Fix circular dependencies of header files on Windows

MappingGui.cpp

@@ -18,6 +18,10 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include "MapperGLCanvas.h"
+#include "ShapeGraphicsItem.h"
+#include "ShapeControlPainter.h"
+
 #include "MappingGui.h"
 
 MappingGui::MappingGui(Mapping::ptr mapping)

MappingGui.h

@@ -37,13 +37,6 @@
 #include "Paint.h"
 #include "Mapping.h"
 
-#include "MapperGLCanvas.h"
-
-#include "ShapeGraphicsItem.h"
-#include "ShapeControlPainter.h"
-
-#include "Util.h"
-
 #include "qtpropertymanager.h"
 #include "qtvariantproperty.h"
 #include "qttreepropertybrowser.h"

Maths.h

@@ -25,6 +25,10 @@
 #include <QtGlobal>
 #include <cmath>
 
+#ifndef M_PI
+# define M_PI 3.14159265358979323846
+#endif
+
 /// Converts from degrees to radians.
 inline qreal degreesToRadians(qreal degrees) { return degrees / 180.0f * M_PI; }
 

Shape.h

@@ -21,7 +21,6 @@
 #define M_SHAPE_H_
 
 #include <iostream>
-#include <cmath>
 
 #include <QtGlobal>