Improve reflections when starting in a corner.

1 files changed, 8 insertions, 8 deletions

diff --git a/crawl-ref/source/ray.cc b/crawl-ref/source/ray.cc
index 78cc133df6..83b25d091c 100644
--- a/crawl-ref/source/ray.cc
+++ b/crawl-ref/source/ray.cc
@@ -282,20 +282,20 @@ void ray_def::bounce(const reflect_grid &rg)
     const coord_def old_pos = pos();
 #endif
 
-    if (on_corner)
-    {
-        // XXX
-        r.dir = -r.dir;
-        ASSERT(_valid());
-        return;
-    }
-
     // Translate to cell (0,0).
     geom::vector p(pos().x, pos().y);
     geom::ray rtrans;
     rtrans.start = r.start - p;
     rtrans.dir = r.dir;
 
+    if (on_corner)
+    {
+        // Move a little bit towards cell center (0.5, 0.5).
+       rtrans.start = 0.9 * rtrans.start + 0.1 * geom::vector(0.5, 0.5);
+       on_corner = false;
+       ASSERT(in_diamond_int(rtrans.start));
+    }
+
     // Move to the diamond edge to determine the side.
     coord_def side;
     bool corner = rtrans.to_grid(diamonds, false);