seen_replace_feat(): replace one feat with another

Replacement for replace_area_wrapper, and a lua accessor for the
function.  Returns true if the player saw the feature being changed.

3 files changed, 32 insertions, 5 deletions

diff --git a/crawl-ref/source/dungeon.cc b/crawl-ref/source/dungeon.cc
index 6eab3cad24..22d4c9735d 100644
--- a/crawl-ref/source/dungeon.cc
+++ b/crawl-ref/source/dungeon.cc
@@ -5226,11 +5226,26 @@ static void _vault_grid( vault_placement &place,
 // Currently only used for Slime: branch end
 // where it will turn the stone walls into clear rock walls
 // once the royal jelly has been killed.
-void replace_area_wrapper(dungeon_feature_type old_feat,
-                          dungeon_feature_type new_feat)
+bool seen_replace_feat(dungeon_feature_type old_feat,
+                       dungeon_feature_type new_feat)
 {
     ASSERT(old_feat != new_feat);
-    _replace_area(0, 0, GXM-1, GYM-1, old_feat, new_feat, 0, false);
+
+    coord_def p1(0, 0);
+    coord_def p2(GXM - 1, GYM - 1);
+
+    bool seen = false;
+    for (rectangle_iterator ri(p1, p2); ri; ++ri)
+    {
+        if (grd(*ri) == old_feat)
+        {
+            grd(*ri) = new_feat;
+            if (you.see_cell(*ri))
+                seen = true;
+        }
+    }
+
+    return (seen);
 }
 
 static void _replace_area( const coord_def& p1, const coord_def& p2,
@@ -5254,6 +5269,7 @@ static void _replace_area( const coord_def& p1, const coord_def& p2,
     }
 }
 
+
 // With apologies to Metallica.
 bool unforbidden(const coord_def &c, unsigned mask)
 {
diff --git a/crawl-ref/source/dungeon.h b/crawl-ref/source/dungeon.h
index c9c236cb9b..793fccc2c8 100644
--- a/crawl-ref/source/dungeon.h
+++ b/crawl-ref/source/dungeon.h
@@ -354,8 +354,8 @@ void level_welcome_messages();
 bool place_specific_trap(const coord_def& where, trap_type spec_type);
 void place_spec_shop(int level_number, const coord_def& where,
                      int force_s_type, bool representative = false);
-void replace_area_wrapper(dungeon_feature_type old_feat,
-                          dungeon_feature_type new_feat);
+bool seen_replace_feat(dungeon_feature_type replace,
+                       dungeon_feature_type feature);
 bool unforbidden(const coord_def &c, unsigned mask);
 coord_def dgn_find_nearby_stair(dungeon_feature_type stair_to_find,
                                 coord_def base_pos, bool find_closest);
diff --git a/crawl-ref/source/l_dgngrd.cc b/crawl-ref/source/l_dgngrd.cc
index 4f2b62dbfe..90657819cd 100644
--- a/crawl-ref/source/l_dgngrd.cc
+++ b/crawl-ref/source/l_dgngrd.cc
@@ -11,6 +11,7 @@
 
 #include "coord.h"
 #include "directn.h"
+#include "dungeon.h"
 #include "env.h"
 #include "religion.h"
 #include "terrain.h"
@@ -255,6 +256,15 @@ LUAFN(_dgn_is_opaque)
     return (1);
 }
 
+LUAFN(dgn_seen_replace_feat)
+{
+    dungeon_feature_type f1 = _get_lua_feature(ls, 1);
+    dungeon_feature_type f2 = _get_lua_feature(ls, 2);
+
+    lua_pushboolean(ls, seen_replace_feat(f1, f2));
+    return (1);
+}
+
 const struct luaL_reg dgn_grid_dlib[] =
 {
 { "feature_number", dgn_feature_number },
@@ -263,6 +273,7 @@ const struct luaL_reg dgn_grid_dlib[] =
 { "feature_desc_at", dgn_feature_desc_at },
 { "set_feature_desc_short", dgn_set_feature_desc_short },
 { "set_feature_desc_long", dgn_set_feature_desc_long },
+{ "seen_replace_feat", dgn_seen_replace_feat },
 
 { "grid", dgn_grid },
 { "is_opaque", _dgn_is_opaque },