[gimp] app: update the display in a "changed" handler of the warp stroke

[Michael Natterer <mitch src gnome org>]

commit b601018e33eb3a8d80a37e246ccac685795ecbc0
Author: Michael Natterer <mitch gimp org>
Date:   Wed May 22 22:43:32 2013 +0200

    app: update the display in a "changed" handler of the warp stroke
    
    and get the update extents from the signal's "roi" parameter. Should
    be more correct but produces more artifacts for me. Either this patch
    is broken, or (more likely) this triggers a bug.

 app/tools/gimpwarptool.c |   79 ++++++++++++++++++++--------------------------
 app/tools/gimpwarptool.h |    1 -
 2 files changed, 34 insertions(+), 46 deletions(-)
---
diff --git a/app/tools/gimpwarptool.c b/app/tools/gimpwarptool.c
index bc73526..f2f834b 100644
--- a/app/tools/gimpwarptool.c
+++ b/app/tools/gimpwarptool.c
@@ -88,12 +88,14 @@ static void       gimp_warp_tool_start              (GimpWarpTool          *wt,
                                                      GimpDisplay           *display);
 static void       gimp_warp_tool_halt               (GimpWarpTool          *wt);
 
-static gboolean   gimp_warp_tool_stroke_timer       (gpointer               data);
+static gboolean   gimp_warp_tool_stroke_timer       (GimpWarpTool          *wt);
 
 static void       gimp_warp_tool_create_graph       (GimpWarpTool          *wt);
 static void       gimp_warp_tool_create_image_map   (GimpWarpTool          *wt,
                                                      GimpDrawable          *drawable);
-static void       gimp_warp_tool_image_map_update   (GimpWarpTool          *wt);
+static void       gimp_warp_tool_stroke_changed     (GeglPath              *stroke,
+                                                     const GeglRectangle   *roi,
+                                                     GimpWarpTool          *wt);
 static void       gimp_warp_tool_image_map_flush    (GimpImageMap          *image_map,
                                                      GimpTool              *tool);
 static void       gimp_warp_tool_add_op             (GimpWarpTool          *wt);
@@ -185,6 +187,7 @@ gimp_warp_tool_button_press (GimpTool            *tool,
                              GimpDisplay         *display)
 {
   GimpWarpTool *wt = GIMP_WARP_TOOL (tool);
+  gint          off_x, off_y;
 
   if (tool->display && display != tool->display)
     gimp_warp_tool_halt (wt);
@@ -193,15 +196,20 @@ gimp_warp_tool_button_press (GimpTool            *tool,
     gimp_warp_tool_start (wt, display);
 
   wt->current_stroke = gegl_path_new ();
-  gegl_path_append (wt->current_stroke,
-                    'M', coords->x, coords->y);
 
   gimp_warp_tool_add_op (wt);
 
-  gimp_warp_tool_image_map_update (wt);
+  g_signal_connect (wt->current_stroke, "changed",
+                    G_CALLBACK (gimp_warp_tool_stroke_changed),
+                    wt);
+
+  gimp_item_get_offset (GIMP_ITEM (tool->drawable), &off_x, &off_y);
+
+  gegl_path_append (wt->current_stroke,
+                    'M', coords->x - off_x, coords->y - off_y);
 
   wt->stroke_timer = g_timeout_add (STROKE_PERIOD,
-                                    gimp_warp_tool_stroke_timer,
+                                    (GSourceFunc) gimp_warp_tool_stroke_timer,
                                     wt);
 
   gimp_tool_control_activate (tool->control);
@@ -224,6 +232,10 @@ gimp_warp_tool_button_release (GimpTool              *tool,
   g_source_remove (wt->stroke_timer);
   wt->stroke_timer = 0;
 
+  g_signal_handlers_disconnect_by_func (wt->current_stroke,
+                                        gimp_warp_tool_stroke_changed,
+                                        wt);
+
 #ifdef WARP_DEBUG
   g_printerr ("%s\n", gegl_path_to_string (wt->current_stroke));
 #endif
@@ -235,12 +247,6 @@ gimp_warp_tool_button_release (GimpTool              *tool,
     {
       gimp_warp_tool_undo (wt);
     }
-  else
-    {
-      gimp_warp_tool_image_map_update (wt);
-    }
-
-  gegl_rectangle_set (&wt->last_region, 0, 0, 0, 0);
 
   gimp_draw_tool_resume (GIMP_DRAW_TOOL (tool));
 }
@@ -397,8 +403,6 @@ gimp_warp_tool_start (GimpWarpTool *wt,
 
   wt->coords_buffer = gegl_buffer_new (&bbox, format);
 
-  gegl_rectangle_set (&wt->last_region, 0, 0, 0, 0);
-
   gimp_warp_tool_create_image_map (wt, drawable);
 
   if (! gimp_draw_tool_is_active (GIMP_DRAW_TOOL (wt)))
@@ -444,21 +448,15 @@ gimp_warp_tool_halt (GimpWarpTool *wt)
 }
 
 static gboolean
-gimp_warp_tool_stroke_timer (gpointer data)
+gimp_warp_tool_stroke_timer (GimpWarpTool *wt)
 {
-  GimpTool     *tool = GIMP_TOOL (data);
-  GimpWarpTool *wt   = GIMP_WARP_TOOL (data);
-  gint          off_x, off_y;
-  gdouble       x, y;
+  GimpTool *tool = GIMP_TOOL (wt);
+  gint      off_x, off_y;
 
   gimp_item_get_offset (GIMP_ITEM (tool->drawable), &off_x, &off_y);
-  x = wt->cursor_x - off_x;
-  y = wt->cursor_y - off_y;
 
   gegl_path_append (wt->current_stroke,
-                    'L', x, y);
-
-  gimp_warp_tool_image_map_update (wt);
+                    'L', wt->cursor_x - off_x, wt->cursor_y - off_y);
 
   return TRUE;
 }
@@ -522,34 +520,25 @@ gimp_warp_tool_create_image_map (GimpWarpTool *wt,
 }
 
 static void
-gimp_warp_tool_image_map_update (GimpWarpTool *wt)
+gimp_warp_tool_stroke_changed (GeglPath            *path,
+                               const GeglRectangle *roi,
+                               GimpWarpTool        *wt)
 {
-  GimpTool        *tool    = GIMP_TOOL (wt);
-  GimpWarpOptions *options = GIMP_WARP_TOOL_GET_OPTIONS (wt);
-  GeglRectangle    region;
-  GeglRectangle    to_update;
-  gint             off_x, off_y;
-  gdouble          x, y;
-
-  gimp_item_get_offset (GIMP_ITEM (tool->drawable), &off_x, &off_y);
-  x = wt->cursor_x - off_x;
-  y = wt->cursor_y - off_y;
-
-  region.x      = x - options->effect_size * 0.5;
-  region.y      = y - options->effect_size * 0.5;
-  region.width  = options->effect_size;
-  region.height = options->effect_size;
-
-  gegl_rectangle_bounding_box (&to_update, &region, &wt->last_region);
+  GimpWarpOptions *options       = GIMP_WARP_TOOL_GET_OPTIONS (wt);
+  GeglRectangle    update_region = *roi;
 
-  gegl_rectangle_copy (&wt->last_region, &region);
+  update_region.x      -= options->effect_size * 0.5;
+  update_region.y      -= options->effect_size * 0.5;
+  update_region.width  += options->effect_size;
+  update_region.height += options->effect_size;
 
 #ifdef WARP_DEBUG
   g_printerr ("update rect: (%d,%d), %dx%d\n",
-              to_update.x, to_update.y, to_update.width, to_update.height);
+              update_region.x, update_region.y,
+              update_region.width, update_region.height);
 #endif
 
-  gimp_image_map_apply (wt->image_map, &to_update);
+  gimp_image_map_apply (wt->image_map, &update_region);
 }
 
 static void
diff --git a/app/tools/gimpwarptool.h b/app/tools/gimpwarptool.h
index c8cea96..dea5c7b 100644
--- a/app/tools/gimpwarptool.h
+++ b/app/tools/gimpwarptool.h
@@ -54,7 +54,6 @@ struct _GimpWarpTool
   guint           stroke_timer;
 
   GimpImageMap   *image_map;
-  GeglRectangle   last_region;
 };
 
 struct _GimpWarpToolClass