Add cstdio include
--- a/src/qwt3d_function.cpp
+++ b/src/qwt3d_function.cpp
@@ -1,3 +1,4 @@
+#include <cstdio>
 #include "qwt3d_surfaceplot.h"
 #include "qwt3d_function.h"
 
--- a/include/qwt3d_openglhelper.h
+++ b/include/qwt3d_openglhelper.h
@@ -7,6 +7,7 @@
 #else
 #include <QtOpenGL/qgl.h>
 #endif
+#include <GL/glu.h>
 
 namespace Qwt3D
 {