Rewrite find_ray to use precomputed cellrays.

During precomputation, we store the minimal cellrays by target
and sort them according to niceness.

find_ray now simply picks the first non-blocked ray to a
target, which means looping through the 10 or so minimal
cellrays with that target -- this should be a lot more
efficient. (An extended findray test went from 150s to 40s
(debug) and 40s to 26s (profile)).

The interface to find_ray has changed: cycle_dir=-1,0,1 was
changed to cyle=false/true since we never cycle in the other
direction anyway. find_shortest was removed: all rays to a
target had the same length all along, but now we also return
the straightest one automatically.

The change also eliminates the duplicate corner-cutting code
between ray_def::advance and find_ray as imbalance calculation
now relies on ray_def::advance.

1 files changed, 1 insertions, 1 deletions

diff --git a/crawl-ref/source/l_los.cc b/crawl-ref/source/l_los.cc
index 3d4c38f498..1ac2f9a3c7 100644
--- a/crawl-ref/source/l_los.cc
+++ b/crawl-ref/source/l_los.cc
@@ -25,7 +25,7 @@ LUAFN(los_find_ray)
     GETCOORD(a, 1, 2, map_bounds);
     GETCOORD(b, 3, 4, map_bounds);
     ray_def *ray = new ray_def;
-    if (find_ray(a, b, *ray, 0, true))
+    if (find_ray(a, b, *ray))
     {
         lua_push_ray(ls, ray);
         return (1);