/* GIMP - The GNU Image Manipulation Program
 * Copyright (C) 1995 Spencer Kimball and Peter Mattis
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */

#include "config.h"

#include <gdk-pixbuf/gdk-pixbuf.h>
#include <gegl.h>

#include "paint-types.h"

#include "gegl/gimp-gegl-utils.h"

#include "core/gimp.h"
#include "core/gimp-palettes.h"
#include "core/gimpdrawable.h"
#include "core/gimpdynamics.h"
#include "core/gimpimage.h"
#include "core/gimppickable.h"
#include "core/gimpsymmetry.h"

#include "gimperaser.h"
#include "gimperaseroptions.h"

#include "gimp-intl.h"


static gboolean   gimp_eraser_get_color_history_color (GimpPaintbrush            *paintbrush,
                                                       GimpDrawable              *drawable,
                                                       GimpPaintOptions          *paint_options,
                                                       GeglColor                **color);
static void       gimp_eraser_get_paint_params        (GimpPaintbrush            *paintbrush,
                                                       GimpDrawable              *drawable,
                                                       GimpPaintOptions          *paint_options,
                                                       GimpSymmetry              *sym,
                                                       gdouble                    grad_point,
                                                       GimpLayerMode             *paint_mode,
                                                       GimpPaintApplicationMode  *paint_appl_mode,
                                                       const GimpTempBuf        **paint_pixmap,
                                                       GeglColor                **paint_color);


G_DEFINE_TYPE (GimpEraser, gimp_eraser, GIMP_TYPE_PAINTBRUSH)


void
gimp_eraser_register (Gimp                      *gimp,
                      GimpPaintRegisterCallback  callback)
{
  (* callback) (gimp,
                GIMP_TYPE_ERASER,
                GIMP_TYPE_ERASER_OPTIONS,
                "gimp-eraser",
                _("Eraser"),
                "gimp-tool-eraser");
}

static void
gimp_eraser_class_init (GimpEraserClass *klass)
{
  GimpPaintbrushClass *paintbrush_class = GIMP_PAINTBRUSH_CLASS (klass);

  paintbrush_class->get_color_history_color = gimp_eraser_get_color_history_color;
  paintbrush_class->get_paint_params        = gimp_eraser_get_paint_params;
}

static void
gimp_eraser_init (GimpEraser *eraser)
{
}

static gboolean
gimp_eraser_get_color_history_color (GimpPaintbrush    *paintbrush,
                                     GimpDrawable      *drawable,
                                     GimpPaintOptions  *paint_options,
                                     GeglColor        **color)
{
  /* Erasing on a drawable without alpha is equivalent to
   * drawing with background color. So let's save history.
   */
  if (! gimp_drawable_has_alpha (drawable))
    {
      GimpContext *context = GIMP_CONTEXT (paint_options);

      *color = gimp_context_get_background (context);

      return TRUE;
    }

  return FALSE;
}

static void
gimp_eraser_get_paint_params (GimpPaintbrush            *paintbrush,
                              GimpDrawable              *drawable,
                              GimpPaintOptions          *paint_options,
                              GimpSymmetry              *sym,
                              gdouble                    grad_point,
                              GimpLayerMode             *paint_mode,
                              GimpPaintApplicationMode  *paint_appl_mode,
                              const GimpTempBuf        **paint_pixmap,
                              GeglColor                **paint_color)
{
  GimpEraserOptions *options = GIMP_ERASER_OPTIONS (paint_options);
  GimpContext       *context = GIMP_CONTEXT (paint_options);

  *paint_color = gegl_color_duplicate (gimp_context_get_background (context));

  if (options->anti_erase)
    *paint_mode = GIMP_LAYER_MODE_ANTI_ERASE;
  else if (gimp_drawable_has_alpha (drawable))
    *paint_mode = GIMP_LAYER_MODE_ERASE;
  else
    *paint_mode = GIMP_LAYER_MODE_NORMAL_LEGACY;
}