extern int SCR_FIELDX, SCR_FIELDY;
-#define MAX_BUF_XSIZE (SCR_FIELDX + 2)
-#define MAX_BUF_YSIZE (SCR_FIELDY + 2)
+#define MAX_BUF_XSIZE (SCR_FIELDX + 2 * CAVE_BUFFER_XOFFSET)
+#define MAX_BUF_YSIZE (SCR_FIELDY + 2 * CAVE_BUFFER_YOFFSET)
/* often used screen positions */
#define DISPLAY_TIME(x) ROUNDED_DIVIDE(x, FRAMES_PER_SECOND)
+#define CAVE_POS_X(x) ((x) - lev.left)
+#define CAVE_POS_Y(x) ((x) - lev.top)
+
// ----------------------------------------------------------------------------
// data structure definitions