Adding upstream version 2.10.22.upstream/2.10.22upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1495 insertions, 0 deletions

diff --git a/app/display/gimptoolpolygon.c b/app/display/gimptoolpolygon.c
new file mode 100644
index 0000000..4f2c20b
--- /dev/null
+++ b/app/display/gimptoolpolygon.c
@@ -0,0 +1,1495 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimptoolpolygon.c
+ * Copyright (C) 2017 Michael Natterer <mitch@gimp.org>
+ *
+ * Based on GimpFreeSelectTool
+ *
+ * Major improvement to support polygonal segments
+ * Copyright (C) 2008 Martin Nordholts
+ *
+ * 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 <string.h>
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+#include <gdk/gdkkeysyms.h>
+
+#include "libgimpbase/gimpbase.h"
+#include "libgimpmath/gimpmath.h"
+
+#include "display-types.h"
+
+#include "core/gimp-utils.h"
+#include "core/gimpmarshal.h"
+
+#include "widgets/gimpwidgets-utils.h"
+
+#include "gimpcanvashandle.h"
+#include "gimpcanvasline.h"
+#include "gimpcanvaspolygon.h"
+#include "gimpdisplayshell.h"
+#include "gimpdisplayshell-utils.h"
+#include "gimptoolpolygon.h"
+
+#include "gimp-intl.h"
+
+
+#define POINT_GRAB_THRESHOLD_SQ SQR (GIMP_CANVAS_HANDLE_SIZE_CIRCLE / 2)
+#define POINT_SHOW_THRESHOLD_SQ SQR (GIMP_CANVAS_HANDLE_SIZE_CIRCLE * 7)
+#define N_ITEMS_PER_ALLOC       1024
+#define INVALID_INDEX           (-1)
+#define NO_CLICK_TIME_AVAILABLE 0
+
+
+enum
+{
+  CHANGE_COMPLETE,
+  LAST_SIGNAL
+};
+
+
+struct _GimpToolPolygonPrivate
+{
+  /* Index of grabbed segment index. */
+  gint               grabbed_segment_index;
+
+  /* We need to keep track of a number of points when we move a
+   * segment vertex
+   */
+  GimpVector2       *saved_points_lower_segment;
+  GimpVector2       *saved_points_higher_segment;
+  gint               max_n_saved_points_lower_segment;
+  gint               max_n_saved_points_higher_segment;
+
+  /* Keeps track whether or not a modification of the polygon has been
+   * made between _button_press and _button_release
+   */
+  gboolean           polygon_modified;
+
+  /* Point which is used to draw the polygon but which is not part of
+   * it yet
+   */
+  GimpVector2        pending_point;
+  gboolean           show_pending_point;
+
+  /* The points of the polygon */
+  GimpVector2       *points;
+  gint               max_n_points;
+
+  /* The number of points actually in use */
+  gint               n_points;
+
+
+  /* Any int array containing the indices for the points in the
+   * polygon that connects different segments together
+   */
+  gint              *segment_indices;
+  gint               max_n_segment_indices;
+
+  /* The number of segment indices actually in use */
+  gint               n_segment_indices;
+
+  /* Is the polygon closed? */
+  gboolean           polygon_closed;
+
+  /* Whether or not to constrain the angle for newly created polygonal
+   * segments.
+   */
+  gboolean           constrain_angle;
+
+  /* Whether or not to suppress handles (so that new segments can be
+   * created immediately after an existing segment vertex.
+   */
+  gboolean           suppress_handles;
+
+  /* Last _oper_update or _motion coords */
+  gboolean           hover;
+  GimpVector2        last_coords;
+
+  /* A double-click commits the selection, keep track of last
+   * click-time and click-position.
+   */
+  guint32            last_click_time;
+  GimpCoords         last_click_coord;
+
+  /* Are we in a click-drag-release? */
+  gboolean           button_down;
+
+  GimpCanvasItem    *polygon;
+  GimpCanvasItem    *pending_line;
+  GimpCanvasItem    *closing_line;
+  GPtrArray         *handles;
+};
+
+
+/*  local function prototypes  */
+
+static void     gimp_tool_polygon_constructed     (GObject               *object);
+static void     gimp_tool_polygon_finalize        (GObject               *object);
+static void     gimp_tool_polygon_set_property    (GObject               *object,
+                                                   guint                  property_id,
+                                                   const GValue          *value,
+                                                   GParamSpec            *pspec);
+static void     gimp_tool_polygon_get_property    (GObject               *object,
+                                                   guint                  property_id,
+                                                   GValue                *value,
+                                                   GParamSpec            *pspec);
+
+static void     gimp_tool_polygon_changed         (GimpToolWidget        *widget);
+static gint     gimp_tool_polygon_button_press    (GimpToolWidget        *widget,
+                                                   const GimpCoords      *coords,
+                                                   guint32                time,
+                                                   GdkModifierType        state,
+                                                   GimpButtonPressType    press_type);
+static void     gimp_tool_polygon_button_release  (GimpToolWidget        *widget,
+                                                   const GimpCoords      *coords,
+                                                   guint32                time,
+                                                   GdkModifierType        state,
+                                                   GimpButtonReleaseType  release_type);
+static void     gimp_tool_polygon_motion          (GimpToolWidget        *widget,
+                                                   const GimpCoords      *coords,
+                                                   guint32                time,
+                                                   GdkModifierType        state);
+static GimpHit  gimp_tool_polygon_hit             (GimpToolWidget        *widget,
+                                                   const GimpCoords      *coords,
+                                                   GdkModifierType        state,
+                                                   gboolean               proximity);
+static void     gimp_tool_polygon_hover           (GimpToolWidget        *widget,
+                                                   const GimpCoords      *coords,
+                                                   GdkModifierType        state,
+                                                   gboolean               proximity);
+static void     gimp_tool_polygon_leave_notify    (GimpToolWidget        *widget);
+static gboolean gimp_tool_polygon_key_press       (GimpToolWidget        *widget,
+                                                   GdkEventKey           *kevent);
+static void     gimp_tool_polygon_motion_modifier (GimpToolWidget        *widget,
+                                                   GdkModifierType        key,
+                                                   gboolean               press,
+                                                   GdkModifierType        state);
+static void     gimp_tool_polygon_hover_modifier  (GimpToolWidget        *widget,
+                                                   GdkModifierType        key,
+                                                   gboolean               press,
+                                                   GdkModifierType        state);
+static gboolean gimp_tool_polygon_get_cursor      (GimpToolWidget        *widget,
+                                                   const GimpCoords      *coords,
+                                                   GdkModifierType        state,
+                                                   GimpCursorType        *cursor,
+                                                   GimpToolCursorType    *tool_cursor,
+                                                   GimpCursorModifier    *modifier);
+
+static void     gimp_tool_polygon_change_complete (GimpToolPolygon       *polygon);
+
+static gint   gimp_tool_polygon_get_segment_index (GimpToolPolygon       *polygon,
+                                                   const GimpCoords      *coords);
+
+
+G_DEFINE_TYPE_WITH_PRIVATE (GimpToolPolygon, gimp_tool_polygon,
+                            GIMP_TYPE_TOOL_WIDGET)
+
+#define parent_class gimp_tool_polygon_parent_class
+
+static guint polygon_signals[LAST_SIGNAL] = { 0, };
+
+static const GimpVector2 vector2_zero = { 0.0, 0.0 };
+
+
+static void
+gimp_tool_polygon_class_init (GimpToolPolygonClass *klass)
+{
+  GObjectClass        *object_class = G_OBJECT_CLASS (klass);
+  GimpToolWidgetClass *widget_class = GIMP_TOOL_WIDGET_CLASS (klass);
+
+  object_class->constructed     = gimp_tool_polygon_constructed;
+  object_class->finalize        = gimp_tool_polygon_finalize;
+  object_class->set_property    = gimp_tool_polygon_set_property;
+  object_class->get_property    = gimp_tool_polygon_get_property;
+
+  widget_class->changed         = gimp_tool_polygon_changed;
+  widget_class->button_press    = gimp_tool_polygon_button_press;
+  widget_class->button_release  = gimp_tool_polygon_button_release;
+  widget_class->motion          = gimp_tool_polygon_motion;
+  widget_class->hit             = gimp_tool_polygon_hit;
+  widget_class->hover           = gimp_tool_polygon_hover;
+  widget_class->leave_notify    = gimp_tool_polygon_leave_notify;
+  widget_class->key_press       = gimp_tool_polygon_key_press;
+  widget_class->motion_modifier = gimp_tool_polygon_motion_modifier;
+  widget_class->hover_modifier  = gimp_tool_polygon_hover_modifier;
+  widget_class->get_cursor      = gimp_tool_polygon_get_cursor;
+
+  polygon_signals[CHANGE_COMPLETE] =
+    g_signal_new ("change-complete",
+                  G_TYPE_FROM_CLASS (klass),
+                  G_SIGNAL_RUN_FIRST,
+                  G_STRUCT_OFFSET (GimpToolPolygonClass, change_complete),
+                  NULL, NULL,
+                  g_cclosure_marshal_VOID__VOID,
+                  G_TYPE_NONE, 0);
+}
+
+static void
+gimp_tool_polygon_init (GimpToolPolygon *polygon)
+{
+  polygon->private = gimp_tool_polygon_get_instance_private (polygon);
+
+  polygon->private->grabbed_segment_index = INVALID_INDEX;
+  polygon->private->last_click_time       = NO_CLICK_TIME_AVAILABLE;
+}
+
+static void
+gimp_tool_polygon_constructed (GObject *object)
+{
+  GimpToolPolygon        *polygon = GIMP_TOOL_POLYGON (object);
+  GimpToolWidget         *widget  = GIMP_TOOL_WIDGET (object);
+  GimpToolPolygonPrivate *private = polygon->private;
+  GimpCanvasGroup        *stroke_group;
+
+  G_OBJECT_CLASS (parent_class)->constructed (object);
+
+  stroke_group = gimp_tool_widget_add_stroke_group (widget);
+
+  gimp_tool_widget_push_group (widget, stroke_group);
+
+  private->polygon = gimp_tool_widget_add_polygon (widget, NULL,
+                                                   NULL, 0, FALSE);
+
+  private->pending_line = gimp_tool_widget_add_line (widget, 0, 0, 0, 0);
+  private->closing_line = gimp_tool_widget_add_line (widget, 0, 0, 0, 0);
+
+  gimp_tool_widget_pop_group (widget);
+
+  private->handles = g_ptr_array_new ();
+
+  gimp_tool_polygon_changed (widget);
+}
+
+static void
+gimp_tool_polygon_finalize (GObject *object)
+{
+  GimpToolPolygon        *polygon = GIMP_TOOL_POLYGON (object);
+  GimpToolPolygonPrivate *private = polygon->private;
+
+  g_free (private->points);
+  g_free (private->segment_indices);
+  g_free (private->saved_points_lower_segment);
+  g_free (private->saved_points_higher_segment);
+
+  g_clear_pointer (&private->handles, g_ptr_array_unref);
+
+  G_OBJECT_CLASS (parent_class)->finalize (object);
+}
+
+static void
+gimp_tool_polygon_set_property (GObject      *object,
+                                guint         property_id,
+                                const GValue *value,
+                                GParamSpec   *pspec)
+{
+  switch (property_id)
+    {
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_tool_polygon_get_property (GObject    *object,
+                                guint       property_id,
+                                GValue     *value,
+                                GParamSpec *pspec)
+{
+  switch (property_id)
+    {
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_tool_polygon_get_segment (GimpToolPolygon  *polygon,
+                               GimpVector2     **points,
+                               gint             *n_points,
+                               gint              segment_start,
+                               gint              segment_end)
+{
+  GimpToolPolygonPrivate *priv = polygon->private;
+
+  *points   = &priv->points[priv->segment_indices[segment_start]];
+  *n_points = priv->segment_indices[segment_end] -
+              priv->segment_indices[segment_start] +
+              1;
+}
+
+static void
+gimp_tool_polygon_get_segment_point (GimpToolPolygon *polygon,
+                                     gdouble         *start_point_x,
+                                     gdouble         *start_point_y,
+                                     gint             segment_index)
+{
+  GimpToolPolygonPrivate *priv = polygon->private;
+
+  *start_point_x = priv->points[priv->segment_indices[segment_index]].x;
+  *start_point_y = priv->points[priv->segment_indices[segment_index]].y;
+}
+
+static gboolean
+gimp_tool_polygon_should_close (GimpToolPolygon  *polygon,
+                                guint32           time,
+                                const GimpCoords *coords)
+{
+  GimpToolWidget         *widget       = GIMP_TOOL_WIDGET (polygon);
+  GimpToolPolygonPrivate *priv         = polygon->private;
+  gboolean                double_click = FALSE;
+  gdouble                 dist;
+
+  if (priv->polygon_modified      ||
+      priv->n_segment_indices < 1 ||
+      priv->n_points          < 3 ||
+      priv->polygon_closed)
+    return FALSE;
+
+  dist = gimp_canvas_item_transform_distance_square (priv->polygon,
+                                                     coords->x,
+                                                     coords->y,
+                                                     priv->points[0].x,
+                                                     priv->points[0].y);
+
+  /* Handle double-click. It must be within GTK+ global double-click
+   * time since last click, and it must be within GTK+ global
+   * double-click distance away from the last point
+   */
+  if (time != NO_CLICK_TIME_AVAILABLE)
+    {
+      GimpDisplayShell *shell    = gimp_tool_widget_get_shell (widget);
+      GtkSettings      *settings = gtk_widget_get_settings (GTK_WIDGET (shell));
+      gint              double_click_time;
+      gint              double_click_distance;
+      gint              click_time_passed;
+      gdouble           dist_from_last_point;
+
+      click_time_passed = time - priv->last_click_time;
+
+      dist_from_last_point =
+        gimp_canvas_item_transform_distance_square (priv->polygon,
+                                                    coords->x,
+                                                    coords->y,
+                                                    priv->last_click_coord.x,
+                                                    priv->last_click_coord.y);
+
+      g_object_get (settings,
+                    "gtk-double-click-time",     &double_click_time,
+                    "gtk-double-click-distance", &double_click_distance,
+                    NULL);
+
+      double_click = click_time_passed    < double_click_time &&
+                     dist_from_last_point < double_click_distance;
+    }
+
+  return ((! priv->suppress_handles && dist < POINT_GRAB_THRESHOLD_SQ) ||
+          double_click);
+}
+
+static void
+gimp_tool_polygon_revert_to_last_segment (GimpToolPolygon *polygon)
+{
+  GimpToolPolygonPrivate *priv = polygon->private;
+
+  priv->n_points = priv->segment_indices[priv->n_segment_indices - 1] + 1;
+}
+
+static void
+gimp_tool_polygon_remove_last_segment (GimpToolPolygon *polygon)
+{
+  GimpToolPolygonPrivate *priv = polygon->private;
+
+  if (priv->polygon_closed)
+    {
+      priv->polygon_closed = FALSE;
+
+      gimp_tool_polygon_changed (GIMP_TOOL_WIDGET (polygon));
+
+      return;
+    }
+
+  if (priv->n_segment_indices > 0)
+    {
+      GimpCanvasItem *handle;
+
+      priv->n_segment_indices--;
+
+      handle = g_ptr_array_index (priv->handles,
+                                  priv->n_segment_indices);
+
+      gimp_tool_widget_remove_item (GIMP_TOOL_WIDGET (polygon), handle);
+      g_ptr_array_remove (priv->handles, handle);
+    }
+
+  if (priv->n_segment_indices <= 0)
+    {
+      priv->grabbed_segment_index = INVALID_INDEX;
+      priv->show_pending_point    = FALSE;
+      priv->n_points              = 0;
+      priv->n_segment_indices     = 0;
+
+      gimp_tool_widget_response (GIMP_TOOL_WIDGET (polygon),
+                                 GIMP_TOOL_WIDGET_RESPONSE_CANCEL);
+    }
+  else
+    {
+      gimp_tool_polygon_revert_to_last_segment (polygon);
+
+      gimp_tool_polygon_changed (GIMP_TOOL_WIDGET (polygon));
+    }
+}
+
+static void
+gimp_tool_polygon_add_point (GimpToolPolygon *polygon,
+                             gdouble          x,
+                             gdouble          y)
+{
+  GimpToolPolygonPrivate *priv = polygon->private;
+
+  if (priv->n_points >= priv->max_n_points)
+    {
+      priv->max_n_points += N_ITEMS_PER_ALLOC;
+
+      priv->points = g_realloc (priv->points,
+                                sizeof (GimpVector2) * priv->max_n_points);
+    }
+
+  priv->points[priv->n_points].x = x;
+  priv->points[priv->n_points].y = y;
+
+  priv->n_points++;
+}
+
+static void
+gimp_tool_polygon_add_segment_index (GimpToolPolygon *polygon,
+                                     gint             index)
+{
+  GimpToolPolygonPrivate *priv = polygon->private;
+
+  if (priv->n_segment_indices >= priv->max_n_segment_indices)
+    {
+      priv->max_n_segment_indices += N_ITEMS_PER_ALLOC;
+
+      priv->segment_indices = g_realloc (priv->segment_indices,
+                                         sizeof (GimpVector2) *
+                                         priv->max_n_segment_indices);
+    }
+
+  priv->segment_indices[priv->n_segment_indices] = index;
+
+  g_ptr_array_add (priv->handles,
+                   gimp_tool_widget_add_handle (GIMP_TOOL_WIDGET (polygon),
+                                                GIMP_HANDLE_CROSS,
+                                                0, 0,
+                                                GIMP_CANVAS_HANDLE_SIZE_CIRCLE,
+                                                GIMP_CANVAS_HANDLE_SIZE_CIRCLE,
+                                                GIMP_HANDLE_ANCHOR_CENTER));
+
+  priv->n_segment_indices++;
+}
+
+static gboolean
+gimp_tool_polygon_is_point_grabbed (GimpToolPolygon *polygon)
+{
+  GimpToolPolygonPrivate *priv = polygon->private;
+
+  return priv->grabbed_segment_index != INVALID_INDEX;
+}
+
+static void
+gimp_tool_polygon_fit_segment (GimpToolPolygon   *polygon,
+                               GimpVector2       *dest_points,
+                               GimpVector2        dest_start_target,
+                               GimpVector2        dest_end_target,
+                               const GimpVector2 *source_points,
+                               gint               n_points)
+{
+  GimpVector2 origo_translation_offset;
+  GimpVector2 untranslation_offset;
+  gdouble     rotation;
+  gdouble     scale;
+
+  /* Handle some quick special cases */
+  if (n_points <= 0)
+    {
+      return;
+    }
+  else if (n_points == 1)
+    {
+      dest_points[0] = dest_end_target;
+      return;
+    }
+  else if (n_points == 2)
+    {
+      dest_points[0] = dest_start_target;
+      dest_points[1] = dest_end_target;
+      return;
+    }
+
+  /* Copy from source to dest; we work on the dest data */
+  memcpy (dest_points, source_points, sizeof (GimpVector2) * n_points);
+
+  /* Transform the destination end point */
+  {
+    GimpVector2 *dest_end;
+    GimpVector2  origo_translated_end_target;
+    gdouble      target_rotation;
+    gdouble      current_rotation;
+    gdouble      target_length;
+    gdouble      current_length;
+
+    dest_end = &dest_points[n_points - 1];
+
+    /* Transate to origin */
+    gimp_vector2_sub (&origo_translation_offset,
+                      &vector2_zero,
+                      &dest_points[0]);
+    gimp_vector2_add (dest_end,
+                      dest_end,
+                      &origo_translation_offset);
+
+    /* Calculate origo_translated_end_target */
+    gimp_vector2_sub (&origo_translated_end_target,
+                      &dest_end_target,
+                      &dest_start_target);
+
+    /* Rotate */
+    target_rotation  = atan2 (vector2_zero.y - origo_translated_end_target.y,
+                              vector2_zero.x - origo_translated_end_target.x);
+    current_rotation = atan2 (vector2_zero.y - dest_end->y,
+                              vector2_zero.x - dest_end->x);
+    rotation         = current_rotation - target_rotation;
+
+    gimp_vector2_rotate (dest_end, rotation);
+
+
+    /* Scale */
+    target_length  = gimp_vector2_length (&origo_translated_end_target);
+    current_length = gimp_vector2_length (dest_end);
+    scale          = target_length / current_length;
+
+    gimp_vector2_mul (dest_end, scale);
+
+
+    /* Untranslate */
+    gimp_vector2_sub (&untranslation_offset,
+                      &dest_end_target,
+                      dest_end);
+    gimp_vector2_add (dest_end,
+                      dest_end,
+                      &untranslation_offset);
+  }
+
+  /* Do the same transformation for the rest of the points */
+  {
+    gint i;
+
+    for (i = 0; i < n_points - 1; i++)
+      {
+        /* Translate */
+        gimp_vector2_add (&dest_points[i],
+                          &origo_translation_offset,
+                          &dest_points[i]);
+
+        /* Rotate */
+        gimp_vector2_rotate (&dest_points[i],
+                             rotation);
+
+        /* Scale */
+        gimp_vector2_mul (&dest_points[i],
+                          scale);
+
+        /* Untranslate */
+        gimp_vector2_add (&dest_points[i],
+                          &dest_points[i],
+                          &untranslation_offset);
+      }
+  }
+}
+
+static void
+gimp_tool_polygon_move_segment_vertex_to (GimpToolPolygon *polygon,
+                                          gint             segment_index,
+                                          gdouble          new_x,
+                                          gdouble          new_y)
+{
+  GimpToolPolygonPrivate *priv         = polygon->private;
+  GimpVector2             cursor_point = { new_x, new_y };
+  GimpVector2            *dest;
+  GimpVector2            *dest_start_target;
+  GimpVector2            *dest_end_target;
+  gint                    n_points;
+
+  /* Handle the segment before the grabbed point */
+  if (segment_index > 0)
+    {
+      gimp_tool_polygon_get_segment (polygon,
+                                     &dest,
+                                     &n_points,
+                                     priv->grabbed_segment_index - 1,
+                                     priv->grabbed_segment_index);
+
+      dest_start_target = &dest[0];
+      dest_end_target   = &cursor_point;
+
+      gimp_tool_polygon_fit_segment (polygon,
+                                     dest,
+                                     *dest_start_target,
+                                     *dest_end_target,
+                                     priv->saved_points_lower_segment,
+                                     n_points);
+    }
+
+  /* Handle the segment after the grabbed point */
+  if (segment_index < priv->n_segment_indices - 1)
+    {
+      gimp_tool_polygon_get_segment (polygon,
+                                     &dest,
+                                     &n_points,
+                                     priv->grabbed_segment_index,
+                                     priv->grabbed_segment_index + 1);
+
+      dest_start_target = &cursor_point;
+      dest_end_target   = &dest[n_points - 1];
+
+      gimp_tool_polygon_fit_segment (polygon,
+                                     dest,
+                                     *dest_start_target,
+                                     *dest_end_target,
+                                     priv->saved_points_higher_segment,
+                                     n_points);
+    }
+
+  /* Handle when there only is one point */
+  if (segment_index == 0 &&
+      priv->n_segment_indices == 1)
+    {
+      priv->points[0].x = new_x;
+      priv->points[0].y = new_y;
+    }
+}
+
+static void
+gimp_tool_polygon_revert_to_saved_state (GimpToolPolygon *polygon)
+{
+  GimpToolPolygonPrivate *priv = polygon->private;
+  GimpVector2            *dest;
+  gint                    n_points;
+
+  /* Without a point grab we have no sensible information to fall back
+   * on, bail out
+   */
+  if (! gimp_tool_polygon_is_point_grabbed (polygon))
+    {
+      return;
+    }
+
+  if (priv->grabbed_segment_index > 0)
+    {
+      gimp_tool_polygon_get_segment (polygon,
+                                     &dest,
+                                     &n_points,
+                                     priv->grabbed_segment_index - 1,
+                                     priv->grabbed_segment_index);
+
+      memcpy (dest,
+              priv->saved_points_lower_segment,
+              sizeof (GimpVector2) * n_points);
+    }
+
+  if (priv->grabbed_segment_index < priv->n_segment_indices - 1)
+    {
+      gimp_tool_polygon_get_segment (polygon,
+                                     &dest,
+                                     &n_points,
+                                     priv->grabbed_segment_index,
+                                     priv->grabbed_segment_index + 1);
+
+      memcpy (dest,
+              priv->saved_points_higher_segment,
+              sizeof (GimpVector2) * n_points);
+    }
+
+  if (priv->grabbed_segment_index == 0 &&
+      priv->n_segment_indices     == 1)
+    {
+      priv->points[0] = *priv->saved_points_lower_segment;
+    }
+}
+
+static void
+gimp_tool_polygon_prepare_for_move (GimpToolPolygon *polygon)
+{
+  GimpToolPolygonPrivate *priv = polygon->private;
+  GimpVector2            *source;
+  gint                    n_points;
+
+  if (priv->grabbed_segment_index > 0)
+    {
+      gimp_tool_polygon_get_segment (polygon,
+                                     &source,
+                                     &n_points,
+                                     priv->grabbed_segment_index - 1,
+                                     priv->grabbed_segment_index);
+
+      if (n_points > priv->max_n_saved_points_lower_segment)
+        {
+          priv->max_n_saved_points_lower_segment = n_points;
+
+          priv->saved_points_lower_segment =
+            g_realloc (priv->saved_points_lower_segment,
+                       sizeof (GimpVector2) * n_points);
+        }
+
+      memcpy (priv->saved_points_lower_segment,
+              source,
+              sizeof (GimpVector2) * n_points);
+    }
+
+  if (priv->grabbed_segment_index < priv->n_segment_indices - 1)
+    {
+      gimp_tool_polygon_get_segment (polygon,
+                                     &source,
+                                     &n_points,
+                                     priv->grabbed_segment_index,
+                                     priv->grabbed_segment_index + 1);
+
+      if (n_points > priv->max_n_saved_points_higher_segment)
+        {
+          priv->max_n_saved_points_higher_segment = n_points;
+
+          priv->saved_points_higher_segment =
+            g_realloc (priv->saved_points_higher_segment,
+                       sizeof (GimpVector2) * n_points);
+        }
+
+      memcpy (priv->saved_points_higher_segment,
+              source,
+              sizeof (GimpVector2) * n_points);
+    }
+
+  /* A special-case when there only is one point */
+  if (priv->grabbed_segment_index == 0 &&
+      priv->n_segment_indices     == 1)
+    {
+      if (priv->max_n_saved_points_lower_segment == 0)
+        {
+          priv->max_n_saved_points_lower_segment = 1;
+
+          priv->saved_points_lower_segment = g_new0 (GimpVector2, 1);
+        }
+
+      *priv->saved_points_lower_segment = priv->points[0];
+    }
+}
+
+static void
+gimp_tool_polygon_update_motion (GimpToolPolygon *polygon,
+                                 gdouble          new_x,
+                                 gdouble          new_y)
+{
+  GimpToolPolygonPrivate *priv = polygon->private;
+
+  if (gimp_tool_polygon_is_point_grabbed (polygon))
+    {
+      priv->polygon_modified = TRUE;
+
+      if (priv->constrain_angle &&
+          priv->n_segment_indices > 1)
+        {
+          gdouble start_point_x;
+          gdouble start_point_y;
+          gint    segment_index;
+
+          /* Base constraints on the last segment vertex if we move
+           * the first one, otherwise base on the previous segment
+           * vertex
+           */
+          if (priv->grabbed_segment_index == 0)
+            {
+              segment_index = priv->n_segment_indices - 1;
+            }
+          else
+            {
+              segment_index = priv->grabbed_segment_index - 1;
+            }
+
+          gimp_tool_polygon_get_segment_point (polygon,
+                                               &start_point_x,
+                                               &start_point_y,
+                                               segment_index);
+
+          gimp_display_shell_constrain_line (
+            gimp_tool_widget_get_shell (GIMP_TOOL_WIDGET (polygon)),
+            start_point_x,
+            start_point_y,
+            &new_x,
+            &new_y,
+            GIMP_CONSTRAIN_LINE_15_DEGREES);
+        }
+
+      gimp_tool_polygon_move_segment_vertex_to (polygon,
+                                                priv->grabbed_segment_index,
+                                                new_x,
+                                                new_y);
+
+      /* We also must update the pending point if we are moving the
+       * first point
+       */
+      if (priv->grabbed_segment_index == 0)
+        {
+          priv->pending_point.x = new_x;
+          priv->pending_point.y = new_y;
+        }
+    }
+  else
+    {
+      /* Don't show the pending point while we are adding points */
+      priv->show_pending_point = FALSE;
+
+      gimp_tool_polygon_add_point (polygon, new_x, new_y);
+    }
+}
+
+static void
+gimp_tool_polygon_status_update (GimpToolPolygon  *polygon,
+                                 const GimpCoords *coords,
+                                 gboolean          proximity)
+{
+  GimpToolWidget         *widget = GIMP_TOOL_WIDGET (polygon);
+  GimpToolPolygonPrivate *priv   = polygon->private;
+
+  if (proximity)
+    {
+      const gchar *status_text = NULL;
+
+      if (gimp_tool_polygon_is_point_grabbed (polygon))
+        {
+          if (gimp_tool_polygon_should_close (polygon,
+                                              NO_CLICK_TIME_AVAILABLE,
+                                              coords))
+            {
+              status_text = _("Click to close shape");
+            }
+          else
+            {
+              status_text = _("Click-Drag to move segment vertex");
+            }
+        }
+      else if (priv->polygon_closed)
+        {
+          status_text = _("Return commits, Escape cancels, Backspace re-opens shape");
+        }
+      else if (priv->n_segment_indices >= 3)
+        {
+          status_text = _("Return commits, Escape cancels, Backspace removes last segment");
+        }
+      else
+        {
+          status_text = _("Click-Drag adds a free segment, Click adds a polygonal segment");
+        }
+
+      if (status_text)
+        {
+          gimp_tool_widget_set_status (widget, status_text);
+        }
+    }
+  else
+    {
+      gimp_tool_widget_set_status (widget, NULL);
+    }
+}
+
+static void
+gimp_tool_polygon_changed (GimpToolWidget *widget)
+{
+  GimpToolPolygon        *polygon               = GIMP_TOOL_POLYGON (widget);
+  GimpToolPolygonPrivate *private               = polygon->private;
+  gboolean                hovering_first_point  = FALSE;
+  gboolean                handles_wants_to_show = FALSE;
+  GimpCoords              coords                = { private->last_coords.x,
+                                                    private->last_coords.y,
+                                                    /* pad with 0 */ };
+  gint                    i;
+
+  gimp_canvas_polygon_set_points (private->polygon,
+                                  private->points, private->n_points);
+
+  if (private->show_pending_point)
+    {
+      GimpVector2 last = private->points[private->n_points - 1];
+
+      gimp_canvas_line_set (private->pending_line,
+                            last.x,
+                            last.y,
+                            private->pending_point.x,
+                            private->pending_point.y);
+    }
+
+  gimp_canvas_item_set_visible (private->pending_line,
+                                private->show_pending_point);
+
+  if (private->polygon_closed)
+    {
+      GimpVector2 first = private->points[0];
+      GimpVector2 last  = private->points[private->n_points - 1];
+
+      gimp_canvas_line_set (private->closing_line,
+                            first.x, first.y,
+                            last.x,  last.y);
+    }
+
+  gimp_canvas_item_set_visible (private->closing_line,
+                                private->polygon_closed);
+
+  hovering_first_point =
+    gimp_tool_polygon_should_close (polygon,
+                                    NO_CLICK_TIME_AVAILABLE,
+                                    &coords);
+
+  /* We always show the handle for the first point, even with button1
+   * down, since releasing the button on the first point will close
+   * the polygon, so it's a significant state which we must give
+   * feedback for
+   */
+  handles_wants_to_show = (hovering_first_point || ! private->button_down);
+
+  for (i = 0; i < private->n_segment_indices; i++)
+    {
+      GimpCanvasItem *handle;
+      GimpVector2    *point;
+
+      handle = g_ptr_array_index (private->handles, i);
+      point  = &private->points[private->segment_indices[i]];
+
+      if (private->hover             &&
+          handles_wants_to_show      &&
+          ! private->suppress_handles &&
+
+          /* If the first point is hovered while button1 is held down,
+           * only draw the first handle, the other handles are not
+           * relevant (see comment a few lines up)
+           */
+          (i == 0 ||
+           ! (private->button_down || hovering_first_point)))
+        {
+          gdouble         dist;
+          GimpHandleType  handle_type = -1;
+
+          dist =
+            gimp_canvas_item_transform_distance_square (handle,
+                                                        private->last_coords.x,
+                                                        private->last_coords.y,
+                                                        point->x,
+                                                        point->y);
+
+          /* If the cursor is over the point, fill, if it's just
+           * close, draw an outline
+           */
+          if (dist < POINT_GRAB_THRESHOLD_SQ)
+            handle_type = GIMP_HANDLE_FILLED_CIRCLE;
+          else if (dist < POINT_SHOW_THRESHOLD_SQ)
+            handle_type = GIMP_HANDLE_CIRCLE;
+
+          if (handle_type != -1)
+            {
+              gint size;
+
+              gimp_canvas_item_begin_change (handle);
+
+              gimp_canvas_handle_set_position (handle, point->x, point->y);
+
+              g_object_set (handle,
+                            "type", handle_type,
+                            NULL);
+
+              size = gimp_canvas_handle_calc_size (handle,
+                                                   private->last_coords.x,
+                                                   private->last_coords.y,
+                                                   GIMP_CANVAS_HANDLE_SIZE_CIRCLE,
+                                                   2 * GIMP_CANVAS_HANDLE_SIZE_CIRCLE);
+              if (FALSE)
+                gimp_canvas_handle_set_size (handle, size, size);
+
+              if (dist < POINT_GRAB_THRESHOLD_SQ)
+                gimp_canvas_item_set_highlight (handle, TRUE);
+              else
+                gimp_canvas_item_set_highlight (handle, FALSE);
+
+              gimp_canvas_item_set_visible (handle, TRUE);
+
+              gimp_canvas_item_end_change (handle);
+            }
+          else
+            {
+              gimp_canvas_item_set_visible (handle, FALSE);
+            }
+        }
+      else
+        {
+          gimp_canvas_item_set_visible (handle, FALSE);
+       }
+    }
+}
+
+static gboolean
+gimp_tool_polygon_button_press (GimpToolWidget      *widget,
+                                const GimpCoords    *coords,
+                                guint32              time,
+                                GdkModifierType      state,
+                                GimpButtonPressType  press_type)
+{
+  GimpToolPolygon        *polygon = GIMP_TOOL_POLYGON (widget);
+  GimpToolPolygonPrivate *priv    = polygon->private;
+
+  if (gimp_tool_polygon_is_point_grabbed (polygon))
+    {
+      gimp_tool_polygon_prepare_for_move (polygon);
+    }
+  else if (priv->polygon_closed)
+    {
+      if (press_type == GIMP_BUTTON_PRESS_DOUBLE &&
+          gimp_canvas_item_hit (priv->polygon, coords->x, coords->y))
+        {
+          gimp_tool_widget_response (widget, GIMP_TOOL_WIDGET_RESPONSE_CONFIRM);
+        }
+
+      return 0;
+    }
+  else
+    {
+      GimpVector2 point_to_add;
+
+      /* Note that we add the pending point (unless it is the first
+       * point we add) because the pending point is setup correctly
+       * with regards to angle constraints.
+       */
+      if (priv->n_points > 0)
+        {
+          point_to_add = priv->pending_point;
+        }
+      else
+        {
+          point_to_add.x = coords->x;
+          point_to_add.y = coords->y;
+        }
+
+      /* No point was grabbed, add a new point and mark this as a
+       * segment divider. For a line segment, this will be the only
+       * new point. For a free segment, this will be the first point
+       * of the free segment.
+       */
+      gimp_tool_polygon_add_point (polygon,
+                                   point_to_add.x,
+                                   point_to_add.y);
+      gimp_tool_polygon_add_segment_index (polygon, priv->n_points - 1);
+    }
+
+  priv->button_down = TRUE;
+
+  gimp_tool_polygon_changed (widget);
+
+  return 1;
+}
+
+static void
+gimp_tool_polygon_button_release (GimpToolWidget        *widget,
+                                  const GimpCoords      *coords,
+                                  guint32                time,
+                                  GdkModifierType        state,
+                                  GimpButtonReleaseType  release_type)
+{
+  GimpToolPolygon        *polygon = GIMP_TOOL_POLYGON (widget);
+  GimpToolPolygonPrivate *priv    = polygon->private;
+
+  g_object_ref (widget);
+
+  priv->button_down = FALSE;
+
+  switch (release_type)
+    {
+    case GIMP_BUTTON_RELEASE_CLICK:
+    case GIMP_BUTTON_RELEASE_NO_MOTION:
+      /* If a click was made, we don't consider the polygon modified */
+      priv->polygon_modified = FALSE;
+
+      /* First finish of the line segment if no point was grabbed */
+      if (! gimp_tool_polygon_is_point_grabbed (polygon))
+        {
+          /* Revert any free segment points that might have been added */
+          gimp_tool_polygon_revert_to_last_segment (polygon);
+        }
+
+      /* After the segments are up to date and we have handled
+       * double-click, see if it's committing time
+       */
+      if (gimp_tool_polygon_should_close (polygon, time, coords))
+        {
+          /* We can get a click notification even though the end point
+           * has been moved a few pixels. Since a move will change the
+           * free selection, revert it before doing the commit.
+           */
+          gimp_tool_polygon_revert_to_saved_state (polygon);
+
+          priv->polygon_closed = TRUE;
+
+          gimp_tool_polygon_change_complete (polygon);
+        }
+
+      priv->last_click_time  = time;
+      priv->last_click_coord = *coords;
+      break;
+
+    case GIMP_BUTTON_RELEASE_NORMAL:
+      /* First finish of the free segment if no point was grabbed */
+      if (! gimp_tool_polygon_is_point_grabbed (polygon))
+        {
+          /* The points are all setup, just make a segment */
+          gimp_tool_polygon_add_segment_index (polygon, priv->n_points - 1);
+        }
+
+      /* After the segments are up to date, see if it's committing time */
+      if (gimp_tool_polygon_should_close (polygon,
+                                          NO_CLICK_TIME_AVAILABLE,
+                                          coords))
+        {
+          priv->polygon_closed = TRUE;
+        }
+
+      gimp_tool_polygon_change_complete (polygon);
+      break;
+
+    case GIMP_BUTTON_RELEASE_CANCEL:
+      if (gimp_tool_polygon_is_point_grabbed (polygon))
+        gimp_tool_polygon_revert_to_saved_state (polygon);
+      else
+        gimp_tool_polygon_remove_last_segment (polygon);
+      break;
+
+    default:
+      break;
+    }
+
+  /* Reset */
+  priv->polygon_modified = FALSE;
+
+  gimp_tool_polygon_changed (widget);
+
+  g_object_unref (widget);
+}
+
+static void
+gimp_tool_polygon_motion (GimpToolWidget   *widget,
+                          const GimpCoords *coords,
+                          guint32           time,
+                          GdkModifierType   state)
+{
+  GimpToolPolygon        *polygon = GIMP_TOOL_POLYGON (widget);
+  GimpToolPolygonPrivate *priv    = polygon->private;
+
+  priv->last_coords.x = coords->x;
+  priv->last_coords.y = coords->y;
+
+  gimp_tool_polygon_update_motion (polygon,
+                                   coords->x,
+                                   coords->y);
+
+  gimp_tool_polygon_changed (widget);
+}
+
+static GimpHit
+gimp_tool_polygon_hit (GimpToolWidget   *widget,
+                       const GimpCoords *coords,
+                       GdkModifierType   state,
+                       gboolean          proximity)
+{
+  GimpToolPolygon        *polygon = GIMP_TOOL_POLYGON (widget);
+  GimpToolPolygonPrivate *priv    = polygon->private;
+
+  if ((priv->n_points > 0 && ! priv->polygon_closed) ||
+      gimp_tool_polygon_get_segment_index (polygon, coords) != INVALID_INDEX)
+    {
+      return GIMP_HIT_DIRECT;
+    }
+  else if (priv->polygon_closed &&
+           gimp_canvas_item_hit (priv->polygon, coords->x, coords->y))
+    {
+      return GIMP_HIT_INDIRECT;
+    }
+
+  return GIMP_HIT_NONE;
+}
+
+static void
+gimp_tool_polygon_hover (GimpToolWidget   *widget,
+                         const GimpCoords *coords,
+                         GdkModifierType   state,
+                         gboolean          proximity)
+{
+  GimpToolPolygon        *polygon = GIMP_TOOL_POLYGON (widget);
+  GimpToolPolygonPrivate *priv    = polygon->private;
+  gboolean                hovering_first_point;
+
+  priv->grabbed_segment_index = gimp_tool_polygon_get_segment_index (polygon,
+                                                                     coords);
+  priv->hover                 = TRUE;
+
+  hovering_first_point =
+    gimp_tool_polygon_should_close (polygon,
+                                    NO_CLICK_TIME_AVAILABLE,
+                                    coords);
+
+  priv->last_coords.x = coords->x;
+  priv->last_coords.y = coords->y;
+
+  if (priv->n_points == 0  ||
+      priv->polygon_closed ||
+      (gimp_tool_polygon_is_point_grabbed (polygon) &&
+       ! hovering_first_point) ||
+      ! proximity)
+    {
+      priv->show_pending_point = FALSE;
+    }
+  else
+    {
+      priv->show_pending_point = TRUE;
+
+      if (hovering_first_point)
+        {
+          priv->pending_point = priv->points[0];
+        }
+      else
+        {
+          priv->pending_point.x = coords->x;
+          priv->pending_point.y = coords->y;
+
+          if (priv->constrain_angle && priv->n_points > 0)
+            {
+              gdouble start_point_x;
+              gdouble start_point_y;
+
+              /*  the last point is the line's start point  */
+              gimp_tool_polygon_get_segment_point (polygon,
+                                                   &start_point_x,
+                                                   &start_point_y,
+                                                   priv->n_segment_indices - 1);
+
+              gimp_display_shell_constrain_line (
+                gimp_tool_widget_get_shell (widget),
+                start_point_x, start_point_y,
+                &priv->pending_point.x,
+                &priv->pending_point.y,
+                GIMP_CONSTRAIN_LINE_15_DEGREES);
+            }
+        }
+    }
+
+  gimp_tool_polygon_status_update (polygon, coords, proximity);
+
+  gimp_tool_polygon_changed (widget);
+}
+
+static void
+gimp_tool_polygon_leave_notify (GimpToolWidget *widget)
+{
+  GimpToolPolygon        *polygon = GIMP_TOOL_POLYGON (widget);
+  GimpToolPolygonPrivate *priv    = polygon->private;
+
+  priv->grabbed_segment_index = INVALID_INDEX;
+  priv->hover                 = FALSE;
+  priv->show_pending_point    = FALSE;
+
+  gimp_tool_polygon_changed (widget);
+}
+
+static gboolean
+gimp_tool_polygon_key_press (GimpToolWidget *widget,
+                             GdkEventKey    *kevent)
+{
+  GimpToolPolygon        *polygon = GIMP_TOOL_POLYGON (widget);
+  GimpToolPolygonPrivate *priv    = polygon->private;
+
+  switch (kevent->keyval)
+    {
+    case GDK_KEY_BackSpace:
+      gimp_tool_polygon_remove_last_segment (polygon);
+
+      if (priv->n_segment_indices > 0)
+        gimp_tool_polygon_change_complete (polygon);
+      return TRUE;
+
+    default:
+      break;
+    }
+
+  return GIMP_TOOL_WIDGET_CLASS (parent_class)->key_press (widget, kevent);
+}
+
+static void
+gimp_tool_polygon_motion_modifier (GimpToolWidget  *widget,
+                                   GdkModifierType  key,
+                                   gboolean         press,
+                                   GdkModifierType  state)
+{
+  GimpToolPolygon        *polygon = GIMP_TOOL_POLYGON (widget);
+  GimpToolPolygonPrivate *priv    = polygon->private;
+
+  priv->constrain_angle = ((state & gimp_get_constrain_behavior_mask ()) ?
+                           TRUE : FALSE);
+
+  /* If we didn't came here due to a mouse release, immediately update
+   * the position of the thing we move.
+   */
+  if (state & GDK_BUTTON1_MASK)
+    {
+      gimp_tool_polygon_update_motion (polygon,
+                                       priv->last_coords.x,
+                                       priv->last_coords.y);
+    }
+
+  gimp_tool_polygon_changed (widget);
+}
+
+static void
+gimp_tool_polygon_hover_modifier (GimpToolWidget  *widget,
+                                  GdkModifierType  key,
+                                  gboolean         press,
+                                  GdkModifierType  state)
+{
+  GimpToolPolygon        *polygon = GIMP_TOOL_POLYGON (widget);
+  GimpToolPolygonPrivate *priv    = polygon->private;
+
+  priv->constrain_angle = ((state & gimp_get_constrain_behavior_mask ()) ?
+                           TRUE : FALSE);
+
+  priv->suppress_handles = ((state & gimp_get_extend_selection_mask ()) ?
+                           TRUE : FALSE);
+
+  gimp_tool_polygon_changed (widget);
+}
+
+static gboolean
+gimp_tool_polygon_get_cursor (GimpToolWidget     *widget,
+                              const GimpCoords   *coords,
+                              GdkModifierType     state,
+                              GimpCursorType     *cursor,
+                              GimpToolCursorType *tool_cursor,
+                              GimpCursorModifier *modifier)
+{
+  GimpToolPolygon *polygon = GIMP_TOOL_POLYGON (widget);
+
+  if (gimp_tool_polygon_is_point_grabbed (polygon) &&
+      ! gimp_tool_polygon_should_close (polygon,
+                                        NO_CLICK_TIME_AVAILABLE,
+                                        coords))
+    {
+      *modifier = GIMP_CURSOR_MODIFIER_MOVE;
+
+      return TRUE;
+    }
+
+  return FALSE;
+}
+
+static void
+gimp_tool_polygon_change_complete (GimpToolPolygon *polygon)
+{
+  g_signal_emit (polygon, polygon_signals[CHANGE_COMPLETE], 0);
+}
+
+static gint
+gimp_tool_polygon_get_segment_index (GimpToolPolygon  *polygon,
+                                     const GimpCoords *coords)
+{
+  GimpToolPolygonPrivate *priv          = polygon->private;
+  gint                    segment_index = INVALID_INDEX;
+
+  if (! priv->suppress_handles)
+    {
+      gdouble shortest_dist = POINT_GRAB_THRESHOLD_SQ;
+      gint    i;
+
+      for (i = 0; i < priv->n_segment_indices; i++)
+        {
+          gdouble      dist;
+          GimpVector2 *point;
+
+          point = &priv->points[priv->segment_indices[i]];
+
+          dist = gimp_canvas_item_transform_distance_square (priv->polygon,
+                                                             coords->x,
+                                                             coords->y,
+                                                             point->x,
+                                                             point->y);
+
+          if (dist < shortest_dist)
+            {
+              shortest_dist = dist;
+
+              segment_index = i;
+            }
+        }
+    }
+
+  return segment_index;
+}
+
+
+/*  public functions  */
+
+GimpToolWidget *
+gimp_tool_polygon_new (GimpDisplayShell *shell)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), NULL);
+
+  return g_object_new (GIMP_TYPE_TOOL_POLYGON,
+                       "shell", shell,
+                       NULL);
+}
+
+gboolean
+gimp_tool_polygon_is_closed (GimpToolPolygon *polygon)
+{
+  GimpToolPolygonPrivate *private;
+
+  g_return_val_if_fail (GIMP_IS_TOOL_POLYGON (polygon), FALSE);
+
+  private = polygon->private;
+
+  return private->polygon_closed;
+}
+
+void
+gimp_tool_polygon_get_points (GimpToolPolygon    *polygon,
+                              const GimpVector2 **points,
+                              gint               *n_points)
+{
+  GimpToolPolygonPrivate *private;
+
+  g_return_if_fail (GIMP_IS_TOOL_POLYGON (polygon));
+
+  private = polygon->private;
+
+  if (points)   *points   = private->points;
+  if (n_points) *n_points = private->n_points;
+}