cairo.xml

按照官方的说法：Cairo is a vector graphics library with cross-device output support. 翻译过来

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                "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd" [
<!ENTITY version SYSTEM "version.xml">
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<refentry id="cairo-cairo-t">
<refmeta>
<refentrytitle id="top_of_page">cairo_t</refentrytitle>
<manvolnum>3</manvolnum>
<refmiscinfo>CAIRO Library</refmiscinfo>
</refmeta>

<refnamediv>
<refname>cairo_t</refname>
<refpurpose>The cairo drawing context</refpurpose>
<!--[<xref linkend="desc" endterm="desc.title"/>]-->
</refnamediv>

<refsynopsisdiv id="synopsis">
<title id="synopsis.title">Synopsis</title>

<synopsis>



typedef     <link linkend="cairo-t">cairo_t</link>;
<link linkend="cairo-t">cairo_t</link>*    <link linkend="cairo-create">cairo_create</link>                    (<link linkend="cairo-surface-t">cairo_surface_t</link> *target);
<link linkend="cairo-t">cairo_t</link>*    <link linkend="cairo-reference">cairo_reference</link>                 (<link linkend="cairo-t">cairo_t</link> *cr);
<link linkend="void">void</link>        <link linkend="cairo-destroy">cairo_destroy</link>                   (<link linkend="cairo-t">cairo_t</link> *cr);
<link linkend="cairo-status-t">cairo_status_t</link> <link linkend="cairo-status">cairo_status</link>                 (<link linkend="cairo-t">cairo_t</link> *cr);
<link linkend="void">void</link>        <link linkend="cairo-save">cairo_save</link>                      (<link linkend="cairo-t">cairo_t</link> *cr);
<link linkend="void">void</link>        <link linkend="cairo-restore">cairo_restore</link>                   (<link linkend="cairo-t">cairo_t</link> *cr);
<link linkend="cairo-surface-t">cairo_surface_t</link>* <link linkend="cairo-get-target">cairo_get_target</link>           (<link linkend="cairo-t">cairo_t</link> *cr);
<link linkend="void">void</link>        <link linkend="cairo-push-group">cairo_push_group</link>                (<link linkend="cairo-t">cairo_t</link> *cr);
<link linkend="void">void</link>        <link linkend="cairo-push-group-with-content">cairo_push_group_with_content</link>   (<link linkend="cairo-t">cairo_t</link> *cr,
                                             <link linkend="cairo-content-t">cairo_content_t</link> content);
<link linkend="cairo-pattern-t">cairo_pattern_t</link>* <link linkend="cairo-pop-group">cairo_pop_group</link>            (<link linkend="cairo-t">cairo_t</link> *cr);
<link linkend="void">void</link>        <link linkend="cairo-pop-group-to-source">cairo_pop_group_to_source</link>       (<link linkend="cairo-t">cairo_t</link> *cr);
<link linkend="cairo-surface-t">cairo_surface_t</link>* <link linkend="cairo-get-group-target">cairo_get_group_target</link>     (<link linkend="cairo-t">cairo_t</link> *cr);
<link linkend="void">void</link>        <link linkend="cairo-set-source-rgb">cairo_set_source_rgb</link>            (<link linkend="cairo-t">cairo_t</link> *cr,
                                             <link linkend="double">double</link> red,
                                             <link linkend="double">double</link> green,
                                             <link linkend="double">double</link> blue);
<link linkend="void">void</link>        <link linkend="cairo-set-source-rgba">cairo_set_source_rgba</link>           (<link linkend="cairo-t">cairo_t</link> *cr,
                                             <link linkend="double">double</link> red,
                                             <link linkend="double">double</link> green,
                                             <link linkend="double">double</link> blue,
                                             <link linkend="double">double</link> alpha);
<link linkend="void">void</link>        <link linkend="cairo-set-source">cairo_set_source</link>                (<link linkend="cairo-t">cairo_t</link> *cr,
                                             <link linkend="cairo-pattern-t">cairo_pattern_t</link> *source);
<link linkend="void">void</link>        <link linkend="cairo-set-source-surface">cairo_set_source_surface</link>        (<link linkend="cairo-t">cairo_t</link> *cr,
                                             <link linkend="cairo-surface-t">cairo_surface_t</link> *surface,
                                             <link linkend="double">double</link> x,
                                             <link linkend="double">double</link> y);
<link linkend="cairo-pattern-t">cairo_pattern_t</link>* <link linkend="cairo-get-source">cairo_get_source</link>           (<link linkend="cairo-t">cairo_t</link> *cr);
enum        <link linkend="cairo-antialias-t">cairo_antialias_t</link>;
<link linkend="void">void</link>        <link linkend="cairo-set-antialias">cairo_set_antialias</link>             (<link linkend="cairo-t">cairo_t</link> *cr,
                                             <link linkend="cairo-antialias-t">cairo_antialias_t</link> antialias);
<link linkend="cairo-antialias-t">cairo_antialias_t</link> <link linkend="cairo-get-antialias">cairo_get_antialias</link>       (<link linkend="cairo-t">cairo_t</link> *cr);
<link linkend="void">void</link>        <link linkend="cairo-set-dash">cairo_set_dash</link>                  (<link linkend="cairo-t">cairo_t</link> *cr,
                                             <link linkend="double">double</link> *dashes,
                                             <link linkend="int">int</link> num_dashes,
                                             <link linkend="double">double</link> offset);
enum        <link linkend="cairo-fill-rule-t">cairo_fill_rule_t</link>;
<link linkend="void">void</link>        <link linkend="cairo-set-fill-rule">cairo_set_fill_rule</link>             (<link linkend="cairo-t">cairo_t</link> *cr,
                                             <link linkend="cairo-fill-rule-t">cairo_fill_rule_t</link> fill_rule);
<link linkend="cairo-fill-rule-t">cairo_fill_rule_t</link> <link linkend="cairo-get-fill-rule">cairo_get_fill_rule</link>       (<link linkend="cairo-t">cairo_t</link> *cr);
enum        <link linkend="cairo-line-cap-t">cairo_line_cap_t</link>;
<link linkend="void">void</link>        <link linkend="cairo-set-line-cap">cairo_set_line_cap</link>              (<link linkend="cairo-t">cairo_t</link> *cr,
                                             <link linkend="cairo-line-cap-t">cairo_line_cap_t</link> line_cap);
<link linkend="cairo-line-cap-t">cairo_line_cap_t</link> <link linkend="cairo-get-line-cap">cairo_get_line_cap</link>         (<link linkend="cairo-t">cairo_t</link> *cr);
enum        <link linkend="cairo-line-join-t">cairo_line_join_t</link>;
<link linkend="void">void</link>        <link linkend="cairo-set-line-join">cairo_set_line_join</link>             (<link linkend="cairo-t">cairo_t</link> *cr,
                                             <link linkend="cairo-line-join-t">cairo_line_join_t</link> line_join);
<link linkend="cairo-line-join-t">cairo_line_join_t</link> <link linkend="cairo-get-line-join">cairo_get_line_join</link>       (<link linkend="cairo-t">cairo_t</link> *cr);
<link linkend="void">void</link>        <link linkend="cairo-set-line-width">cairo_set_line_width</link>            (<link linkend="cairo-t">cairo_t</link> *cr,
                                             <link linkend="double">double</link> width);
<link linkend="double">double</link>      <link linkend="cairo-get-line-width">cairo_get_line_width</link>            (<link linkend="cairo-t">cairo_t</link> *cr);
<link linkend="void">void</link>        <link linkend="cairo-set-miter-limit">cairo_set_miter_limit</link>           (<link linkend="cairo-t">cairo_t</link> *cr,
                                             <link linkend="double">double</link> limit);
<link linkend="double">double</link>      <link linkend="cairo-get-miter-limit">cairo_get_miter_limit</link>           (<link linkend="cairo-t">cairo_t</link> *cr);
enum        <link linkend="cairo-operator-t">cairo_operator_t</link>;
<link linkend="void">void</link>        <link linkend="cairo-set-operator">cairo_set_operator</link>              (<link linkend="cairo-t">cairo_t</link> *cr,
                                             <link linkend="cairo-operator-t">cairo_operator_t</link> op);
<link linkend="cairo-operator-t">cairo_operator_t</link> <link linkend="cairo-get-operator">cairo_get_operator</link>         (<link linkend="cairo-t">cairo_t</link> *cr);
<link linkend="void">void</link>        <link linkend="cairo-set-tolerance">cairo_set_tolerance</link>             (<link linkend="cairo-t">cairo_t</link> *cr,
                                             <link linkend="double">double</link> tolerance);
<link linkend="double">double</link>      <link linkend="cairo-get-tolerance">cairo_get_tolerance</link>             (<link linkend="cairo-t">cairo_t</link> *cr);
<link linkend="void">void</link>        <link linkend="cairo-clip">cairo_clip</link>                      (<link linkend="cairo-t">cairo_t</link> *cr);
<link linkend="void">void</link>        <link linkend="cairo-clip-preserve">cairo_clip_preserve</link>             (<link linkend="cairo-t">cairo_t</link> *cr);
<link linkend="void">void</link>        <link linkend="cairo-reset-clip">cairo_reset_clip</link>                (<link linkend="cairo-t">cairo_t</link> *cr);
<link linkend="void">void</link>        <link linkend="cairo-fill">cairo_fill</link>                      (<link linkend="cairo-t">cairo_t</link> *cr);
<link linkend="void">void</link>        <link linkend="cairo-fill-preserve">cairo_fill_preserve</link>             (<link linkend="cairo-t">cairo_t</link> *cr);
<link linkend="void">void</link>        <link linkend="cairo-fill-extents">cairo_fill_extents</link>              (<link linkend="cairo-t">cairo_t</link> *cr,
                                             <link linkend="double">double</link> *x1,
                                             <link linkend="double">double</link> *y1,
                                             <link linkend="double">double</link> *x2,
                                             <link linkend="double">double</link> *y2);
<link linkend="cairo-bool-t">cairo_bool_t</link> <link linkend="cairo-in-fill">cairo_in_fill</link>                  (<link linkend="cairo-t">cairo_t</link> *cr,
                                             <link linkend="double">double</link> x,
                                             <link linkend="double">double</link> y);
<link linkend="void">void</link>        <link linkend="cairo-mask">cairo_mask</link>                      (<link linkend="cairo-t">cairo_t</link> *cr,
                                             <link linkend="cairo-pattern-t">cairo_pattern_t</link> *pattern);
<link linkend="void">void</link>        <link linkend="cairo-mask-surface">cairo_mask_surface</link>              (<link linkend="cairo-t">cairo_t</link> *cr,
                                             <link linkend="cairo-surface-t">cairo_surface_t</link> *surface,
                                             <link linkend="double">double</link> surface_x,
                                             <link linkend="double">double</link> surface_y);
<link linkend="void">void</link>        <link linkend="cairo-paint">cairo_paint</link>                     (<link linkend="cairo-t">cairo_t</link> *cr);
<link linkend="void">void</link>        <link linkend="cairo-paint-with-alpha">cairo_paint_with_alpha</link>          (<link linkend="cairo-t">cairo_t</link> *cr,
                                             <link linkend="double">double</link> alpha);
<link linkend="void">void</link>        <link linkend="cairo-stroke">cairo_stroke</link>                    (<link linkend="cairo-t">cairo_t</link> *cr);
<link linkend="void">void</link>        <link linkend="cairo-stroke-preserve">cairo_stroke_preserve</link>           (<link linkend="cairo-t">cairo_t</link> *cr);
<link linkend="void">void</link>        <link linkend="cairo-stroke-extents">cairo_stroke_extents</link>            (<link linkend="cairo-t">cairo_t</link> *cr,
                                             <link linkend="double">double</link> *x1,
                                             <link linkend="double">double</link> *y1,
                                             <link linkend="double">double</link> *x2,
                                             <link linkend="double">double</link> *y2);
<link linkend="cairo-bool-t">cairo_bool_t</link> <link linkend="cairo-in-stroke">cairo_in_stroke</link>                (<link linkend="cairo-t">cairo_t</link> *cr,
                                             <link linkend="double">double</link> x,
                                             <link linkend="double">double</link> y);
<link linkend="void">void</link>        <link linkend="cairo-copy-page">cairo_copy_page</link>                 (<link linkend="cairo-t">cairo_t</link> *cr);
<link linkend="void">void</link>        <link linkend="cairo-show-page">cairo_show_page</link>                 (<link linkend="cairo-t">cairo_t</link> *cr);

</synopsis>
</refsynopsisdiv>









<refsect1 id="desc">
<title id="desc.title">Description</title>

  <para>
    <link linkend="cairo-t"><type>cairo_t</type></link> is the main object used when drawing with cairo. To
    draw with cairo, you create a <link linkend="cairo-t"><type>cairo_t</type></link>, set the target surface,
    and drawing options for the <link linkend="cairo-t"><type>cairo_t</type></link>, create shapes with
    functions like <link linkend="cairo-move-to"><function>cairo_move_to()</function></link> and <link linkend="cairo-line-to"><function>cairo_line_to()</function></link>, and then
    draw shapes with <link linkend="cairo-stroke"><function>cairo_stroke()</function></link> or <link linkend="cairo-fill"><function>cairo_fill()</function></link>.
  </para>
  <para>
    <link linkend="cairo-t"><type>cairo_t</type></link><!-- -->'s can be pushed to a stack via <link linkend="cairo-save"><function>cairo_save()</function></link>.
    They may then safely be changed, without loosing the current state.
    Use <link linkend="cairo-restore"><function>cairo_restore()</function></link> to restore to the saved state.
  </para>
</refsect1>

<refsect1 id="details">
<title id="details.title">Details</title>
<refsect2>
<title><anchor id="cairo-t" role="typedef"/>cairo_t</title>
<indexterm><primary>cairo_t</primary></indexterm><programlisting>typedef struct _cairo cairo_t;
</programlisting>
<para>
A <link linkend="cairo-t"><type>cairo_t</type></link> contains the current state of the rendering device,
including coordinates of yet to be drawn shapes.</para>
<para>

</para></refsect2>
<refsect2>
<title><anchor id="cairo-create" role="function"/>cairo_create ()</title>
<indexterm><primary>cairo_create</primary></indexterm><programlisting><link linkend="cairo-t">cairo_t</link>*    cairo_create                    (<link linkend="cairo-surface-t">cairo_surface_t</link> *target);</programlisting>
</refsect2>
<refsect2>
<title><anchor id="cairo-reference" role="function"/>cairo_reference ()</title>
<indexterm><primary>cairo_reference</primary></indexterm><programlisting><link linkend="cairo-t">cairo_t</link>*    cairo_reference                 (<link linkend="cairo-t">cairo_t</link> *cr);</programlisting>
</refsect2>
<refsect2>
<title><anchor id="cairo-destroy" role="function"/>cairo_destroy ()</title>
<indexterm><primary>cairo_destroy</primary></indexterm><programlisting><link linkend="void">void</link>        cairo_destroy                   (<link linkend="cairo-t">cairo_t</link> *cr);</programlisting>
</refsect2>
<refsect2>
<title><anchor id="cairo-status" role="function"/>cairo_status ()</title>
<indexterm><primary>cairo_status</primary></indexterm><programlisting><link linkend="cairo-status-t">cairo_status_t</link> cairo_status                 (<link linkend="cairo-t">cairo_t</link> *cr);</programlisting>
</refsect2>
<refsect2>
<title><anchor id="cairo-save" role="function"/>cairo_save ()</title>
<indexterm><primary>cairo_save</primary></indexterm><programlisting><link linkend="void">void</link>        cairo_save                      (<link linkend="cairo-t">cairo_t</link> *cr);</programlisting>
</refsect2>
<refsect2>
<title><anchor id="cairo-restore" role="function"/>cairo_restore ()</title>
<indexterm><primary>cairo_restore</primary></indexterm><programlisting><link linkend="void">void</link>        cairo_restore                   (<link linkend="cairo-t">cairo_t</link> *cr);</programlisting>
</refsect2>