[gimp/soc-2010-cage-2] gimpcageconfig: displace the cage by a small delta to avoid having pixel exactly on edges

[Michael Muré <mmure src gnome org>]

commit e2a7ef2e3261c909ce5eac91c7592b2009769c6d
Author: Michael Muré <batolettre gmail com>
Date:   Sun Aug 15 12:59:49 2010 +0200

    gimpcageconfig: displace the cage by a small delta to avoid having pixel exactly on edges

 app/gegl/gimpcageconfig.c |   17 +++++++++--------
 1 files changed, 9 insertions(+), 8 deletions(-)
---
diff --git a/app/gegl/gimpcageconfig.c b/app/gegl/gimpcageconfig.c
index 11c5b87..0b19a99 100644
--- a/app/gegl/gimpcageconfig.c
+++ b/app/gegl/gimpcageconfig.c
@@ -47,6 +47,7 @@ G_DEFINE_TYPE_WITH_CODE (GimpCageConfig, gimp_cage_config,
 #define parent_class gimp_cage_config_parent_class
 
 #define N_ITEMS_PER_ALLOC       10
+#define DELTA                   0.010309278351
 
 static void       gimp_cage_config_finalize                   (GObject *object);
 static void       gimp_cage_config_get_property               (GObject    *object,
@@ -177,11 +178,11 @@ gimp_cage_config_add_cage_point (GimpCageConfig  *gcc,
                             gcc->cage_vertices_max);
   }
 
-  gcc->cage_vertices[gcc->cage_vertice_number].x = x;
-  gcc->cage_vertices[gcc->cage_vertice_number].y = y;
+  gcc->cage_vertices[gcc->cage_vertice_number].x = x + DELTA;
+  gcc->cage_vertices[gcc->cage_vertice_number].y = y + DELTA;
 
-  gcc->cage_vertices_d[gcc->cage_vertice_number].x = x;
-  gcc->cage_vertices_d[gcc->cage_vertice_number].y = y;
+  gcc->cage_vertices_d[gcc->cage_vertice_number].x = x + DELTA;
+  gcc->cage_vertices_d[gcc->cage_vertice_number].y = y + DELTA;
 
   gcc->cage_vertice_number++;
 
@@ -252,13 +253,13 @@ gimp_cage_config_move_cage_point  (GimpCageConfig  *gcc,
 
   if (mode == GIMP_CAGE_MODE_CAGE_CHANGE)
   {
-    gcc->cage_vertices[point_number].x = x;
-    gcc->cage_vertices[point_number].y = y;
+    gcc->cage_vertices[point_number].x = x + DELTA;
+    gcc->cage_vertices[point_number].y = y + DELTA;
   }
   else
   {
-    gcc->cage_vertices_d[point_number].x = x;
-    gcc->cage_vertices_d[point_number].y = y;
+    gcc->cage_vertices_d[point_number].x = x + DELTA;
+    gcc->cage_vertices_d[point_number].y = y + DELTA;
   }
 
   gimp_cage_config_compute_scaling_factor (gcc);