/* 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 <http://www.gnu.org/licenses/>.
 */

#include "config.h"

#include <string.h>

#include <gegl.h>
#include <gtk/gtk.h>

#include "libgimpmath/gimpmath.h"

#include "tools-types.h"

#include "config/gimpdisplayconfig.h"

#include "core/gimp.h"
#include "core/gimpbrush.h"
#include "core/gimpimage.h"
#include "core/gimptoolinfo.h"

#include "paint/gimpbrushcore.h"
#include "paint/gimppaintoptions.h"

#include "display/gimpdisplay.h"
#include "display/gimpdisplayshell.h"

#include "gimpbrushtool.h"
#include "gimptoolcontrol.h"


static GObject * gimp_brush_tool_constructor (GType                type,
                                              guint                n_params,
                                              GObjectConstructParam *params);

static void   gimp_brush_tool_motion         (GimpTool            *tool,
                                              const GimpCoords    *coords,
                                              guint32              time,
                                              GdkModifierType      state,
                                              GimpDisplay         *display);
static void   gimp_brush_tool_oper_update    (GimpTool            *tool,
                                              const GimpCoords    *coords,
                                              GdkModifierType      state,
                                              gboolean             proximity,
                                              GimpDisplay         *display);
static void   gimp_brush_tool_cursor_update  (GimpTool            *tool,
                                              const GimpCoords    *coords,
                                              GdkModifierType      state,
                                              GimpDisplay         *display);
static void   gimp_brush_tool_options_notify (GimpTool            *tool,
                                              GimpToolOptions     *options,
                                              const GParamSpec    *pspec);

static void   gimp_brush_tool_draw           (GimpDrawTool        *draw_tool);

static void   gimp_brush_tool_brush_changed     (GimpContext         *context,
                                                 GimpBrush           *brush,
                                                 GimpBrushTool       *brush_tool);
static void   gimp_brush_tool_set_brush         (GimpBrushCore       *brush_core,
                                                 GimpBrush           *brush,
                                                 GimpBrushTool       *brush_tool);
static void   gimp_brush_tool_set_brush_after   (GimpBrushCore       *brush_core,
                                                 GimpBrush           *brush,
                                                 GimpBrushTool       *brush_tool);
static void   gimp_brush_tool_notify_brush      (GimpDisplayConfig   *config,
                                                 GParamSpec          *pspec,
                                                 GimpBrushTool       *brush_tool);


G_DEFINE_TYPE (GimpBrushTool, gimp_brush_tool, GIMP_TYPE_PAINT_TOOL)

#define parent_class gimp_brush_tool_parent_class


static void
gimp_brush_tool_class_init (GimpBrushToolClass *klass)
{
  GObjectClass      *object_class    = G_OBJECT_CLASS (klass);
  GimpToolClass     *tool_class      = GIMP_TOOL_CLASS (klass);
  GimpDrawToolClass *draw_tool_class = GIMP_DRAW_TOOL_CLASS (klass);

  object_class->constructor = gimp_brush_tool_constructor;

  tool_class->motion         = gimp_brush_tool_motion;
  tool_class->oper_update    = gimp_brush_tool_oper_update;
  tool_class->cursor_update  = gimp_brush_tool_cursor_update;
  tool_class->options_notify = gimp_brush_tool_options_notify;

  draw_tool_class->draw     = gimp_brush_tool_draw;
}

static void
gimp_brush_tool_init (GimpBrushTool *brush_tool)
{
  GimpTool *tool = GIMP_TOOL (brush_tool);

  gimp_tool_control_set_action_value_2 (tool->control,
                                        "tools/tools-paint-brush-size-set");
  gimp_tool_control_set_action_value_3  (tool->control,
                                         "context/context-brush-aspect-set");
  gimp_tool_control_set_action_value_4  (tool->control,
                                         "context/context-brush-angle-set");
  gimp_tool_control_set_action_object_1 (tool->control,
                                         "context/context-brush-select-set");

  brush_tool->show_cursor = TRUE;
  brush_tool->draw_brush  = TRUE;
  brush_tool->brush_x     = 0.0;
  brush_tool->brush_y     = 0.0;
}

static GObject *
gimp_brush_tool_constructor (GType                  type,
                             guint                  n_params,
                             GObjectConstructParam *params)
{
  GObject           *object;
  GimpTool          *tool;
  GimpPaintTool     *paint_tool;
  GimpBrushTool     *brush_tool;
  GimpDisplayConfig *display_config;

  object = G_OBJECT_CLASS (parent_class)->constructor (type, n_params, params);

  tool       = GIMP_TOOL (object);
  paint_tool = GIMP_PAINT_TOOL (object);
  brush_tool = GIMP_BRUSH_TOOL (object);

  g_assert (GIMP_IS_BRUSH_CORE (paint_tool->core));

  display_config = GIMP_DISPLAY_CONFIG (tool->tool_info->gimp->config);

  brush_tool->show_cursor = display_config->show_paint_tool_cursor;
  brush_tool->draw_brush  = display_config->show_brush_outline;

  g_signal_connect_object (display_config, "notify::show-paint-tool-cursor",
                           G_CALLBACK (gimp_brush_tool_notify_brush),
                           brush_tool, 0);
  g_signal_connect_object (display_config, "notify::show-brush-outline",
                           G_CALLBACK (gimp_brush_tool_notify_brush),
                           brush_tool, 0);

  g_signal_connect_object (gimp_tool_get_options (tool), "brush-changed",
                           G_CALLBACK (gimp_brush_tool_brush_changed),
                           brush_tool, 0);

  g_signal_connect (paint_tool->core, "set-brush",
                    G_CALLBACK (gimp_brush_tool_set_brush),
                    brush_tool);
  g_signal_connect_after (paint_tool->core, "set-brush",
                          G_CALLBACK (gimp_brush_tool_set_brush_after),
                          brush_tool);

  return object;
}

static void
gimp_brush_tool_motion (GimpTool         *tool,
                        const GimpCoords *coords,
                        guint32           time,
                        GdkModifierType   state,
                        GimpDisplay      *display)
{
  GimpBrushTool *brush_tool = GIMP_BRUSH_TOOL (tool);

  gimp_draw_tool_pause (GIMP_DRAW_TOOL (tool));

  GIMP_TOOL_CLASS (parent_class)->motion (tool, coords, time, state, display);

  if (! gimp_color_tool_is_enabled (GIMP_COLOR_TOOL (tool)))
    {
      brush_tool->brush_x = coords->x;
      brush_tool->brush_y = coords->y;
    }

  gimp_draw_tool_resume (GIMP_DRAW_TOOL (tool));
}

static void
gimp_brush_tool_oper_update (GimpTool         *tool,
                             const GimpCoords *coords,
                             GdkModifierType   state,
                             gboolean          proximity,
                             GimpDisplay      *display)
{
  GimpBrushTool    *brush_tool    = GIMP_BRUSH_TOOL (tool);
  GimpPaintOptions *paint_options = GIMP_PAINT_TOOL_GET_OPTIONS (tool);
  GimpDrawable     *drawable      = gimp_image_get_active_drawable (gimp_display_get_image (display));

  gimp_draw_tool_pause (GIMP_DRAW_TOOL (tool));

  GIMP_TOOL_CLASS (parent_class)->oper_update (tool, coords, state,
                                               proximity, display);

  if (! gimp_color_tool_is_enabled (GIMP_COLOR_TOOL (tool))             &&
        drawable && proximity)
    {
      GimpPaintTool *paint_tool = GIMP_PAINT_TOOL (tool);
      GimpBrushCore *brush_core = GIMP_BRUSH_CORE (paint_tool->core);
      GimpBrush     *brush;
      GimpDynamics  *dynamics;

      brush_tool->brush_x = coords->x;
      brush_tool->brush_y = coords->y;

      brush = gimp_context_get_brush (GIMP_CONTEXT (paint_options));

      if (brush_core->main_brush != brush)
        gimp_brush_core_set_brush (brush_core, brush);

      dynamics = gimp_context_get_dynamics (GIMP_CONTEXT (paint_options));

      if (brush_core->dynamics != dynamics)
        gimp_brush_core_set_dynamics (brush_core, dynamics);

      if (GIMP_BRUSH_CORE_GET_CLASS (brush_core)->handles_transforming_brush)
        {
          gimp_brush_core_eval_transform_dynamics (paint_tool->core,
                                                   drawable,
                                                   paint_options,
                                                   coords);
        }
    }

  gimp_draw_tool_resume (GIMP_DRAW_TOOL (tool));
}

static void
gimp_brush_tool_cursor_update (GimpTool         *tool,
                               const GimpCoords *coords,
                               GdkModifierType   state,
                               GimpDisplay      *display)
{
  GimpBrushTool *brush_tool = GIMP_BRUSH_TOOL (tool);

  if (! brush_tool->show_cursor &&
      ! gimp_color_tool_is_enabled (GIMP_COLOR_TOOL (tool)) &&
      gimp_tool_control_get_cursor_modifier (tool->control) !=
      GIMP_CURSOR_MODIFIER_BAD)
    {
      gimp_tool_set_cursor (tool, display,
                            GIMP_CURSOR_NONE,
                            GIMP_TOOL_CURSOR_NONE,
                            GIMP_CURSOR_MODIFIER_NONE);
    }
  else
    {
      GIMP_TOOL_CLASS (parent_class)->cursor_update (tool,
                                                     coords, state, display);
    }
}

static void
gimp_brush_tool_options_notify (GimpTool         *tool,
                                GimpToolOptions  *options,
                                const GParamSpec *pspec)
{
  GIMP_TOOL_CLASS (parent_class)->options_notify (tool, options, pspec);

  if (! strcmp (pspec->name, "brush-size")  ||
      ! strcmp (pspec->name, "brush-angle") ||
      ! strcmp (pspec->name, "brush-aspect-ratio"))
    {
      GimpPaintTool *paint_tool = GIMP_PAINT_TOOL (tool);
      GimpBrushCore *brush_core = GIMP_BRUSH_CORE (paint_tool->core);

      gimp_brush_core_set_brush (brush_core, brush_core->main_brush);
    }
}

static void
gimp_brush_tool_draw (GimpDrawTool *draw_tool)
{
  GimpBrushTool *brush_tool = GIMP_BRUSH_TOOL (draw_tool);

  GIMP_DRAW_TOOL_CLASS (parent_class)->draw (draw_tool);

  if (gimp_color_tool_is_enabled (GIMP_COLOR_TOOL (draw_tool)))
    return;

  gimp_brush_tool_draw_brush (brush_tool,
                              brush_tool->brush_x, brush_tool->brush_y,
                              ! brush_tool->show_cursor);
}

void
gimp_brush_tool_draw_brush (GimpBrushTool *brush_tool,
                            gdouble        x,
                            gdouble        y,
                            gboolean       draw_fallback)
{
  GimpDrawTool     *draw_tool;
  GimpBrushCore    *brush_core;
  GimpPaintOptions *options;
  GimpMatrix3       matrix;

  g_return_if_fail (GIMP_IS_BRUSH_TOOL (brush_tool));

  if (! brush_tool->draw_brush)
    return;

  draw_tool  = GIMP_DRAW_TOOL (brush_tool);
  brush_core = GIMP_BRUSH_CORE (GIMP_PAINT_TOOL (brush_tool)->core);
  options    = GIMP_PAINT_TOOL_GET_OPTIONS (brush_tool);

  if (! brush_core->brush_bound_segs && brush_core->main_brush)
    gimp_brush_core_create_boundary (brush_core, options);

  if (brush_core->brush_bound_segs &&
      gimp_brush_core_get_transform (brush_core, &matrix))
    {
      GimpDisplayShell *shell  = gimp_display_get_shell (draw_tool->display);
      gdouble           width  = brush_core->transformed_brush_bound_width;
      gdouble           height = brush_core->transformed_brush_bound_height;

      /*  don't draw the boundary if it becomes too small  */
      if (SCALEX (shell, width) > 4 && SCALEY (shell, height) > 4)
        {
          x -= width  / 2.0;
          y -= height / 2.0;

          if (gimp_paint_options_get_brush_mode (options) == GIMP_BRUSH_HARD)
            {
#define EPSILON 0.000001
              /*  Add EPSILON before rounding since e.g.
               *  (5.0 - 0.5) may end up at (4.499999999....)
               *  due to floating point fnords
               */
              x = RINT (x + EPSILON);
              y = RINT (y + EPSILON);
#undef EPSILON
            }

          gimp_draw_tool_add_boundary (draw_tool,
                                       brush_core->brush_bound_segs,
                                       brush_core->n_brush_bound_segs,
                                       &matrix,
                                       x, y);
        }
      else if (draw_fallback)
        {
          gimp_draw_tool_add_handle (draw_tool, GIMP_HANDLE_CROSS,
                                     x, y,
                                     5, 5, GIMP_HANDLE_ANCHOR_CENTER);
        }
    }
}

static void
gimp_brush_tool_brush_changed (GimpContext   *context,
                               GimpBrush     *brush,
                               GimpBrushTool *brush_tool)
{
  GimpPaintTool *paint_tool = GIMP_PAINT_TOOL (brush_tool);
  GimpBrushCore *brush_core = GIMP_BRUSH_CORE (paint_tool->core);

  if (brush_core->main_brush != brush)
    gimp_brush_core_set_brush (brush_core, brush);

}

static void
gimp_brush_tool_set_brush (GimpBrushCore *brush_core,
                           GimpBrush     *brush,
                           GimpBrushTool *brush_tool)
{
  GimpPaintCore *paint_core = GIMP_PAINT_CORE (brush_core);

  gimp_draw_tool_pause (GIMP_DRAW_TOOL (brush_tool));

  if (GIMP_BRUSH_CORE_GET_CLASS (brush_core)->handles_transforming_brush)
    {
      gimp_brush_core_eval_transform_dynamics (paint_core,
                                               NULL,
                                               GIMP_PAINT_TOOL_GET_OPTIONS (brush_tool),
                                               &paint_core->cur_coords);
    }
}

static void
gimp_brush_tool_set_brush_after (GimpBrushCore *brush_core,
                                 GimpBrush     *brush,
                                 GimpBrushTool *brush_tool)
{
  gimp_draw_tool_resume (GIMP_DRAW_TOOL (brush_tool));
}

static void
gimp_brush_tool_notify_brush (GimpDisplayConfig *config,
                              GParamSpec        *pspec,
                              GimpBrushTool     *brush_tool)
{
  gimp_draw_tool_pause (GIMP_DRAW_TOOL (brush_tool));

  brush_tool->show_cursor = config->show_paint_tool_cursor;
  brush_tool->draw_brush  = config->show_brush_outline;

  gimp_draw_tool_resume (GIMP_DRAW_TOOL (brush_tool));
}