Rewriting the drainaquifer script

The original drainaquifer script could occasionally fail to notice aquifer layers if they happen to skip each of the special tiles that it checks, two per block.  It also left the block-level aquifer flags set, which seems like a minor waste of FPS.

The new script uses the block-level flags to determine which blocks to check, which seems to be both more correct and faster.  It's also written in Lua instead of Ruby, for clarity and ease of debugging.  The name has changed slightly to prevent problems if both scripts are installed for some reason.

NEWS

@@ -1,4 +1,6 @@
 DFHack future
+    Fixes:
+        - replaced drainaquifer.rb with a faster less buggy drain-aquifer.lua
 
 DFHack 0.40.13-r1
     Internals:

Readme.html

@@ -501,7 +501,7 @@ access DF memory and allow for easier development of new tools.</p>
 <li><a class="reference internal" href="#binpatch" id="id132">binpatch</a></li>
 <li><a class="reference internal" href="#create-items" id="id133">create-items</a></li>
 <li><a class="reference internal" href="#digfort" id="id134">digfort</a></li>
-<li><a class="reference internal" href="#drainaquifer" id="id135">drainaquifer</a></li>
+<li><a class="reference internal" href="#drain-aquifer" id="id135">drain-aquifer</a></li>
 <li><a class="reference internal" href="#deathcause" id="id136">deathcause</a></li>
 <li><a class="reference internal" href="#dfstatus" id="id137">dfstatus</a></li>
 <li><a class="reference internal" href="#embark" id="id138">embark</a></li>
@@ -2873,8 +2873,8 @@ as an offset for the pattern: instead of starting at the cursor, it will start
 <p>The script takes the plan filename, starting from the root df folder (where
 Dwarf Fortress.exe is found).</p>
 </div>
-<div class="section" id="drainaquifer">
-<h2><a class="toc-backref" href="#id135">drainaquifer</a></h2>
+<div class="section" id="drain-aquifer">
+<h2><a class="toc-backref" href="#id135">drain-aquifer</a></h2>
 <p>Remove all 'aquifer' tag from the map blocks. Irreversible.</p>
 </div>
 <div class="section" id="deathcause">

Readme.rst

@@ -2149,8 +2149,8 @@ as an offset for the pattern: instead of starting at the cursor, it will start
 The script takes the plan filename, starting from the root df folder (where
 Dwarf Fortress.exe is found).
 
-drainaquifer
-============
+drain-aquifer
+=============
 Remove all 'aquifer' tag from the map blocks. Irreversible.
 
 deathcause

scripts/drain-aquifer.lua

@@ -0,0 +1,33 @@
+-- Remove all aquifers from the map
+
+local function drain()
+    local last_layer = nil
+    local layer_count = 0
+    local tile_count = 0
+
+    for k, block in ipairs(df.global.world.map.map_blocks) do
+        if block.flags.has_aquifer then
+            block.flags.has_aquifer = false
+            block.flags.check_aquifer = false
+            
+            for x, row in ipairs(block.designation) do
+                for y, tile in ipairs(row) do
+                    if tile.water_table then
+                        tile.water_table = false
+                        tile_count = tile_count + 1
+                    end
+                end
+            end
+            
+            if block.map_pos.z ~= last_layer then
+                last_layer = block.map_pos.z
+                layer_count = layer_count + 1
+            end
+        end
+    end
+
+    print("Cleared "..tile_count.." aquifer tile"..((tile_count ~= 1) and "s" or "")..
+        " in "..layer_count.." layer"..((layer_count ~= 1) and "s" or "")..".")
+end
+
+drain(...)

scripts/drainaquifer.rb

@@ -1,13 +0,0 @@
-# remove all aquifers from the map
-
-count = 0
-df.each_map_block { |b|
-	if b.designation[0][0].water_table or b.designation[8][8].water_table
-		count += 1
-		df.each_map_block_z(b.map_pos.z) { |bz|
-			bz.designation.each { |dx| dx.each { |dy| dy.water_table = false } }
-		}
-	end
-}
-
-puts "cleared #{count} aquifer#{'s' if count > 1}"