--- a/QTfrontend/drawmapscene.cpp	Wed May 16 18:22:28 2018 +0200
+++ b/QTfrontend/drawmapscene.cpp	Wed Jul 31 23:14:27 2019 +0200
@@ -29,6 +29,10 @@
 #define DRAWN_MAP_COLOR_CURSOR_PEN (Qt::green)
 #define DRAWN_MAP_COLOR_CURSOR_ERASER (Qt::red)
 
+#ifndef M_PI
+#define M_PI 3.14159265358979323846
+#endif
+
 template <class T> T sqr(const T & x)
 {
     return x*x;