piechart: Use definition of M_PI from GSL.

The GSL header <gsl/gsl_math.h> makes sure that the standard BSD
mathematical constants are defined, so we don't have to do it ourselves.

diff --git a/src/output/charts/piechart.c b/src/output/charts/piechart.c
index 4eeb10ca63af06f70f764477cd0865401c34a8c0..edb83ddb2e90dfd947e200abf9cb3ba7095b74a9 100644 (file)
--- a/src/output/charts/piechart.c
+++ b/src/output/charts/piechart.c
@@ -19,6 +19,7 @@
 
 #include <float.h>
 #include <assert.h>
+#include <gsl/gsl_math.h>
 #include <math.h>
 #include <stdio.h>
 
@@ -32,14 +33,6 @@
 
 #include "minmax.h"
 
-
-/* Pie charts of course need to know Pi :) */
-#ifndef M_PI
-#define M_PI ( 22.0 / 7.0 )
-#endif
-
-
-
 /* Draw a single slice of the pie */
 static void
 draw_segment(struct chart *ch,