[gimp/blend-tool-fun: 6/6] foo

[Michael Henning <mhenning src gnome org>]

commit 67a2849377045faf0be6070bc6d9f7cc2ad5c87d
Author: Michael Henning <drawoc darkrefraction com>
Date:   Sun Apr 26 21:38:11 2015 -0400

    foo

 app/tools/gimpblendtool.c |   57 +++++++++++++++++++++++++++++++++++++++++++-
 app/tools/gimpblendtool.h |    4 +++
 2 files changed, 59 insertions(+), 2 deletions(-)
---
diff --git a/app/tools/gimpblendtool.c b/app/tools/gimpblendtool.c
index 265653c..97930df 100644
--- a/app/tools/gimpblendtool.c
+++ b/app/tools/gimpblendtool.c
@@ -915,9 +915,19 @@ gimp_blend_tool_push_status (GimpBlendTool   *blend_tool,
 static void
 gimp_blend_tool_create_graph (GimpBlendTool *blend_tool)
 {
+  GimpTool *tool = GIMP_TOOL (blend_tool);
+
   GimpBlendOptions *options = GIMP_BLEND_TOOL_GET_OPTIONS (blend_tool);
   GimpContext      *context = GIMP_CONTEXT (options);
-  GeglNode *graph, *output, *render;
+  GeglNode         *graph, *output, *render, *shapeburst, *translate, *subtract, *divide;
+  GimpImage        *image         = gimp_display_get_image (tool->display);
+  GimpDrawable     *drawable      = gimp_image_get_active_drawable (image);
+  GeglBuffer *buf = NULL;
+
+  gint        x, y, width, height;
+
+  if (! gimp_item_mask_intersect (GIMP_ITEM (drawable), &x, &y, &width, &height))
+    return;
 
   /* render_node is not supposed to be recreated */
   g_return_if_fail (blend_tool->graph == NULL);
@@ -931,10 +941,28 @@ gimp_blend_tool_create_graph (GimpBlendTool *blend_tool)
                                 "operation", "gimp:blend",
                                 NULL);
 
-  gegl_node_link (render, output);
+  buf = gimp_drawable_blend_shapeburst_distmap (drawable, FALSE,
+                                                GEGL_RECTANGLE (0, 0, width, height),
+                                               GIMP_PROGRESS (blend_tool));
+
+  translate = gegl_node_new_child (graph, "operation", "gegl:translate",
+                                    "x", (gdouble) x, "y", (gdouble) y, NULL);
+
+  subtract = gegl_node_new_child (graph, "operation", "gegl:subtract", NULL);
+  divide = gegl_node_new_child (graph, "operation", "gegl:divide", NULL);
+
+  shapeburst = gegl_node_new_child (graph, "operation", "gegl:buffer-source",
+                                    "buffer", buf, NULL);
+
+  gegl_node_link_many (/*render*/shapeburst, translate, subtract, divide, render, output, NULL);
 
   blend_tool->graph       = graph;
   blend_tool->render_node = render;
+  blend_tool->subtract_node = subtract;
+  blend_tool->divide_node = divide;
+  blend_tool->dist_buffer = buf;
+  blend_tool->dist_buffer_off_x = x;
+  blend_tool->dist_buffer_off_y = y;
 
   gegl_node_set (render,
                  "context", context,
@@ -955,6 +983,31 @@ gimp_blend_tool_update_preview_coords (GimpBlendTool *blend_tool)
                  "end_x",   blend_tool->end_x - off_x,
                  "end_y",   blend_tool->end_y - off_y,
                  NULL);
+
+  gfloat start, end;
+
+  gegl_buffer_get (blend_tool->dist_buffer,
+                   GEGL_RECTANGLE (blend_tool->start_x - blend_tool->dist_buffer_off_x,
+                                   blend_tool->start_y - blend_tool->dist_buffer_off_y,
+                                   1, 1),
+                   1.0, babl_format("Y float"), &start,
+                   GEGL_AUTO_ROWSTRIDE, GEGL_ABYSS_NONE);
+
+  gegl_buffer_get (blend_tool->dist_buffer,
+                   GEGL_RECTANGLE (blend_tool->end_x - blend_tool->dist_buffer_off_x,
+                                   blend_tool->end_y - blend_tool->dist_buffer_off_y,
+                                   1, 1),
+                   1.0, babl_format("Y float"), &end,
+                   GEGL_AUTO_ROWSTRIDE, GEGL_ABYSS_NONE);
+
+  if (start != end) {
+    gegl_node_set (blend_tool->subtract_node,
+                   "value", (gdouble) start,
+                   NULL);
+    gegl_node_set (blend_tool->divide_node,
+                   "value", (gdouble) (end - start),
+                   NULL);
+  }
 }
 
 static void
diff --git a/app/tools/gimpblendtool.h b/app/tools/gimpblendtool.h
index 0362b0b..0159491 100644
--- a/app/tools/gimpblendtool.h
+++ b/app/tools/gimpblendtool.h
@@ -68,6 +68,10 @@ struct _GimpBlendTool
 
   GeglNode       *graph;
   GeglNode       *render_node;
+  GeglNode       *subtract_node;
+  GeglNode       *divide_node;
+  GeglBuffer     *dist_buffer;
+  gint           dist_buffer_off_x, dist_buffer_off_y;
   GimpImageMap   *image_map;
 };