add ambient noise levels to branches

noise loudness is increased or decreased by a branch-dependent amount to
simulate having background noise. hive is very noisy and crypt is very
quiet, and a couple other branches are in between... we might want to
give values to a couple other ones, but couldn't really think of good
ideas for that off the top of my head.

i'm not sure how much this actually affects with our current noise
system, but i think it's a reasonable concept to build on.

this also gives a bonus/malus to stealth, the size of which is certainly
up for tweaking (with the current numbers, hive is +40 and crypt is
-40).

1 files changed, 4 insertions, 0 deletions

diff --git a/crawl-ref/source/branch.h b/crawl-ref/source/branch.h
index a620560ccf..0be1b09092 100644
--- a/crawl-ref/source/branch.h
+++ b/crawl-ref/source/branch.h
@@ -56,6 +56,7 @@ struct Branch
     int travel_shortcut;         // Which key to press for travel.
     bool any_upstair_exits;      // any upstair exits the branch (Hell branches)
     bool dangerous_bottom_level; // bottom level is more dangerous than normal
+    int ambient_noise;
 };
 
 extern Branch branches[];
@@ -70,6 +71,9 @@ level_id current_level_parent();
 branch_type str_to_branch(const std::string &branch,
                           branch_type err = NUM_BRANCHES);
 
+int branch_ambient_noise(branch_type branch);
+int current_level_ambient_noise();
+
 const char *level_area_type_name(int level_type);
 level_area_type str_to_level_area_type(const std::string &s);