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<a href="#id2598904" class="shortcut">Description</a></nobr></td></tr>
</table>
<div class="refentry" lang="en">
<a name="cairo-cairo-surface-t"></a><div class="titlepage"></div>
<div class="refnamediv"><table width="100%"><tr>
<td valign="top">
<h2>
<a name="id2557483"></a><span class="refentrytitle">cairo_surface_t</span>
</h2>
<p>cairo_surface_t — Base class for surfaces</p>
</td>
<td valign="top" align="right"></td>
</tr></table></div>
<div class="refsynopsisdiv">
<h2>Synopsis</h2>
<pre class="synopsis">
typedef <a href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a>;
enum <a href="cairo-cairo-surface-t.html#cairo-content-t">cairo_content_t</a>;
<a href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a>* <a href="cairo-cairo-surface-t.html#cairo-surface-create-similar">cairo_surface_create_similar</a>
(<a href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *other,
<a href="cairo-cairo-surface-t.html#cairo-content-t">cairo_content_t</a> content,
int width,
int height);
void <a href="cairo-cairo-surface-t.html#cairo-surface-destroy">cairo_surface_destroy</a> (<a href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface);
void <a href="cairo-cairo-surface-t.html#cairo-surface-finish">cairo_surface_finish</a> (<a href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface);
void <a href="cairo-cairo-surface-t.html#cairo-surface-flush">cairo_surface_flush</a> (<a href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface);
void <a href="cairo-cairo-surface-t.html#cairo-surface-get-font-options">cairo_surface_get_font_options</a> (<a href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface,
<a href="cairo-Font-Options.html#cairo-font-options-t">cairo_font_options_t</a> *options);
<a href="cairo-cairo-surface-t.html#cairo-content-t">cairo_content_t</a> <a href="cairo-cairo-surface-t.html#cairo-surface-get-content">cairo_surface_get_content</a> (<a href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface);
<a href="cairo-Error-handling.html#cairo-status-t">cairo_status_t</a> <a href="cairo-cairo-surface-t.html#cairo-surface-set-user-data">cairo_surface_set_user_data</a> (<a href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface,
const <a href="cairo-Types.html#cairo-user-data-key-t">cairo_user_data_key_t</a> *key,
void *user_data,
<a href="cairo-Types.html#cairo-destroy-func-t">cairo_destroy_func_t</a> destroy);
void* <a href="cairo-cairo-surface-t.html#cairo-surface-get-user-data">cairo_surface_get_user_data</a> (<a href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface,
const <a href="cairo-Types.html#cairo-user-data-key-t">cairo_user_data_key_t</a> *key);
void <a href="cairo-cairo-surface-t.html#cairo-surface-mark-dirty">cairo_surface_mark_dirty</a> (<a href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface);
void <a href="cairo-cairo-surface-t.html#cairo-surface-mark-dirty-rectangle">cairo_surface_mark_dirty_rectangle</a>
(<a href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface,
int x,
int y,
int width,
int height);
<a href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a>* <a href="cairo-cairo-surface-t.html#cairo-surface-reference">cairo_surface_reference</a> (<a href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface);
void <a href="cairo-cairo-surface-t.html#cairo-surface-set-device-offset">cairo_surface_set_device_offset</a> (<a href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface,
double x_offset,
double y_offset);
void <a href="cairo-cairo-surface-t.html#cairo-surface-get-device-offset">cairo_surface_get_device_offset</a> (<a href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface,
double *x_offset,
double *y_offset);
void <a href="cairo-cairo-surface-t.html#cairo-surface-set-fallback-resolution">cairo_surface_set_fallback_resolution</a>
(<a href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface,
double x_pixels_per_inch,
double y_pixels_per_inch);
<a href="cairo-Error-handling.html#cairo-status-t">cairo_status_t</a> <a href="cairo-cairo-surface-t.html#cairo-surface-status">cairo_surface_status</a> (<a href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface);
enum <a href="cairo-cairo-surface-t.html#cairo-surface-type-t">cairo_surface_type_t</a>;
<a href="cairo-cairo-surface-t.html#cairo-surface-type-t">cairo_surface_type_t</a> <a href="cairo-cairo-surface-t.html#cairo-surface-get-type">cairo_surface_get_type</a> (<a href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface);
</pre>
</div>
<div class="refsect1" lang="en">
<a name="id2598904"></a><h2>Description</h2>
<p>
</p>
</div>
<div class="refsect1" lang="en">
<a name="id2598920"></a><h2>Details</h2>
<div class="refsect2" lang="en">
<a name="id2598930"></a><h3>
<a name="cairo-surface-t"></a>cairo_surface_t</h3>
<a class="indexterm" name="id2598943"></a><pre class="programlisting">typedef struct _cairo_surface cairo_surface_t;
</pre>
<p>
A <a href="cairo-cairo-surface-t.html#cairo-surface-t"><span class="type">cairo_surface_t</span></a> represents an image, either as the destination
of a drawing operation or as source when drawing onto another
surface. There are different subtypes of cairo_surface_t for
different drawing backends; for example, <a href="cairo-Image-Surfaces.html#cairo-image-surface-create"><code class="function">cairo_image_surface_create()</code></a>
creates a bitmap image in memory.
</p>
<p>
Memory management of <a href="cairo-cairo-surface-t.html#cairo-surface-t"><span class="type">cairo_surface_t</span></a> is done with
<a href="cairo-cairo-surface-t.html#cairo-surface-reference"><code class="function">cairo_surface_reference()</code></a> and <a href="cairo-cairo-surface-t.html#cairo-surface-destroy"><code class="function">cairo_surface_destroy()</code></a>.</p>
<p>
</p>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2599011"></a><h3>
<a name="cairo-content-t"></a>enum cairo_content_t</h3>
<a class="indexterm" name="id2599023"></a><pre class="programlisting">typedef enum _cairo_content {
CAIRO_CONTENT_COLOR = 0x1000,
CAIRO_CONTENT_ALPHA = 0x2000,
CAIRO_CONTENT_COLOR_ALPHA = 0x3000
} cairo_content_t;
</pre>
<p>
<a href="cairo-cairo-surface-t.html#cairo-content-t"><span class="type">cairo_content_t</span></a> is used to describe the content that a surface will
contain, whether color information, alpha information (translucence
vs. opacity), or both.
</p>
<p>
Note: The large values here are designed to keep cairo_content_t
values distinct from cairo_format_t values so that the
implementation can detect the error if users confuse the two types.</p>
<p>
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td>
<span class="term"><a name="CAIRO-CONTENT-COLOR:CAPS"></a><code class="literal">CAIRO_CONTENT_COLOR</code></span></td>
<td> The surface will hold color content only.
</td>
</tr>
<tr>
<td>
<span class="term"><a name="CAIRO-CONTENT-ALPHA:CAPS"></a><code class="literal">CAIRO_CONTENT_ALPHA</code></span></td>
<td> The surface will hold alpha content only.
</td>
</tr>
<tr>
<td>
<span class="term"><a name="CAIRO-CONTENT-COLOR-ALPHA:CAPS"></a><code class="literal">CAIRO_CONTENT_COLOR_ALPHA</code></span></td>
<td> The surface will hold color and alpha content.
</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2591939"></a><h3>
<a name="cairo-surface-create-similar"></a>cairo_surface_create_similar ()</h3>
<a class="indexterm" name="id2591952"></a><pre class="programlisting"><a href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a>* cairo_surface_create_similar
(<a href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *other,
<a href="cairo-cairo-surface-t.html#cairo-content-t">cairo_content_t</a> content,
int width,
int height);</pre>
<p>
Create a new surface that is as compatible as possible with an
existing surface. For example the new surface will have the same
fallback resolution and font options as <em class="parameter"><code>other</code></em>. Generally, the new
surface will also use the same backend as <em class="parameter"><code>other</code></em>, unless that is
not possible for some reason. The type of the returned surface may
be examined with <a href="cairo-cairo-surface-t.html#cairo-surface-get-type"><code class="function">cairo_surface_get_type()</code></a>.
</p>
<p>
Initially the surface contents are all 0 (transparent if contents
have transparency, black otherwise.)</p>
<p>
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td>
<span class="term"><em class="parameter"><code>other</code></em> :</span></td>
<td> an existing surface used to select the backend of the new surface
</td>
</tr>
<tr>
<td>
<span class="term"><em class="parameter"><code>content</code></em> :</span></td>
<td> the content for the new surface
</td>
</tr>
<tr>
<td>
<span class="term"><em class="parameter"><code>width</code></em> :</span></td>
<td> width of the new surface, (in device-space units)
</td>
</tr>
<tr>
<td>
<span class="term"><em class="parameter"><code>height</code></em> :</span></td>
<td> height of the new surface (in device-space units)
</td>
</tr>
<tr>
<td>
<span class="term"><span class="emphasis"><em>Returns</em></span> :</span></td>
<td> a pointer to the newly allocated surface. The caller
owns the surface and should call cairo_surface_destroy when done
with it.
This function always returns a valid pointer, but it will return a
pointer to a "nil" surface if <em class="parameter"><code>other</code></em> is already in an error state
or any other error occurs.
</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2592121"></a><h3>
<a name="cairo-surface-destroy"></a>cairo_surface_destroy ()</h3>
<a class="indexterm" name="id2592133"></a><pre class="programlisting">void cairo_surface_destroy (<a href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface);</pre>
<p>
Decreases the reference count on <em class="parameter"><code>surface</code></em> by one. If the result is
zero, then <em class="parameter"><code>surface</code></em> and all associated resources are freed. See
<a href="cairo-cairo-surface-t.html#cairo-surface-reference"><code class="function">cairo_surface_reference()</code></a>.</p>
<p>
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody><tr>
<td>
<span class="term"><em class="parameter"><code>surface</code></em> :</span></td>
<td> a <a href="cairo-cairo-t.html#cairo-t"><span class="type">cairo_t</span></a>
</td>
</tr></tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2600930"></a><h3>
<a name="cairo-surface-finish"></a>cairo_surface_finish ()</h3>
<a class="indexterm" name="id2600941"></a><pre class="programlisting">void cairo_surface_finish (<a href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface);</pre>
<p>
This function finishes the surface and drops all references to
external resources. For example, for the Xlib backend it means
that cairo will no longer access the drawable, which can be freed.
After calling <a href="cairo-cairo-surface-t.html#cairo-surface-finish"><code class="function">cairo_surface_finish()</code></a> the only valid operations on a
surface are getting and setting user data and referencing and
destroying it. Further drawing to the surface will not affect the
surface but will instead trigger a CAIRO_STATUS_SURFACE_FINISHED
error.
</p>
<p>
When the last call to <a href="cairo-cairo-surface-t.html#cairo-surface-destroy"><code class="function">cairo_surface_destroy()</code></a> decreases the
reference count to zero, cairo will call <a href="cairo-cairo-surface-t.html#cairo-surface-finish"><code class="function">cairo_surface_finish()</code></a> if
it hasn't been called already, before freeing the resources
associated with the surface.</p>
<p>
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody><tr>
<td>
<span class="term"><em class="parameter"><code>surface</code></em> :</span></td>
<td> the <a href="cairo-cairo-surface-t.html#cairo-surface-t"><span class="type">cairo_surface_t</span></a> to finish
</td>
</tr></tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2568677"></a><h3>
<a name="cairo-surface-flush"></a>cairo_surface_flush ()</h3>
<a class="indexterm" name="id2550471"></a><pre class="programlisting">void cairo_surface_flush (<a href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface);</pre>
<p>
Do any pending drawing for the surface and also restore any
temporary modification's cairo has made to the surface's
state. This function must be called before switching from
drawing on the surface with cairo to drawing on it directly
with native APIs. If the surface doesn't support direct access,
then this function does nothing.</p>
<p>
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody><tr>
<td>
<span class="term"><em class="parameter"><code>surface</code></em> :</span></td>
<td> a <a href="cairo-cairo-surface-t.html#cairo-surface-t"><span class="type">cairo_surface_t</span></a>
</td>
</tr></tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2601075"></a><h3>
<a name="cairo-surface-get-font-options"></a>cairo_surface_get_font_options ()</h3>
<a class="indexterm" name="id2601088"></a><pre class="programlisting">void cairo_surface_get_font_options (<a href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface,
<a href="cairo-Font-Options.html#cairo-font-options-t">cairo_font_options_t</a> *options);</pre>
<p>
Retrieves the default font rendering options for the surface.
This allows display surfaces to report the correct subpixel order
for rendering on them, print surfaces to disable hinting of
metrics and so forth. The result can then be used with
<a href="cairo-Scaled-Fonts.html#cairo-scaled-font-create"><code class="function">cairo_scaled_font_create()</code></a>.</p>
<p>
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td>
<span class="term"><em class="parameter"><code>surface</code></em> :</span></td>
<td> a <a href="cairo-cairo-surface-t.html#cairo-surface-t"><span class="type">cairo_surface_t</span></a>
</td>
</tr>
<tr>
<td>
<span class="term"><em class="parameter"><code>options</code></em> :</span></td>
<td> a <a href="cairo-Font-Options.html#cairo-font-options-t"><span class="type">cairo_font_options_t</span></a> object into which to store
the retrieved options. All existing values are overwritten
</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2601178"></a><h3>
<a name="cairo-surface-get-content"></a>cairo_surface_get_content ()</h3>
<a class="indexterm" name="id2601191"></a><pre class="programlisting"><a href="cairo-cairo-surface-t.html#cairo-content-t">cairo_content_t</a> cairo_surface_get_content (<a href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface);</pre>
<p>
</p>
<p>
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td>
<span class="term"><em class="parameter"><code>surface</code></em> :</span></td>
<td> a <a href="cairo-cairo-surface-t.html#cairo-surface-t"><span class="type">cairo_surface_t</span></a>
</td>
</tr>
<tr>
<td>
<span class="term"><span class="emphasis"><em>Returns</em></span> :</span></td>
<td> The content type of <em class="parameter"><code>surface</code></em> which indicates whether
the surface contains color and/or alpha information. See
<a href="cairo-cairo-surface-t.html#cairo-content-t"><span class="type">cairo_content_t</span></a>.
</td>
</tr>
</tbody>
</table></div>
<p>Since 1.2
</p>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2601267"></a><h3>
<a name="cairo-surface-set-user-data"></a>cairo_surface_set_user_data ()</h3>
<a class="indexterm" name="id2601278"></a><pre class="programlisting"><a href="cairo-Error-handling.html#cairo-status-t">cairo_status_t</a> cairo_surface_set_user_data (<a href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface,
const <a href="cairo-Types.html#cairo-user-data-key-t">cairo_user_data_key_t</a> *key,
void *user_data,
<a href="cairo-Types.html#cairo-destroy-func-t">cairo_destroy_func_t</a> destroy);</pre>
<p>
Attach user data to <em class="parameter"><code>surface</code></em>. To remove user data from a surface,
call this function with the key that was used to set it and <code class="literal">NULL</code>
for <em class="parameter"><code>data</code></em>.</p>
<p>
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td>
<span class="term"><em class="parameter"><code>surface</code></em> :</span></td>
<td> a <a href="cairo-cairo-surface-t.html#cairo-surface-t"><span class="type">cairo_surface_t</span></a>
</td>
</tr>
<tr>
<td>
<span class="term"><em class="parameter"><code>key</code></em> :</span></td>
<td> the address of a <a href="cairo-Types.html#cairo-user-data-key-t"><span class="type">cairo_user_data_key_t</span></a> to attach the user data to
</td>
</tr>
<tr>
<td>
<span class="term"><em class="parameter"><code>user_data</code></em> :</span></td>
<td> the user data to attach to the surface
</td>
</tr>
<tr>
<td>
<span class="term"><em class="parameter"><code>destroy</code></em> :</span></td>
<td> a <a href="cairo-Types.html#cairo-destroy-func-t"><span class="type">cairo_destroy_func_t</span></a> which will be called when the
surface is destroyed or when new user data is attached using the
same key.
</td>
</tr>
<tr>
<td>
<span class="term"><span class="emphasis"><em>Returns</em></span> :</span></td>
<td> <a href="cairo-Error-handling.html#CAIRO-STATUS-SUCCESS:CAPS"><code class="literal">CAIRO_STATUS_SUCCESS</code></a> or <a href="cairo-Error-handling.html#CAIRO-STATUS-NO-MEMORY:CAPS"><code class="literal">CAIRO_STATUS_NO_MEMORY</code></a> if a
slot could not be allocated for the user data.
</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2601449"></a><h3>
<a name="cairo-surface-get-user-data"></a>cairo_surface_get_user_data ()</h3>
<a class="indexterm" name="id2601460"></a><pre class="programlisting">void* cairo_surface_get_user_data (<a href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface,
const <a href="cairo-Types.html#cairo-user-data-key-t">cairo_user_data_key_t</a> *key);</pre>
<p>
Return user data previously attached to <em class="parameter"><code>surface</code></em> using the specified
key. If no user data has been attached with the given key this
function returns <code class="literal">NULL</code>.</p>
<p>
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td>
<span class="term"><em class="parameter"><code>surface</code></em> :</span></td>
<td> a <a href="cairo-cairo-surface-t.html#cairo-surface-t"><span class="type">cairo_surface_t</span></a>
</td>
</tr>
<tr>
<td>
<span class="term"><em class="parameter"><code>key</code></em> :</span></td>
<td> the address of the <a href="cairo-Types.html#cairo-user-data-key-t"><span class="type">cairo_user_data_key_t</span></a> the user data was
attached to
</td>
</tr>
<tr>
<td>
<span class="term"><span class="emphasis"><em>Returns</em></span> :</span></td>
<td> the user data previously attached or <code class="literal">NULL</code>.
</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2601571"></a><h3>
<a name="cairo-surface-mark-dirty"></a>cairo_surface_mark_dirty ()</h3>
<a class="indexterm" name="id2601581"></a><pre class="programlisting">void cairo_surface_mark_dirty (<a href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface);</pre>
<p>
Tells cairo that drawing has been done to surface using means other
than cairo, and that cairo should reread any cached areas. Note
that you must call <a href="cairo-cairo-surface-t.html#cairo-surface-flush"><code class="function">cairo_surface_flush()</code></a> before doing such drawing.</p>
<p>
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody><tr>
<td>
<span class="term"><em class="parameter"><code>surface</code></em> :</span></td>
<td> a <a href="cairo-cairo-surface-t.html#cairo-surface-t"><span class="type">cairo_surface_t</span></a>
</td>
</tr></tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2601642"></a><h3>
<a name="cairo-surface-mark-dirty-rectangle"></a>cairo_surface_mark_dirty_rectangle ()</h3>
<a class="indexterm" name="id2601655"></a><pre class="programlisting">void cairo_surface_mark_dirty_rectangle
(<a href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface,
int x,
int y,
int width,
int height);</pre>
<p>
Like <a href="cairo-cairo-surface-t.html#cairo-surface-mark-dirty"><code class="function">cairo_surface_mark_dirty()</code></a>, but drawing has been done only to
the specified rectangle, so that cairo can retain cached contents
for other parts of the surface.
</p>
<p>
Any cached clip set on the surface will be reset by this function,
to make sure that future cairo calls have the clip set that they
expect.</p>
<p>
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td>
<span class="term"><em class="parameter"><code>surface</code></em> :</span></td>
<td> a <a href="cairo-cairo-surface-t.html#cairo-surface-t"><span class="type">cairo_surface_t</span></a>
</td>
</tr>
<tr>
<td>
<span class="term"><em class="parameter"><code>x</code></em> :</span></td>
<td> X coordinate of dirty rectangle
</td>
</tr>
<tr>
<td>
<span class="term"><em class="parameter"><code>y</code></em> :</span></td>
<td> Y coordinate of dirty rectangle
</td>
</tr>
<tr>
<td>
<span class="term"><em class="parameter"><code>width</code></em> :</span></td>
<td> width of dirty rectangle
</td>
</tr>
<tr>
<td>
<span class="term"><em class="parameter"><code>height</code></em> :</span></td>
<td> height of dirty rectangle
</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2601799"></a><h3>
<a name="cairo-surface-reference"></a>cairo_surface_reference ()</h3>
<a class="indexterm" name="id2601810"></a><pre class="programlisting"><a href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a>* cairo_surface_reference (<a href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface);</pre>
<p>
Increases the reference count on <em class="parameter"><code>surface</code></em> by one. This prevents
<em class="parameter"><code>surface</code></em> from being destroyed until a matching call to
<a href="cairo-cairo-surface-t.html#cairo-surface-destroy"><code class="function">cairo_surface_destroy()</code></a> is made.</p>
<p>
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td>
<span class="term"><em class="parameter"><code>surface</code></em> :</span></td>
<td> a <a href="cairo-cairo-surface-t.html#cairo-surface-t"><span class="type">cairo_surface_t</span></a>
</td>
</tr>
<tr>
<td>
<span class="term"><span class="emphasis"><em>Returns</em></span> :</span></td>
<td> the referenced <a href="cairo-cairo-surface-t.html#cairo-surface-t"><span class="type">cairo_surface_t</span></a>.
</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2601896"></a><h3>
<a name="cairo-surface-set-device-offset"></a>cairo_surface_set_device_offset ()</h3>
<a class="indexterm" name="id2601908"></a><pre class="programlisting">void cairo_surface_set_device_offset (<a href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface,
double x_offset,
double y_offset);</pre>
<p>
Sets an offset that is added to the device coordinates determined
by the CTM when drawing to <em class="parameter"><code>surface</code></em>. One use case for this function
is when we want to create a <a href="cairo-cairo-surface-t.html#cairo-surface-t"><span class="type">cairo_surface_t</span></a> that redirects drawing
for a portion of an onscreen surface to an offscreen surface in a
way that is completely invisible to the user of the cairo
API. Setting a transformation via <a href="cairo-Transformations.html#cairo-translate"><code class="function">cairo_translate()</code></a> isn't
sufficient to do this, since functions like
<a href="cairo-Transformations.html#cairo-device-to-user"><code class="function">cairo_device_to_user()</code></a> will expose the hidden offset.
</p>
<p>
Note that the offset affects drawing to the surface as well as
using the surface in a source pattern.</p>
<p>
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td>
<span class="term"><em class="parameter"><code>surface</code></em> :</span></td>
<td> a <a href="cairo-cairo-surface-t.html#cairo-surface-t"><span class="type">cairo_surface_t</span></a>
</td>
</tr>
<tr>
<td>
<span class="term"><em class="parameter"><code>x_offset</code></em> :</span></td>
<td> the offset in the X direction, in device units
</td>
</tr>
<tr>
<td>
<span class="term"><em class="parameter"><code>y_offset</code></em> :</span></td>
<td> the offset in the Y direction, in device units
</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2602039"></a><h3>
<a name="cairo-surface-get-device-offset"></a>cairo_surface_get_device_offset ()</h3>
<a class="indexterm" name="id2602054"></a><pre class="programlisting">void cairo_surface_get_device_offset (<a href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface,
double *x_offset,
double *y_offset);</pre>
<p>
This function returns the previous device offset set by
<a href="cairo-cairo-surface-t.html#cairo-surface-set-device-offset"><code class="function">cairo_surface_set_device_offset()</code></a>.</p>
<p>
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td>
<span class="term"><em class="parameter"><code>surface</code></em> :</span></td>
<td> a <a href="cairo-cairo-surface-t.html#cairo-surface-t"><span class="type">cairo_surface_t</span></a>
</td>
</tr>
<tr>
<td>
<span class="term"><em class="parameter"><code>x_offset</code></em> :</span></td>
<td> the offset in the X direction, in device units
</td>
</tr>
<tr>
<td>
<span class="term"><em class="parameter"><code>y_offset</code></em> :</span></td>
<td> the offset in the Y direction, in device units
</td>
</tr>
</tbody>
</table></div>
<p>Since 1.2
</p>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2602159"></a><h3>
<a name="cairo-surface-set-fallback-resolution"></a>cairo_surface_set_fallback_resolution ()</h3>
<a class="indexterm" name="id2602174"></a><pre class="programlisting">void cairo_surface_set_fallback_resolution
(<a href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface,
double x_pixels_per_inch,
double y_pixels_per_inch);</pre>
<p>
Set the horizontal and vertical resolution for image fallbacks.
</p>
<p>
When certain operations aren't supported natively by a backend,
cairo will fallback by rendering operations to an image and then
overlaying that image onto the output. For backends that are
natively vector-oriented, this function can be used to set the
resolution used for these image fallbacks, (larger values will
result in more detailed images, but also larger file sizes).
</p>
<p>
Some examples of natively vector-oriented backends are the ps, pdf,
and svg backends.
</p>
<p>
For backends that are natively raster-oriented, image fallbacks are
still possible, but they are always performed at the native
device resolution. So this function has no effect on those
backends.
</p>
<p>
NOTE: The fallback resolution only takes effect at the time of
completing a page (with <a href="cairo-cairo-t.html#cairo-show-page"><code class="function">cairo_show_page()</code></a> or <a href="cairo-cairo-t.html#cairo-copy-page"><code class="function">cairo_copy_page()</code></a>) so
there is currently no way to have more than one fallback resolution
in effect on a single page.</p>
<p>
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td>
<span class="term"><em class="parameter"><code>surface</code></em> :</span></td>
<td> a <a href="cairo-cairo-surface-t.html#cairo-surface-t"><span class="type">cairo_surface_t</span></a>
</td>
</tr>
<tr>
<td>
<span class="term"><em class="parameter"><code>x_pixels_per_inch</code></em> :</span></td>
<td> horizontal setting for pixels per inch
</td>
</tr>
<tr>
<td>
<span class="term"><em class="parameter"><code>y_pixels_per_inch</code></em> :</span></td>
<td> vertical setting for pixels per inch
</td>
</tr>
</tbody>
</table></div>
<p>Since 1.2
</p>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2602314"></a><h3>
<a name="cairo-surface-status"></a>cairo_surface_status ()</h3>
<a class="indexterm" name="id2602325"></a><pre class="programlisting"><a href="cairo-Error-handling.html#cairo-status-t">cairo_status_t</a> cairo_surface_status (<a href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface);</pre>
<p>
Checks whether an error has previously occurred for this
surface.</p>
<p>
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td>
<span class="term"><em class="parameter"><code>surface</code></em> :</span></td>
<td> a <a href="cairo-cairo-surface-t.html#cairo-surface-t"><span class="type">cairo_surface_t</span></a>
</td>
</tr>
<tr>
<td>
<span class="term"><span class="emphasis"><em>Returns</em></span> :</span></td>
<td> <a href="cairo-Error-handling.html#CAIRO-STATUS-SUCCESS:CAPS"><code class="literal">CAIRO_STATUS_SUCCESS</code></a>, <a href="cairo-Error-handling.html#CAIRO-STATUS-NULL-POINTER:CAPS"><code class="literal">CAIRO_STATUS_NULL_POINTER</code></a>,
<a href="cairo-Error-handling.html#CAIRO-STATUS-NO-MEMORY:CAPS"><code class="literal">CAIRO_STATUS_NO_MEMORY</code></a>, <a href="cairo-Error-handling.html#CAIRO-STATUS-READ-ERROR:CAPS"><code class="literal">CAIRO_STATUS_READ_ERROR</code></a>,
<a href="cairo-Error-handling.html#CAIRO-STATUS-INVALID-CONTENT:CAPS"><code class="literal">CAIRO_STATUS_INVALID_CONTENT</code></a>, <code class="literal">CAIRO_STATUS_INVALUE_FORMAT</code>, or
<a href="cairo-Error-handling.html#CAIRO-STATUS-INVALID-VISUAL:CAPS"><code class="literal">CAIRO_STATUS_INVALID_VISUAL</code></a>.
</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2602447"></a><h3>
<a name="cairo-surface-type-t"></a>enum cairo_surface_type_t</h3>
<a class="indexterm" name="id2602460"></a><pre class="programlisting">typedef enum _cairo_surface_type {
CAIRO_SURFACE_TYPE_IMAGE,
CAIRO_SURFACE_TYPE_PDF,
CAIRO_SURFACE_TYPE_PS,
CAIRO_SURFACE_TYPE_XLIB,
CAIRO_SURFACE_TYPE_XCB,
CAIRO_SURFACE_TYPE_GLITZ,
CAIRO_SURFACE_TYPE_QUARTZ,
CAIRO_SURFACE_TYPE_WIN32,
CAIRO_SURFACE_TYPE_BEOS,
CAIRO_SURFACE_TYPE_DIRECTFB,
CAIRO_SURFACE_TYPE_SVG
} cairo_surface_type_t;
</pre>
<p>
<a href="cairo-cairo-surface-t.html#cairo-surface-type-t"><span class="type">cairo_surface_type_t</span></a> is used to describe the type of a given
surface. The surface types are also known as "backends" or "surface
backends" within cairo.
</p>
<p>
The type of a surface is determined by the function used to create
it, which will generally be of the form cairo_<span class="emphasis"><em>type</em></span>_surface_create,
(though see cairo_surface_create_similar as well).
</p>
<p>
The surface type can be queried with <a href="cairo-cairo-surface-t.html#cairo-surface-get-type"><code class="function">cairo_surface_get_type()</code></a>
</p>
<p>
The various cairo_surface functions can be used with surfaces of
any type, but some backends also provide type-specific functions
that must only be called with a surface of the appropriate
type. These functions have names that begin with
cairo_<span class="emphasis"><em>type</em></span>_surface such as <a href="cairo-Image-Surfaces.html#cairo-image-surface-get-width"><code class="function">cairo_image_surface_get_width()</code></a>.
</p>
<p>
The behavior of calling a type-specific function with a surface of
the wrong type is undefined.
</p>
<p>
New entries may be added in future versions.</p>
<p>
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td>
<span class="term"><a name="CAIRO-SURFACE-TYPE-IMAGE:CAPS"></a><code class="literal">CAIRO_SURFACE_TYPE_IMAGE</code></span></td>
<td> The surface is of type image
</td>
</tr>
<tr>
<td>
<span class="term"><a name="CAIRO-SURFACE-TYPE-PDF:CAPS"></a><code class="literal">CAIRO_SURFACE_TYPE_PDF</code></span></td>
<td> The surface is of type pdf
</td>
</tr>
<tr>
<td>
<span class="term"><a name="CAIRO-SURFACE-TYPE-PS:CAPS"></a><code class="literal">CAIRO_SURFACE_TYPE_PS</code></span></td>
<td> The surface is of type ps
</td>
</tr>
<tr>
<td>
<span class="term"><a name="CAIRO-SURFACE-TYPE-XLIB:CAPS"></a><code class="literal">CAIRO_SURFACE_TYPE_XLIB</code></span></td>
<td> The surface is of type xlib
</td>
</tr>
<tr>
<td>
<span class="term"><a name="CAIRO-SURFACE-TYPE-XCB:CAPS"></a><code class="literal">CAIRO_SURFACE_TYPE_XCB</code></span></td>
<td> The surface is of type xcb
</td>
</tr>
<tr>
<td>
<span class="term"><a name="CAIRO-SURFACE-TYPE-GLITZ:CAPS"></a><code class="literal">CAIRO_SURFACE_TYPE_GLITZ</code></span></td>
<td> The surface is of type glitz
</td>
</tr>
<tr>
<td>
<span class="term"><a name="CAIRO-SURFACE-TYPE-QUARTZ:CAPS"></a><code class="literal">CAIRO_SURFACE_TYPE_QUARTZ</code></span></td>
<td> The surface is of type quartz
</td>
</tr>
<tr>
<td>
<span class="term"><a name="CAIRO-SURFACE-TYPE-WIN32:CAPS"></a><code class="literal">CAIRO_SURFACE_TYPE_WIN32</code></span></td>
<td> The surface is of type win32
</td>
</tr>
<tr>
<td>
<span class="term"><a name="CAIRO-SURFACE-TYPE-BEOS:CAPS"></a><code class="literal">CAIRO_SURFACE_TYPE_BEOS</code></span></td>
<td> The surface is of type beos
</td>
</tr>
<tr>
<td>
<span class="term"><a name="CAIRO-SURFACE-TYPE-DIRECTFB:CAPS"></a><code class="literal">CAIRO_SURFACE_TYPE_DIRECTFB</code></span></td>
<td> The surface is of type directfb
</td>
</tr>
<tr>
<td>
<span class="term"><a name="CAIRO-SURFACE-TYPE-SVG:CAPS"></a><code class="literal">CAIRO_SURFACE_TYPE_SVG</code></span></td>
<td> The surface is of type svg
</td>
</tr>
</tbody>
</table></div>
<p>Since 1.2
</p>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2602774"></a><h3>
<a name="cairo-surface-get-type"></a>cairo_surface_get_type ()</h3>
<a class="indexterm" name="id2602786"></a><pre class="programlisting"><a href="cairo-cairo-surface-t.html#cairo-surface-type-t">cairo_surface_type_t</a> cairo_surface_get_type (<a href="cairo-cairo-surface-t.html#cairo-surface-t">cairo_surface_t</a> *surface);</pre>
<p>
This function returns the type of the backend used to create
a surface. See <a href="cairo-cairo-surface-t.html#cairo-surface-type-t"><span class="type">cairo_surface_type_t</span></a> for available types.</p>
<p>
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td>
<span class="term"><em class="parameter"><code>surface</code></em> :</span></td>
<td> a <a href="cairo-cairo-surface-t.html#cairo-surface-t"><span class="type">cairo_surface_t</span></a>
</td>
</tr>
<tr>
<td>
<span class="term"><span class="emphasis"><em>Returns</em></span> :</span></td>
<td> The type of <em class="parameter"><code>surface</code></em>.
</td>
</tr>
</tbody>
</table></div>
<p>Since 1.2
</p>
</div>
</div>
</div>
</body>
</html>