fire effect only over official goban concrete (tm)

rules.lua

@@ -33,6 +33,7 @@ Stype: a go stone of some type
 W: full block wall
 WE0-WE3: edge concrete
 WC0-WC3: corner concrete
+WB: other goban concrete
 --]]
 local function _check_position_uncached(pos)
     local node = minetest.get_node(pos)
@@ -60,6 +61,10 @@ local function _check_position_uncached(pos)
             return "WE" .. node.param2
         elseif reg_item.pattern_def.name == "corny" then
             return "WC" .. node.param2
+        elseif reg_item.pattern_def.name == "crossy" then
+            return "WB"
+        elseif reg_item.pattern_def.name == "starcrossy" then
+            return "WB"
         end
     end
 
@@ -257,7 +262,13 @@ function lc_liberties.handle_placement(pos)
                 local proximal_c = 0
 
                 for i2, v2 in pairs(v.stones) do
-                    nodecore.set_loud(v2, {name = "nc_fire:fire"})
+                    local under = check_position(v2 + down)
+                    print(under)
+                    if (under:sub(1, 1) == "W") and (under:len() > 1) then
+                        nodecore.set_loud(v2, {name = "nc_fire:fire"})
+                    else
+                        nodecore.set_loud(v2, {name = "air"})
+                    end
                     count = count + 1
                     if (v2:distance(pos) < 2.3) then
                         proximal_c = proximal_c + 1