gdk-pixbufs.html

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<td><p><span class="term"><em class="parameter"><code>mask_return</code></em>&#160;:</span></p></td>
<td> Location to store a pointer to the created mask,
  or <a
href="/usr/share/gtk-doc/html/liboil/liboil-liboiljunk.html#NULL:CAPS"
><code class="literal">NULL</code></a> if the mask is not needed.
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>alpha_threshold</code></em>&#160;:</span></p></td>
<td> Threshold value for opacity values.
</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id3141417"></a><h3>
<a name="gdk-pixbuf-get-from-drawable"></a>gdk_pixbuf_get_from_drawable ()</h3>
<a class="indexterm" name="id3141431"></a><pre class="programlisting"><a
href="/usr/share/gtk-doc/html/gdk-pixbuf/gdk-pixbuf-gdk-pixbuf.html#GdkPixbuf"
>GdkPixbuf</a>*          gdk_pixbuf_get_from_drawable        (<a
href="/usr/share/gtk-doc/html/gdk-pixbuf/gdk-pixbuf-gdk-pixbuf.html#GdkPixbuf"
>GdkPixbuf</a> *dest,
                                                         <a class="link" href="gdk-Drawing-Primitives.html#GdkDrawable">GdkDrawable</a> *src,
                                                         <a class="link" href="gdk-Colormaps-and-Colors.html#GdkColormap">GdkColormap</a> *cmap,
                                                         int src_x,
                                                         int src_y,
                                                         int dest_x,
                                                         int dest_y,
                                                         int width,
                                                         int height);</pre>
<p>
Transfers image data from a <a class="link" href="gdk-Drawing-Primitives.html#GdkDrawable"><span class="type">GdkDrawable</span></a> and converts it to an RGB(A)
representation inside a <a
href="/usr/share/gtk-doc/html/gdk-pixbuf/gdk-pixbuf-gdk-pixbuf.html#GdkPixbuf"
><span class="type">GdkPixbuf</span></a>. In other words, copies
image data from a server-side drawable to a client-side RGB(A) buffer.
This allows you to efficiently read individual pixels on the client side.
</p>
<p>
If the drawable <em class="parameter"><code>src</code></em> has no colormap (<a class="link" href="gdk-Drawing-Primitives.html#gdk-drawable-get-colormap"><code class="function">gdk_drawable_get_colormap()</code></a>
returns <a
href="/usr/share/gtk-doc/html/liboil/liboil-liboiljunk.html#NULL:CAPS"
><code class="literal">NULL</code></a>), then a suitable colormap must be specified.
Typically a <a class="link" href="gdk-Windows.html#GdkWindow"><span class="type">GdkWindow</span></a> or a pixmap created by passing a <a class="link" href="gdk-Windows.html#GdkWindow"><span class="type">GdkWindow</span></a>
to <a class="link" href="gdk-Bitmaps-and-Pixmaps.html#gdk-pixmap-new"><code class="function">gdk_pixmap_new()</code></a> will already have a colormap associated with
it.  If the drawable has a colormap, the <em class="parameter"><code>cmap</code></em> argument will be
ignored.  If the drawable is a bitmap (1 bit per pixel pixmap),
then a colormap is not required; pixels with a value of 1 are
assumed to be white, and pixels with a value of 0 are assumed to be
black. For taking screenshots, <a class="link" href="gdk-Colormaps-and-Colors.html#gdk-colormap-get-system"><code class="function">gdk_colormap_get_system()</code></a> returns
the correct colormap to use.
</p>
<p>
If the specified destination pixbuf <em class="parameter"><code>dest</code></em> is <a
href="/usr/share/gtk-doc/html/liboil/liboil-liboiljunk.html#NULL:CAPS"
><code class="literal">NULL</code></a>, then this
function will create an RGB pixbuf with 8 bits per channel and no
alpha, with the same size specified by the <em class="parameter"><code>width</code></em> and <em class="parameter"><code>height</code></em>
arguments.  In this case, the <em class="parameter"><code>dest_x</code></em> and <em class="parameter"><code>dest_y</code></em> arguments must be
specified as 0.  If the specified destination pixbuf is not <a
href="/usr/share/gtk-doc/html/liboil/liboil-liboiljunk.html#NULL:CAPS"
><code class="literal">NULL</code></a>
and it contains alpha information, then the filled pixels will be
set to full opacity (alpha = 255).
</p>
<p>
If the specified drawable is a pixmap, then the requested source
rectangle must be completely contained within the pixmap, otherwise
the function will return <a
href="/usr/share/gtk-doc/html/liboil/liboil-liboiljunk.html#NULL:CAPS"
><code class="literal">NULL</code></a>. For pixmaps only (not for windows)
passing -1 for width or height is allowed to mean the full width
or height of the pixmap.
</p>
<p>
If the specified drawable is a window, and the window is off the
screen, then there is no image data in the obscured/offscreen
regions to be placed in the pixbuf. The contents of portions of the
pixbuf corresponding to the offscreen region are undefined.
</p>
<p>
If the window you're obtaining data from is partially obscured by
other windows, then the contents of the pixbuf areas corresponding
to the obscured regions are undefined.
</p>
<p>
If the target drawable is not mapped (typically because it's
iconified/minimized or not on the current workspace), then <a
href="/usr/share/gtk-doc/html/liboil/liboil-liboiljunk.html#NULL:CAPS"
><code class="literal">NULL</code></a>
will be returned.
</p>
<p>
If memory can't be allocated for the return value, <a
href="/usr/share/gtk-doc/html/liboil/liboil-liboiljunk.html#NULL:CAPS"
><code class="literal">NULL</code></a> will be returned
instead.
</p>
<p>
(In short, there are several ways this function can fail, and if it fails
 it returns <a
href="/usr/share/gtk-doc/html/liboil/liboil-liboiljunk.html#NULL:CAPS"
><code class="literal">NULL</code></a>; so check the return value.)
</p>
<p>
This function calls <a class="link" href="gdk-Drawing-Primitives.html#gdk-drawable-get-image"><code class="function">gdk_drawable_get_image()</code></a> internally and
converts the resulting image to a <a
href="/usr/share/gtk-doc/html/gdk-pixbuf/gdk-pixbuf-gdk-pixbuf.html#GdkPixbuf"
><span class="type">GdkPixbuf</span></a>, so the
documentation for <a class="link" href="gdk-Drawing-Primitives.html#gdk-drawable-get-image"><code class="function">gdk_drawable_get_image()</code></a> may also be relevant.</p>
<p>

</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>dest</code></em>&#160;:</span></p></td>
<td> Destination pixbuf, or <a
href="/usr/share/gtk-doc/html/liboil/liboil-liboiljunk.html#NULL:CAPS"
><code class="literal">NULL</code></a> if a new pixbuf should be created.
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>src</code></em>&#160;:</span></p></td>
<td> Source drawable.
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>cmap</code></em>&#160;:</span></p></td>
<td> A colormap if <em class="parameter"><code>src</code></em> doesn't have one set.
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>src_x</code></em>&#160;:</span></p></td>
<td> Source X coordinate within drawable.
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>src_y</code></em>&#160;:</span></p></td>
<td> Source Y coordinate within drawable.
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>dest_x</code></em>&#160;:</span></p></td>
<td> Destination X coordinate in pixbuf, or 0 if <em class="parameter"><code>dest</code></em> is NULL.
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>dest_y</code></em>&#160;:</span></p></td>
<td> Destination Y coordinate in pixbuf, or 0 if <em class="parameter"><code>dest</code></em> is NULL.
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>width</code></em>&#160;:</span></p></td>
<td> Width in pixels of region to get.
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>height</code></em>&#160;:</span></p></td>
<td> Height in pixels of region to get.
</td>
</tr>
<tr>
<td><p><span class="term"><span class="emphasis"><em>Returns</em></span>&#160;:</span></p></td>
<td> The same pixbuf as <em class="parameter"><code>dest</code></em> if it was non-<a
href="/usr/share/gtk-doc/html/liboil/liboil-liboiljunk.html#NULL:CAPS"
><code class="literal">NULL</code></a>, or a newly-created
pixbuf with a reference count of 1 if no destination pixbuf was specified, or <a
href="/usr/share/gtk-doc/html/liboil/liboil-liboiljunk.html#NULL:CAPS"
><code class="literal">NULL</code></a> on error
</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id3141998"></a><h3>
<a name="gdk-pixbuf-get-from-image"></a>gdk_pixbuf_get_from_image ()</h3>
<a class="indexterm" name="id3142012"></a><pre class="programlisting"><a
href="/usr/share/gtk-doc/html/gdk-pixbuf/gdk-pixbuf-gdk-pixbuf.html#GdkPixbuf"
>GdkPixbuf</a>*          gdk_pixbuf_get_from_image           (<a
href="/usr/share/gtk-doc/html/gdk-pixbuf/gdk-pixbuf-gdk-pixbuf.html#GdkPixbuf"
>GdkPixbuf</a> *dest,
                                                         <a class="link" href="gdk-Images.html#GdkImage">GdkImage</a> *src,
                                                         <a class="link" href="gdk-Colormaps-and-Colors.html#GdkColormap">GdkColormap</a> *cmap,
                                                         int src_x,
                                                         int src_y,
                                                         int dest_x,
                                                         int dest_y,
                                                         int width,
                                                         int height);</pre>
<p>
Same as <a class="link" href="gdk-Pixbufs.html#gdk-pixbuf-get-from-drawable"><code class="function">gdk_pixbuf_get_from_drawable()</code></a> but gets the pixbuf from
an image.</p>
<p>

</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>dest</code></em>&#160;:</span></p></td>
<td> Destination pixbuf, or <a
href="/usr/share/gtk-doc/html/liboil/liboil-liboiljunk.html#NULL:CAPS"
><code class="literal">NULL</code></a> if a new pixbuf should be created.
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>src</code></em>&#160;:</span></p></td>
<td> Source <a class="link" href="gdk-Images.html#GdkImage"><span class="type">GdkImage</span></a>.
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>cmap</code></em>&#160;:</span></p></td>
<td> A colormap, or <a
href="/usr/share/gtk-doc/html/liboil/liboil-liboiljunk.html#NULL:CAPS"
><code class="literal">NULL</code></a> to use the one for <em class="parameter"><code>src</code></em>
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>src_x</code></em>&#160;:</span></p></td>
<td> Source X coordinate within drawable.
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>src_y</code></em>&#160;:</span></p></td>
<td> Source Y coordinate within drawable.
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>dest_x</code></em>&#160;:</span></p></td>
<td> Destination X coordinate in pixbuf, or 0 if <em class="parameter"><code>dest</code></em> is NULL.
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>dest_y</code></em>&#160;:</span></p></td>
<td> Destination Y coordinate in pixbuf, or 0 if <em class="parameter"><code>dest</code></em> is NULL.
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>width</code></em>&#160;:</span></p></td>
<td> Width in pixels of region to get.
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>height</code></em>&#160;:</span></p></td>
<td> Height in pixels of region to get.
</td>
</tr>
<tr>
<td><p><span class="term"><span class="emphasis"><em>Returns</em></span>&#160;:</span></p></td>
<td> <em class="parameter"><code>dest</code></em>, newly-created pixbuf if <em class="parameter"><code>dest</code></em> was <a
href="/usr/share/gtk-doc/html/liboil/liboil-liboiljunk.html#NULL:CAPS"
><code class="literal">NULL</code></a>, <a
href="/usr/share/gtk-doc/html/liboil/liboil-liboiljunk.html#NULL:CAPS"
><code class="literal">NULL</code></a> on error
</td>
</tr>
</tbody>
</table></div>
</div>
</div>
<div class="refsect1" lang="en">
<a name="id3142336"></a><div class="refsect2" lang="en"><a name="id3142337"></a></div>
<hr>
<div class="refsect2" lang="en"><a name="id3142338"></a></div>
</div>
</div>
</body>
</html>