From 59b053efd22ccd197d042ed5731b117e4846599b Mon Sep 17 00:00:00 2001
From: j-p-e-g <j-p-e-g@c06c8d41-db1a-0410-9941-cceddc491573>
Date: Tue, 4 Nov 2008 13:14:08 +0000
Subject: Apply the first part of the labyrinth tweaks: * labyrinths are
 bordered by (undiggable) metal walls * teleporting inside a labyrinth will
 always send you away from the centre   (as the crow flies: you'll end
 somewhere in the stone or rock area)

Also make sure melded equipment cannot corrode.
(I'm still undecided about whether curses should affect melded items.)


git-svn-id: https://crawl-ref.svn.sourceforge.net/svnroot/crawl-ref/trunk@7383 c06c8d41-db1a-0410-9941-cceddc491573
---
 crawl-ref/source/dungeon.cc | 49 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 49 insertions(+)

(limited to 'crawl-ref/source/dungeon.cc')

diff --git a/crawl-ref/source/dungeon.cc b/crawl-ref/source/dungeon.cc
index f3c51fedc7..6f4f28af82 100644
--- a/crawl-ref/source/dungeon.cc
+++ b/crawl-ref/source/dungeon.cc
@@ -6589,6 +6589,53 @@ static void _init_minivault_placement(int vault, vault_placement &place)
     vault_main(vgrid, place, vault);
 }
 
+// Checks whether a given grid has at least one neighbour surrounded
+// entirely by non-floor.
+static bool _has_no_floor_neighbours(const coord_def &pos, bool recurse = false)
+{
+    for (int x = -1; x <= 1; x++)
+        for (int y = -1; y <= 1; y++)
+        {
+            if (x == 0 && y == 0)
+                continue;
+
+            const coord_def p = pos + coord_def(x, y);
+            if (!in_bounds(p))
+                return (true);
+
+            if (recurse)
+            {
+                if (grd(p) == DNGN_FLOOR)
+                    return (false);
+            }
+            else if (_has_no_floor_neighbours(p, true))
+                return (true);
+        }
+
+    return (recurse);
+}
+
+// Change the borders of the labyrinth to another (undiggable) wall type.
+static void _change_labyrinth_border(const dgn_region &region,
+                                     const dungeon_feature_type wall)
+{
+    const coord_def &end = region.pos + region.size;
+    for (int y = region.pos.y-1; y <= end.y; ++y)
+        for (int x = region.pos.x-1; x <= end.x; ++x)
+        {
+            const coord_def c(x, y);
+            if (!in_bounds(c)) // paranoia
+                continue;
+
+            if (grd(c) == wall || !grid_is_wall(grd(c)))
+                continue;
+
+            // All border grids have neighbours without any access to floor.
+            if (_has_no_floor_neighbours(c))
+                grd[x][y] = wall;
+        }
+}
+
 static void _change_walls_from_centre(const dgn_region &region,
                                       const coord_def &centre,
                                       bool  rectangular,
@@ -6783,6 +6830,8 @@ static void _labyrinth_level(int level_number)
                               34 * 34, DNGN_STONE_WALL,
                               0);
 
+    _change_labyrinth_border(lab, DNGN_METAL_WALL);
+
     _labyrinth_place_entry_point(lab, end);
 
     link_items();
-- 
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