cairo-image.xml

来自「按照官方的说法：Cairo is a vector graphics libra」· XML 代码 · 共 167 行

<?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-Image-Surfaces">
<refmeta>
<refentrytitle id="top_of_page">Image Surfaces</refentrytitle>
<manvolnum>3</manvolnum>
<refmiscinfo>CAIRO Library</refmiscinfo>
</refmeta>

<refnamediv>
<refname>Image Surfaces</refname>
<refpurpose>Rendering to memory buffers</refpurpose>
<!--[<xref linkend="desc" endterm="desc.title"/>]-->
</refnamediv>

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

<synopsis>



enum        <link linkend="cairo-format-t">cairo_format_t</link>;
<link linkend="cairo-surface-t">cairo_surface_t</link>* <link linkend="cairo-image-surface-create">cairo_image_surface_create</link> (<link linkend="cairo-format-t">cairo_format_t</link> format,
                                             <link linkend="int">int</link> width,
                                             <link linkend="int">int</link> height);
<link linkend="cairo-surface-t">cairo_surface_t</link>* <link linkend="cairo-image-surface-create-for-data">cairo_image_surface_create_for_data</link>
                                            (unsigned <link linkend="char">char</link> *data,
                                             <link linkend="cairo-format-t">cairo_format_t</link> format,
                                             <link linkend="int">int</link> width,
                                             <link linkend="int">int</link> height,
                                             <link linkend="int">int</link> stride);
unsigned <link linkend="char">char</link>* <link linkend="cairo-image-surface-get-data">cairo_image_surface_get_data</link> (<link linkend="cairo-surface-t">cairo_surface_t</link> *surface);
<link linkend="cairo-format-t">cairo_format_t</link> <link linkend="cairo-image-surface-get-format">cairo_image_surface_get_format</link>
                                            (<link linkend="cairo-surface-t">cairo_surface_t</link> *surface);
<link linkend="int">int</link>         <link linkend="cairo-image-surface-get-width">cairo_image_surface_get_width</link>   (<link linkend="cairo-surface-t">cairo_surface_t</link> *surface);
<link linkend="int">int</link>         <link linkend="cairo-image-surface-get-height">cairo_image_surface_get_height</link>  (<link linkend="cairo-surface-t">cairo_surface_t</link> *surface);
<link linkend="int">int</link>         <link linkend="cairo-image-surface-get-stride">cairo_image_surface_get_stride</link>  (<link linkend="cairo-surface-t">cairo_surface_t</link> *surface);
</synopsis>
</refsynopsisdiv>









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

  <para>
    Image surfaces provide the ability to render to memory buffers
    either allocated by cairo or by the calling code.  The supported
    image formats are those defined in <link linkend="cairo-format-t"><type>cairo_format_t</type></link>.
  </para>
</refsect1>

<refsect1 id="details">
<title id="details.title">Details</title>
<refsect2>
<title><anchor id="cairo-format-t" role="enum"/>enum cairo_format_t</title>
<indexterm><primary>cairo_format_t</primary></indexterm><programlisting>typedef enum _cairo_format {
    CAIRO_FORMAT_ARGB32,
    CAIRO_FORMAT_RGB24,
    CAIRO_FORMAT_A8,
    CAIRO_FORMAT_A1,
    CAIRO_FORMAT_RGB16_565
} cairo_format_t;
</programlisting>
<para>
<link linkend="cairo-format-t"><type>cairo_format_t</type></link> is used to identify the memory format of
image data.</para>
<para>

</para><variablelist role="enum">
<varlistentry>
<term><anchor id="CAIRO-FORMAT-ARGB32:CAPS" role="constant"/><literal>CAIRO_FORMAT_ARGB32</literal></term>
<listitem><simpara> each pixel is a 32-bit quantity, with
  alpha in the upper 8 bits, then red, then green, then blue.
  The 32-bit quantities are stored native-endian. Pre-multiplied
  alpha is used. (That is, 50% transparent red is 0x80800000,
  not 0x80ff0000.)
</simpara></listitem>
</varlistentry>
<varlistentry>
<term><anchor id="CAIRO-FORMAT-RGB24:CAPS" role="constant"/><literal>CAIRO_FORMAT_RGB24</literal></term>
<listitem><simpara> each pixel is a 32-bit quantity, with
  the upper 8 bits unused. Red, Green, and Blue are stored
  in the remaining 24 bits in that order.
</simpara></listitem>
</varlistentry>
<varlistentry>
<term><anchor id="CAIRO-FORMAT-A8:CAPS" role="constant"/><literal>CAIRO_FORMAT_A8</literal></term>
<listitem><simpara> each pixel is a 8-bit quantity holding
  an alpha value.
</simpara></listitem>
</varlistentry>
<varlistentry>
<term><anchor id="CAIRO-FORMAT-A1:CAPS" role="constant"/><literal>CAIRO_FORMAT_A1</literal></term>
<listitem><simpara> each pixel is a 1-bit quantity holding
  an alpha value. Pixels are packed together into 32-bit
  quantities. The ordering of the bits matches the
  endianess of the platform. On a big-endian machine, the
  first pixel is in the uppermost bit, on a little-endian
  machine the first pixel is in the least-significant bit.
</simpara></listitem>
</varlistentry>
<varlistentry>
<term><anchor id="CAIRO-FORMAT-RGB16-565:CAPS" role="constant"/><literal>CAIRO_FORMAT_RGB16_565</literal></term>
<listitem><simpara> each pixel is a 16-bit quantity,
  with red in the upper 5 bits, then green in the next 6,
  then blue in the lowest 5 bits. (Since 1.2)
</simpara></listitem>
</varlistentry>
</variablelist></refsect2>
<refsect2>
<title><anchor id="cairo-image-surface-create" role="function"/>cairo_image_surface_create ()</title>
<indexterm><primary>cairo_image_surface_create</primary></indexterm><programlisting><link linkend="cairo-surface-t">cairo_surface_t</link>* cairo_image_surface_create (<link linkend="cairo-format-t">cairo_format_t</link> format,
                                             <link linkend="int">int</link> width,
                                             <link linkend="int">int</link> height);</programlisting>
</refsect2>
<refsect2>
<title><anchor id="cairo-image-surface-create-for-data" role="function"/>cairo_image_surface_create_for_data ()</title>
<indexterm><primary>cairo_image_surface_create_for_data</primary></indexterm><programlisting><link linkend="cairo-surface-t">cairo_surface_t</link>* cairo_image_surface_create_for_data
                                            (unsigned <link linkend="char">char</link> *data,
                                             <link linkend="cairo-format-t">cairo_format_t</link> format,
                                             <link linkend="int">int</link> width,
                                             <link linkend="int">int</link> height,
                                             <link linkend="int">int</link> stride);</programlisting>
</refsect2>
<refsect2>
<title><anchor id="cairo-image-surface-get-data" role="function" condition="since:1.2"/>cairo_image_surface_get_data ()</title>
<indexterm role="1.2"><primary>cairo_image_surface_get_data</primary></indexterm><programlisting>unsigned <link linkend="char">char</link>* cairo_image_surface_get_data (<link linkend="cairo-surface-t">cairo_surface_t</link> *surface);</programlisting>
<para>Since  1.2
</para></refsect2>
<refsect2>
<title><anchor id="cairo-image-surface-get-format" role="function" condition="since:1.2"/>cairo_image_surface_get_format ()</title>
<indexterm role="1.2"><primary>cairo_image_surface_get_format</primary></indexterm><programlisting><link linkend="cairo-format-t">cairo_format_t</link> cairo_image_surface_get_format
                                            (<link linkend="cairo-surface-t">cairo_surface_t</link> *surface);</programlisting>
<para>Since  1.2
</para></refsect2>
<refsect2>
<title><anchor id="cairo-image-surface-get-width" role="function"/>cairo_image_surface_get_width ()</title>
<indexterm><primary>cairo_image_surface_get_width</primary></indexterm><programlisting><link linkend="int">int</link>         cairo_image_surface_get_width   (<link linkend="cairo-surface-t">cairo_surface_t</link> *surface);</programlisting>
</refsect2>
<refsect2>
<title><anchor id="cairo-image-surface-get-height" role="function"/>cairo_image_surface_get_height ()</title>
<indexterm><primary>cairo_image_surface_get_height</primary></indexterm><programlisting><link linkend="int">int</link>         cairo_image_surface_get_height  (<link linkend="cairo-surface-t">cairo_surface_t</link> *surface);</programlisting>
</refsect2>
<refsect2>
<title><anchor id="cairo-image-surface-get-stride" role="function" condition="since:1.2"/>cairo_image_surface_get_stride ()</title>
<indexterm role="1.2"><primary>cairo_image_surface_get_stride</primary></indexterm><programlisting><link linkend="int">int</link>         cairo_image_surface_get_stride  (<link linkend="cairo-surface-t">cairo_surface_t</link> *surface);</programlisting>
<para>Since  1.2
</para></refsect2>

</refsect1>




</refentry>