[gimp/gimp-2-10] app: add incremental mode to the Dodge/Burn tool

[Ell <ell src gnome org>]

commit 0ee8e5f17a97367b44f0e547dd53c77f7656e7a0
Author: Ell <ell_se yahoo com>
Date:   Wed Apr 17 09:55:35 2019 -0400

    app: add incremental mode to the Dodge/Burn tool
    
    Add an "Incremental" option to the Dodge/Burn tool, which,
    similarly to the Paintbrush, Pencil, and Eraser tools, applies the
    effect incrementally as the pointer moves.
    
    (cherry picked from commit 83184d16260ba3e8f0a5920ac439cd4d0dc1efeb)

 app/paint/gimpdodgeburn.c        | 11 +++++++++--
 app/tools/gimppaintoptions-gui.c |  3 ++-
 2 files changed, 11 insertions(+), 3 deletions(-)
---
diff --git a/app/paint/gimpdodgeburn.c b/app/paint/gimpdodgeburn.c
index 3376ceb9d7..86a9754736 100644
--- a/app/paint/gimpdodgeburn.c
+++ b/app/paint/gimpdodgeburn.c
@@ -116,6 +116,7 @@ gimp_dodge_burn_motion (GimpPaintCore    *paint_core,
   GimpContext          *context   = GIMP_CONTEXT (paint_options);
   GimpDynamics         *dynamics  = GIMP_BRUSH_CORE (paint_core)->dynamics;
   GimpImage            *image     = gimp_item_get_image (GIMP_ITEM (drawable));
+  GeglBuffer           *src_buffer;
   GeglBuffer           *paint_buffer;
   gint                  paint_buffer_x;
   gint                  paint_buffer_y;
@@ -140,6 +141,11 @@ gimp_dodge_burn_motion (GimpPaintCore    *paint_core,
   if (opacity == 0.0)
     return;
 
+  if (paint_options->application_mode == GIMP_PAINT_CONSTANT)
+    src_buffer = gimp_paint_core_get_orig_image (paint_core);
+  else
+    src_buffer = gimp_drawable_get_buffer (drawable);
+
   gimp_brush_core_eval_transform_dynamics (GIMP_BRUSH_CORE (paint_core),
                                            drawable,
                                            paint_options,
@@ -165,7 +171,7 @@ gimp_dodge_burn_motion (GimpPaintCore    *paint_core,
                                         paint_height);
 
       /*  DodgeBurn the region  */
-      gimp_gegl_dodgeburn (gimp_paint_core_get_orig_image (paint_core),
+      gimp_gegl_dodgeburn (src_buffer,
                            GEGL_RECTANGLE (paint_buffer_x,
                                            paint_buffer_y,
                                            gegl_buffer_get_width  (paint_buffer),
@@ -192,6 +198,7 @@ gimp_dodge_burn_motion (GimpPaintCore    *paint_core,
                                       gimp_context_get_opacity (context),
                                       gimp_paint_options_get_brush_mode (paint_options),
                                       force,
-                                      GIMP_PAINT_CONSTANT, op);
+                                      paint_options->application_mode,
+                                      op);
     }
 }
diff --git a/app/tools/gimppaintoptions-gui.c b/app/tools/gimppaintoptions-gui.c
index 23aef019e6..211270f976 100644
--- a/app/tools/gimppaintoptions-gui.c
+++ b/app/tools/gimppaintoptions-gui.c
@@ -258,7 +258,8 @@ gimp_paint_options_gui (GimpToolOptions *tool_options)
   /*  the "incremental" toggle  */
   if (tool_type == GIMP_TYPE_PENCIL_TOOL     ||
       tool_type == GIMP_TYPE_PAINTBRUSH_TOOL ||
-      tool_type == GIMP_TYPE_ERASER_TOOL)
+      tool_type == GIMP_TYPE_ERASER_TOOL     ||
+      tool_type == GIMP_TYPE_DODGE_BURN_TOOL)
     {
       GtkWidget *button;