A temporary speed-up to actor_by_mid().

It can be done better, but for now, I prefer a simpler solution.  This can
be turned into an efficient no extra memory hash, etc, later.

Also, this is the only non-debug interface so it's trivial to change the
implementation.

1 files changed, 3 insertions, 0 deletions

diff --git a/crawl-ref/source/env.h b/crawl-ref/source/env.h
index 957dc4c4a0..3286154d65 100644
--- a/crawl-ref/source/env.h
+++ b/crawl-ref/source/env.h
@@ -108,6 +108,9 @@ struct crawl_environment
     // Volatile level flags, not saved.
     uint32_t level_state;
 
+    // Mapping mid->mindex until the transition is finished.
+    std::map<mid_t, unsigned short> mid_cache;
+
     // Temp stuff.
     std::vector<final_effect> final_effects;
 };