[gegl] Add some needed math.h includes

[Mikael Magnusson <mikachu src gnome org>]

commit b21186eb0c5869a960c2a793c923bc0ff26ee862
Author: Mikael Magnusson <mikachu gmail com>
Date:   Fri Dec 17 20:15:22 2010 +0100

    Add some needed math.h includes

 operations/external/matting-levin.c   |    1 +
 operations/workshop/linear-gradient.c |    2 ++
 operations/workshop/radial-gradient.c |    2 ++
 3 files changed, 5 insertions(+), 0 deletions(-)
---
diff --git a/operations/external/matting-levin.c b/operations/external/matting-levin.c
index ea22ae2..4361fec 100644
--- a/operations/external/matting-levin.c
+++ b/operations/external/matting-levin.c
@@ -49,6 +49,7 @@ gegl_chant_int    (active_levels, _("Active Levels"),
 
 #include <stdlib.h>
 #include <stdio.h>
+#include <math.h>
 
 /* XXX: We have two options for the two common installation locations of
  * UMFPACK. Ideally this would be sorted out purely in autoconf; see
diff --git a/operations/workshop/linear-gradient.c b/operations/workshop/linear-gradient.c
index cbb15d2..4fe71d9 100644
--- a/operations/workshop/linear-gradient.c
+++ b/operations/workshop/linear-gradient.c
@@ -37,6 +37,8 @@ gegl_chant_color (color2,   _("Other color"), "white",
 
 #include "gegl-chant.h"
 
+#include <math.h>
+
 static void
 prepare (GeglOperation *operation)
 {
diff --git a/operations/workshop/radial-gradient.c b/operations/workshop/radial-gradient.c
index e4bc73f..a23045f 100644
--- a/operations/workshop/radial-gradient.c
+++ b/operations/workshop/radial-gradient.c
@@ -37,6 +37,8 @@ gegl_chant_color (color2,   _("Other color"), "white",
 
 #include "gegl-chant.h"
 
+#include <math.h>
+
 static void
 prepare (GeglOperation *operation)
 {