Adding upstream version 2.10.36.upstream/2.10.36

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

1 files changed, 1484 insertions, 0 deletions

diff --git a/app/tools/gimpwarptool.c b/app/tools/gimpwarptool.c
new file mode 100644
index 0000000..c76f950
--- /dev/null
+++ b/app/tools/gimpwarptool.c
@@ -0,0 +1,1484 @@
+/* GIMP - The GNU Image Manipulation Program
+ *
+ * gimpwarptool.c
+ * Copyright (C) 2011 Michael Muré <batolettre@gmail.com>
+ *
+ * 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 <gegl.h>
+#include <gegl-plugin.h>
+#include <gtk/gtk.h>
+#include <gdk/gdkkeysyms.h>
+
+#include "libgimpmath/gimpmath.h"
+#include "libgimpwidgets/gimpwidgets.h"
+
+#include "tools-types.h"
+
+#include "config/gimpdisplayconfig.h"
+#include "config/gimpguiconfig.h"
+
+#include "gegl/gimp-gegl-apply-operation.h"
+
+#include "core/gimp.h"
+#include "core/gimpchannel.h"
+#include "core/gimpdrawablefilter.h"
+#include "core/gimpimage.h"
+#include "core/gimplayer.h"
+#include "core/gimpprogress.h"
+#include "core/gimpprojection.h"
+#include "core/gimpsubprogress.h"
+#include "core/gimptoolinfo.h"
+
+#include "widgets/gimphelp-ids.h"
+#include "widgets/gimpwidgets-utils.h"
+
+#include "display/gimpdisplay.h"
+
+#include "gimpwarptool.h"
+#include "gimpwarpoptions.h"
+#include "gimptoolcontrol.h"
+#include "gimptools-utils.h"
+
+#include "gimp-intl.h"
+
+
+#define STROKE_TIMER_MAX_FPS 20
+#define PREVIEW_SAMPLER      GEGL_SAMPLER_NEAREST
+
+
+static void            gimp_warp_tool_constructed               (GObject               *object);
+
+static void            gimp_warp_tool_control                   (GimpTool              *tool,
+                                                                 GimpToolAction         action,
+                                                                 GimpDisplay           *display);
+static void            gimp_warp_tool_button_press              (GimpTool              *tool,
+                                                                 const GimpCoords      *coords,
+                                                                 guint32                time,
+                                                                 GdkModifierType        state,
+                                                                 GimpButtonPressType    press_type,
+                                                                 GimpDisplay           *display);
+static void            gimp_warp_tool_button_release            (GimpTool              *tool,
+                                                                 const GimpCoords      *coords,
+                                                                 guint32                time,
+                                                                 GdkModifierType        state,
+                                                                 GimpButtonReleaseType  release_type,
+                                                                 GimpDisplay           *display);
+static void            gimp_warp_tool_motion                    (GimpTool              *tool,
+                                                                 const GimpCoords      *coords,
+                                                                 guint32                time,
+                                                                 GdkModifierType        state,
+                                                                 GimpDisplay           *display);
+static gboolean        gimp_warp_tool_key_press                 (GimpTool              *tool,
+                                                                 GdkEventKey           *kevent,
+                                                                 GimpDisplay           *display);
+static void            gimp_warp_tool_oper_update               (GimpTool              *tool,
+                                                                 const GimpCoords      *coords,
+                                                                 GdkModifierType        state,
+                                                                 gboolean               proximity,
+                                                                 GimpDisplay           *display);
+static void            gimp_warp_tool_cursor_update             (GimpTool              *tool,
+                                                                 const GimpCoords      *coords,
+                                                                 GdkModifierType        state,
+                                                                 GimpDisplay           *display);
+const gchar          * gimp_warp_tool_can_undo                  (GimpTool              *tool,
+                                                                 GimpDisplay           *display);
+const gchar          * gimp_warp_tool_can_redo                  (GimpTool              *tool,
+                                                                 GimpDisplay           *display);
+static gboolean        gimp_warp_tool_undo                      (GimpTool              *tool,
+                                                                 GimpDisplay           *display);
+static gboolean        gimp_warp_tool_redo                      (GimpTool              *tool,
+                                                                 GimpDisplay           *display);
+static void            gimp_warp_tool_options_notify            (GimpTool              *tool,
+                                                                 GimpToolOptions       *options,
+                                                                 const GParamSpec      *pspec);
+
+static void            gimp_warp_tool_draw                      (GimpDrawTool          *draw_tool);
+
+static void            gimp_warp_tool_cursor_notify             (GimpDisplayConfig     *config,
+                                                                 GParamSpec            *pspec,
+                                                                 GimpWarpTool          *wt);
+
+static gboolean        gimp_warp_tool_can_stroke                (GimpWarpTool          *wt,
+                                                                 GimpDisplay           *display,
+                                                                 gboolean               show_message);
+
+static gboolean        gimp_warp_tool_start                     (GimpWarpTool          *wt,
+                                                                 GimpDisplay           *display);
+static void            gimp_warp_tool_halt                      (GimpWarpTool          *wt);
+static void            gimp_warp_tool_commit                    (GimpWarpTool          *wt);
+
+static void            gimp_warp_tool_start_stroke_timer        (GimpWarpTool          *wt);
+static void            gimp_warp_tool_stop_stroke_timer         (GimpWarpTool          *wt);
+static gboolean        gimp_warp_tool_stroke_timer              (GimpWarpTool          *wt);
+
+static void            gimp_warp_tool_create_graph              (GimpWarpTool          *wt);
+static void            gimp_warp_tool_create_filter             (GimpWarpTool          *wt,
+                                                                 GimpDrawable          *drawable);
+static void            gimp_warp_tool_set_sampler               (GimpWarpTool          *wt,
+                                                                 gboolean               commit);
+static GeglRectangle
+                       gimp_warp_tool_get_stroke_bounds         (GeglNode              *node);
+static GeglRectangle   gimp_warp_tool_get_node_bounds           (GeglNode              *node);
+static void            gimp_warp_tool_clear_node_bounds         (GeglNode              *node);
+static GeglRectangle   gimp_warp_tool_get_invalidated_by_change (GimpWarpTool          *wt,
+                                                                 const GeglRectangle   *area);
+static void            gimp_warp_tool_update_bounds             (GimpWarpTool          *wt);
+static void            gimp_warp_tool_update_area               (GimpWarpTool          *wt,
+                                                                 const GeglRectangle   *area,
+                                                                 gboolean               synchronous);
+static void            gimp_warp_tool_update_stroke             (GimpWarpTool          *wt,
+                                                                 GeglNode              *node);
+static void            gimp_warp_tool_stroke_append             (GimpWarpTool          *wt,
+                                                                 gchar                  type,
+                                                                 gdouble                x,
+                                                                 gdouble                y);
+static void            gimp_warp_tool_filter_flush              (GimpDrawableFilter    *filter,
+                                                                 GimpTool              *tool);
+static void            gimp_warp_tool_add_op                    (GimpWarpTool          *wt,
+                                                                 GeglNode              *op);
+static void            gimp_warp_tool_remove_op                 (GimpWarpTool          *wt,
+                                                                 GeglNode              *op);
+static void            gimp_warp_tool_free_op                   (GeglNode              *op);
+
+static void            gimp_warp_tool_animate                   (GimpWarpTool          *wt);
+
+
+G_DEFINE_TYPE (GimpWarpTool, gimp_warp_tool, GIMP_TYPE_DRAW_TOOL)
+
+#define parent_class gimp_warp_tool_parent_class
+
+
+void
+gimp_warp_tool_register (GimpToolRegisterCallback  callback,
+                         gpointer                  data)
+{
+  (* callback) (GIMP_TYPE_WARP_TOOL,
+                GIMP_TYPE_WARP_OPTIONS,
+                gimp_warp_options_gui,
+                0,
+                "gimp-warp-tool",
+                _("Warp Transform"),
+                _("Warp Transform: Deform with different tools"),
+                N_("_Warp Transform"), "W",
+                NULL, GIMP_HELP_TOOL_WARP,
+                GIMP_ICON_TOOL_WARP,
+                data);
+}
+
+static void
+gimp_warp_tool_class_init (GimpWarpToolClass *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->constructed  = gimp_warp_tool_constructed;
+
+  tool_class->control        = gimp_warp_tool_control;
+  tool_class->button_press   = gimp_warp_tool_button_press;
+  tool_class->button_release = gimp_warp_tool_button_release;
+  tool_class->motion         = gimp_warp_tool_motion;
+  tool_class->key_press      = gimp_warp_tool_key_press;
+  tool_class->oper_update    = gimp_warp_tool_oper_update;
+  tool_class->cursor_update  = gimp_warp_tool_cursor_update;
+  tool_class->can_undo       = gimp_warp_tool_can_undo;
+  tool_class->can_redo       = gimp_warp_tool_can_redo;
+  tool_class->undo           = gimp_warp_tool_undo;
+  tool_class->redo           = gimp_warp_tool_redo;
+  tool_class->options_notify = gimp_warp_tool_options_notify;
+
+  draw_tool_class->draw      = gimp_warp_tool_draw;
+}
+
+static void
+gimp_warp_tool_init (GimpWarpTool *self)
+{
+  GimpTool *tool = GIMP_TOOL (self);
+
+  gimp_tool_control_set_motion_mode     (tool->control, GIMP_MOTION_MODE_EXACT);
+  gimp_tool_control_set_scroll_lock     (tool->control, TRUE);
+  gimp_tool_control_set_preserve        (tool->control, FALSE);
+  gimp_tool_control_set_dirty_mask      (tool->control,
+                                         GIMP_DIRTY_IMAGE           |
+                                         GIMP_DIRTY_DRAWABLE        |
+                                         GIMP_DIRTY_SELECTION       |
+                                         GIMP_DIRTY_ACTIVE_DRAWABLE);
+  gimp_tool_control_set_dirty_action    (tool->control,
+                                         GIMP_TOOL_ACTION_COMMIT);
+  gimp_tool_control_set_wants_click     (tool->control, TRUE);
+  gimp_tool_control_set_precision       (tool->control,
+                                         GIMP_CURSOR_PRECISION_SUBPIXEL);
+  gimp_tool_control_set_tool_cursor     (tool->control,
+                                         GIMP_TOOL_CURSOR_WARP);
+  gimp_tool_control_set_action_size     (tool->control,
+                                         "tools/tools-warp-effect-size-set");
+  gimp_tool_control_set_action_hardness (tool->control,
+                                         "tools/tools-warp-effect-hardness-set");
+
+  self->show_cursor = TRUE;
+  self->draw_brush  = TRUE;
+  self->snap_brush  = FALSE;
+}
+
+static void
+gimp_warp_tool_constructed (GObject *object)
+{
+  GimpWarpTool      *wt   = GIMP_WARP_TOOL (object);
+  GimpTool          *tool = GIMP_TOOL (object);
+  GimpDisplayConfig *display_config;
+
+  G_OBJECT_CLASS (parent_class)->constructed (object);
+
+  display_config = GIMP_DISPLAY_CONFIG (tool->tool_info->gimp->config);
+
+  wt->show_cursor = display_config->show_paint_tool_cursor;
+  wt->draw_brush  = display_config->show_brush_outline;
+  wt->snap_brush  = display_config->snap_brush_outline;
+
+  g_signal_connect_object (display_config, "notify::show-paint-tool-cursor",
+                           G_CALLBACK (gimp_warp_tool_cursor_notify),
+                           wt, 0);
+  g_signal_connect_object (display_config, "notify::show-brush-outline",
+                           G_CALLBACK (gimp_warp_tool_cursor_notify),
+                           wt, 0);
+  g_signal_connect_object (display_config, "notify::snap-brush-outline",
+                           G_CALLBACK (gimp_warp_tool_cursor_notify),
+                           wt, 0);
+}
+
+static void
+gimp_warp_tool_control (GimpTool       *tool,
+                        GimpToolAction  action,
+                        GimpDisplay    *display)
+{
+  GimpWarpTool *wt = GIMP_WARP_TOOL (tool);
+
+  switch (action)
+    {
+    case GIMP_TOOL_ACTION_PAUSE:
+    case GIMP_TOOL_ACTION_RESUME:
+      break;
+
+    case GIMP_TOOL_ACTION_HALT:
+      gimp_warp_tool_halt (wt);
+      break;
+
+    case GIMP_TOOL_ACTION_COMMIT:
+      gimp_warp_tool_commit (wt);
+      break;
+    }
+
+  GIMP_TOOL_CLASS (parent_class)->control (tool, action, display);
+}
+
+static void
+gimp_warp_tool_button_press (GimpTool            *tool,
+                             const GimpCoords    *coords,
+                             guint32              time,
+                             GdkModifierType      state,
+                             GimpButtonPressType  press_type,
+                             GimpDisplay         *display)
+{
+  GimpWarpTool    *wt      = GIMP_WARP_TOOL (tool);
+  GimpWarpOptions *options = GIMP_WARP_TOOL_GET_OPTIONS (wt);
+  GeglNode        *new_op;
+  gint             off_x, off_y;
+
+  if (tool->display && display != tool->display)
+    gimp_tool_control (tool, GIMP_TOOL_ACTION_HALT, tool->display);
+
+  if (! tool->display)
+    {
+      if (! gimp_warp_tool_start (wt, display))
+        return;
+    }
+
+  if (! gimp_warp_tool_can_stroke (wt, display, TRUE))
+    return;
+
+  wt->current_stroke = gegl_path_new ();
+
+  wt->last_pos.x = coords->x;
+  wt->last_pos.y = coords->y;
+
+  wt->total_dist = 0.0;
+
+  new_op = gegl_node_new_child (NULL,
+                                "operation", "gegl:warp",
+                                "behavior",  options->behavior,
+                                "size",      options->effect_size,
+                                "hardness",  options->effect_hardness / 100.0,
+                                "strength",  options->effect_strength,
+                                /* we implement spacing manually.
+                                 * anything > 1 will do.
+                                 */
+                                "spacing",   10.0,
+                                "stroke",    wt->current_stroke,
+                                NULL);
+
+  gimp_warp_tool_add_op (wt, new_op);
+  g_object_unref (new_op);
+
+  gimp_item_get_offset (GIMP_ITEM (tool->drawable), &off_x, &off_y);
+
+  gimp_warp_tool_stroke_append (wt,
+                                'M', wt->last_pos.x - off_x,
+                                     wt->last_pos.y - off_y);
+
+  gimp_warp_tool_start_stroke_timer (wt);
+
+  gimp_tool_control_activate (tool->control);
+}
+
+void
+gimp_warp_tool_button_release (GimpTool              *tool,
+                               const GimpCoords      *coords,
+                               guint32                time,
+                               GdkModifierType        state,
+                               GimpButtonReleaseType  release_type,
+                               GimpDisplay           *display)
+{
+  GimpWarpTool *wt = GIMP_WARP_TOOL (tool);
+
+  gimp_draw_tool_pause (GIMP_DRAW_TOOL (wt));
+
+  gimp_tool_control_halt (tool->control);
+
+  gimp_warp_tool_stop_stroke_timer (wt);
+
+#ifdef WARP_DEBUG
+  g_printerr ("%s\n", gegl_path_to_string (wt->current_stroke));
+#endif
+
+  g_clear_object (&wt->current_stroke);
+
+  if (release_type == GIMP_BUTTON_RELEASE_CANCEL)
+    {
+      gimp_warp_tool_undo (tool, display);
+
+      /*  the just undone stroke has no business on the redo stack  */
+      gimp_warp_tool_free_op (wt->redo_stack->data);
+      wt->redo_stack = g_list_remove_link (wt->redo_stack, wt->redo_stack);
+    }
+  else
+    {
+      if (wt->redo_stack)
+        {
+          /*  the redo stack becomes invalid by actually doing a stroke  */
+          g_list_free_full (wt->redo_stack,
+                            (GDestroyNotify) gimp_warp_tool_free_op);
+          wt->redo_stack = NULL;
+        }
+
+      gimp_tool_push_status (tool, tool->display,
+                             _("Press ENTER to commit the transform"));
+    }
+
+  gimp_draw_tool_resume (GIMP_DRAW_TOOL (tool));
+
+  /*  update the undo actions / menu items  */
+  gimp_image_flush (gimp_display_get_image (GIMP_TOOL (wt)->display));
+}
+
+static void
+gimp_warp_tool_motion (GimpTool         *tool,
+                       const GimpCoords *coords,
+                       guint32           time,
+                       GdkModifierType   state,
+                       GimpDisplay      *display)
+{
+  GimpWarpTool    *wt             = GIMP_WARP_TOOL (tool);
+  GimpWarpOptions *options        = GIMP_WARP_TOOL_GET_OPTIONS (wt);
+  GimpVector2      old_cursor_pos;
+  GimpVector2      delta;
+  gdouble          dist;
+  gdouble          step;
+  gboolean         stroke_changed = FALSE;
+
+  if (! wt->snap_brush)
+    gimp_draw_tool_pause (GIMP_DRAW_TOOL (wt));
+
+  old_cursor_pos = wt->cursor_pos;
+
+  wt->cursor_pos.x = coords->x;
+  wt->cursor_pos.y = coords->y;
+
+  gimp_vector2_sub (&delta, &wt->cursor_pos, &old_cursor_pos);
+  dist = gimp_vector2_length (&delta);
+
+  step = options->effect_size * options->stroke_spacing / 100.0;
+
+  while (wt->total_dist + dist >= step)
+    {
+      gdouble diff = step - wt->total_dist;
+
+      gimp_vector2_mul (&delta, diff / dist);
+      gimp_vector2_add (&old_cursor_pos, &old_cursor_pos, &delta);
+
+      gimp_vector2_sub (&delta, &wt->cursor_pos, &old_cursor_pos);
+      dist -= diff;
+
+      wt->last_pos   = old_cursor_pos;
+      wt->total_dist = 0.0;
+
+      if (options->stroke_during_motion)
+        {
+          gint off_x, off_y;
+
+          if (! stroke_changed)
+            {
+              stroke_changed = TRUE;
+
+              gimp_draw_tool_pause (GIMP_DRAW_TOOL (tool));
+            }
+
+          gimp_item_get_offset (GIMP_ITEM (tool->drawable), &off_x, &off_y);
+
+          gimp_warp_tool_stroke_append (wt,
+                                        'L', wt->last_pos.x - off_x,
+                                             wt->last_pos.y - off_y);
+        }
+    }
+
+  wt->total_dist += dist;
+
+  if (stroke_changed)
+    {
+      gimp_warp_tool_start_stroke_timer (wt);
+
+      gimp_draw_tool_resume (GIMP_DRAW_TOOL (tool));
+    }
+
+  if (! wt->snap_brush)
+    gimp_draw_tool_resume (GIMP_DRAW_TOOL (wt));
+}
+
+static gboolean
+gimp_warp_tool_key_press (GimpTool    *tool,
+                          GdkEventKey *kevent,
+                          GimpDisplay *display)
+{
+  switch (kevent->keyval)
+    {
+    case GDK_KEY_BackSpace:
+      return TRUE;
+
+    case GDK_KEY_Return:
+    case GDK_KEY_KP_Enter:
+    case GDK_KEY_ISO_Enter:
+      gimp_tool_control (tool, GIMP_TOOL_ACTION_COMMIT, display);
+      return TRUE;
+
+    case GDK_KEY_Escape:
+      gimp_tool_control (tool, GIMP_TOOL_ACTION_HALT, display);
+      return TRUE;
+
+    default:
+      break;
+    }
+
+  return FALSE;
+}
+
+static void
+gimp_warp_tool_oper_update (GimpTool         *tool,
+                            const GimpCoords *coords,
+                            GdkModifierType   state,
+                            gboolean          proximity,
+                            GimpDisplay      *display)
+{
+  GimpWarpTool *wt        = GIMP_WARP_TOOL (tool);
+  GimpDrawTool *draw_tool = GIMP_DRAW_TOOL (tool);
+
+  if (proximity)
+    {
+      gimp_draw_tool_pause (draw_tool);
+
+      if (! tool->display || display == tool->display)
+        {
+          wt->cursor_pos.x = coords->x;
+          wt->cursor_pos.y = coords->y;
+
+          wt->last_pos = wt->cursor_pos;
+        }
+
+      if (! gimp_draw_tool_is_active (draw_tool))
+        gimp_draw_tool_start (draw_tool, display);
+
+      gimp_draw_tool_resume (draw_tool);
+    }
+  else if (gimp_draw_tool_is_active (draw_tool))
+    {
+      gimp_draw_tool_stop (draw_tool);
+    }
+}
+
+static void
+gimp_warp_tool_cursor_update (GimpTool         *tool,
+                              const GimpCoords *coords,
+                              GdkModifierType   state,
+                              GimpDisplay      *display)
+{
+  GimpWarpTool       *wt       = GIMP_WARP_TOOL (tool);
+  GimpWarpOptions    *options  = GIMP_WARP_TOOL_GET_OPTIONS (tool);
+  GimpCursorModifier  modifier = GIMP_CURSOR_MODIFIER_NONE;
+
+  if (! gimp_warp_tool_can_stroke (wt, display, FALSE))
+    {
+      modifier = GIMP_CURSOR_MODIFIER_BAD;
+    }
+  else if (display == tool->display)
+    {
+#if 0
+      /* FIXME have better cursors  */
+
+      switch (options->behavior)
+        {
+        case GIMP_WARP_BEHAVIOR_MOVE:
+        case GIMP_WARP_BEHAVIOR_GROW:
+        case GIMP_WARP_BEHAVIOR_SHRINK:
+        case GIMP_WARP_BEHAVIOR_SWIRL_CW:
+        case GIMP_WARP_BEHAVIOR_SWIRL_CCW:
+        case GIMP_WARP_BEHAVIOR_ERASE:
+        case GIMP_WARP_BEHAVIOR_SMOOTH:
+          modifier = GIMP_CURSOR_MODIFIER_MOVE;
+          break;
+        }
+#else
+      (void) options;
+#endif
+    }
+
+  if (! wt->show_cursor && modifier != GIMP_CURSOR_MODIFIER_BAD)
+    {
+      gimp_tool_set_cursor (tool, display,
+                            GIMP_CURSOR_NONE,
+                            GIMP_TOOL_CURSOR_NONE,
+                            GIMP_CURSOR_MODIFIER_NONE);
+      return;
+    }
+
+  gimp_tool_control_set_cursor_modifier (tool->control, modifier);
+
+  GIMP_TOOL_CLASS (parent_class)->cursor_update (tool, coords, state, display);
+}
+
+const gchar *
+gimp_warp_tool_can_undo (GimpTool    *tool,
+                         GimpDisplay *display)
+{
+  GimpWarpTool *wt = GIMP_WARP_TOOL (tool);
+  GeglNode     *to_delete;
+  const gchar  *type;
+
+  if (! wt->render_node)
+    return NULL;
+
+  to_delete = gegl_node_get_producer (wt->render_node, "aux", NULL);
+  type = gegl_node_get_operation (to_delete);
+
+  if (strcmp (type, "gegl:warp"))
+    return NULL;
+
+  return _("Warp Tool Stroke");
+}
+
+const gchar *
+gimp_warp_tool_can_redo (GimpTool    *tool,
+                         GimpDisplay *display)
+{
+  GimpWarpTool *wt = GIMP_WARP_TOOL (tool);
+
+  if (! wt->render_node || ! wt->redo_stack)
+    return NULL;
+
+  return _("Warp Tool Stroke");
+}
+
+static gboolean
+gimp_warp_tool_undo (GimpTool    *tool,
+                     GimpDisplay *display)
+{
+  GimpWarpTool *wt = GIMP_WARP_TOOL (tool);
+  GeglNode     *to_delete;
+  GeglNode     *prev_node;
+
+  to_delete = gegl_node_get_producer (wt->render_node, "aux", NULL);
+
+  wt->redo_stack = g_list_prepend (wt->redo_stack, to_delete);
+
+  /* we connect render_node to the previous node, but keep the current node
+   * in the graph, connected to the previous node as well, so that it doesn't
+   * get invalidated and maintains its cache.  this way, redoing it doesn't
+   * require reprocessing.
+   */
+  prev_node = gegl_node_get_producer (to_delete, "input", NULL);
+
+  gegl_node_connect_to (prev_node,       "output",
+                        wt->render_node, "aux");
+
+  gimp_warp_tool_update_bounds (wt);
+  gimp_warp_tool_update_stroke (wt, to_delete);
+
+  return TRUE;
+}
+
+static gboolean
+gimp_warp_tool_redo (GimpTool    *tool,
+                     GimpDisplay *display)
+{
+  GimpWarpTool *wt = GIMP_WARP_TOOL (tool);
+  GeglNode     *to_add;
+
+  to_add = wt->redo_stack->data;
+
+  gegl_node_connect_to (to_add,          "output",
+                        wt->render_node, "aux");
+
+  wt->redo_stack = g_list_remove_link (wt->redo_stack, wt->redo_stack);
+
+  gimp_warp_tool_update_bounds (wt);
+  gimp_warp_tool_update_stroke (wt, to_add);
+
+  return TRUE;
+}
+
+static void
+gimp_warp_tool_options_notify (GimpTool         *tool,
+                               GimpToolOptions  *options,
+                               const GParamSpec *pspec)
+{
+  GimpWarpTool    *wt         = GIMP_WARP_TOOL (tool);
+  GimpWarpOptions *wt_options = GIMP_WARP_OPTIONS (options);
+
+  GIMP_TOOL_CLASS (parent_class)->options_notify (tool, options, pspec);
+
+  if (! strcmp (pspec->name, "effect-size"))
+    {
+      gimp_draw_tool_pause (GIMP_DRAW_TOOL (tool));
+      gimp_draw_tool_resume (GIMP_DRAW_TOOL (tool));
+    }
+  else if (! strcmp (pspec->name, "interpolation"))
+    {
+      gimp_warp_tool_set_sampler (wt, /* commit = */ FALSE);
+    }
+  else if (! strcmp (pspec->name, "abyss-policy"))
+    {
+      if (wt->render_node)
+        {
+          gegl_node_set (wt->render_node,
+                         "abyss-policy", wt_options->abyss_policy,
+                         NULL);
+
+          gimp_warp_tool_update_stroke (wt, NULL);
+        }
+    }
+  else if (! strcmp (pspec->name, "high-quality-preview"))
+    {
+      gimp_warp_tool_set_sampler (wt, /* commit = */ FALSE);
+    }
+}
+
+static void
+gimp_warp_tool_draw (GimpDrawTool *draw_tool)
+{
+  GimpWarpTool    *wt      = GIMP_WARP_TOOL (draw_tool);
+  GimpWarpOptions *options = GIMP_WARP_TOOL_GET_OPTIONS (wt);
+  gdouble          x, y;
+
+  if (wt->snap_brush)
+    {
+      x = wt->last_pos.x;
+      y = wt->last_pos.y;
+    }
+  else
+    {
+      x = wt->cursor_pos.x;
+      y = wt->cursor_pos.y;
+    }
+
+  if (wt->draw_brush)
+    {
+      gimp_draw_tool_add_arc (draw_tool,
+                              FALSE,
+                              x - options->effect_size * 0.5,
+                              y - options->effect_size * 0.5,
+                              options->effect_size,
+                              options->effect_size,
+                              0.0, 2.0 * G_PI);
+    }
+  else if (! wt->show_cursor)
+    {
+      /*  don't leave the user without any indication and draw
+       *  a fallback crosshair
+       */
+      gimp_draw_tool_add_handle (draw_tool,
+                                 GIMP_HANDLE_CROSSHAIR,
+                                 x, y,
+                                 GIMP_TOOL_HANDLE_SIZE_CROSSHAIR,
+                                 GIMP_TOOL_HANDLE_SIZE_CROSSHAIR,
+                                 GIMP_HANDLE_ANCHOR_CENTER);
+    }
+}
+
+static void
+gimp_warp_tool_cursor_notify (GimpDisplayConfig *config,
+                              GParamSpec        *pspec,
+                              GimpWarpTool      *wt)
+{
+  gimp_draw_tool_pause (GIMP_DRAW_TOOL (wt));
+
+  wt->show_cursor = config->show_paint_tool_cursor;
+  wt->draw_brush  = config->show_brush_outline;
+  wt->snap_brush  = config->snap_brush_outline;
+
+  gimp_draw_tool_resume (GIMP_DRAW_TOOL (wt));
+}
+
+static gboolean
+gimp_warp_tool_can_stroke (GimpWarpTool *wt,
+                           GimpDisplay  *display,
+                           gboolean      show_message)
+{
+  GimpTool        *tool     = GIMP_TOOL (wt);
+  GimpWarpOptions *options  = GIMP_WARP_TOOL_GET_OPTIONS (wt);
+  GimpGuiConfig   *config   = GIMP_GUI_CONFIG (display->gimp->config);
+  GimpImage       *image    = gimp_display_get_image (display);
+  GimpDrawable    *drawable = gimp_image_get_active_drawable (image);
+
+  if (gimp_viewable_get_children (GIMP_VIEWABLE (drawable)))
+    {
+      if (show_message)
+        {
+          gimp_tool_message_literal (tool, display,
+                                     _("Cannot warp layer groups."));
+        }
+
+      return FALSE;
+    }
+
+  if (gimp_item_is_content_locked (GIMP_ITEM (drawable)))
+    {
+      if (show_message)
+        {
+          gimp_tool_message_literal (tool, display,
+                                     _("The active layer's pixels are locked."));
+
+          gimp_tools_blink_lock_box (display->gimp, GIMP_ITEM (drawable));
+        }
+
+      return FALSE;
+    }
+
+  if (! gimp_item_is_visible (GIMP_ITEM (drawable)) &&
+      ! config->edit_non_visible)
+    {
+      if (show_message)
+        {
+          gimp_tool_message_literal (tool, display,
+                                     _("The active layer is not visible."));
+        }
+
+      return FALSE;
+    }
+
+  if (! options->stroke_during_motion &&
+      ! options->stroke_periodically)
+    {
+      if (show_message)
+        {
+          gimp_tool_message_literal (tool, display,
+                                     _("No stroke events selected."));
+
+          gimp_widget_blink (options->stroke_frame);
+        }
+
+      return FALSE;
+    }
+
+  if (! wt->filter || ! gimp_tool_can_undo (tool, display))
+    {
+      const gchar *message = NULL;
+
+      switch (options->behavior)
+        {
+        case GIMP_WARP_BEHAVIOR_MOVE:
+        case GIMP_WARP_BEHAVIOR_GROW:
+        case GIMP_WARP_BEHAVIOR_SHRINK:
+        case GIMP_WARP_BEHAVIOR_SWIRL_CW:
+        case GIMP_WARP_BEHAVIOR_SWIRL_CCW:
+          break;
+
+        case GIMP_WARP_BEHAVIOR_ERASE:
+          message = _("No warp to erase.");
+          break;
+
+        case GIMP_WARP_BEHAVIOR_SMOOTH:
+          message = _("No warp to smooth.");
+          break;
+        }
+
+      if (message)
+        {
+          if (show_message)
+            {
+              gimp_tool_message_literal (tool, display, message);
+
+              gimp_widget_blink (options->behavior_combo);
+            }
+
+          return FALSE;
+        }
+    }
+
+  return TRUE;
+}
+
+static gboolean
+gimp_warp_tool_start (GimpWarpTool *wt,
+                      GimpDisplay  *display)
+{
+  GimpTool        *tool     = GIMP_TOOL (wt);
+  GimpWarpOptions *options  = GIMP_WARP_TOOL_GET_OPTIONS (wt);
+  GimpImage       *image    = gimp_display_get_image (display);
+  GimpDrawable    *drawable = gimp_image_get_active_drawable (image);
+  const Babl      *format;
+  GeglRectangle    bbox;
+
+  if (! gimp_warp_tool_can_stroke (wt, display, TRUE))
+    return FALSE;
+
+  tool->display  = display;
+  tool->drawable = drawable;
+
+  /* Create the coords buffer, with the size of the selection */
+  format = babl_format_n (babl_type ("float"), 2);
+
+  gimp_item_mask_intersect (GIMP_ITEM (drawable), &bbox.x, &bbox.y,
+                            &bbox.width, &bbox.height);
+
+#ifdef WARP_DEBUG
+  g_printerr ("Initialize coordinate buffer (%d,%d) at %d,%d\n",
+              bbox.width, bbox.height, bbox.x, bbox.y);
+#endif
+
+  wt->coords_buffer = gegl_buffer_new (&bbox, format);
+
+  gimp_warp_tool_create_filter (wt, drawable);
+
+  if (! gimp_draw_tool_is_active (GIMP_DRAW_TOOL (wt)))
+    gimp_draw_tool_start (GIMP_DRAW_TOOL (wt), display);
+
+  if (options->animate_button)
+    {
+      g_signal_connect_swapped (options->animate_button, "clicked",
+                                G_CALLBACK (gimp_warp_tool_animate),
+                                wt);
+
+      gtk_widget_set_sensitive (options->animate_button, TRUE);
+    }
+
+  return TRUE;
+}
+
+static void
+gimp_warp_tool_halt (GimpWarpTool *wt)
+{
+  GimpTool        *tool    = GIMP_TOOL (wt);
+  GimpWarpOptions *options = GIMP_WARP_TOOL_GET_OPTIONS (wt);
+
+  g_clear_object (&wt->coords_buffer);
+
+  g_clear_object (&wt->graph);
+  wt->render_node = NULL;
+
+  if (wt->filter)
+    {
+      gimp_drawable_filter_abort (wt->filter);
+      g_clear_object (&wt->filter);
+
+      gimp_image_flush (gimp_display_get_image (tool->display));
+    }
+
+  if (wt->redo_stack)
+    {
+      g_list_free (wt->redo_stack);
+      wt->redo_stack = NULL;
+    }
+
+  tool->display  = NULL;
+  tool->drawable = NULL;
+
+  if (gimp_draw_tool_is_active (GIMP_DRAW_TOOL (wt)))
+    gimp_draw_tool_stop (GIMP_DRAW_TOOL (wt));
+
+  if (options->animate_button)
+    {
+      gtk_widget_set_sensitive (options->animate_button, FALSE);
+
+      g_signal_handlers_disconnect_by_func (options->animate_button,
+                                            gimp_warp_tool_animate,
+                                            wt);
+    }
+}
+
+static void
+gimp_warp_tool_commit (GimpWarpTool *wt)
+{
+  GimpTool *tool = GIMP_TOOL (wt);
+
+  /* don't commit a nop */
+  if (tool->display && gimp_tool_can_undo (tool, tool->display))
+    {
+      gimp_tool_control_push_preserve (tool->control, TRUE);
+
+      gimp_warp_tool_set_sampler (wt, /* commit = */ TRUE);
+
+      gimp_drawable_filter_commit (wt->filter, GIMP_PROGRESS (tool), FALSE);
+      g_clear_object (&wt->filter);
+
+      gimp_tool_control_pop_preserve (tool->control);
+
+      gimp_image_flush (gimp_display_get_image (tool->display));
+    }
+}
+
+static void
+gimp_warp_tool_start_stroke_timer (GimpWarpTool *wt)
+{
+  GimpWarpOptions *options = GIMP_WARP_TOOL_GET_OPTIONS (wt);
+
+  gimp_warp_tool_stop_stroke_timer (wt);
+
+  if (options->stroke_periodically                    &&
+      options->stroke_periodically_rate > 0.0         &&
+      ! (options->behavior == GIMP_WARP_BEHAVIOR_MOVE &&
+         options->stroke_during_motion))
+    {
+      gdouble fps;
+
+      fps = STROKE_TIMER_MAX_FPS * options->stroke_periodically_rate / 100.0;
+
+      wt->stroke_timer = g_timeout_add (1000.0 / fps,
+                                        (GSourceFunc) gimp_warp_tool_stroke_timer,
+                                        wt);
+    }
+}
+
+static void
+gimp_warp_tool_stop_stroke_timer (GimpWarpTool *wt)
+{
+  if (wt->stroke_timer)
+    g_source_remove (wt->stroke_timer);
+
+  wt->stroke_timer = 0;
+}
+
+static gboolean
+gimp_warp_tool_stroke_timer (GimpWarpTool *wt)
+{
+  GimpTool *tool = GIMP_TOOL (wt);
+  gint      off_x, off_y;
+
+  gimp_item_get_offset (GIMP_ITEM (tool->drawable), &off_x, &off_y);
+
+  gimp_warp_tool_stroke_append (wt,
+                                'L', wt->last_pos.x - off_x,
+                                     wt->last_pos.y - off_y);
+
+  return TRUE;
+}
+
+static void
+gimp_warp_tool_create_graph (GimpWarpTool *wt)
+{
+  GimpWarpOptions *options = GIMP_WARP_TOOL_GET_OPTIONS (wt);
+  GeglNode        *graph;           /* Wrapper to be returned */
+  GeglNode        *input, *output;  /* Proxy nodes */
+  GeglNode        *coords, *render; /* Render nodes */
+
+  /* render_node is not supposed to be recreated */
+  g_return_if_fail (wt->graph == NULL);
+
+  graph = gegl_node_new ();
+
+  input  = gegl_node_get_input_proxy  (graph, "input");
+  output = gegl_node_get_output_proxy (graph, "output");
+
+  coords = gegl_node_new_child (graph,
+                               "operation", "gegl:buffer-source",
+                               "buffer",    wt->coords_buffer,
+                               NULL);
+
+  render = gegl_node_new_child (graph,
+                                "operation",    "gegl:map-relative",
+                                "abyss-policy", options->abyss_policy,
+                                NULL);
+
+  gegl_node_connect_to (input,  "output",
+                        render, "input");
+
+  gegl_node_connect_to (coords, "output",
+                        render, "aux");
+
+  gegl_node_connect_to (render, "output",
+                        output, "input");
+
+  wt->graph       = graph;
+  wt->render_node = render;
+}
+
+static void
+gimp_warp_tool_create_filter (GimpWarpTool *wt,
+                              GimpDrawable *drawable)
+{
+  if (! wt->graph)
+    gimp_warp_tool_create_graph (wt);
+
+  gimp_warp_tool_set_sampler (wt, /* commit = */ FALSE);
+
+  wt->filter = gimp_drawable_filter_new (drawable,
+                                         _("Warp transform"),
+                                         wt->graph,
+                                         GIMP_ICON_TOOL_WARP);
+
+  gimp_drawable_filter_set_region (wt->filter, GIMP_FILTER_REGION_DRAWABLE);
+
+#if 0
+  g_object_set (wt->filter, "gegl-caching", TRUE, NULL);
+#endif
+
+  g_signal_connect (wt->filter, "flush",
+                    G_CALLBACK (gimp_warp_tool_filter_flush),
+                    wt);
+}
+
+static void
+gimp_warp_tool_set_sampler (GimpWarpTool *wt,
+                            gboolean      commit)
+{
+  GimpWarpOptions *options = GIMP_WARP_TOOL_GET_OPTIONS (wt);
+  GeglSamplerType  sampler;
+  GeglSamplerType  old_sampler;
+
+  if (! wt->render_node)
+    return;
+
+  if (commit || options->high_quality_preview)
+    sampler = (GeglSamplerType) options->interpolation;
+  else
+    sampler = PREVIEW_SAMPLER;
+
+  gegl_node_get (wt->render_node,
+                 "sampler-type", &old_sampler,
+                 NULL);
+
+  if (sampler != old_sampler)
+    {
+      gegl_node_set (wt->render_node,
+                     "sampler-type", sampler,
+                     NULL);
+
+      gimp_warp_tool_update_bounds (wt);
+      gimp_warp_tool_update_stroke (wt, NULL);
+    }
+}
+
+static GeglRectangle
+gimp_warp_tool_get_stroke_bounds (GeglNode *node)
+{
+  GeglRectangle  bbox = {0, 0, 0, 0};
+  GeglPath      *stroke;
+  gdouble        size;
+
+  gegl_node_get (node,
+                 "stroke", &stroke,
+                 "size",   &size,
+                 NULL);
+
+  if (stroke)
+    {
+      gdouble        min_x;
+      gdouble        max_x;
+      gdouble        min_y;
+      gdouble        max_y;
+
+      gegl_path_get_bounds (stroke, &min_x, &max_x, &min_y, &max_y);
+      g_object_unref (stroke);
+
+      bbox.x      = floor (min_x - size * 0.5);
+      bbox.y      = floor (min_y - size * 0.5);
+      bbox.width  = ceil (max_x + size * 0.5) - bbox.x;
+      bbox.height = ceil (max_y + size * 0.5) - bbox.y;
+    }
+
+  return bbox;
+}
+
+static GeglRectangle
+gimp_warp_tool_get_node_bounds (GeglNode *node)
+{
+  GeglRectangle *bounds;
+
+  if (! node || strcmp (gegl_node_get_operation (node), "gegl:warp"))
+    return *GEGL_RECTANGLE (0, 0, 0, 0);
+
+  bounds = g_object_get_data (G_OBJECT (node), "gimp-warp-tool-bounds");
+
+  if (! bounds)
+    {
+      GeglNode      *input_node;
+      GeglRectangle  input_bounds;
+      GeglRectangle  stroke_bounds;
+
+      input_node   = gegl_node_get_producer (node, "input", NULL);
+      input_bounds = gimp_warp_tool_get_node_bounds (input_node);
+
+      stroke_bounds = gimp_warp_tool_get_stroke_bounds (node);
+
+      gegl_rectangle_bounding_box (&input_bounds,
+                                   &input_bounds, &stroke_bounds);
+
+      bounds = gegl_rectangle_dup (&input_bounds);
+
+      g_object_set_data_full (G_OBJECT (node), "gimp-warp-tool-bounds",
+                              bounds, g_free);
+    }
+
+  return *bounds;
+}
+
+static void
+gimp_warp_tool_clear_node_bounds (GeglNode *node)
+{
+  if (node && ! strcmp (gegl_node_get_operation (node), "gegl:warp"))
+    g_object_set_data (G_OBJECT (node), "gimp-warp-tool-bounds", NULL);
+}
+
+static GeglRectangle
+gimp_warp_tool_get_invalidated_by_change (GimpWarpTool        *wt,
+                                          const GeglRectangle *area)
+{
+  GeglRectangle result = *area;
+
+  if (! wt->filter)
+    return result;
+
+  if (wt->render_node)
+    {
+      GeglOperation *operation = gegl_node_get_gegl_operation (wt->render_node);
+
+      result = gegl_operation_get_invalidated_by_change (operation,
+                                                         "aux", area);
+    }
+
+  return result;
+}
+
+static void
+gimp_warp_tool_update_bounds (GimpWarpTool *wt)
+{
+  GeglRectangle bounds = {0, 0, 0, 0};
+
+  if (! wt->filter)
+    return;
+
+  if (wt->render_node)
+    {
+      GeglNode *node = gegl_node_get_producer (wt->render_node, "aux", NULL);
+
+      bounds = gimp_warp_tool_get_node_bounds (node);
+
+      bounds = gimp_warp_tool_get_invalidated_by_change (wt, &bounds);
+    }
+
+  gimp_drawable_filter_set_crop (wt->filter, &bounds, FALSE);
+}
+
+static void
+gimp_warp_tool_update_area (GimpWarpTool        *wt,
+                            const GeglRectangle *area,
+                            gboolean             synchronous)
+{
+  GeglRectangle rect;
+
+  if (! wt->filter)
+    return;
+
+  rect = gimp_warp_tool_get_invalidated_by_change (wt, area);
+
+  if (synchronous)
+    {
+      GimpTool  *tool  = GIMP_TOOL (wt);
+      GimpImage *image = gimp_display_get_image (tool->display);
+
+      g_signal_handlers_block_by_func (wt->filter,
+                                       gimp_warp_tool_filter_flush,
+                                       wt);
+
+      gimp_drawable_filter_apply (wt->filter, &rect);
+
+      gimp_projection_flush_now (gimp_image_get_projection (image), TRUE);
+      gimp_display_flush_now (tool->display);
+
+      g_signal_handlers_unblock_by_func (wt->filter,
+                                         gimp_warp_tool_filter_flush,
+                                         wt);
+    }
+  else
+    {
+      gimp_drawable_filter_apply (wt->filter, &rect);
+    }
+}
+
+static void
+gimp_warp_tool_update_stroke (GimpWarpTool *wt,
+                              GeglNode     *node)
+{
+  GeglRectangle bounds = {0, 0, 0, 0};
+
+  if (! wt->filter)
+    return;
+
+  if (node)
+    {
+      /* update just this stroke */
+      bounds = gimp_warp_tool_get_stroke_bounds (node);
+    }
+  else if (wt->render_node)
+    {
+      node = gegl_node_get_producer (wt->render_node, "aux", NULL);
+
+      bounds = gimp_warp_tool_get_node_bounds (node);
+    }
+
+  if (! gegl_rectangle_is_empty (&bounds))
+    {
+#ifdef WARP_DEBUG
+  g_printerr ("update stroke: (%d,%d), %dx%d\n",
+              bounds.x, bounds.y,
+              bounds.width, bounds.height);
+#endif
+
+      gimp_warp_tool_update_area (wt, &bounds, FALSE);
+    }
+}
+
+static void
+gimp_warp_tool_stroke_append (GimpWarpTool *wt,
+                              gchar         type,
+                              gdouble       x,
+                              gdouble       y)
+{
+  GimpWarpOptions *options = GIMP_WARP_TOOL_GET_OPTIONS (wt);
+  GeglRectangle    area;
+
+  if (! wt->filter)
+    return;
+
+  gegl_path_append (wt->current_stroke, type, x, y);
+
+  area.x      = floor (x - options->effect_size * 0.5);
+  area.y      = floor (y - options->effect_size * 0.5);
+  area.width  = ceil  (x + options->effect_size * 0.5) - area.x;
+  area.height = ceil  (y + options->effect_size * 0.5) - area.y;
+
+#ifdef WARP_DEBUG
+  g_printerr ("update rect: (%d,%d), %dx%d\n",
+              area.x, area.y,
+              area.width, area.height);
+#endif
+
+  if (wt->render_node)
+    {
+      GeglNode *node = gegl_node_get_producer (wt->render_node, "aux", NULL);
+
+      gimp_warp_tool_clear_node_bounds (node);
+
+      gimp_warp_tool_update_bounds (wt);
+    }
+
+  gimp_warp_tool_update_area (wt, &area, options->real_time_preview);
+}
+
+static void
+gimp_warp_tool_filter_flush (GimpDrawableFilter *filter,
+                             GimpTool           *tool)
+{
+  GimpImage *image = gimp_display_get_image (tool->display);
+
+  gimp_projection_flush (gimp_image_get_projection (image));
+}
+
+static void
+gimp_warp_tool_add_op (GimpWarpTool *wt,
+                       GeglNode     *op)
+{
+  GeglNode *last_op;
+
+  g_return_if_fail (GEGL_IS_NODE (wt->render_node));
+
+  gegl_node_add_child (wt->graph, op);
+
+  last_op = gegl_node_get_producer (wt->render_node, "aux", NULL);
+
+  gegl_node_disconnect (wt->render_node, "aux");
+  gegl_node_connect_to (last_op,         "output",
+                        op    ,          "input");
+  gegl_node_connect_to (op,              "output",
+                        wt->render_node, "aux");
+}
+
+static void
+gimp_warp_tool_remove_op (GimpWarpTool *wt,
+                          GeglNode     *op)
+{
+  GeglNode *previous;
+
+  g_return_if_fail (GEGL_IS_NODE (wt->render_node));
+
+  previous = gegl_node_get_producer (op, "input", NULL);
+
+  gegl_node_disconnect (op,              "input");
+  gegl_node_connect_to (previous,        "output",
+                        wt->render_node, "aux");
+
+  gegl_node_remove_child (wt->graph, op);
+}
+
+static void
+gimp_warp_tool_free_op (GeglNode *op)
+{
+  GeglNode *parent;
+
+  parent = gegl_node_get_parent (op);
+
+  gimp_assert (parent != NULL);
+
+  gegl_node_remove_child (parent, op);
+}
+
+static void
+gimp_warp_tool_animate (GimpWarpTool *wt)
+{
+  GimpTool        *tool    = GIMP_TOOL (wt);
+  GimpWarpOptions *options = GIMP_WARP_TOOL_GET_OPTIONS (wt);
+  GimpImage       *orig_image;
+  GimpImage       *image;
+  GimpLayer       *layer;
+  GimpLayer       *first_layer;
+  GeglNode        *scale_node;
+  GimpProgress    *progress;
+  GtkWidget       *widget;
+  gint             i;
+
+  if (! gimp_warp_tool_can_undo (tool, tool->display))
+    {
+      gimp_tool_message_literal (tool, tool->display,
+                                 _("Please add some warp strokes first."));
+      return;
+    }
+
+  /*  get rid of the image map so we can use wt->graph  */
+  if (wt->filter)
+    {
+      gimp_drawable_filter_abort (wt->filter);
+      g_clear_object (&wt->filter);
+    }
+
+  gimp_warp_tool_set_sampler (wt, /* commit = */ TRUE);
+
+  gimp_progress_start (GIMP_PROGRESS (tool), FALSE,
+                       _("Rendering Frame %d"), 1);
+
+  orig_image = gimp_item_get_image (GIMP_ITEM (tool->drawable));
+
+  image = gimp_create_image (orig_image->gimp,
+                             gimp_item_get_width  (GIMP_ITEM (tool->drawable)),
+                             gimp_item_get_height (GIMP_ITEM (tool->drawable)),
+                             gimp_drawable_get_base_type (tool->drawable),
+                             gimp_drawable_get_precision (tool->drawable),
+                             TRUE);
+
+  /*  the first frame is always the unwarped image  */
+  layer = GIMP_LAYER (gimp_item_convert (GIMP_ITEM (tool->drawable), image,
+                                         GIMP_TYPE_LAYER));
+  gimp_object_take_name (GIMP_OBJECT (layer),
+                         g_strdup_printf (_("Frame %d"), 1));
+
+  gimp_item_set_offset (GIMP_ITEM (layer), 0, 0);
+  gimp_item_set_visible (GIMP_ITEM (layer), TRUE, FALSE);
+  gimp_layer_set_mode (layer, gimp_image_get_default_new_layer_mode (image),
+                       FALSE);
+  gimp_layer_set_opacity (layer, GIMP_OPACITY_OPAQUE, FALSE);
+  gimp_image_add_layer (image, layer, NULL, 0, FALSE);
+
+  first_layer = layer;
+
+  scale_node = gegl_node_new_child (NULL,
+                                    "operation",    "gimp:scalar-multiply",
+                                    "n-components", 2,
+                                    NULL);
+  gimp_warp_tool_add_op (wt, scale_node);
+
+  progress = gimp_sub_progress_new (GIMP_PROGRESS (tool));
+
+  for (i = 1; i < options->n_animation_frames; i++)
+    {
+      gimp_progress_set_text (GIMP_PROGRESS (tool),
+                              _("Rendering Frame %d"), i + 1);
+
+      gimp_sub_progress_set_step (GIMP_SUB_PROGRESS (progress),
+                                  i, options->n_animation_frames);
+
+      layer = GIMP_LAYER (gimp_item_duplicate (GIMP_ITEM (first_layer),
+                                               GIMP_TYPE_LAYER));
+      gimp_object_take_name (GIMP_OBJECT (layer),
+                             g_strdup_printf (_("Frame %d"), i + 1));
+
+      gegl_node_set (scale_node,
+                     "factor", (gdouble) i /
+                               (gdouble) (options->n_animation_frames - 1),
+                     NULL);
+
+      gimp_gegl_apply_operation (gimp_drawable_get_buffer (GIMP_DRAWABLE (first_layer)),
+                                 progress,
+                                 _("Frame"),
+                                 wt->graph,
+                                 gimp_drawable_get_buffer (GIMP_DRAWABLE (layer)),
+                                 NULL, FALSE);
+
+      gimp_image_add_layer (image, layer, NULL, 0, FALSE);
+    }
+
+  g_object_unref (progress);
+
+  gimp_warp_tool_remove_op (wt, scale_node);
+
+  gimp_progress_end (GIMP_PROGRESS (tool));
+
+  /*  recreate the image map  */
+  gimp_warp_tool_create_filter (wt, tool->drawable);
+  gimp_warp_tool_update_stroke (wt, NULL);
+
+  widget = GTK_WIDGET (gimp_display_get_shell (tool->display));
+  gimp_create_display (orig_image->gimp, image, GIMP_UNIT_PIXEL, 1.0,
+                       G_OBJECT (gtk_widget_get_screen (widget)),
+                       gimp_widget_get_monitor (widget));
+  g_object_unref (image);
+}