[gegl] add documentation on the header of each subclasses of GeglOperation

[Michael Murà <mmure src gnome org>]

commit b57401795292a2e222ab40960cc577abff6f10f7
Author: Michael Murà <batolettre gmail com>
Date:   Thu Jun 16 14:35:05 2011 +0200

    add documentation on the header of each subclasses of GeglOperation

 gegl/operation/gegl-operation-area-filter.h    |    6 ++++++
 gegl/operation/gegl-operation-composer.h       |    5 +++++
 gegl/operation/gegl-operation-filter.h         |    4 ++++
 gegl/operation/gegl-operation-meta.h           |    6 ++++++
 gegl/operation/gegl-operation-point-composer.h |    5 +++++
 gegl/operation/gegl-operation-point-filter.h   |    7 +++++++
 gegl/operation/gegl-operation-sink.h           |    5 +++++
 gegl/operation/gegl-operation-source.h         |    5 +++++
 gegl/operation/gegl-operation-temporal.h       |    6 ++++++
 9 files changed, 49 insertions(+), 0 deletions(-)
---
diff --git a/gegl/operation/gegl-operation-area-filter.h b/gegl/operation/gegl-operation-area-filter.h
index 3cc1613..1411b9c 100644
--- a/gegl/operation/gegl-operation-area-filter.h
+++ b/gegl/operation/gegl-operation-area-filter.h
@@ -16,6 +16,12 @@
  * Copyright 2007 Ãyvind KolÃs
  */
 
+/* GeglOperationAreaFilter
+ * The AreaFilter base class allows defining operations where the output data depends on a neighbourhood
+ * with an input window that extends beyond the output window, the information about needed extra pixels
+ * in different directions should be set up in the prepare callback for the operation.
+*/
+
 #ifndef __GEGL_OPERATION_AREA_FILTER_H__
 #define __GEGL_OPERATION_AREA_FILTER_H__
 
diff --git a/gegl/operation/gegl-operation-composer.h b/gegl/operation/gegl-operation-composer.h
index 4cad823..34e8d53 100644
--- a/gegl/operation/gegl-operation-composer.h
+++ b/gegl/operation/gegl-operation-composer.h
@@ -16,6 +16,11 @@
  * Copyright 2006 Ãyvind KolÃs
  */
 
+/* GeglOperationComposer
+ * Composer operations are operations that take two inputs named input and aux and write
+ * their output to the output pad output
+ */
+
 #ifndef __GEGL_OPERATION_COMPOSER_H__
 #define __GEGL_OPERATION_COMPOSER_H__
 
diff --git a/gegl/operation/gegl-operation-filter.h b/gegl/operation/gegl-operation-filter.h
index 9f2f71b..207d754 100644
--- a/gegl/operation/gegl-operation-filter.h
+++ b/gegl/operation/gegl-operation-filter.h
@@ -16,6 +16,10 @@
  * Copyright 2006 Ãyvind KolÃs
  */
 
+/* GeglOperationFilter:
+ * The filter base class sets up GeglBuffers for input and output pads
+ */
+
 #ifndef __GEGL_OPERATION_FILTER_H__
 #define __GEGL_OPERATION_FILTER_H__
 
diff --git a/gegl/operation/gegl-operation-meta.h b/gegl/operation/gegl-operation-meta.h
index 87a1573..2704f87 100644
--- a/gegl/operation/gegl-operation-meta.h
+++ b/gegl/operation/gegl-operation-meta.h
@@ -16,6 +16,12 @@
  * Copyright 2006 Ãyvind KolÃs
  */
 
+/* GeglOperationMeta
+ * Used for GEGL operations that are implemented as a sub-graph, at the moment
+ * these are defined as C files but should in the future be possible to declare
+ * as XML instead.
+ */
+
 #ifndef __GEGL_OPERATION_META_H__
 #define __GEGL_OPERATION_META_H__
 
diff --git a/gegl/operation/gegl-operation-point-composer.h b/gegl/operation/gegl-operation-point-composer.h
index e434434..1c82248 100644
--- a/gegl/operation/gegl-operation-point-composer.h
+++ b/gegl/operation/gegl-operation-point-composer.h
@@ -16,6 +16,11 @@
  * Copyright 2006 Ãyvind KolÃs
  */
 
+/* GeglOperationPointComposer
+ * A baseclass for composer functions where the output pixels' values depends only on
+ * the values of the single corresponding input and aux pixels.
+ */
+
 #ifndef __GEGL_OPERATION_POINT_COMPOSER_H__
 #define __GEGL_OPERATION_POINT_COMPOSER_H__
 
diff --git a/gegl/operation/gegl-operation-point-filter.h b/gegl/operation/gegl-operation-point-filter.h
index 29e352c..e4efba2 100644
--- a/gegl/operation/gegl-operation-point-filter.h
+++ b/gegl/operation/gegl-operation-point-filter.h
@@ -16,6 +16,13 @@
  * Copyright 2006 Ãyvind KolÃs
  */
 
+/* GeglOperationPointFilter
+ * The point-filter base class is for filters where an output pixel only depends on the color and alpha values
+ * of the corresponding input pixel. This allows you to do the processing on linear buffers, in the future 
+ * versions of GEGL operations implemented using the point-filter will get speed increases due to more 
+ * intelligent processing possible in the point filter class
+ */
+
 #ifndef __GEGL_OPERATION_POINT_FILTER_H__
 #define __GEGL_OPERATION_POINT_FILTER_H__
 
diff --git a/gegl/operation/gegl-operation-sink.h b/gegl/operation/gegl-operation-sink.h
index 31c9073..05b60a9 100644
--- a/gegl/operation/gegl-operation-sink.h
+++ b/gegl/operation/gegl-operation-sink.h
@@ -16,6 +16,11 @@
  * Copyright 2006 Ãyvind KolÃs
  */
 
+/* GeglOperationSink
+ * An operation that consumes a GeglBuffer, used for filewriters, display 
+ * (for the sdl display node)
+ */
+
 #ifndef __GEGL_OPERATION_SINK_H__
 #define __GEGL_OPERATION_SINK_H__
 
diff --git a/gegl/operation/gegl-operation-source.h b/gegl/operation/gegl-operation-source.h
index 1fb970a..1933d9e 100644
--- a/gegl/operation/gegl-operation-source.h
+++ b/gegl/operation/gegl-operation-source.h
@@ -16,6 +16,11 @@
  * Copyright 2006 Ãyvind KolÃs
  */
 
+/* GeglOperationSource
+ * Operations used as render sources or file loaders, the process method receives a
+ * GeglBuffer to write itâs output into
+ */
+
 #ifndef __GEGL_OPERATION_SOURCE_H__
 #define __GEGL_OPERATION_SOURCE_H__
 
diff --git a/gegl/operation/gegl-operation-temporal.h b/gegl/operation/gegl-operation-temporal.h
index 7225884..3f97519 100644
--- a/gegl/operation/gegl-operation-temporal.h
+++ b/gegl/operation/gegl-operation-temporal.h
@@ -16,6 +16,12 @@
  * Copyright 2008 Ãyvind KolÃs
  */
 
+/* GeglOperationTemporal
+ * Base class for operations that want access to previous frames in a video sequence,
+ * it contains API to configure the amounts of frames to store as well as getting a
+ * GeglBuffer pointing to any of the previously stored frames.
+ */
+
 #ifndef __GEGL_OPERATION_TEMPORAL_H__
 #define __GEGL_OPERATION_TEMPORAL_H__