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<head>
<title>GEGL API</title>
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<body>
<div id='toc'>
<div class='print'>
<h3>Contents</h3>
</div>
<ul>
<li><a href='index.html' style='padding-top: 0.5em;'>GEGL</a></li>
<li><a href='index.html#Documentation' style='padding-top: 0.5em;'>Documentation</a></li>
<li><a href='index.html#_glossary'> Glossary</a></li>
<li><a href='operations.html'> Operations</a></li>
<li><a href='#The_GEGL_API'><div style='padding-top:0.5em'>The GEGL API</div></a></li>
<li><a href='#Introduction'>Introduction</a></li>
<li><a href='#Initialization'>Initialization</a></li>
<li><a href='#gegl_init'> gegl_init</a></li>
<li><a href='#gegl_get_option_group'> gegl_get_option_group</a></li>
<li><a href='#gegl_exit'> gegl_exit</a></li>
<li><a href='#'></a></li>
<li><a href='#gegl_get_version'> gegl_get_version</a></li>
<li><a href='#Available_operations'>Available operations</a></li>
<li><a href='#gegl_list_operations'> gegl_list_operations</a></li>
<li><a href='#gegl_list_properties'> gegl_list_properties</a></li>
<li><a href='#GeglNode'><div style='padding-top:0.5em'>GeglNode</div></a></li>
<li><a href='#gegl_node_new'> gegl_node_new</a></li>
<li><a href='#gegl_node_new_child'> gegl_node_new_child</a></li>
<li><a href='#Making_connections'>Making connections</a></li>
<li><a href='#gegl_node_connect_from'> gegl_node_connect_from</a></li>
<li><a href='#gegl_node_connect_to'> gegl_node_connect_to</a></li>
<li><a href='#gegl_node_link'> gegl_node_link</a></li>
<li><a href='#gegl_node_link_many'> gegl_node_link_many</a></li>
<li><a href='#gegl_node_disconnect'> gegl_node_disconnect</a></li>
<li><a href='#Properties'>Properties</a></li>
<li><a href='#gegl_node_set'> gegl_node_set</a></li>
<li><a href='#gegl_node_get'> gegl_node_get</a></li>
<li><a href='#Processing'>Processing</a></li>
<li><a href='#gegl_node_blit'> gegl_node_blit</a></li>
<li><a href='#gegl_node_process'> gegl_node_process</a></li>
<li><a href='#Reparenting'>Reparenting</a></li>
<li><a href='#gegl_node_adopt_child'> gegl_node_adopt_child</a></li>
<li><a href='#gegl_node_get_parent'> gegl_node_get_parent</a></li>
<li><a href='#State_queries'>State queries</a></li>
<li><a href='#gegl_node_detect'> gegl_node_detect</a></li>
<li><a href='#gegl_node_find_property'> gegl_node_find_property</a></li>
<li><a href='#gegl_node_get_bounding_box'> gegl_node_get_bounding_box</a></li>
<li><a href='#gegl_node_get_children'> gegl_node_get_children</a></li>
<li><a href='#gegl_node_get_consumers'> gegl_node_get_consumers</a></li>
<li><a href='#gegl_node_get_input_proxy'> gegl_node_get_input_proxy</a></li>
<li><a href='#gegl_node_get_operation'> gegl_node_get_operation</a></li>
<li><a href='#gegl_node_get_output_proxy'> gegl_node_get_output_proxy</a></li>
<li><a href='#gegl_node_get_producer'> gegl_node_get_producer</a></li>
<li><a href='#Binding_conveniences'>Binding conveniences</a></li>
<li><a href='#gegl_node_create_child'> gegl_node_create_child</a></li>
<li><a href='#gegl_node_get_property'> gegl_node_get_property</a></li>
<li><a href='#gegl_node_set_property'> gegl_node_set_property</a></li>
<li><a href='#XML'><div style='padding-top:0.5em'>XML</div></a></li>
<li><a href='#gegl_node_new_from_xml'> gegl_node_new_from_xml</a></li>
<li><a href='#gegl_node_new_from_file'> gegl_node_new_from_file</a></li>
<li><a href='#gegl_node_to_xml'> gegl_node_to_xml</a></li>
<li><a href='#GeglProcessor'><div style='padding-top:0.5em'>GeglProcessor</div></a></li>
<li><a href='#gegl_node_new_processor'> gegl_node_new_processor</a></li>
<li><a href='#gegl_processor_set_rectangle'> gegl_processor_set_rectangle</a></li>
<li><a href='#gegl_processor_work'> gegl_processor_work</a></li>
<li><a href='#gegl_processor_destroy'> gegl_processor_destroy</a></li>
<li><a href='#gegl_config'> gegl_config</a></li>
<li><a href='#GeglRectangle'><div style='padding-top:0.5em'>GeglRectangle</div></a></li>
<li><a href='#'></a></li>
<li><a href='#GeglBuffer'><div style='padding-top:0.5em'>GeglBuffer</div></a></li>
<li><a href='#gegl_buffer_new'> gegl_buffer_new</a></li>
<li><a href='#gegl_buffer_open'> gegl_buffer_open</a></li>
<li><a href='#gegl_buffer_save'> gegl_buffer_save</a></li>
<li><a href='#gegl_buffer_load'> gegl_buffer_load</a></li>
<li><a href='#gegl_buffer_flush'> gegl_buffer_flush</a></li>
<li><a href='#gegl_buffer_create_sub_buffer'> gegl_buffer_create_sub_buffer</a></li>
<li><a href='#gegl_buffer_destroy'> gegl_buffer_destroy</a></li>
<li><a href='#gegl_buffer_get_extent'> gegl_buffer_get_extent</a></li>
<li><a href='#gegl_buffer_set_extent'> gegl_buffer_set_extent</a></li>
<li><a href='#gegl_buffer_get_x'> gegl_buffer_get_x</a></li>
<li><a href='#gegl_buffer_get_y'> gegl_buffer_get_y</a></li>
<li><a href='#gegl_buffer_get_width'> gegl_buffer_get_width</a></li>
<li><a href='#gegl_buffer_get_height'> gegl_buffer_get_height</a></li>
<li><a href='#gegl_buffer_get_pixel_count'> gegl_buffer_get_pixel_count</a></li>
<li><a href='#gegl_buffer_get'> gegl_buffer_get</a></li>
<li><a href='#gegl_buffer_set'> gegl_buffer_set</a></li>
<li><a href='#gegl_buffer_clear'> gegl_buffer_clear</a></li>
<li><a href='#gegl_buffer_copy'> gegl_buffer_copy</a></li>
<li><a href='#gegl_buffer_dup'> gegl_buffer_dup</a></li>
<li><a href='#gegl_buffer_sample'> gegl_buffer_sample</a></li>
<li><a href='#gegl_buffer_sample_cleanup'> gegl_buffer_sample_cleanup</a></li>
<li><a href='#gegl_buffer_interpolation_from_string'> gegl_buffer_interpolation_from_string</a></li>
<li><a href='#'> </a></li>
<li><a href='#GeglOperation'>GeglOperation</a></li>
</ul></div>
<div class='paper'><div class='content'>
<div class='section' id='section_The_GEGL_API'><a name='The_GEGL_API'></a><div class='sect'>
<h2>The GEGL API</h2><div class='sect_doc'><p>
This document is both a tutorial and a reference for the C API of GEGL.
The concepts covered in this reference should also be applicable when
using other languages.
</p><p> The core API of GEGL isn't frozen yet and feedback regarding its use as
well as the clarity of this documentation is most welcome.
</p><pre class='sample_code'></pre></div></div></div>
<div class='section' id='section_Introduction'><a name='Introduction'></a><div class='sect'>
<h2>Introduction</h2><div class='sect_doc'><p>
Algorithms created with GEGL are expressed as graphs of nodes. The nodes
have associated image processing operations. A node has output and input
pads which can be connected. By connecting these nodes in chains a set of
image operation filters and combinators can be applied to the image data.
</p><p> To make GEGL process data you request a rectangular region of a node's
output pad to be rendered into a provided linear buffer of any (supported
by babl) pixel format. GEGL uses information provided by the nodes to
determine the smallest buffers needed at each stage of processing.
</p><pre class='sample_code'></pre></div></div></div>
<div class='section' id='section_Initialization'><a name='Initialization'></a><div class='sect'>
<h2>Initialization</h2><div class='sect_doc'><p>
Before GEGL can be used the engine should be initialized by either calling
<a href='#gegl_init'>gegl_init</a> or through the use of <a href='#gegl_get_option_group'>gegl_get_option_group</a>. To shut down the
GEGL engine call <a href='#gegl_exit'>gegl_exit</a>.
</p><p></p><pre class='sample_code'>#include <gegl.h>
int main(int argc, char **argv)
{
gegl_init (&argc, &argv);
<span style='color:gray;text-style:italic'># other GEGL code</span>
gegl_exit ();
}
</pre></div></div></div>
<div class='section' id='section_gegl_init'><a name='gegl_init'></a><div class='function'>
<!--<h3>gegl_init</h3>-->
<div class='function_signature'>
<div class='function_header'>
<div class='return_type'>void </div>
<div class='function_name'>gegl_init</div>
</div><div class='function_args'><div class='argument'>
<div class='arg_type'><span class='const'>(</span>gint <span class='pointer'>*</span></div>
<div class='arg_name'>argc<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'>gchar <span class='pointer'>*</span><span class='pointer'>*</span><span class='pointer'>*</span></div>
<div class='arg_name'>argv<span class='const'>)</span></div>
</div>
</div><div class='float_breaker'></div></div><div class='function_doc'><p> Call this function before using any other GEGL functions. It will
initialize everything needed to operate GEGL and parses some
standard command line options. <span class='arg_name'>argc</span> and <span class='arg_name'>argv</span> are adjusted
accordingly so your own code will never see those standard
arguments. gegl_init() will call g_thread_init(), unless you, or
some other code already has initialized gthread.
</p><p> Note that there is an alternative way to initialize GEGL: if you
are calling g_option_context_parse() with the option group returned
by <a href='#gegl_get_option_group'>gegl_get_option_group</a>(), you don't have to call <a href='#gegl_init'>gegl_init</a>() but
you have to call g_thread_init() before any glib or glib dependant code
yourself.
</p><p><b>Arguments:</b></p><table>
<tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>argc</span></td><td> a pointer to the number of command line arguments.</td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>argv</span></td><td> a pointer to the array of command line arguments.</td></tr></table>
</div><div class='return_doc'></div><pre class='sample_code'></pre></div></div>
<div class='section' id='section_gegl_get_option_group'><a name='gegl_get_option_group'></a><div class='function'>
<!--<h3>gegl_get_option_group</h3>-->
<div class='function_signature'>
<div class='function_header'>
<div class='return_type'><a href='http://developer.gnome.org/doc/API/2.2/glib/glib-Commandline-option-parser.html#GOptionGroup'>GOptionGroup</a> <span class='pointer'>*</span> </div>
<div class='function_name'>gegl_get_option_group</div>
</div><div class='function_args'><div class='argument'><div class='arg_type'><span class='const'>(void)</span></div></div>
</div><div class='float_breaker'></div></div><div class='function_doc'><p></p></div><div class='return_doc'><b>Returns</b> a GOptionGroup for the commandline arguments recognized
by GEGL. You should add this group to your GOptionContext
with g_option_context_add_group() if you are using
g_option_context_parse() to parse your commandline arguments.
</div><pre class='sample_code'></pre></div></div>
<div class='section' id='section_gegl_exit'><a name='gegl_exit'></a><div class='function'>
<!--<h3>gegl_exit</h3>-->
<div class='function_signature'>
<div class='function_header'>
<div class='return_type'>void </div>
<div class='function_name'>gegl_exit</div>
</div><div class='function_args'><div class='argument'><div class='arg_type'><span class='const'>(void)</span></div></div>
</div><div class='float_breaker'></div></div><div class='function_doc'><p> Call this function when you're done using GEGL. It will clean up
caches and write/dump debug information if the correct debug flags
are set.
</p></div><div class='return_doc'></div><pre class='sample_code'></pre></div></div>
<div class='section' id='section_gegl_get_version'><a name='gegl_get_version'></a><div class='function'>
<!--<h3>gegl_get_version</h3>-->
<div class='function_signature'>
<div class='function_header'>
<div class='return_type'>void </div>
<div class='function_name'>gegl_get_version</div>
</div><div class='function_args'><div class='argument'>
<div class='arg_type'><span class='const'>(</span><a href='#int'>int</a> <span class='pointer'>*</span></div>
<div class='arg_name'>major<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'><a href='#int'>int</a> <span class='pointer'>*</span></div>
<div class='arg_name'>minor<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'><a href='#int'>int</a> <span class='pointer'>*</span></div>
<div class='arg_name'>micro<span class='const'>)</span></div>
</div>
</div><div class='float_breaker'></div></div><div class='function_doc'><p> This function fetches the version of the GEGL library being used by
the running process.
</p><p><b>Arguments:</b></p><table>
<tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>major</span></td><td> a pointer to a int where the major version number will be stored</td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>minor</span></td><td> ditto for the minor version number</td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>micro</span></td><td> ditto for the micro version number</td></tr></table>
</div><div class='return_doc'></div><pre class='sample_code'></pre></div></div>
<div class='section' id='section_Available_operations'><a name='Available_operations'></a><div class='sect'>
<h2>Available operations</h2><div class='sect_doc'><p> Gegl provides means to check for available processing operations that
can be used with nodes using <a href='#gegl_list_operations'>gegl_list_operations</a> and for a specified
op give a list of properties with <a href='#gegl_list_properties'>gegl_list_properties</a>.
</p><pre class='sample_code'></pre></div></div></div>
<div class='section' id='section_gegl_list_operations'><a name='gegl_list_operations'></a><div class='function'>
<!--<h3>gegl_list_operations</h3>-->
<div class='function_signature'>
<div class='function_header'>
<div class='return_type'>gchar <span class='pointer'>*</span><span class='pointer'>*</span></div>
<div class='function_name'>gegl_list_operations</div>
</div><div class='function_args'><div class='argument'>
<div class='arg_type'><span class='const'>(</span>guint <span class='pointer'>*</span></div>
<div class='arg_name'>n_operations_p<span class='const'>)</span></div>
</div>
</div><div class='float_breaker'></div></div><div class='function_doc'><p></p><p><b>Arguments:</b></p><table>
<tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>n_operations_p</span></td><td> return location for number of operations.</td></tr></table>
</div><div class='return_doc'><b>Returns</b> an alphabetically sorted array of available operation names. The
list should be freed with g_free after use.
</div><pre class='sample_code'>gchar **operations;
guint n_operations;
gint i;
operations = gegl_list_operations (&n_operations);
g_print ("Available operations:\n");
for (i=0; i < n_operations; i++)
{
g_print ("\t%s\n", operations[i]);
}
g_free (operations);
</pre></div></div>
<div class='section' id='section_gegl_list_properties'><a name='gegl_list_properties'></a><div class='function'>
<!--<h3>gegl_list_properties</h3>-->
<div class='function_signature'>
<div class='function_header'>
<div class='return_type'><a href='http://developer.gnome.org/doc/API/2.0/gobject/gobject-GParamSpec.html#GParamSpec'>GParamSpec</a><span class='pointer'>*</span><span class='pointer'>*</span> </div>
<div class='function_name'>gegl_list_properties</div>
</div><div class='function_args'><div class='argument'>
<div class='arg_type'><span class='const'>(</span><span class='const'>const</span> gchar <span class='pointer'>*</span></div>
<div class='arg_name'>operation_type<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'>guint <span class='pointer'>*</span></div>
<div class='arg_name'>n_properties_p<span class='const'>)</span></div>
</div>
</div><div class='float_breaker'></div></div><div class='function_doc'><p></p><p><b>Arguments:</b></p><table>
<tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>operation_type</span></td><td> the name of the operation type we want to query to properties of.</td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>n_properties_p</span></td><td> return location for number of properties.</td></tr></table>
</div><div class='return_doc'><b>Returns</b> an allocated array of <a href='#GParamSpecs'>GParamSpecs</a> describing the properties
of the operation available when a node has operation_type set.
</div><pre class='sample_code'></pre></div></div>
<div class='section' id='section_GeglNode'><a name='GeglNode'></a><div class='sect'>
<h2>GeglNode</h2><div class='sect_doc'><p>
The Node is the image processing primitive connected to create compositions
in GEGL. The toplevel <a href='#GeglNode'>GeglNode</a> which contains a graph of <a href='#GeglNodes'>GeglNodes</a> is
created with <a href='#gegl_node_new'>gegl_node_new</a>. Using this toplevel node we can create children
of this node which are individual processing elements using <a href='#gegl_node_new_child'>gegl_node_new_child</a>
</p><p> A node either has an associated operation or is a parent for other nodes,
that are connected to their parent through proxies created with
<a href='#gegl_node_get_input_proxy'>gegl_node_get_input_proxy</a> and <a href='#gegl_node_get_output_proxy'>gegl_node_get_output_proxy</a>.
</p><p> The properties available on a node depends on which <a
href='operations.html'>operation</a> is specified.
</p><p></p><pre class='sample_code'>GeglNode *gegl, *load, *bcontrast;
gegl = gegl_node_new ();
load = gegl_node_new_child (gegl,
"operation", "load",
"path", "input.png",
NULL);
bcontrast = gegl_node_new_child (gegl,
"operation", "brightness-contrast",
"brightness", 0.2,
"contrast", 1.5,
NULL);
</pre></div></div></div>
<div class='section' id='section_gegl_node_new'><a name='gegl_node_new'></a><div class='function'>
<!--<h3>gegl_node_new</h3>-->
<div class='function_signature'>
<div class='function_header'>
<div class='return_type'><a href='#GeglNode'>GeglNode</a> <span class='pointer'>*</span> </div>
<div class='function_name'>gegl_node_new</div>
</div><div class='function_args'><div class='argument'><div class='arg_type'><span class='const'>(void)</span></div></div>
</div><div class='float_breaker'></div></div><div class='function_doc'><p> Create a new graph that can contain further processing nodes.
</p><p></p></div><div class='return_doc'><b>Returns</b> a new top level <a href='#GeglNode'>GeglNode</a> (which can be used as a graph). When you
are done using this graph instance it should be unreferenced with g_object_unref.
This will also free any sub nodes created from this node.
</div><pre class='sample_code'></pre></div></div>
<div class='section' id='section_gegl_node_new_child'><a name='gegl_node_new_child'></a><div class='function'>
<!--<h3>gegl_node_new_child</h3>-->
<div class='function_signature'>
<div class='function_header'>
<div class='return_type'><a href='#GeglNode'>GeglNode</a> <span class='pointer'>*</span> </div>
<div class='function_name'>gegl_node_new_child</div>
</div><div class='function_args'><div class='argument'>
<div class='arg_type'><span class='const'>(</span><a href='#GeglNode'>GeglNode</a> <span class='pointer'>*</span></div>
<div class='arg_name'>parent<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'><span class='const'>const</span> gchar <span class='pointer'>*</span></div>
<div class='arg_name'>first_property_name<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'><a href='#'></a></div>
<div class='arg_name'><span class='varargs'>..., NULL</span><span class='const'>)</span></div>
</div>
</div><div class='float_breaker'></div></div><div class='function_doc'><p> Creates a new processing node that performs the specified operation with
a <span class='keyword'>NULL</span> terminated list of key/value pairs for initial parameter values
configuring the operation. Usually the first pair should be "operation"
and the type of operation to be associated. If no operation is provided
the node doesn't have an initial operation and can be used to construct
a subgraph with special middle-man routing nodes created with
<a href='#gegl_node_get_output_proxy'>gegl_node_get_output_proxy</a> and <a href='#gegl_node_get_input_proxy'>gegl_node_get_input_proxy</a>.
</p><p></p><p><b>Arguments:</b></p><table>
<tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>parent</span></td><td> a <a href='#GeglNode'>GeglNode</a></td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>first_property_name</span></td><td> the first property name</td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>...</span></td><td> first property value, optionally followed by more key/value pairs, ended terminated with <span class='keyword'>NULL</span>.
</td></tr></table>
</div><div class='return_doc'><b>Returns</b> a newly created node. The node will be destroyed by the parent.
Calling g_object_unref on a node will cause the node to be dropped by the
parent. (You may also add additional references using
g_object_ref/g_object_unref, but in general relying on the parents reference
counting is easiest.)
</div><pre class='sample_code'></pre></div></div>
<div class='section' id='section_Making_connections'><a name='Making_connections'></a><div class='sect'>
<h2>Making connections</h2><div class='sect_doc'><p>
Nodes in GEGL are connected to each other. The resulting graph of nodes
represents the image processing pipeline to be processed.
</p><p></p><pre class='sample_code'>gegl_node_link_many (background, over, png_save, NULL);
gegl_node_connect_to (translate, "output", over, "aux");
gegl_node_link_many (text, blur, translate, NULL);
</pre></div></div></div>
<div class='section' id='section_gegl_node_connect_from'><a name='gegl_node_connect_from'></a><div class='function'>
<!--<h3>gegl_node_connect_from</h3>-->
<div class='function_signature'>
<div class='function_header'>
<div class='return_type'>gboolean </div>
<div class='function_name'>gegl_node_connect_from</div>
</div><div class='function_args'><div class='argument'>
<div class='arg_type'><span class='const'>(</span><a href='#GeglNode'>GeglNode</a> <span class='pointer'>*</span></div>
<div class='arg_name'>sink<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'><span class='const'>const</span> gchar <span class='pointer'>*</span></div>
<div class='arg_name'>input_pad_name<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'><a href='#GeglNode'>GeglNode</a> <span class='pointer'>*</span></div>
<div class='arg_name'>source<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'><span class='const'>const</span> gchar <span class='pointer'>*</span></div>
<div class='arg_name'>output_pad_name<span class='const'>)</span></div>
</div>
</div><div class='float_breaker'></div></div><div class='function_doc'><p> Makes a connection between the pads of two nodes.
</p><p></p><p><b>Arguments:</b></p><table>
<tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>sink</span></td><td> the node we're connecting an input to</td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>input_pad_name</span></td><td> the name of the input pad we are connecting to</td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>source</span></td><td> the node producing data we want to connect.</td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>output_pad_name</span></td><td> the output pad we want to use on the source.</td></tr></table>
</div><div class='return_doc'><b>Returns</b> <span class='keyword'>TRUE</span> if the connection was succesfully made.
</div><pre class='sample_code'></pre></div></div>
<div class='section' id='section_gegl_node_connect_to'><a name='gegl_node_connect_to'></a><div class='function'>
<!--<h3>gegl_node_connect_to</h3>-->
<div class='function_signature'>
<div class='function_header'>
<div class='return_type'>gboolean </div>
<div class='function_name'>gegl_node_connect_to</div>
</div><div class='function_args'><div class='argument'>
<div class='arg_type'><span class='const'>(</span><a href='#GeglNode'>GeglNode</a> <span class='pointer'>*</span></div>
<div class='arg_name'>source<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'><span class='const'>const</span> gchar <span class='pointer'>*</span></div>
<div class='arg_name'>output_pad_name<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'><a href='#GeglNode'>GeglNode</a> <span class='pointer'>*</span></div>
<div class='arg_name'>sink<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'><span class='const'>const</span> gchar <span class='pointer'>*</span></div>
<div class='arg_name'>input_pad_name<span class='const'>)</span></div>
</div>
</div><div class='float_breaker'></div></div><div class='function_doc'><p> Makes a connection between the pads of two nodes.
</p><p></p><p><b>Arguments:</b></p><table>
<tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>source</span></td><td> the node producing data we want to connect.</td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>output_pad_name</span></td><td> the output pad we want to use on the source.</td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>sink</span></td><td> the node we're connecting an input to</td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>input_pad_name</span></td><td> the name of the input pad we are connecting to</td></tr></table>
</div><div class='return_doc'><b>Returns</b> <span class='keyword'>TRUE</span> if the connection was succesfully made.
</div><pre class='sample_code'></pre></div></div>
<div class='section' id='section_gegl_node_link'><a name='gegl_node_link'></a><div class='function'>
<!--<h3>gegl_node_link</h3>-->
<div class='function_signature'>
<div class='function_header'>
<div class='return_type'>void </div>
<div class='function_name'>gegl_node_link</div>
</div><div class='function_args'><div class='argument'>
<div class='arg_type'><span class='const'>(</span><a href='#GeglNode'>GeglNode</a> <span class='pointer'>*</span></div>
<div class='arg_name'>source<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'><a href='#GeglNode'>GeglNode</a> <span class='pointer'>*</span></div>
<div class='arg_name'>sink<span class='const'>)</span></div>
</div>
</div><div class='float_breaker'></div></div><div class='function_doc'><p> Synthetic sugar for linking the "output" pad of <span class='arg_name'>source</span> to the "input"
pad of <span class='arg_name'>sink</span>.
</p><p><b>Arguments:</b></p><table>
<tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>source</span></td><td> the producer of data.</td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>sink</span></td><td> the consumer of data.</td></tr></table>
</div><div class='return_doc'></div><pre class='sample_code'></pre></div></div>
<div class='section' id='section_gegl_node_link_many'><a name='gegl_node_link_many'></a><div class='function'>
<!--<h3>gegl_node_link_many</h3>-->
<div class='function_signature'>
<div class='function_header'>
<div class='return_type'>void </div>
<div class='function_name'>gegl_node_link_many</div>
</div><div class='function_args'><div class='argument'>
<div class='arg_type'><span class='const'>(</span><a href='#GeglNode'>GeglNode</a> <span class='pointer'>*</span></div>
<div class='arg_name'>source<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'><a href='#GeglNode'>GeglNode</a> <span class='pointer'>*</span></div>
<div class='arg_name'>first_sink<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'><a href='#'></a></div>
<div class='arg_name'><span class='varargs'>..., NULL</span><span class='const'>)</span></div>
</div>
</div><div class='float_breaker'></div></div><div class='function_doc'><p> Synthetic sugar for linking a chain of nodes with "input"->"output". The
list is <span class='keyword'>NULL</span> terminated.
</p><p><b>Arguments:</b></p><table>
<tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>source</span></td><td> the producer of data.</td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>first_sink</span></td><td> the first consumer of data.</td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>...</span></td><td> <span class='keyword'>NULL</span>, or optionally more consumers followed by <span class='keyword'>NULL</span>.</td></tr></table>
</div><div class='return_doc'></div><pre class='sample_code'></pre></div></div>
<div class='section' id='section_gegl_node_disconnect'><a name='gegl_node_disconnect'></a><div class='function'>
<!--<h3>gegl_node_disconnect</h3>-->
<div class='function_signature'>
<div class='function_header'>
<div class='return_type'>gboolean </div>
<div class='function_name'>gegl_node_disconnect</div>
</div><div class='function_args'><div class='argument'>
<div class='arg_type'><span class='const'>(</span><a href='#GeglNode'>GeglNode</a> <span class='pointer'>*</span></div>
<div class='arg_name'>node<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'><span class='const'>const</span> gchar <span class='pointer'>*</span></div>
<div class='arg_name'>input_pad<span class='const'>)</span></div>
</div>
</div><div class='float_breaker'></div></div><div class='function_doc'><p> Disconnects node connected to <span class='arg_name'>input_pad</span> of <span class='arg_name'>node</span> (if any).
</p><p></p><p><b>Arguments:</b></p><table>
<tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>node</span></td><td> a <a href='#GeglNode'>GeglNode</a></td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>input_pad</span></td><td> the input pad to disconnect.</td></tr></table>
</div><div class='return_doc'><b>Returns</b> <span class='keyword'>TRUE</span> if a connection was broken.
</div><pre class='sample_code'></pre></div></div>
<div class='section' id='section_Properties'><a name='Properties'></a><div class='sect'>
<h2>Properties</h2><div class='sect_doc'><p>
Properties can be set either when creating the node with
<a href='#gegl_node_new_child'>gegl_node_new_child</a> as well as later when changing the initial
value with <a href='#gegl_node_set'>gegl_node_set</a>.
</p><p> To see what properties are available for a given operation look in the <a
href='operations.html'>Operations reference</a> or use
<a href='#gegl_node_get'>gegl_node_get</a>.
</p><pre class='sample_code'></pre></div></div></div>
<div class='section' id='section_gegl_node_set'><a name='gegl_node_set'></a><div class='function'>
<!--<h3>gegl_node_set</h3>-->
<div class='function_signature'>
<div class='function_header'>
<div class='return_type'>void </div>
<div class='function_name'>gegl_node_set</div>
</div><div class='function_args'><div class='argument'>
<div class='arg_type'><span class='const'>(</span><a href='#GeglNode'>GeglNode</a> <span class='pointer'>*</span></div>
<div class='arg_name'>node<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'><span class='const'>const</span> gchar <span class='pointer'>*</span></div>
<div class='arg_name'>first_property_name<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'><a href='#'></a></div>
<div class='arg_name'><span class='varargs'>..., NULL</span><span class='const'>)</span></div>
</div>
</div><div class='float_breaker'></div></div><div class='function_doc'><p> Set properties on a node, possible properties to be set are the properties
of the currently set operations as well as <em>"name"</em> and
<em>"operation"</em>. <em>"operation"</em> changes the current operations
set for the node, <em>"name"</em> doesn't have any role internally in
GEGL.
</p><p><b>Arguments:</b></p><table>
<tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>node</span></td><td> a <a href='#GeglNode'>GeglNode</a></td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>first_property_name</span></td><td> name of the first property to set</td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>...</span></td><td> value for the first property, followed optionally by more name/value pairs, followed by <span class='keyword'>NULL</span>.
</td></tr></table>
</div><div class='return_doc'></div><pre class='sample_code'>gegl_node_set (node, "brightness", -0.2,
"contrast", 2.0,
NULL);
</pre></div></div>
<div class='section' id='section_gegl_node_get'><a name='gegl_node_get'></a><div class='function'>
<!--<h3>gegl_node_get</h3>-->
<div class='function_signature'>
<div class='function_header'>
<div class='return_type'>void </div>
<div class='function_name'>gegl_node_get</div>
</div><div class='function_args'><div class='argument'>
<div class='arg_type'><span class='const'>(</span><a href='#GeglNode'>GeglNode</a> <span class='pointer'>*</span></div>
<div class='arg_name'>node<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'><span class='const'>const</span> gchar <span class='pointer'>*</span></div>
<div class='arg_name'>first_property_name<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'><a href='#'></a></div>
<div class='arg_name'><span class='varargs'>..., NULL</span><span class='const'>)</span></div>
</div>
</div><div class='float_breaker'></div></div><div class='function_doc'><p> Gets properties of a <a href='#GeglNode'>GeglNode</a>.
</p><p><b>Arguments:</b></p><table>
<tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>node</span></td><td> a <a href='#GeglNode'>GeglNode</a></td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>first_property_name</span></td><td> name of the first property to get.</td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>...</span></td><td> return location for the first property, followed optionally by more name/value pairs, followed by <span class='keyword'>NULL</span>.
</td></tr></table>
</div><div class='return_doc'></div><pre class='sample_code'>double level;
char *path;
gegl_node_get (png_save, "path", &path, NULL);
gegl_node_get (threshold, "level", &level, NULL);
</pre></div></div>
<div class='section' id='section_Processing'><a name='Processing'></a><div class='sect'>
<h2>Processing</h2><div class='sect_doc'><p>
There are two different ways to do processing with GEGL, either you
query any node providing output for a rectangular region to be rendered
using <a href='#gegl_node_blit'>gegl_node_blit</a>, or you use <a href='#gegl_node_process'>gegl_node_process</a> on a sink node (A
display node, an image file writer or similar). To do iterative processing
you need to use a <a href='#GeglProcessor'>GeglProcessor</a>. See <a href='#gegl_processor_work'>gegl_processor_work</a> for a code
sample.
</p><pre class='sample_code'></pre></div></div></div>
<div class='section' id='section_gegl_node_blit'><a name='gegl_node_blit'></a><div class='function'>
<!--<h3>gegl_node_blit</h3>-->
<div class='function_signature'>
<div class='function_header'>
<div class='return_type'>void </div>
<div class='function_name'>gegl_node_blit</div>
</div><div class='function_args'><div class='argument'>
<div class='arg_type'><span class='const'>(</span><a href='#GeglNode'>GeglNode</a> <span class='pointer'>*</span></div>
<div class='arg_name'>node<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'>gdouble </div>
<div class='arg_name'>scale<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'><span class='const'>const</span> <a href='#GeglRectangle'>GeglRectangle</a> <span class='pointer'>*</span></div>
<div class='arg_name'>roi<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'><span class='const'>const</span> <a href='#Babl'>Babl</a> <span class='pointer'>*</span></div>
<div class='arg_name'>format<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'>gpointer </div>
<div class='arg_name'>destination_buf<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'>gint </div>
<div class='arg_name'>rowstride<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'><a href='#GeglBlitFlags'>GeglBlitFlags</a> </div>
<div class='arg_name'>flags<span class='const'>)</span></div>
</div>
</div><div class='float_breaker'></div></div><div class='function_doc'><p> Render a rectangular region from a node.
</p><p><b>Arguments:</b></p><table>
<tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>node</span></td><td> a <a href='#GeglNode'>GeglNode</a></td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>scale</span></td><td> the scale to render at 1.0 is default, other values changes the width/height of the sampled region.
</td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>roi</span></td><td> the rectangle to render from the node, the coordinate system used is coordinates after scale has been applied.
</td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>format</span></td><td> the <a href='#BablFormat'>BablFormat</a> desired.</td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>destination_buf</span></td><td> a memory buffer large enough to contain the data, can be left as <span class='keyword'>NULL</span> when forcing a rendering of a region.
</td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>rowstride</span></td><td> rowstride in bytes, or GEGL_AUTO_ROWSTRIDE to compute the rowstride based on the width and bytes per pixel for the specified format.
</td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>flags</span></td><td> an or'ed combination of GEGL_BLIT_DEFAULT, GEGL_BLIT_CACHE and GEGL_BLIT_DIRTY. if cache is enabled, a cache will be set up for subsequent
requests of image data from this node. By passing in GEGL_BLIT_DIRTY the
function will return with the latest rendered results in the cache without
regard to wheter the regions has been rendered or not.
</td></tr></table>
</div><div class='return_doc'></div><pre class='sample_code'></pre></div></div>
<div class='section' id='section_gegl_node_process'><a name='gegl_node_process'></a><div class='function'>
<!--<h3>gegl_node_process</h3>-->
<div class='function_signature'>
<div class='function_header'>
<div class='return_type'>void </div>
<div class='function_name'>gegl_node_process</div>
</div><div class='function_args'><div class='argument'>
<div class='arg_type'><span class='const'>(</span><a href='#GeglNode'>GeglNode</a> <span class='pointer'>*</span></div>
<div class='arg_name'>sink_node<span class='const'>)</span></div>
</div>
</div><div class='float_breaker'></div></div><div class='function_doc'><p> Render a composition. This can be used for instance on a node with a "png-save"
operation to render all neccesary data, and make it be written to file. This
function wraps the usage of a GeglProcessor in a single blocking function
call. If you need a non-blocking operation, then make a direct use of
<a href='#gegl_processor_work'>gegl_processor_work</a>. See <a href='#GeglProcessor'>GeglProcessor</a>.
</p><p></p><p><b>Arguments:</b></p><table>
<tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>sink_node</span></td><td> a <a href='#GeglNode'>GeglNode</a> without outputs.</td></tr></table>
</div><div class='return_doc'></div><pre class='sample_code'>GeglNode *gegl;
GeglRectangle roi;
GeglNode *png_save;
unsigned char *buffer;
gegl = gegl_parse_xml (xml_data);
roi = gegl_node_get_bounding_box (gegl);
# create png_save from the graph, the parent/child relationship
# only mean anything when it comes to memory management.
png_save = gegl_node_new_child (gegl,
"operation", "png-save",
"path", "output.png",
NULL);
gegl_node_link (gegl, png_save);
gegl_node_process (png_save);
buffer = malloc (roi.w*roi.h*4);
gegl_node_blit (gegl,
&roi,
1.0,
babl_format("R'G'B'A u8",
roi.w*4,
buffer,
GEGL_BLIT_DEFAULT);
</pre></div></div>
<div class='section' id='section_Reparenting'><a name='Reparenting'></a><div class='sect'>
<h2>Reparenting</h2><div class='sect_doc'><p>
Sometimes it is useful to be able to move nodes between graphs or even
handle orphaned nods that are not part of a graph. gegl_node_adopt_child
and gegl_node_get_parent are provided ot handle such cases.
</p><pre class='sample_code'></pre></div></div></div>
<div class='section' id='section_gegl_node_adopt_child'><a name='gegl_node_adopt_child'></a><div class='function'>
<!--<h3>gegl_node_adopt_child</h3>-->
<div class='function_signature'>
<div class='function_header'>
<div class='return_type'><a href='#GeglNode'>GeglNode</a> <span class='pointer'>*</span> </div>
<div class='function_name'>gegl_node_adopt_child</div>
</div><div class='function_args'><div class='argument'>
<div class='arg_type'><span class='const'>(</span><a href='#GeglNode'>GeglNode</a> <span class='pointer'>*</span></div>
<div class='arg_name'>parent<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'><a href='#GeglNode'>GeglNode</a> <span class='pointer'>*</span></div>
<div class='arg_name'>child<span class='const'>)</span></div>
</div>
</div><div class='float_breaker'></div></div><div class='function_doc'><p> Adds <span class='arg_name'>child</span> to the responsibilities of <span class='arg_name'>node</span>, this makes the parent node
take a reference on the child that is kept as long as the parent itself is
being referenced. The node is stolen from an existing parent if there is one,
or a presumed existing reference is used. If <span class='arg_name'>parent</span> is <span class='keyword'>NULL</span> the child will
be orphaned and the developer is given a reference to be responsible of.
</p><p></p><p><b>Arguments:</b></p><table>
<tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>parent</span></td><td> a <a href='#GeglNode'>GeglNode</a> or <span class='keyword'>NULL</span>.</td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>child</span></td><td> a <a href='#GeglNode'>GeglNode</a></td></tr></table>
</div><div class='return_doc'><b>Returns</b> the child, or <span class='keyword'>NULL</span> if there was a problem with the arguments.
</div><pre class='sample_code'></pre></div></div>
<div class='section' id='section_gegl_node_get_parent'><a name='gegl_node_get_parent'></a><div class='function'>
<!--<h3>gegl_node_get_parent</h3>-->
<div class='function_signature'>
<div class='function_header'>
<div class='return_type'><a href='#GeglNode'>GeglNode</a> <span class='pointer'>*</span> </div>
<div class='function_name'>gegl_node_get_parent</div>
</div><div class='function_args'><div class='argument'>
<div class='arg_type'><span class='const'>(</span><a href='#GeglNode'>GeglNode</a> <span class='pointer'>*</span></div>
<div class='arg_name'>node<span class='const'>)</span></div>
</div>
</div><div class='float_breaker'></div></div><div class='function_doc'><p></p><p><b>Arguments:</b></p><table>
<tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>node</span></td><td> a <a href='#GeglNode'>GeglNode</a></td></tr></table>
</div><div class='return_doc'><b>Returns</b> a GeglNode that keeps a reference on a child.
</p><p> Returns the parent of a node or <span class='keyword'>NULL</span>.
</div><pre class='sample_code'></pre></div></div>
<div class='section' id='section_State_queries'><a name='State_queries'></a><div class='sect'>
<h2>State queries</h2><div class='sect_doc'><p>
This section lists functions that retrieve information, mostly needed
for interacting with a graph in a GUI, not creating one from scratch.
</p><p> You can figure out what the bounding box of a node is with <a href='#gegl_node_get_bounding_box'>gegl_node_get_bounding_box</a>,
retrieve the values of named properties using <a href='#gegl_node_get'>gegl_node_get</a>.
</p><pre class='sample_code'></pre></div></div></div>
<div class='section' id='section_gegl_node_detect'><a name='gegl_node_detect'></a><div class='function'>
<!--<h3>gegl_node_detect</h3>-->
<div class='function_signature'>
<div class='function_header'>
<div class='return_type'><a href='#GeglNode'>GeglNode</a> <span class='pointer'>*</span> </div>
<div class='function_name'>gegl_node_detect</div>
</div><div class='function_args'><div class='argument'>
<div class='arg_type'><span class='const'>(</span><a href='#GeglNode'>GeglNode</a> <span class='pointer'>*</span></div>
<div class='arg_name'>node<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'>gint </div>
<div class='arg_name'>x<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'>gint </div>
<div class='arg_name'>y<span class='const'>)</span></div>
</div>
</div><div class='float_breaker'></div></div><div class='function_doc'><p> Performs hit detection by returning the node providing data at a given
coordinate pair. Currently operates only on bounding boxes and not
pixel data.
</p><p></p><p><b>Arguments:</b></p><table>
<tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>node</span></td><td> a <a href='#GeglNode'>GeglNode</a></td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>x</span></td><td> x coordinate</td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>y</span></td><td> y coordinate</td></tr></table>
</div><div class='return_doc'><b>Returns</b> the GeglNode providing the data ending up at <span class='arg_name'>x</span>,<span class='arg_name'>y</span> in the output
of <span class='arg_name'>node</span>.
</div><pre class='sample_code'></pre></div></div>
<div class='section' id='section_gegl_node_find_property'><a name='gegl_node_find_property'></a><div class='function'>
<!--<h3>gegl_node_find_property</h3>-->
<div class='function_signature'>
<div class='function_header'>
<div class='return_type'><a href='http://developer.gnome.org/doc/API/2.0/gobject/gobject-GParamSpec.html#GParamSpec'>GParamSpec</a> <span class='pointer'>*</span> </div>
<div class='function_name'>gegl_node_find_property</div>
</div><div class='function_args'><div class='argument'>
<div class='arg_type'><span class='const'>(</span><a href='#GeglNode'>GeglNode</a> <span class='pointer'>*</span></div>
<div class='arg_name'>node<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'><span class='const'>const</span> gchar <span class='pointer'>*</span></div>
<div class='arg_name'>property_name<span class='const'>)</span></div>
</div>
</div><div class='float_breaker'></div></div><div class='function_doc'><p></p><p><b>Arguments:</b></p><table>
<tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>node</span></td><td> the node to lookup a paramspec on</td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>property_name</span></td><td> the name of the property to get a paramspec for.</td></tr></table>
</div><div class='return_doc'><b>Returns</b> the GParamSpec of property or <span class='keyword'>NULL</span> if no such property exists.
</div><pre class='sample_code'></pre></div></div>
<div class='section' id='section_gegl_node_get_bounding_box'><a name='gegl_node_get_bounding_box'></a><div class='function'>
<!--<h3>gegl_node_get_bounding_box</h3>-->
<div class='function_signature'>
<div class='function_header'>
<div class='return_type'><a href='#GeglRectangle'>GeglRectangle</a> </div>
<div class='function_name'>gegl_node_get_bounding_box</div>
</div><div class='function_args'><div class='argument'>
<div class='arg_type'><span class='const'>(</span><a href='#GeglNode'>GeglNode</a> <span class='pointer'>*</span></div>
<div class='arg_name'>node<span class='const'>)</span></div>
</div>
</div><div class='float_breaker'></div></div><div class='function_doc'><p></p><p><b>Arguments:</b></p><table>
<tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>node</span></td><td> a <a href='#GeglNode'>GeglNode</a></td></tr></table>
</div><div class='return_doc'><b>Returns</b> the position and dimensions of a rectangle spanning the area
defined by a node.
</div><pre class='sample_code'></pre></div></div>
<div class='section' id='section_gegl_node_get_children'><a name='gegl_node_get_children'></a><div class='function'>
<!--<h3>gegl_node_get_children</h3>-->
<div class='function_signature'>
<div class='function_header'>
<div class='return_type'><a href='http://developer.gnome.org/doc/API/2.0/glib/glib-Singly-Linked-Lists.html#GSList'>GSList</a> <span class='pointer'>*</span> </div>
<div class='function_name'>gegl_node_get_children</div>
</div><div class='function_args'><div class='argument'>
<div class='arg_type'><span class='const'>(</span><a href='#GeglNode'>GeglNode</a> <span class='pointer'>*</span></div>
<div class='arg_name'>node<span class='const'>)</span></div>
</div>
</div><div class='float_breaker'></div></div><div class='function_doc'><p></p><p><b>Arguments:</b></p><table>
<tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>node</span></td><td> the node to retrieve the children of.</td></tr></table>
</div><div class='return_doc'><b>Returns</b> a list of nodes with children/internal nodes. The list must be
freed by the caller.
</div><pre class='sample_code'></pre></div></div>
<div class='section' id='section_gegl_node_get_consumers'><a name='gegl_node_get_consumers'></a><div class='function'>
<!--<h3>gegl_node_get_consumers</h3>-->
<div class='function_signature'>
<div class='function_header'>
<div class='return_type'>gint </div>
<div class='function_name'>gegl_node_get_consumers</div>
</div><div class='function_args'><div class='argument'>
<div class='arg_type'><span class='const'>(</span><a href='#GeglNode'>GeglNode</a> <span class='pointer'>*</span></div>
<div class='arg_name'>node<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'><span class='const'>const</span> gchar <span class='pointer'>*</span></div>
<div class='arg_name'>output_pad<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'><a href='#GeglNode'>GeglNode</a> <span class='pointer'>*</span><span class='pointer'>*</span><span class='pointer'>*</span></div>
<div class='arg_name'>nodes<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'><span class='const'>const</span> gchar <span class='pointer'>*</span><span class='pointer'>*</span><span class='pointer'>*</span></div>
<div class='arg_name'>pads<span class='const'>)</span></div>
</div>
</div><div class='float_breaker'></div></div><div class='function_doc'><p> Retrieve which pads on which nodes are connected to a named output_pad,
and the number of connections. Both the location for the generated
nodes array and pads array can be left as <span class='keyword'>NULL</span>. If they are non <span class='keyword'>NULL</span>
both should be freed with g_free. The arrays are <span class='keyword'>NULL</span> terminated.
</p><p></p><p><b>Arguments:</b></p><table>
<tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>node</span></td><td> the node we are querying.</td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>output_pad</span></td><td> the output pad we want to know who uses.</td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>nodes</span></td><td> optional return location for array of nodes.</td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>pads</span></td><td> optional return location for array of pad names.</td></tr></table>
</div><div class='return_doc'><b>Returns</b> the number of consumers connected to this output_pad.
</div><pre class='sample_code'></pre></div></div>
<div class='section' id='section_gegl_node_get_input_proxy'><a name='gegl_node_get_input_proxy'></a><div class='function'>
<!--<h3>gegl_node_get_input_proxy</h3>-->
<div class='function_signature'>
<div class='function_header'>
<div class='return_type'><a href='#GeglNode'>GeglNode</a> <span class='pointer'>*</span> </div>
<div class='function_name'>gegl_node_get_input_proxy</div>
</div><div class='function_args'><div class='argument'>
<div class='arg_type'><span class='const'>(</span><a href='#GeglNode'>GeglNode</a> <span class='pointer'>*</span></div>
<div class='arg_name'>node<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'><span class='const'>const</span> gchar <span class='pointer'>*</span></div>
<div class='arg_name'>pad_name<span class='const'>)</span></div>
</div>
</div><div class='float_breaker'></div></div><div class='function_doc'><p> Proxies are used to route between nodes of a subgraph contained within
a node.
</p><p></p><p><b>Arguments:</b></p><table>
<tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>node</span></td><td> a <a href='#GeglNode'>GeglNode</a></td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>pad_name</span></td><td> the name of the pad.</td></tr></table>
</div><div class='return_doc'><b>Returns</b> an input proxy for the named pad. If no input proxy exists with
this name a new one will be created.
</div><pre class='sample_code'></pre></div></div>
<div class='section' id='section_gegl_node_get_operation'><a name='gegl_node_get_operation'></a><div class='function'>
<!--<h3>gegl_node_get_operation</h3>-->
<div class='function_signature'>
<div class='function_header'>
<div class='return_type'><span class='const'>const</span> gchar <span class='pointer'>*</span> </div>
<div class='function_name'>gegl_node_get_operation</div>
</div><div class='function_args'><div class='argument'>
<div class='arg_type'><span class='const'>(</span><span class='const'>const</span> <a href='#GeglNode'>GeglNode</a> <span class='pointer'>*</span></div>
<div class='arg_name'>node<span class='const'>)</span></div>
</div>
</div><div class='float_breaker'></div></div><div class='function_doc'><p></p><p><b>Arguments:</b></p><table>
<tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>node</span></td><td> a <a href='#GeglNode'>GeglNode</a></td></tr></table>
</div><div class='return_doc'><b>Returns</b> the type of processing operation associated with this node, or
<span class='keyword'>NULL</span> if there is no op associated. The special name "GraphNode"
is returned if the node is the container of a subgraph.
</div><pre class='sample_code'></pre></div></div>
<div class='section' id='section_gegl_node_get_output_proxy'><a name='gegl_node_get_output_proxy'></a><div class='function'>
<!--<h3>gegl_node_get_output_proxy</h3>-->
<div class='function_signature'>
<div class='function_header'>
<div class='return_type'><a href='#GeglNode'>GeglNode</a> <span class='pointer'>*</span> </div>
<div class='function_name'>gegl_node_get_output_proxy</div>
</div><div class='function_args'><div class='argument'>
<div class='arg_type'><span class='const'>(</span><a href='#GeglNode'>GeglNode</a> <span class='pointer'>*</span></div>
<div class='arg_name'>node<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'><span class='const'>const</span> gchar <span class='pointer'>*</span></div>
<div class='arg_name'>pad_name<span class='const'>)</span></div>
</div>
</div><div class='float_breaker'></div></div><div class='function_doc'><p> Proxies are used to route between nodes of a subgraph contained within
a node.
</p><p></p><p><b>Arguments:</b></p><table>
<tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>node</span></td><td> a <a href='#GeglNode'>GeglNode</a></td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>pad_name</span></td><td> the name of the pad.</td></tr></table>
</div><div class='return_doc'><b>Returns</b> a output proxy for the named pad. If no output proxy exists with
this name a new one will be created.
</div><pre class='sample_code'></pre></div></div>
<div class='section' id='section_gegl_node_get_producer'><a name='gegl_node_get_producer'></a><div class='function'>
<!--<h3>gegl_node_get_producer</h3>-->
<div class='function_signature'>
<div class='function_header'>
<div class='return_type'><a href='#GeglNode'>GeglNode</a> <span class='pointer'>*</span> </div>
<div class='function_name'>gegl_node_get_producer</div>
</div><div class='function_args'><div class='argument'>
<div class='arg_type'><span class='const'>(</span><a href='#GeglNode'>GeglNode</a> <span class='pointer'>*</span></div>
<div class='arg_name'>node<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'>gchar <span class='pointer'>*</span></div>
<div class='arg_name'>input_pad_name<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'>gchar <span class='pointer'>*</span><span class='pointer'>*</span></div>
<div class='arg_name'>output_pad_name<span class='const'>)</span></div>
</div>
</div><div class='float_breaker'></div></div><div class='function_doc'><p></p><p><b>Arguments:</b></p><table>
<tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>node</span></td><td> the node we are querying</td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>input_pad_name</span></td><td> the input pad we want to get the producer for</td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>output_pad_name</span></td><td> optional pointer to a location where we can store a freshly allocated string with the name of the output pad.
</td></tr></table>
</div><div class='return_doc'><b>Returns</b> the node providing data or <span class='keyword'>NULL</span> if no node is connected to the
input_pad.
</div><pre class='sample_code'></pre></div></div>
<div class='section' id='section_Binding_conveniences'><a name='Binding_conveniences'></a><div class='sect'>
<h2>Binding conveniences</h2><div class='sect_doc'><p>
The following functions are mostly included to make it easier to create
language bindings for the nodes. The varargs versions will in most cases
lead to both more efficient and readable code from C.
</p><pre class='sample_code'></pre></div></div></div>
<div class='section' id='section_gegl_node_create_child'><a name='gegl_node_create_child'></a><div class='function'>
<!--<h3>gegl_node_create_child</h3>-->
<div class='function_signature'>
<div class='function_header'>
<div class='return_type'><a href='#GeglNode'>GeglNode</a> <span class='pointer'>*</span> </div>
<div class='function_name'>gegl_node_create_child</div>
</div><div class='function_args'><div class='argument'>
<div class='arg_type'><span class='const'>(</span><a href='#GeglNode'>GeglNode</a> <span class='pointer'>*</span></div>
<div class='arg_name'>parent<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'><span class='const'>const</span> gchar <span class='pointer'>*</span></div>
<div class='arg_name'>operation<span class='const'>)</span></div>
</div>
</div><div class='float_breaker'></div></div><div class='function_doc'><p> Creates a new processing node that performs the specified operation.
All properties of the operation will have their default values. This
is included as an addiiton to <a href='#gegl_node_new_child'>gegl_node_new_child</a> in the public API to have
a non varargs entry point for bindings as well as sometimes simpler more
readable code.
</p><p></p><p><b>Arguments:</b></p><table>
<tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>parent</span></td><td> a <a href='#GeglNode'>GeglNode</a></td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>operation</span></td><td> the type of node to create.</td></tr></table>
</div><div class='return_doc'><b>Returns</b> a newly created node. The node will be destroyed by the parent.
Calling g_object_unref on a node will cause the node to be dropped by the
parent. (You may also add additional references using
g_object_ref/g_object_unref, but in general relying on the parents reference
counting is easiest.)
</div><pre class='sample_code'></pre></div></div>
<div class='section' id='section_gegl_node_get_property'><a name='gegl_node_get_property'></a><div class='function'>
<!--<h3>gegl_node_get_property</h3>-->
<div class='function_signature'>
<div class='function_header'>
<div class='return_type'>void </div>
<div class='function_name'>gegl_node_get_property</div>
</div><div class='function_args'><div class='argument'>
<div class='arg_type'><span class='const'>(</span><a href='#GeglNode'>GeglNode</a> <span class='pointer'>*</span></div>
<div class='arg_name'>node<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'><span class='const'>const</span> gchar <span class='pointer'>*</span></div>
<div class='arg_name'>property_name<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'><a href='http://developer.gnome.org/doc/API/2.0/gobject/gobject-Generic-values.html#GValue'>GValue</a> <span class='pointer'>*</span></div>
<div class='arg_name'>value<span class='const'>)</span></div>
</div>
</div><div class='float_breaker'></div></div><div class='function_doc'><p> This is mainly included for language bindings. Using <a href='#gegl_node_get'>gegl_node_get</a> is
more convenient when programming in C.
</p><p></p><p><b>Arguments:</b></p><table>
<tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>node</span></td><td> the node to get a property from</td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>property_name</span></td><td> the name of the property to get</td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>value</span></td><td> pointer to a GValue where the value of the property should be stored</td></tr></table>
</div><div class='return_doc'></div><pre class='sample_code'></pre></div></div>
<div class='section' id='section_gegl_node_set_property'><a name='gegl_node_set_property'></a><div class='function'>
<!--<h3>gegl_node_set_property</h3>-->
<div class='function_signature'>
<div class='function_header'>
<div class='return_type'>void </div>
<div class='function_name'>gegl_node_set_property</div>
</div><div class='function_args'><div class='argument'>
<div class='arg_type'><span class='const'>(</span><a href='#GeglNode'>GeglNode</a> <span class='pointer'>*</span></div>
<div class='arg_name'>node<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'><span class='const'>const</span> gchar <span class='pointer'>*</span></div>
<div class='arg_name'>property_name<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'><span class='const'>const</span> <a href='http://developer.gnome.org/doc/API/2.0/gobject/gobject-Generic-values.html#GValue'>GValue</a> <span class='pointer'>*</span></div>
<div class='arg_name'>value<span class='const'>)</span></div>
</div>
</div><div class='float_breaker'></div></div><div class='function_doc'><p> This is mainly included for language bindings. Using <a href='#gegl_node_set'>gegl_node_set</a> is
more convenient when programming in C.
</p><p><b>Arguments:</b></p><table>
<tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>node</span></td><td> a <a href='#GeglNode'>GeglNode</a></td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>property_name</span></td><td> the name of the property to set</td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>value</span></td><td> a GValue containing the value to be set in the property.</td></tr></table>
</div><div class='return_doc'></div><pre class='sample_code'></pre></div></div>
<div class='section' id='section_XML'><a name='XML'></a><div class='sect'>
<h2>XML</h2><div class='sect_doc'><p> The XML format used by GEGL is not stable and should not be relied on
for anything but testing purposes yet.
</p><pre class='sample_code'></pre></div></div></div>
<div class='section' id='section_gegl_node_new_from_xml'><a name='gegl_node_new_from_xml'></a><div class='function'>
<!--<h3>gegl_node_new_from_xml</h3>-->
<div class='function_signature'>
<div class='function_header'>
<div class='return_type'><a href='#GeglNode'>GeglNode</a> <span class='pointer'>*</span> </div>
<div class='function_name'>gegl_node_new_from_xml</div>
</div><div class='function_args'><div class='argument'>
<div class='arg_type'><span class='const'>(</span><span class='const'>const</span> gchar <span class='pointer'>*</span></div>
<div class='arg_name'>xmldata<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'><span class='const'>const</span> gchar <span class='pointer'>*</span></div>
<div class='arg_name'>path_root<span class='const'>)</span></div>
</div>
</div><div class='float_breaker'></div></div><div class='function_doc'><p> The <a href='#GeglNode'>GeglNode</a> returned contains the graph described by the tree of stacks
in the XML document. The tree is connected to the "output" pad of the
returned node and thus can be used directly for processing.
</p><p></p><p><b>Arguments:</b></p><table>
<tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>xmldata</span></td><td> a \0 terminated string containing XML data to be parsed.</td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>path_root</span></td><td> a file system path that relative paths in the XML will be resolved in relation to.
</td></tr></table>
</div><div class='return_doc'><b>Returns</b> a GeglNode containing the parsed XML as a subgraph.
</div><pre class='sample_code'></pre></div></div>
<div class='section' id='section_gegl_node_new_from_file'><a name='gegl_node_new_from_file'></a><div class='function'>
<!--<h3>gegl_node_new_from_file</h3>-->
<div class='function_signature'>
<div class='function_header'>
<div class='return_type'><a href='#GeglNode'>GeglNode</a> <span class='pointer'>*</span> </div>
<div class='function_name'>gegl_node_new_from_file</div>
</div><div class='function_args'><div class='argument'>
<div class='arg_type'><span class='const'>(</span><span class='const'>const</span> gchar <span class='pointer'>*</span></div>
<div class='arg_name'>path<span class='const'>)</span></div>
</div>
</div><div class='float_breaker'></div></div><div class='function_doc'><p> The <a href='#GeglNode'>GeglNode</a> returned contains the graph described by the tree of stacks
in the XML document. The tree is connected to the "output" pad of the
returned node and thus can be used directly for processing.
</p><p></p><p><b>Arguments:</b></p><table>
<tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>path</span></td><td> the path to a file on the local file system to be parsed.</td></tr></table>
</div><div class='return_doc'><b>Returns</b> a GeglNode containing the parsed XML as a subgraph.
</div><pre class='sample_code'></pre></div></div>
<div class='section' id='section_gegl_node_to_xml'><a name='gegl_node_to_xml'></a><div class='function'>
<!--<h3>gegl_node_to_xml</h3>-->
<div class='function_signature'>
<div class='function_header'>
<div class='return_type'>gchar <span class='pointer'>*</span> </div>
<div class='function_name'>gegl_node_to_xml</div>
</div><div class='function_args'><div class='argument'>
<div class='arg_type'><span class='const'>(</span><a href='#GeglNode'>GeglNode</a> <span class='pointer'>*</span></div>
<div class='arg_name'>node<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'><span class='const'>const</span> gchar <span class='pointer'>*</span></div>
<div class='arg_name'>path_root<span class='const'>)</span></div>
</div>
</div><div class='float_breaker'></div></div><div class='function_doc'><p></p><p><b>Arguments:</b></p><table>
<tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>node</span></td><td> a <a href='#GeglNode'>GeglNode</a></td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>path_root</span></td><td> filesystem path to construct relative paths from.</td></tr></table>
</div><div class='return_doc'><b>Returns</b> a freshly allocated \0 terminated string containing a XML
serialization of the composition produced by a node (and thus also
the nodes contributing data to the specified node). To export a
gegl graph, connect the internal output node to an output proxy (see
<a href='#gegl_node_get_output_proxy'>gegl_node_get_output_proxy</a>.) and use the proxy node as the basis
for the serialization.
</div><pre class='sample_code'></pre></div></div>
<div class='section' id='section_GeglProcessor'><a name='GeglProcessor'></a><div class='sect'>
<h2>GeglProcessor</h2><div class='sect_doc'><p>
A <a href='#GeglProcessor'>GeglProcessor</a>, is a worker that can be used for background rendering
of regions in a node's cache. Or for processing a sink node. For most
non GUI tasks using <a href='#gegl_node_blit'>gegl_node_blit</a> and <a href='#gegl_node_process'>gegl_node_process</a> directly
should be sufficient. See <a href='#gegl_processor_work'>gegl_processor_work</a> for a code sample.
</p><p></p><pre class='sample_code'></pre></div></div></div>
<div class='section' id='section_gegl_node_new_processor'><a name='gegl_node_new_processor'></a><div class='function'>
<!--<h3>gegl_node_new_processor</h3>-->
<div class='function_signature'>
<div class='function_header'>
<div class='return_type'><a href='#GeglProcessor'>GeglProcessor</a> <span class='pointer'>*</span></div>
<div class='function_name'>gegl_node_new_processor</div>
</div><div class='function_args'><div class='argument'>
<div class='arg_type'><span class='const'>(</span><a href='#GeglNode'>GeglNode</a> <span class='pointer'>*</span></div>
<div class='arg_name'>node<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'><span class='const'>const</span> <a href='#GeglRectangle'>GeglRectangle</a> <span class='pointer'>*</span></div>
<div class='arg_name'>rectangle<span class='const'>)</span></div>
</div>
</div><div class='float_breaker'></div></div><div class='function_doc'><p></p><p><b>Arguments:</b></p><table>
<tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>node</span></td><td> a <a href='#GeglNode'>GeglNode</a></td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>rectangle</span></td><td> the <a href='#GeglRectangle'>GeglRectangle</a> to work on or <span class='keyword'>NULL</span> to work on all available data.
</td></tr></table>
</div><div class='return_doc'><b>Returns</b> a new <a href='#GeglProcessor'>GeglProcessor</a>.
</div><pre class='sample_code'></pre></div></div>
<div class='section' id='section_gegl_processor_set_rectangle'><a name='gegl_processor_set_rectangle'></a><div class='function'>
<!--<h3>gegl_processor_set_rectangle</h3>-->
<div class='function_signature'>
<div class='function_header'>
<div class='return_type'>void </div>
<div class='function_name'>gegl_processor_set_rectangle</div>
</div><div class='function_args'><div class='argument'>
<div class='arg_type'><span class='const'>(</span><a href='#GeglProcessor'>GeglProcessor</a> <span class='pointer'>*</span></div>
<div class='arg_name'>processor<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'><span class='const'>const</span> <a href='#GeglRectangle'>GeglRectangle</a> <span class='pointer'>*</span></div>
<div class='arg_name'>rectangle<span class='const'>)</span></div>
</div>
</div><div class='float_breaker'></div></div><div class='function_doc'><p> Change the rectangle a <a href='#GeglProcessor'>GeglProcessor</a> is working on.
</p><p><b>Arguments:</b></p><table>
<tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>processor</span></td><td> a <a href='#GeglProcessor'>GeglProcessor</a></td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>rectangle</span></td><td> the new <a href='#GeglRectangle'>GeglRectangle</a> the processor shold work on or <span class='keyword'>NULL</span> to make it work on all data in the buffer.
</td></tr></table>
</div><div class='return_doc'></div><pre class='sample_code'></pre></div></div>
<div class='section' id='section_gegl_processor_work'><a name='gegl_processor_work'></a><div class='function'>
<!--<h3>gegl_processor_work</h3>-->
<div class='function_signature'>
<div class='function_header'>
<div class='return_type'>gboolean </div>
<div class='function_name'>gegl_processor_work</div>
</div><div class='function_args'><div class='argument'>
<div class='arg_type'><span class='const'>(</span><a href='#GeglProcessor'>GeglProcessor</a> <span class='pointer'>*</span></div>
<div class='arg_name'>processor<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'>gdouble <span class='pointer'>*</span></div>
<div class='arg_name'>progress<span class='const'>)</span></div>
</div>
</div><div class='float_breaker'></div></div><div class='function_doc'><p> Do an iteration of work for the processor.
</p><p></p><p><b>Arguments:</b></p><table>
<tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>processor</span></td><td> a <a href='#GeglProcessor'>GeglProcessor</a></td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>progress</span></td><td> a location to store the (estimated) percentage complete.</td></tr></table>
</div><div class='return_doc'><b>Returns</b> <span class='keyword'>TRUE</span> if there is more work to be done.
</p><p></div><pre class='sample_code'>GeglProcessor *processor = gegl_node_new_processor (node, &roi);
double progress;
while (gegl_processor_work (processor, &progress))
g_warning ("%f%% complete", progress);
gegl_processor_destroy (processor);
</pre></div></div>
<div class='section' id='section_gegl_processor_destroy'><a name='gegl_processor_destroy'></a><div class='function'>
<!--<h3>gegl_processor_destroy</h3>-->
<div class='function_signature'>
<div class='function_header'>
<div class='return_type'>void </div>
<div class='function_name'>gegl_processor_destroy</div>
</div><div class='function_args'><div class='argument'>
<div class='arg_type'><span class='const'>(</span><a href='#GeglProcessor'>GeglProcessor</a> <span class='pointer'>*</span></div>
<div class='arg_name'>processor<span class='const'>)</span></div>
</div>
</div><div class='float_breaker'></div></div><div class='function_doc'><p> Frees up resources used by a processing handle.
</p><p><b>Arguments:</b></p><table>
<tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>processor</span></td><td> a <a href='#GeglProcessor'>GeglProcessor</a></td></tr></table>
</div><div class='return_doc'></div><pre class='sample_code'></pre></div></div>
<div class='section' id='section_gegl_config'><a name='gegl_config'></a><div class='function'>
<!--<h3>gegl_config</h3>-->
<div class='function_signature'>
<div class='function_header'>
<div class='return_type'><a href='#GObject'>GObject</a> <span class='pointer'>*</span> </div>
<div class='function_name'>gegl_config</div>
</div><div class='function_args'><div class='argument'><div class='arg_type'><span class='const'>(void)</span></div></div>
</div><div class='float_breaker'></div></div><div class='function_doc'><p></p></div><div class='return_doc'><b>Returns</b> a GObject with properties that can be manipulated to control
GEGLs behavior. Properties available on the object are:
</p><p> "cache-size" "quality" and "swap", the two first is an integer denoting
number of bytes, the secons a double value between 0 and 1 and the last
the path of the directory to swap to (or "ram" to not use diskbased swap)
</div><pre class='sample_code'></pre></div></div>
<div class='section' id='section_GeglRectangle'><a name='GeglRectangle'></a><div class='sect'>
<h2>GeglRectangle</h2><div class='sect_doc'><p>
GeglRectangles are used in <a href='#gegl_node_get_bounding_box'>gegl_node_get_bounding_box</a> and <a href='#gegl_node_blit'>gegl_node_blit</a>
for specifying rectangles.
</p><p> </p><pre>struct GeglRectangle
{
gint x;
gint y;
gint width;
gint height;
};</pre><p>
</p><p></p><pre class='sample_code'></pre></div></div></div>
<div class='section' id='section_GeglBuffer'><a name='GeglBuffer'></a><div class='sect'>
<h2>GeglBuffer</h2><div class='sect_doc'><p>
GeglBuffer is the API used by GEGL for storing and retrieving raster data.
GeglBuffer heavily relies on babl for translation and description of
different pixel formats.
</p><p> Internally GeglBuffer currently uses a tiled mipmap pyramid structure that
can be swapped to disk. In the future GeglBuffer might also support a linear
backend, a GPU memory backend and a network backend for buffers.
</p><pre class='sample_code'></pre></div></div></div>
<div class='section' id='section_gegl_buffer_new'><a name='gegl_buffer_new'></a><div class='function'>
<!--<h3>gegl_buffer_new</h3>-->
<div class='function_signature'>
<div class='function_header'>
<div class='return_type'><a href='#GeglBuffer'>GeglBuffer</a><span class='pointer'>*</span> </div>
<div class='function_name'>gegl_buffer_new</div>
</div><div class='function_args'><div class='argument'>
<div class='arg_type'><span class='const'>(</span><span class='const'>const</span> <a href='#GeglRectangle'>GeglRectangle</a> <span class='pointer'>*</span></div>
<div class='arg_name'>extent<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'><span class='const'>const</span> <a href='#Babl'>Babl</a> <span class='pointer'>*</span></div>
<div class='arg_name'>format<span class='const'>)</span></div>
</div>
</div><div class='float_breaker'></div></div><div class='function_doc'><p> Create a new GeglBuffer of a given format with a given extent. It is
possible to pass in <span class='keyword'>NULL</span> for both extent and format, a <span class='keyword'>NULL</span> extent creates
an exmpty buffer and a <span class='keyword'>NULL</span> format makes the buffer default to "RGBA float".
</p><p><b>Arguments:</b></p><table>
<tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>extent</span></td><td> the geometry of the buffer (origin, width and height) a GeglRectangle.
</td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>format</span></td><td> the Babl pixel format to be used, create one with babl_format("RGBA u8") and similar.
</td></tr></table>
</div><div class='return_doc'></div><pre class='sample_code'></pre></div></div>
<div class='section' id='section_gegl_buffer_open'><a name='gegl_buffer_open'></a><div class='function'>
<!--<h3>gegl_buffer_open</h3>-->
<div class='function_signature'>
<div class='function_header'>
<div class='return_type'><a href='#GeglBuffer'>GeglBuffer</a><span class='pointer'>*</span> </div>
<div class='function_name'>gegl_buffer_open</div>
</div><div class='function_args'><div class='argument'>
<div class='arg_type'><span class='const'>(</span><span class='const'>const</span> gchar <span class='pointer'>*</span></div>
<div class='arg_name'>path<span class='const'>)</span></div>
</div>
</div><div class='float_breaker'></div></div><div class='function_doc'><p> Open an existing on-disk GeglBuffer, this buffer is opened in a monitored
state so multiple instances of gegl can share the same buffer. Sets on
one buffer are reflected in the other.
</p><p></p><p><b>Arguments:</b></p><table>
<tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>path</span></td><td> the path to a gegl buffer on disk. be opened.
</td></tr></table>
</div><div class='return_doc'><b>Returns</b>: a GeglBuffer object.
</div><pre class='sample_code'></pre></div></div>
<div class='section' id='section_gegl_buffer_save'><a name='gegl_buffer_save'></a><div class='function'>
<!--<h3>gegl_buffer_save</h3>-->
<div class='function_signature'>
<div class='function_header'>
<div class='return_type'>void </div>
<div class='function_name'>gegl_buffer_save</div>
</div><div class='function_args'><div class='argument'>
<div class='arg_type'><span class='const'>(</span><a href='#GeglBuffer'>GeglBuffer</a> <span class='pointer'>*</span></div>
<div class='arg_name'>buffer<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'><span class='const'>const</span> gchar <span class='pointer'>*</span></div>
<div class='arg_name'>path<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'><span class='const'>const</span> <a href='#GeglRectangle'>GeglRectangle</a> <span class='pointer'>*</span></div>
<div class='arg_name'>roi<span class='const'>)</span></div>
</div>
</div><div class='float_breaker'></div></div><div class='function_doc'><p> Write a GeglBuffer to a file.
</p><p><b>Arguments:</b></p><table>
<tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>buffer</span></td><td> a <a href='#GeglBuffer'>GeglBuffer</a>.</td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>path</span></td><td> the path where the gegl buffer will be saved, any writable GIO uri is valid.</td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>roi</span></td><td> the region of interest to write, this is the tiles that will be collected and written to disk.
</td></tr></table>
</div><div class='return_doc'></div><pre class='sample_code'></pre></div></div>
<div class='section' id='section_gegl_buffer_load'><a name='gegl_buffer_load'></a><div class='function'>
<!--<h3>gegl_buffer_load</h3>-->
<div class='function_signature'>
<div class='function_header'>
<div class='return_type'><a href='#GeglBuffer'>GeglBuffer</a> <span class='pointer'>*</span></div>
<div class='function_name'>gegl_buffer_load</div>
</div><div class='function_args'><div class='argument'>
<div class='arg_type'><span class='const'>(</span><span class='const'>const</span> gchar <span class='pointer'>*</span></div>
<div class='arg_name'>path<span class='const'>)</span></div>
</div>
</div><div class='float_breaker'></div></div><div class='function_doc'><p> Loads an existing GeglBuffer from disk, if it has previously been saved with
gegl_buffer_save it should be possible to open through any GIO transport, buffers
that have been used as swap needs random access to be opened.
</p><p></p><p><b>Arguments:</b></p><table>
<tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>path</span></td><td> the path to a gegl buffer on disk. be opened.
</td></tr></table>
</div><div class='return_doc'><b>Returns</b>: a <a href='#GeglBuffer'>GeglBuffer</a> object.
</div><pre class='sample_code'></pre></div></div>
<div class='section' id='section_gegl_buffer_flush'><a name='gegl_buffer_flush'></a><div class='function'>
<!--<h3>gegl_buffer_flush</h3>-->
<div class='function_signature'>
<div class='function_header'>
<div class='return_type'>void </div>
<div class='function_name'>gegl_buffer_flush</div>
</div><div class='function_args'><div class='argument'>
<div class='arg_type'><span class='const'>(</span><a href='#GeglBuffer'>GeglBuffer</a> <span class='pointer'>*</span></div>
<div class='arg_name'>buffer<span class='const'>)</span></div>
</div>
</div><div class='float_breaker'></div></div><div class='function_doc'><p> Flushes all unsaved data to disk, this is not neccesary for shared
geglbuffers opened with gegl_buffer_open since they auto-sync on writes.
</p><p><b>Arguments:</b></p><table>
<tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>buffer</span></td><td> a <a href='#GeglBuffer'>GeglBuffer</a></td></tr></table>
</div><div class='return_doc'></div><pre class='sample_code'></pre></div></div>
<div class='section' id='section_gegl_buffer_create_sub_buffer'><a name='gegl_buffer_create_sub_buffer'></a><div class='function'>
<!--<h3>gegl_buffer_create_sub_buffer</h3>-->
<div class='function_signature'>
<div class='function_header'>
<div class='return_type'><a href='#GeglBuffer'>GeglBuffer</a><span class='pointer'>*</span> </div>
<div class='function_name'>gegl_buffer_create_sub_buffer</div>
</div><div class='function_args'><div class='argument'>
<div class='arg_type'><span class='const'>(</span><a href='#GeglBuffer'>GeglBuffer</a> <span class='pointer'>*</span></div>
<div class='arg_name'>buffer<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'><span class='const'>const</span> <a href='#GeglRectangle'>GeglRectangle</a> <span class='pointer'>*</span></div>
<div class='arg_name'>extent<span class='const'>)</span></div>
</div>
</div><div class='float_breaker'></div></div><div class='function_doc'><p> Create a new sub GeglBuffer, that is a view on a larger buffer.
</p><p><b>Arguments:</b></p><table>
<tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>buffer</span></td><td> parent buffer.</td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>extent</span></td><td> coordinates of new buffer.</td></tr></table>
</div><div class='return_doc'></div><pre class='sample_code'></pre></div></div>
<div class='section' id='section_gegl_buffer_destroy'><a name='gegl_buffer_destroy'></a><div class='function'>
<!--<h3>gegl_buffer_destroy</h3>-->
<div class='function_signature'>
<div class='function_header'>
<div class='return_type'>void </div>
<div class='function_name'>gegl_buffer_destroy</div>
</div><div class='function_args'><div class='argument'>
<div class='arg_type'><span class='const'>(</span><a href='#GeglBuffer'>GeglBuffer</a> <span class='pointer'>*</span></div>
<div class='arg_name'>buffer<span class='const'>)</span></div>
</div>
</div><div class='float_breaker'></div></div><div class='function_doc'><p> Destroys a buffer and frees up the resources used by a buffer, internally
this is done with reference counting and gobject, and gegl_buffer_destroy
is a thin wrapper around g_object_unref.
</p><p><b>Arguments:</b></p><table>
<tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>buffer</span></td><td> the buffer we're done with.</td></tr></table>
</div><div class='return_doc'></div><pre class='sample_code'></pre></div></div>
<div class='section' id='section_gegl_buffer_get_extent'><a name='gegl_buffer_get_extent'></a><div class='function'>
<!--<h3>gegl_buffer_get_extent</h3>-->
<div class='function_signature'>
<div class='function_header'>
<div class='return_type'><span class='const'>const</span> <a href='#GeglRectangle'>GeglRectangle</a> <span class='pointer'>*</span> </div>
<div class='function_name'>gegl_buffer_get_extent</div>
</div><div class='function_args'><div class='argument'>
<div class='arg_type'><span class='const'>(</span><a href='#GeglBuffer'>GeglBuffer</a> <span class='pointer'>*</span></div>
<div class='arg_name'>buffer<span class='const'>)</span></div>
</div>
</div><div class='float_breaker'></div></div><div class='function_doc'><p></p><p><b>Arguments:</b></p><table>
<tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>buffer</span></td><td> the buffer to operate on.</td></tr></table>
</div><div class='return_doc'><b>Returns</b> a pointer to a GeglRectangle structure defining the geometry of a
specific GeglBuffer, this is also the default width/height of buffers passed
in to gegl_buffer_set and gegl_buffer_get (with a scale of 1.0 at least).
</div><pre class='sample_code'></pre></div></div>
<div class='section' id='section_gegl_buffer_set_extent'><a name='gegl_buffer_set_extent'></a><div class='function'>
<!--<h3>gegl_buffer_set_extent</h3>-->
<div class='function_signature'>
<div class='function_header'>
<div class='return_type'>gboolean </div>
<div class='function_name'>gegl_buffer_set_extent</div>
</div><div class='function_args'><div class='argument'>
<div class='arg_type'><span class='const'>(</span><a href='#GeglBuffer'>GeglBuffer</a> <span class='pointer'>*</span></div>
<div class='arg_name'>buffer<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'><span class='const'>const</span> <a href='#GeglRectangle'>GeglRectangle</a> <span class='pointer'>*</span></div>
<div class='arg_name'>extent<span class='const'>)</span></div>
</div>
</div><div class='float_breaker'></div></div><div class='function_doc'><p> Changes the size and position that is considered active in a buffer, this
operation is valid on any buffer, reads on subbuffers outside the master
buffers extent are at the moment undefined.
</p><p></p><p><b>Arguments:</b></p><table>
<tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>buffer</span></td><td> the buffer to operate on.</td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>extent</span></td><td> new extent.</td></tr></table>
</div><div class='return_doc'><b>Returns</b> <span class='keyword'>TRUE</span> if the change of extent was succesful.
</div><pre class='sample_code'></pre></div></div>
<div class='section' id='section_gegl_buffer_get_x'><a name='gegl_buffer_get_x'></a><div class='function'>
<!--<h3>gegl_buffer_get_x</h3>-->
<div class='function_signature'>
<div class='function_header'>
<div class='return_type'><a href='#'></a></div>
<div class='function_name'>gegl_buffer_get_x</div>
</div><div class='function_args'><div class='argument'>
<div class='arg_type'><span class='const'>(</span><a href='#'></a></div>
<div class='arg_name'>buffer<span class='const'>)</span></div>
</div>
</div><div class='float_breaker'></div></div><div class='function_doc'><p> Evaluates to the X coordinate of the upper left corner of the buffers extent.
</p><p><b>Arguments:</b></p><table>
<tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>buffer</span></td><td> a GeglBuffer</td></tr></table>
</div><div class='return_doc'></div><pre class='sample_code'></pre></div></div>
<div class='section' id='section_gegl_buffer_get_y'><a name='gegl_buffer_get_y'></a><div class='function'>
<!--<h3>gegl_buffer_get_y</h3>-->
<div class='function_signature'>
<div class='function_header'>
<div class='return_type'><a href='#'></a></div>
<div class='function_name'>gegl_buffer_get_y</div>
</div><div class='function_args'><div class='argument'>
<div class='arg_type'><span class='const'>(</span><a href='#'></a></div>
<div class='arg_name'>buffer<span class='const'>)</span></div>
</div>
</div><div class='float_breaker'></div></div><div class='function_doc'><p> Evaluates to the Y coordinate of the upper left corner of the buffers extent.
</p><p><b>Arguments:</b></p><table>
<tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>buffer</span></td><td> a GeglBuffer</td></tr></table>
</div><div class='return_doc'></div><pre class='sample_code'></pre></div></div>
<div class='section' id='section_gegl_buffer_get_width'><a name='gegl_buffer_get_width'></a><div class='function'>
<!--<h3>gegl_buffer_get_width</h3>-->
<div class='function_signature'>
<div class='function_header'>
<div class='return_type'><a href='#'></a></div>
<div class='function_name'>gegl_buffer_get_width</div>
</div><div class='function_args'><div class='argument'>
<div class='arg_type'><span class='const'>(</span><a href='#'></a></div>
<div class='arg_name'>buffer<span class='const'>)</span></div>
</div>
</div><div class='float_breaker'></div></div><div class='function_doc'><p> Evaluates to the width of the buffers extent.
</p><p><b>Arguments:</b></p><table>
<tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>buffer</span></td><td> a GeglBuffer</td></tr></table>
</div><div class='return_doc'></div><pre class='sample_code'></pre></div></div>
<div class='section' id='section_gegl_buffer_get_height'><a name='gegl_buffer_get_height'></a><div class='function'>
<!--<h3>gegl_buffer_get_height</h3>-->
<div class='function_signature'>
<div class='function_header'>
<div class='return_type'><a href='#'></a></div>
<div class='function_name'>gegl_buffer_get_height</div>
</div><div class='function_args'><div class='argument'>
<div class='arg_type'><span class='const'>(</span><a href='#'></a></div>
<div class='arg_name'>buffer<span class='const'>)</span></div>
</div>
</div><div class='float_breaker'></div></div><div class='function_doc'><p> Evaluates to the height of the buffers extent.
</p><p><b>Arguments:</b></p><table>
<tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>buffer</span></td><td> a GeglBuffer</td></tr></table>
</div><div class='return_doc'></div><pre class='sample_code'></pre></div></div>
<div class='section' id='section_gegl_buffer_get_pixel_count'><a name='gegl_buffer_get_pixel_count'></a><div class='function'>
<!--<h3>gegl_buffer_get_pixel_count</h3>-->
<div class='function_signature'>
<div class='function_header'>
<div class='return_type'><a href='#'></a></div>
<div class='function_name'>gegl_buffer_get_pixel_count</div>
</div><div class='function_args'><div class='argument'>
<div class='arg_type'><span class='const'>(</span><a href='#'></a></div>
<div class='arg_name'>buffer<span class='const'>)</span></div>
</div>
</div><div class='float_breaker'></div></div><div class='function_doc'><p></p><p><b>Arguments:</b></p><table>
<tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>buffer</span></td><td> a GeglBuffer</td></tr></table>
</div><div class='return_doc'><b>Returns</b> the number of pixels of the extent of the buffer.
</div><pre class='sample_code'></pre></div></div>
<div class='section' id='section_gegl_buffer_get'><a name='gegl_buffer_get'></a><div class='function'>
<!--<h3>gegl_buffer_get</h3>-->
<div class='function_signature'>
<div class='function_header'>
<div class='return_type'>void </div>
<div class='function_name'>gegl_buffer_get</div>
</div><div class='function_args'><div class='argument'>
<div class='arg_type'><span class='const'>(</span><a href='#GeglBuffer'>GeglBuffer</a> <span class='pointer'>*</span></div>
<div class='arg_name'>buffer<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'>gdouble </div>
<div class='arg_name'>scale<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'><span class='const'>const</span> <a href='#GeglRectangle'>GeglRectangle</a> <span class='pointer'>*</span></div>
<div class='arg_name'>rect<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'><span class='const'>const</span> <a href='#Babl'>Babl</a> <span class='pointer'>*</span></div>
<div class='arg_name'>format<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'>gpointer </div>
<div class='arg_name'>dest<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'>gint </div>
<div class='arg_name'>rowstride<span class='const'>)</span></div>
</div>
</div><div class='float_breaker'></div></div><div class='function_doc'><p> Fetch a rectangular linear buffer of pixel data from the GeglBuffer, the
data is converted to the desired BablFormat, if the BablFormat stored and
fetched is the same this amounts to a series of memcpy's aligned to demux
the tile structure into a linear buffer.
</p><p><b>Arguments:</b></p><table>
<tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>buffer</span></td><td> the buffer to retrieve data from.</td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>scale</span></td><td> sampling scale, 1.0 = pixel for pixel 2.0 = magnify, 0.5 scale down.</td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>rect</span></td><td> the coordinates we want to retrieve data from, and width/height of destination buffer, if <span class='keyword'>NULL</span> equal to the extent of the buffer. The
coordinates and dimensions are after scale has been applied.
</td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>format</span></td><td> the BablFormat to store in the linear buffer <span class='arg_name'>dest</span>.</td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>dest</span></td><td> the memory destination for a linear buffer for the pixels, the size needed depends on the requested BablFormat.
</td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>rowstride</span></td><td> rowstride in bytes, or GEGL_AUTO_ROWSTRIDE to compute the rowstride based on the width and bytes per pixel for the specified format.
</td></tr></table>
</div><div class='return_doc'></div><pre class='sample_code'></pre></div></div>
<div class='section' id='section_gegl_buffer_set'><a name='gegl_buffer_set'></a><div class='function'>
<!--<h3>gegl_buffer_set</h3>-->
<div class='function_signature'>
<div class='function_header'>
<div class='return_type'><span class='const'>const</span> <a href='#Babl'>Babl</a> <span class='pointer'>*</span></div>
<div class='function_name'>gegl_buffer_set</div>
</div><div class='function_args'><div class='argument'>
<div class='arg_type'><span class='const'>(</span><a href='#GeglBuffer'>GeglBuffer</a> <span class='pointer'>*</span></div>
<div class='arg_name'>buffer<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'><span class='const'>const</span> <a href='#GeglRectangle'>GeglRectangle</a> <span class='pointer'>*</span></div>
<div class='arg_name'>rect<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'><span class='const'>const</span> <a href='#Babl'>Babl</a> <span class='pointer'>*</span></div>
<div class='arg_name'>format<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'>void <span class='pointer'>*</span></div>
<div class='arg_name'>src<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'>gint </div>
<div class='arg_name'>rowstride<span class='const'>)</span></div>
</div>
</div><div class='float_breaker'></div></div><div class='function_doc'><p> Store a linear raster buffer into the GeglBuffer.
</p><p><b>Arguments:</b></p><table>
<tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>buffer</span></td><td> the buffer to modify.</td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>rect</span></td><td> the coordinates we want to change the data of and the width/height extent, if <span class='keyword'>NULL</span> equal to the extent of the buffer.</td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>format</span></td><td> the babl_format the linear buffer <span class='arg_name'>src</span>.</td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>src</span></td><td> linear buffer of image data to be stored in <span class='arg_name'>buffer</span>.</td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>rowstride</span></td><td> rowstride in bytes, or GEGL_AUTO_ROWSTRIDE to compute the rowstride based on the width and bytes per pixel for the specified format.
</td></tr></table>
</div><div class='return_doc'></div><pre class='sample_code'></pre></div></div>
<div class='section' id='section_gegl_buffer_clear'><a name='gegl_buffer_clear'></a><div class='function'>
<!--<h3>gegl_buffer_clear</h3>-->
<div class='function_signature'>
<div class='function_header'>
<div class='return_type'>void </div>
<div class='function_name'>gegl_buffer_clear</div>
</div><div class='function_args'><div class='argument'>
<div class='arg_type'><span class='const'>(</span><a href='#GeglBuffer'>GeglBuffer</a> <span class='pointer'>*</span></div>
<div class='arg_name'>buffer<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'><span class='const'>const</span> <a href='#GeglRectangle'>GeglRectangle</a> <span class='pointer'>*</span></div>
<div class='arg_name'>roi<span class='const'>)</span></div>
</div>
</div><div class='float_breaker'></div></div><div class='function_doc'><p> Clears the provided rectangular region by setting all the associated memory
to 0
</p><p><b>Arguments:</b></p><table>
<tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>buffer</span></td><td> a <a href='#GeglBuffer'>GeglBuffer</a></td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>roi</span></td><td> a rectangular region</td></tr></table>
</div><div class='return_doc'></div><pre class='sample_code'></pre></div></div>
<div class='section' id='section_gegl_buffer_copy'><a name='gegl_buffer_copy'></a><div class='function'>
<!--<h3>gegl_buffer_copy</h3>-->
<div class='function_signature'>
<div class='function_header'>
<div class='return_type'>void </div>
<div class='function_name'>gegl_buffer_copy</div>
</div><div class='function_args'><div class='argument'>
<div class='arg_type'><span class='const'>(</span><a href='#GeglBuffer'>GeglBuffer</a> <span class='pointer'>*</span></div>
<div class='arg_name'>src<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'><span class='const'>const</span> <a href='#GeglRectangle'>GeglRectangle</a> <span class='pointer'>*</span></div>
<div class='arg_name'>src_rect<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'><a href='#GeglBuffer'>GeglBuffer</a> <span class='pointer'>*</span></div>
<div class='arg_name'>dst<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'><span class='const'>const</span> <a href='#GeglRectangle'>GeglRectangle</a> <span class='pointer'>*</span></div>
<div class='arg_name'>dst_rect<span class='const'>)</span></div>
</div>
</div><div class='float_breaker'></div></div><div class='function_doc'><p> copies a region from source buffer to destination buffer.
</p><p> If the babl_formats of the buffers are the same, and the tile boundaries
align, this should optimally lead to shared tiles that are copy on write,
this functionality is not implemented yet.
</p><p><b>Arguments:</b></p><table>
<tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>src</span></td><td> source buffer.</td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>src_rect</span></td><td> source rectangle (or <span class='keyword'>NULL</span> to copy entire source buffer)</td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>dst</span></td><td> destination buffer.</td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>dst_rect</span></td><td> position of upper left destination pixel, or <span class='keyword'>NULL</span> for top left coordinates of the buffer extents.
</td></tr></table>
</div><div class='return_doc'></div><pre class='sample_code'></pre></div></div>
<div class='section' id='section_gegl_buffer_dup'><a name='gegl_buffer_dup'></a><div class='function'>
<!--<h3>gegl_buffer_dup</h3>-->
<div class='function_signature'>
<div class='function_header'>
<div class='return_type'><a href='#GeglBuffer'>GeglBuffer</a> <span class='pointer'>*</span> </div>
<div class='function_name'>gegl_buffer_dup</div>
</div><div class='function_args'><div class='argument'>
<div class='arg_type'><span class='const'>(</span><a href='#GeglBuffer'>GeglBuffer</a> <span class='pointer'>*</span></div>
<div class='arg_name'>buffer<span class='const'>)</span></div>
</div>
</div><div class='float_breaker'></div></div><div class='function_doc'><p> duplicate a buffer (internally uses gegl_buffer_copy), this should ideally
lead to a buffer that shares the raster data with the original on a tile
by tile COW basis. This is not yet implemented
</p><p><b>Arguments:</b></p><table>
<tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>buffer</span></td><td> the GeglBuffer to duplicate.</td></tr></table>
</div><div class='return_doc'></div><pre class='sample_code'></pre></div></div>
<div class='section' id='section_gegl_buffer_sample'><a name='gegl_buffer_sample'></a><div class='function'>
<!--<h3>gegl_buffer_sample</h3>-->
<div class='function_signature'>
<div class='function_header'>
<div class='return_type'>void </div>
<div class='function_name'>gegl_buffer_sample</div>
</div><div class='function_args'><div class='argument'>
<div class='arg_type'><span class='const'>(</span><a href='#GeglBuffer'>GeglBuffer</a> <span class='pointer'>*</span></div>
<div class='arg_name'>buffer<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'>gdouble </div>
<div class='arg_name'>x<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'>gdouble </div>
<div class='arg_name'>y<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'>gdouble </div>
<div class='arg_name'>scale<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'>gpointer </div>
<div class='arg_name'>dest<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'><span class='const'>const</span> <a href='#Babl'>Babl</a> <span class='pointer'>*</span></div>
<div class='arg_name'>format<span class='const'>,</span></div>
</div>
<div class='argument'>
<div class='arg_type'><a href='#GeglInterpolation'>GeglInterpolation</a> </div>
<div class='arg_name'>interpolation<span class='const'>)</span></div>
</div>
</div><div class='float_breaker'></div></div><div class='function_doc'><p> Resample the buffer at some given coordinates using a specified format. For
some operations this might be sufficient, but it might be considered
prototyping convenience that needs to be optimized away from algorithms
using it later.
</p><p><b>Arguments:</b></p><table>
<tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>buffer</span></td><td> the GeglBuffer to sample from</td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>x</span></td><td> x coordinate to sample in buffer coordinates</td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>y</span></td><td> y coordinate to sample in buffer coordinates</td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>scale</span></td><td> the scale we're fetching at (<1.0 can leads to decimation)</td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>dest</span></td><td> buffer capable of storing one pixel in <span class='arg_name'>format</span>.</td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>format</span></td><td> the format to store the sampled color in.</td></tr><tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>interpolation</span></td><td> the interpolation behavior to use, currently only nearest neighbour is implemented for this API, bilinear, bicubic and lanczos needs
to be ported from working code. Valid values: GEGL_INTERPOLATION_NEAREST and
GEGL_INTERPOLATION_LINEAR, CUBIC and LANCZOS will become available for now they
fall back to linear.
</td></tr></table>
</div><div class='return_doc'></div><pre class='sample_code'></pre></div></div>
<div class='section' id='section_gegl_buffer_sample_cleanup'><a name='gegl_buffer_sample_cleanup'></a><div class='function'>
<!--<h3>gegl_buffer_sample_cleanup</h3>-->
<div class='function_signature'>
<div class='function_header'>
<div class='return_type'>void </div>
<div class='function_name'>gegl_buffer_sample_cleanup</div>
</div><div class='function_args'><div class='argument'>
<div class='arg_type'><span class='const'>(</span><a href='#GeglBuffer'>GeglBuffer</a> <span class='pointer'>*</span></div>
<div class='arg_name'>buffer<span class='const'>)</span></div>
</div>
</div><div class='float_breaker'></div></div><div class='function_doc'><p> Clean up resources used by sampling framework of buffer (will be freed
automatically later when the buffer is destroyed, for long lived buffers
cleaning up the sampling infrastructure when it has been used for its
purpose will sometimes be more efficient).
</p><p><b>Arguments:</b></p><table>
<tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>buffer</span></td><td> the GeglBuffer to sample from</td></tr></table>
</div><div class='return_doc'></div><pre class='sample_code'></pre></div></div>
<div class='section' id='section_gegl_buffer_interpolation_from_string'><a name='gegl_buffer_interpolation_from_string'></a><div class='function'>
<!--<h3>gegl_buffer_interpolation_from_string</h3>-->
<div class='function_signature'>
<div class='function_header'>
<div class='return_type'><a href='#GeglInterpolation'>GeglInterpolation</a> </div>
<div class='function_name'>gegl_buffer_interpolation_from_string</div>
</div><div class='function_args'><div class='argument'>
<div class='arg_type'><span class='const'>(</span><span class='const'>const</span> gchar <span class='pointer'>*</span></div>
<div class='arg_name'>string<span class='const'>)</span></div>
</div>
</div><div class='float_breaker'></div></div><div class='function_doc'><p> Looks up the GeglInterpolation corresponding to a string, if no matching
interpolation is found returns GEGL_INTERPOLATION_NEAREST.
</p><p><b>Arguments:</b></p><table>
<tr><td style='padding-right:1em;vertical-align:top'><span class='arg_name'>string</span></td><td> the string to look up</td></tr></table>
</div><div class='return_doc'></div><pre class='sample_code'></pre></div></div>
<div class='section' id='section_GeglOperation'><a name='GeglOperation'></a><div class='sect'>
<h2>GeglOperation</h2><div class='sect_doc'><p>
All the image processing code in GEGL is implemented as GeglOperations,
GEGL oeprations are implemented as GObject with a convenience API called
chanting that abstracts away the boiler plater needed to generate introspectable
named properties of different types.
</p><p> Most types of operations like: filters, composers, sources, sinks, point
operations, compositing operations, and spatial operations with fixed
neighbourhoods. These base classes builds on top of the GeglOperationsClass:
</p><p> See <a href='gegl-plugin.h.html'>gegl-plugin.h</a> for details.
</p><pre class='sample_code'></pre></div></div></div>
</div></div>
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