a user-font. +See <link linkend="cairo-user-scaled-font-text-to-glyphs-func-t"><type>cairo_user_scaled_font_text_to_glyphs_func_t</type></link> for details of how the callback +works.</para> +<para>The font-face should not be immutable or a <link linkend="CAIRO-STATUS-USER-FONT-IMMUTABLE:CAPS"><literal>CAIRO_STATUS_USER_FONT_IMMUTABLE</literal></link> +error will occur. A user font-face is immutable as soon as a scaled-font +is created from it.</para> +<refsect3 id="cairo-user-font-face-set-text-to-glyphs-func.parameters" role="parameters"> +<title>Parameters</title> +<informaltable role="parameters_table" pgwide="1" frame="none"> +<tgroup cols="3"> +<colspec colname="parameters_name" colwidth="150px"/> +<colspec colname="parameters_description"/> +<colspec colname="parameters_annotations" colwidth="200px"/> +<tbody> +<row><entry role="parameter_name"><para>font_face</para></entry> +<entry role="parameter_description"><para>A user font face</para></entry> +<entry role="parameter_annotations"></entry></row> +<row><entry role="parameter_name"><para>text_to_glyphs_func</para></entry> +<entry role="parameter_description"><para>The text_to_glyphs callback, or <link linkend="NULL:CAPS"><literal>NULL</literal></link></para></entry> +<entry role="parameter_annotations"></entry></row> +</tbody></tgroup></informaltable> +</refsect3><para role="since">Since: <link linkend="api-index-1.8">1.8</link></para></refsect2> +<refsect2 id="cairo-user-font-face-get-text-to-glyphs-func" role="function" condition="since:1.8"> +<title>cairo_user_font_face_get_text_to_glyphs_func ()</title> +<indexterm zone="cairo-user-font-face-get-text-to-glyphs-func" role="1.8"><primary sortas="user_font_face_get_text_to_glyphs_func">cairo_user_font_face_get_text_to_glyphs_func</primary></indexterm> +<programlisting language="C"><link linkend="cairo-user-scaled-font-text-to-glyphs-func-t"><returnvalue>cairo_user_scaled_font_text_to_glyphs_func_t</returnvalue></link> +cairo_user_font_face_get_text_to_glyphs_func + (<parameter><link linkend="cairo-font-face-t"><type>cairo_font_face_t</type></link> *font_face</parameter>);</programlisting> +<para>Gets the text-to-glyphs conversion function of a user-font.</para> +<refsect3 id="cairo-user-font-face-get-text-to-glyphs-func.parameters" role="parameters"> +<title>Parameters</title> +<informaltable role="parameters_table" pgwide="1" frame="none"> +<tgroup cols="3"> +<colspec colname="parameters_name" colwidth="150px"/> +<colspec colname="parameters_description"/> +<colspec colname="parameters_annotations" colwidth="200px"/> +<tbody> +<row><entry role="parameter_name"><para>font_face</para></entry> +<entry role="parameter_description"><para>A user font face</para></entry> +<entry role="parameter_annotations"></entry></row> +</tbody></tgroup></informaltable> +</refsect3><refsect3 id="cairo-user-font-face-get-text-to-glyphs-func.returns" role="returns"> +<title>Returns</title> +<para> The text_to_glyphs callback of <parameter>font_face</parameter> +or <link linkend="NULL:CAPS"><literal>NULL</literal></link> if none set or an error occurred.</para> +</refsect3><para role="since">Since: <link linkend="api-index-1.8">1.8</link></para></refsect2> + +</refsect1> +<refsect1 id="cairo-User-Fonts.other_details" role="details"> +<title role="details.title">Types and Values</title> +<refsect2 id="CAIRO-HAS-USER-FONT:CAPS" role="macro" condition="since:1.8"> +<title>CAIRO_HAS_USER_FONT</title> +<indexterm zone="CAIRO-HAS-USER-FONT:CAPS" role="1.8"><primary sortas="HAS_USER_FONT">CAIRO_HAS_USER_FONT</primary></indexterm> +<programlisting language="C">#define CAIRO_HAS_USER_FONT 1 +</programlisting> +<para>Defined if the user font backend is available. +This macro can be used to conditionally compile backend-specific code. +The user font backend is always built in versions of cairo that support +this feature (1.8 and later).</para> +<para role="since">Since: <link linkend="api-index-1.8">1.8</link></para></refsect2> + +</refsect1> + +</refentry> |