[gimp/gimp-2-10] app: add "real-time preview" option to the warp tool

[Ell <ell src gnome org>]

commit 9b6604d011e6d64f855c4bf1ee481dce3a02e6eb
Author: Ell <ell_se yahoo com>
Date:   Sun Mar 3 16:18:50 2019 -0500

    app: add "real-time preview" option to the warp tool
    
    Add a "real-time preview" option to the warp tool, which, when
    toggled, causes the preview to be rendered synchronously during
    motion.  This is slower, but gives better feedback.
    
    (cherry picked from commit a93af839fe10534310a2446cd7d824b64337b4b0)

 app/tools/gimpwarpoptions.c | 18 ++++++++++++++++++
 app/tools/gimpwarpoptions.h |  1 +
 app/tools/gimpwarptool.c    | 33 ++++++++++++++++++++++++++++-----
 3 files changed, 47 insertions(+), 5 deletions(-)
---
diff --git a/app/tools/gimpwarpoptions.c b/app/tools/gimpwarpoptions.c
index f534c279c4..2c2d3d961f 100644
--- a/app/tools/gimpwarpoptions.c
+++ b/app/tools/gimpwarpoptions.c
@@ -47,6 +47,7 @@ enum
   PROP_INTERPOLATION,
   PROP_ABYSS_POLICY,
   PROP_HIGH_QUALITY_PREVIEW,
+  PROP_REAL_TIME_PREVIEW,
   PROP_STROKE_DURING_MOTION,
   PROP_STROKE_PERIODICALLY,
   PROP_STROKE_PERIODICALLY_RATE,
@@ -137,6 +138,13 @@ gimp_warp_options_class_init (GimpWarpOptionsClass *klass)
                             FALSE,
                             GIMP_PARAM_STATIC_STRINGS);
 
+  GIMP_CONFIG_PROP_BOOLEAN (object_class, PROP_REAL_TIME_PREVIEW,
+                            "real-time-preview",
+                            _("Real-time preview"),
+                            _("Render preview in real time (slower)"),
+                            FALSE,
+                            GIMP_PARAM_STATIC_STRINGS);
+
   GIMP_CONFIG_PROP_BOOLEAN (object_class, PROP_STROKE_DURING_MOTION,
                             "stroke-during-motion",
                             _("During motion"),
@@ -205,6 +213,9 @@ gimp_warp_options_set_property (GObject      *object,
     case PROP_HIGH_QUALITY_PREVIEW:
       options->high_quality_preview = g_value_get_boolean (value);
       break;
+    case PROP_REAL_TIME_PREVIEW:
+      options->real_time_preview = g_value_get_boolean (value);
+      break;
     case PROP_STROKE_DURING_MOTION:
       options->stroke_during_motion = g_value_get_boolean (value);
       break;
@@ -258,6 +269,9 @@ gimp_warp_options_get_property (GObject    *object,
     case PROP_HIGH_QUALITY_PREVIEW:
       g_value_set_boolean (value, options->high_quality_preview);
       break;
+    case PROP_REAL_TIME_PREVIEW:
+      g_value_set_boolean (value, options->real_time_preview);
+      break;
     case PROP_STROKE_DURING_MOTION:
       g_value_set_boolean (value, options->stroke_during_motion);
       break;
@@ -337,6 +351,10 @@ gimp_warp_options_gui (GimpToolOptions *tool_options)
   gtk_box_pack_start (GTK_BOX (vbox), button, FALSE, FALSE, 0);
   gtk_widget_show (button);
 
+  button = gimp_prop_check_button_new (config, "real-time-preview", NULL);
+  gtk_box_pack_start (GTK_BOX (vbox), button, FALSE, FALSE, 0);
+  gtk_widget_show (button);
+
   /*  the stroke frame  */
   frame = gimp_frame_new (_("Stroke"));
   gtk_box_pack_start (GTK_BOX (vbox), frame, FALSE, FALSE, 0);
diff --git a/app/tools/gimpwarpoptions.h b/app/tools/gimpwarpoptions.h
index d7e14fe714..eacfb714b2 100644
--- a/app/tools/gimpwarpoptions.h
+++ b/app/tools/gimpwarpoptions.h
@@ -47,6 +47,7 @@ struct _GimpWarpOptions
   GimpInterpolationType  interpolation;
   GeglAbyssPolicy        abyss_policy;
   gboolean               high_quality_preview;
+  gboolean               real_time_preview;
 
   gboolean               stroke_during_motion;
   gboolean               stroke_periodically;
diff --git a/app/tools/gimpwarptool.c b/app/tools/gimpwarptool.c
index 76d414714c..1f786f77fb 100644
--- a/app/tools/gimpwarptool.c
+++ b/app/tools/gimpwarptool.c
@@ -128,7 +128,8 @@ static GeglRectangle
 static void       gimp_warp_tool_clear_node_bounds  (GeglNode              *node);
 static void       gimp_warp_tool_update_bounds      (GimpWarpTool          *wt);
 static void       gimp_warp_tool_update_area        (GimpWarpTool          *wt,
-                                                     const GeglRectangle   *area);
+                                                     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,
@@ -1091,7 +1092,8 @@ gimp_warp_tool_update_bounds (GimpWarpTool *wt)
 
 static void
 gimp_warp_tool_update_area (GimpWarpTool        *wt,
-                            const GeglRectangle *area)
+                            const GeglRectangle *area,
+                            gboolean             synchronous)
 {
   GeglRectangle rect = *area;
 
@@ -1105,7 +1107,28 @@ gimp_warp_tool_update_area (GimpWarpTool        *wt,
       rect = gegl_operation_get_invalidated_by_change (operation, "aux", &rect);
     }
 
-  gimp_drawable_filter_apply (wt->filter, &rect);
+  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
@@ -1137,7 +1160,7 @@ gimp_warp_tool_update_stroke (GimpWarpTool *wt,
               bounds.width, bounds.height);
 #endif
 
-      gimp_warp_tool_update_area (wt, &bounds);
+      gimp_warp_tool_update_area (wt, &bounds, FALSE);
     }
 }
 
@@ -1175,7 +1198,7 @@ gimp_warp_tool_stroke_append (GimpWarpTool *wt,
       gimp_warp_tool_update_bounds (wt);
     }
 
-  gimp_warp_tool_update_area (wt, &area);
+  gimp_warp_tool_update_area (wt, &area, options->real_time_preview);
 }
 
 static void