Pedantic compiler fixes (Sven Panne)
diff --git a/progs/demos/terrain.c b/progs/demos/terrain.c
index 5b5ad3e..da5b90d 100644
--- a/progs/demos/terrain.c
+++ b/progs/demos/terrain.c
@@ -11,6 +11,7 @@
 #include <stdio.h>
 #include <math.h>
 #include <stdlib.h>
+#include <string.h>
 #include <time.h>
 
 #ifdef WIN32