#define SXSIZE (SCR_FIELDX * TILEX)
#define SYSIZE (SCR_FIELDY * TILEY)
+#define REAL_SX (SX - 2)
+#define REAL_SY (SY - 2)
+#define FULL_SXSIZE (2 + SXSIZE + 2)
+#define FULL_SYSIZE (2 + SYSIZE + 2)
+
/* ------------------------------------------------------------------------- */
/* data structure definitions */