Comment polishing.

[open-adventure.git] / advent.h

diff --git a/advent.h b/advent.h
index cb2b71b62ea6f4273e77b6fcf31396b1d865eb0e..946fcae266de938cdbddbe10ebbe25f4a377c3e1 100644 (file)
--- a/advent.h
+++ b/advent.h
@@ -48,12 +48,28 @@
 #define IS_FIXED -1
 #define IS_FREE 0
 
-/* PROP_STASHED maps a state property value to a negative range, where the object
- * cannot be picked up but the value can be recovered later. */
 #ifndef FOUNDBOOL
-/* PROP_STASHED needs ro avoid colliding with -1,
- * which has its own meaning as STATE_NOTFOUND. */
-#define PROP_STASHED(obj)      (STATE_NOTFOUND - game.objects[obj].prop)
+/* (ESR) It is fitting that translation of the original ADVENT should
+ * have left us a maze of twisty little conditionals that resists all
+ * understanding.  Setting and use of what is now the per-object state
+ * member (which used to be an array of its own) is our mystery. This
+ * state tangles together information about whether the object is a
+ * treasure, whether the player has seen it yet, and its activation
+ * state.
+ *
+ * Things we think we know:
+ *
+ * STATE_NOTFOUND is only set on treasures. Non-treasures start the
+ * game in STATE_FOUND.
+ *
+ * PROP_STASHED is supposed to map a state property value to a
+ * negative range, where the object cannot be picked up but the value
+ * can be recovered later.  Various objects get this property when
+ * the cave starts to close. On;y seems to be signifucant for the bird 
+ * and readable objects, notably the clam/oyster - but the code around
+ * those test is difficult to read.
+ */
+#define PROP_STASHIFY(n)       (-1 - (n))
 #define PROP_IS_STASHED(obj)   (game.objects[obj].prop < STATE_NOTFOUND)
 #define PROP_IS_NOTFOUND(obj)  (game.objects[obj].prop == STATE_NOTFOUND)
 #define PROP_IS_FOUND(obj)     (game.objects[obj].prop == STATE_FOUND)
@@ -63,7 +79,16 @@
 #define PROP_IS_NOTFOUND2(g, o)        (g.objects[o].prop == STATE_NOTFOUND)
 #define PROP_IS_INVALID(val)   (val < -MAX_STATE - 1 || val > MAX_STATE)
 #else
-#define PROP_STASHED(obj)      (-game.objects[obj].prop)
+/* (ESR) Only the boldest of adventurers will explore here.  This
+ * alternate set of definitions for the macros above was an attempt to
+ * break from out of the state encoding a per-object "found" member
+ * telling whether or not the player has seen the object. 
+ *
+ * What's broken when you try to use thus is
+ * PROP_IS_STASHED_OR_UNSEEN. The symptom is game.tally getting
+ * decremented on non-treasures.
+ */
+#define PROP_STASHIFY(n)       (-(n))
 #define PROP_IS_STASHED(obj)   (game.objects[obj].prop < 0)
 #define PROP_IS_NOTFOUND(obj)  (!game.objects[obj].found)
 #define PROP_IS_FOUND(obj)     (game.objects[obj].found && game.objects[obj].prop == 0)
@@ -72,7 +97,9 @@
 #define PROP_SET_NOT_FOUND(obj)        game.objects[obj].found = false
 #define PROP_IS_NOTFOUND2(g, o)        (!g.objects[o].found)
 #define PROP_IS_INVALID(val)   (val < -MAX_STATE || val > MAX_STATE)
+#define PROP_SET_SEEN(obj)     game.objects[object].found = true
 #endif
+#define PROP_STASHED(obj)      PROP_STASHIFY(game.objects[obj].prop)
 
 #define PROMPT "> "