# ../gegl/operation/gegl-operation-area-filter.h

    /* This file is part of GEGL
     *
     * GEGL is free software; you can redistribute it and/or
     * modify it under the terms of the GNU Lesser General Public
     * License as published by the Free Software Foundation; either
     * version 3 of the License, or (at your option) any later version.
     *
     * GEGL is distributed in the hope that it will be useful,
     * but WITHOUT ANY WARRANTY; without even the implied warranty of
     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     * Lesser General Public License for more details.
     *
     * You should have received a copy of the GNU Lesser General Public
     * License along with GEGL; if not, see <https://www.gnu.org/licenses/>.
     *
     * Copyright 2007 Øyvind Kolås
     */

    /* 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__

    #include "gegl-operation-filter.h"

    G_BEGIN_DECLS

    #define GEGL_TYPE_OPERATION_AREA_FILTER            (gegl_operation_area_filter_get_type ())
    #define GEGL_OPERATION_AREA_FILTER(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), GEGL_TYPE_OPERATION_AREA_FILTER, GeglOperationAreaFilter))
    #define GEGL_OPERATION_AREA_FILTER_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass),  GEGL_TYPE_OPERATION_AREA_FILTER, GeglOperationAreaFilterClass))
    #define GEGL_IS_OPERATION_AREA_FILTER(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GEGL_TYPE_OPERATION_AREA_FILTER))
    #define GEGL_IS_OPERATION_AREA_FILTER_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass),  GEGL_TYPE_OPERATION_AREA_FILTER))
    #define GEGL_OPERATION_AREA_FILTER_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj),  GEGL_TYPE_OPERATION_AREA_FILTER, GeglOperationAreaFilterClass))

    typedef struct _GeglOperationAreaFilter  GeglOperationAreaFilter;
    struct _GeglOperationAreaFilter
    {
      GeglOperationFilter parent_instance;

      gint                left;   /* extra pixels needed in each direction */
      gint                right;
      gint                top;
      gint                bottom;
    };

    typedef struct _GeglOperationAreaFilterClass GeglOperationAreaFilterClass;
    struct _GeglOperationAreaFilterClass
    {
      GeglOperationFilterClass    parent_class;

      /* returns the abyss policy used when reading the input.  if not overridden,
       * GEGL_ABYSS_NONE is assumed.
       */
      GeglAbyssPolicy          (* get_abyss_policy) (GeglOperation *operation,
                                                     const gchar   *input_pad);

      gpointer                    pad[3];
    };

    GType gegl_operation_area_filter_get_type (void) G_GNUC_CONST;

    G_DEFINE_AUTOPTR_CLEANUP_FUNC (GeglOperationAreaFilter, g_object_unref)

    G_END_DECLS

    #endif