+int SXSIZE = 17 * TILEX; /* SCR_FIELDX * TILEX */
+int SYSIZE = 17 * TILEY; /* SCR_FIELDY * TILEY */
+int FULL_SXSIZE = 2 + 17 * TILEX + 2; /* 2 + SXSIZE + 2 */
+int FULL_SYSIZE = 2 + 17 * TILEY + 2; /* 2 + SYSIZE + 2 */
+int TILESIZE_VAR = TILESIZE / 2;