# ../gegl/gegl-plugin.h

    /* This file is the public operation GEGL API, this API will change to much
     * larger degrees than the api provided by gegl.h
     *
     * 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 <http://www.gnu.org/licenses/>.
     *
     * 2000-2008 Øyvind Kolås.
     */

    #ifndef __GEGL_PLUGIN_H__
    #define __GEGL_PLUGIN_H__

    #ifdef HAVE_CONFIG_H
    #include "config.h"
    #endif

    #include <string.h>
    #include <glib-object.h>
    #include <gegl.h>

    G_BEGIN_DECLS

    /* Extra types needed when coding operations */
    typedef struct _GeglOperation        GeglOperation;
    typedef struct _GeglOperationContext GeglOperationContext;
    typedef struct _GeglPad              GeglPad;
    typedef struct _GeglConnection       GeglConnection;

    #include <gegl-matrix.h>
    #include <gegl-utils.h>
    #include <gegl-buffer.h>
    #include <gegl-paramspecs.h>
    #include <gmodule.h>

    typedef struct _GeglModule     GeglModule;
    typedef struct _GeglModuleInfo GeglModuleInfo;
    typedef struct _GeglModuleDB   GeglModuleDB;

    /***
     * Writing GEGL operations
     *
     */

    /*#include <geglmodule.h>*/

    /*  increment the ABI version each time one of the following changes:
     *
     *  - the libgeglmodule implementation (if the change affects modules).
     *  - GeglOperation or one of it's base classes changes. (XXX:-
     *    should be extended so a range of abi versions are accepted.
     */

    #define GEGL_MODULE_ABI_VERSION 0x000A

    struct _GeglModuleInfo
    {
      guint32  abi_version;
    };

    GType gegl_module_register_type (GTypeModule     *module,
                                     GType            parent_type,
                                     const gchar     *type_name,
                                     const GTypeInfo *type_info,
                                     GTypeFlags       flags);

    gint            gegl_operation_context_get_level  (GeglOperationContext *self);
    GeglBuffer     *gegl_operation_context_get_source (GeglOperationContext *self,
                                                       const gchar          *padname);
    GeglBuffer     *gegl_operation_context_get_target (GeglOperationContext *self,
                                                       const gchar          *padname);
    void            gegl_operation_context_set_object (GeglOperationContext *context,
                                                       const gchar          *padname,
                                                       GObject              *data);
    void            gegl_operation_context_take_object(GeglOperationContext *context,
                                                       const gchar          *padname,
                                                       GObject              *data);
    GObject        *gegl_operation_context_get_object (GeglOperationContext *context,
                                                       const gchar          *padname);

    void            gegl_extension_handler_register    (const gchar         *extension,
                                                        const gchar         *handler);
    void            gegl_extension_handler_register_saver
                                                       (const gchar         *extension,
                                                        const gchar         *handler);
    const gchar   * gegl_extension_handler_get         (const gchar         *extension);
    const gchar   * gegl_extension_handler_get_saver   (const gchar         *extension);

    /* code template utility, updates the jacobian matrix using
     * a user defined mapping function for displacement, example
     * with an identity transform (note that for the identity
     * transform this is massive computational overhead that can
     * be skipped by passing NULL to the sampler.
     *
     * #define gegl_unmap(x,y,dx,dy) { dx=x; dy=y; }
     *
     * gegl_sampler_compute_scale (scale, x, y);
     * gegl_unmap(x,y,sample_x,sample_y);
     * gegl_buffer_sample (buffer, sample_x, sample_y, scale, dest, format,
     *                     GEGL_SAMPLER_LOHALO);
     *
     * #undef gegl_unmap      // IMPORTANT undefine map macro
     */
    #define gegl_sampler_compute_scale(matrix, x, y) \
    {                                       \
      float ax, ay, bx, by;                 \
      gegl_unmap(x + 0.5, y, ax, ay);       \
      gegl_unmap(x - 0.5, y, bx, by);       \
      matrix.coeff[0][0] = ax - bx;         \
      matrix.coeff[1][0] = ay - by;         \
      gegl_unmap(x, y + 0.5, ax, ay);       \
      gegl_unmap(x, y - 0.5, bx, by);       \
      matrix.coeff[0][1] = ax - bx;         \
      matrix.coeff[1][1] = ay - by;         \
    }

    typedef struct
    {
      GObject       parent_instance;
      void (* get) (GeglSampler *self,
                    gdouble      x,
                    gdouble      y,
                    GeglMatrix2 *scale,
                    void        *output);
    } SamplerMock;

    #define gegl_sampler_get(sampler,x,y,scale,dest) \
      ((SamplerMock*)(sampler))->get((sampler),(x),(y),(scale),(dest))

    #include <glib-object.h>
    #include <babl/babl.h>
    #include <operation/gegl-operation.h>
    #include <operation/gegl-operation-filter.h>
    #include <operation/gegl-operation-area-filter.h>
    #include <operation/gegl-operation-point-filter.h>
    #include <operation/gegl-operation-composer.h>
    #include <operation/gegl-operation-composer3.h>
    #include <operation/gegl-operation-point-composer.h>
    #include <operation/gegl-operation-point-composer3.h>
    #include <operation/gegl-operation-point-render.h>
    #include <operation/gegl-operation-temporal.h>
    #include <operation/gegl-operation-source.h>
    #include <operation/gegl-operation-sink.h>
    #include <operation/gegl-operation-meta.h>

    #include <gegl-lookup.h>

    G_END_DECLS
    #endif  /* __GEGL_PLUGIN_H__ */