Abstract out some state arithmetic.

[open-adventure.git] / advent.h

diff --git a/advent.h b/advent.h
index cca1dbab1d328e310643fc1f389639d03444f0c4..3c3372576b8c9cfdec568b5a296e286e8357a661 100644 (file)
--- a/advent.h
+++ b/advent.h
@@ -29,6 +29,11 @@
 #define STATE_NOTFOUND  -1       // 'Not found" state of treasures */
 #define STATE_GROUND   0         // After discovered, before messed with
 
+/* Map a state property value to a negative range, where the object cannot be
+ * picked up but the value can be recovered later.  Avoid colliding with -1,
+ * which has its own meaning. */
+#define STASHED(obj)   (-1 - game.prop[obj])
+
 /*
  *  MOD(N,M)    = Arithmetic modulus
  *  AT(OBJ)     = true if on either side of two-placed object