[gegl] motion-blur-zoom.c: Allow negative factor.

[Téo Mazars <teom src gnome org>]

commit 49db0ab0bbd302b8ba73eeb9d6466f3b9ef40c58
Author: Téo Mazars <teo mazars ensimag fr>
Date:   Wed Jul 3 00:23:15 2013 +0200

    motion-blur-zoom.c: Allow negative factor.
    
    To simulate inward blur

 operations/common/motion-blur-zoom.c |    8 ++++----
 1 files changed, 4 insertions(+), 4 deletions(-)
---
diff --git a/operations/common/motion-blur-zoom.c b/operations/common/motion-blur-zoom.c
index 81873bb..841c1c2 100644
--- a/operations/common/motion-blur-zoom.c
+++ b/operations/common/motion-blur-zoom.c
@@ -48,8 +48,8 @@ gegl_chant_double_ui (center_y, _("Y"),
                       _("Vertical center position"))
 
 gegl_chant_double_ui (factor, _("Factor"),
-                      0.0, 1.0, 0.1,
-                      0.0, 1.0, 2.0,
+                      -10.0, 1.0, 0.1,
+                      -0.5, 1.0, 2.0,
                       _("Bluring factor"))
 
 #else
@@ -77,11 +77,11 @@ prepare (GeglOperation *operation)
     {
       op_area->left = op_area->right
         = MAX (fabs (whole_region->x - o->center_x),
-               fabs (whole_region->width + whole_region->x - o->center_x)) * o->factor +1;
+               fabs (whole_region->width + whole_region->x - o->center_x)) * fabs (o->factor) +1;
 
       op_area->top = op_area->bottom
         = MAX (fabs (whole_region->y - o->center_y),
-               fabs (whole_region->height + whole_region->y - o->center_y)) * o->factor +1;
+               fabs (whole_region->height + whole_region->y - o->center_y)) * fabs (o->factor) +1;
     }
   else
     {