diff --git a/src/common.h b/src/common.h
new file mode 100644
index 0000000..64e3595
--- /dev/null
+++ b/src/common.h
@@ -0,0 +1,27 @@
+#ifndef __COMMON_H_INCLUDED__
+#define __COMMON_H_INCLUDED__
+
+#include <stdint.h>
+
+#if !defined(TRUE) && !defined(FALSE)
+typedef int32_t BOOL;
+const BOOL TRUE = 1;
+const BOOL FALSE = 0;
+#endif
+
+#ifndef SAFE_RELEASE
+#define SAFE_RELEASE(x)	                                   if (x) { (x)->Release(); (x) = NULL; }
+#endif
+
+#ifndef SAFE_DELETE
+#define SAFE_DELETE(x)	                                   if (x) { delete (x); (x) = NULL; }
+#endif
+
+#ifndef SAFE_DELETE_ARRAY
+#define SAFE_DELETE_ARRAY(x)	                           if (x) { delete [] (x); (x) = NULL; }
+#endif
+
+#define MAX(a, b)                                          ( (a) > (b) ? (a) : (b) )
+#define MIN(a, b)                                          ( (a) < (b) ? (a) : (b) )
+
+#endif