stop a second tower stamping behind the Pokemon Tower

The tower's twelve ROUTE_10 rows are `gabled_block_6x6` tile for tile --
the artist drew the top of the tower as an ordinary six-cell block -- so
that template matched at (24,132) and stood a whole second building
behind it. Templates were matched and stamped independently, with
nothing stopping two grids claiming one drawing.

Placement is now first-claim-wins: a template never stamps into cells
another already claimed, which makes the list order the priority order.
The tower's own two templates move to the front so they take those
cells first.

Also corrects the split: the Route 10 half is TWELVE rows, not eight --
the 64px purple roof band plus two window courses -- so topRows and the
claimOnly twin now carry all of it, and the model is the complete
twenty-row drawing (96px facade under a real 64px roof). Both templates
verified to place exactly once world-wide.

The mound probe gains a MOUND_LEVEL knob; the low rungs are where this
was visible.

data/voxel_heights.lua

@@ -2140,6 +2140,85 @@ return {
   -- placement.
   buildings = {
     OVERWORLD = {
+      -- assets/docs/buildings/B30: the POKEMON TOWER -- the one drawing
+      -- in the catalogue that STRADDLES A MAP BOUNDARY.  Twelve of its
+      -- twenty rows stand in ROUTE_10's last rows (the 64px purple roof
+      -- band plus two window courses); the other eight -- five more
+      -- courses and the base with the door -- are on LAVENDER_TOWN,
+      -- where the tower begins at tile row 0.  Modelled per map it came
+      -- out as two buildings, one per half.
+      --
+      -- `topRows` composites ROUTE_10's twelve rows ABOVE the matched
+      -- grid, so the model is built from the COMPLETE twenty-row drawing
+      -- -- 96px of facade under the real 64px roof -- while placement
+      -- still matches only the eight Lavender rows.  Its `claimOnly`
+      -- twin below claims the ROUTE_10 rows and stamps nothing, so the
+      -- roof half does not also stand as its own building.
+      --
+      -- BOTH COME FIRST IN THIS LIST ON PURPOSE.  The tower's upper
+      -- twelve rows are `gabled_block_6x6` tile for tile -- the artist
+      -- drew the top of the tower as an ordinary six-cell block -- so
+      -- that template matches at ROUTE_10 (24,132) too.  Placement is
+      -- first-claim-wins (see Buildings.build), so claiming here before
+      -- the generic block reaches it is what keeps the second tower from
+      -- being stamped behind this one.
+      --
+      -- The 13-id last row is kept from the first attempt: the bare
+      -- 12-wide body grid is B14's lower two-thirds tile for tile, and
+      -- the extra id stops this template stamping inside
+      -- `flat_block_6x6`'s three placements (`matches` walks a row to
+      -- its own length, while `read` composites only #tiles[1] columns,
+      -- so a 13th id constrains placement without entering the drawing).
+      {
+        id = "pokemon_tower",
+        topRows = {
+          {  5,  6, 83, 83, 83, 83, 83, 83, 83, 83,  8,  9 },
+          { 21, 56, 18, 18, 18, 18, 18, 18, 18, 18, 56, 25 },
+          { 21, 56, 18, 18, 18, 18, 18, 18, 18, 18, 56, 25 },
+          { 21, 22, 23, 23, 23, 23, 23, 23, 23, 23, 24, 25 },
+          { 21, 56, 18, 18, 18, 18, 18, 18, 18, 18, 56, 25 },
+          { 21, 56, 18, 18, 18, 18, 18, 18, 18, 18, 56, 25 },
+          { 21, 22, 23, 23, 23, 23, 23, 23, 23, 23, 24, 25 },
+          { 37, 38, 34, 34, 34, 34, 34, 34, 34, 34, 40, 41 },
+          { 15, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 31 },
+          { 15, 75, 75, 75, 75, 75, 75, 75, 75, 75, 75, 31 },
+          { 15, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 31 },
+          { 15, 75, 75, 75, 75, 75, 75, 75, 75, 75, 75, 31 },
+        },
+        tiles = {
+          { 15, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 31 },
+          { 15, 75, 75, 75, 75, 75, 75, 75, 75, 75, 75, 31 },
+          { 15, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 31 },
+          { 15, 75, 75, 75, 75, 75, 75, 75, 75, 75, 75, 31 },
+          { 15, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 31 },
+          { 15, 75, 75, 75, 75, 75, 75, 75, 75, 75, 75, 31 },
+          { 15, 75, 75, 75, 75, 75, 75, 75, 75, 75, 75, 31 },
+          { 78, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 79, 17 },
+        },
+        roofRows = 64, roofBack = 8, roofFront = 8, roofCycle = { 8, 31 },
+        slab = 4, frontEave = 4, ledge = nil,
+      },
+      -- the tower's roof half, where it actually stands on ROUTE_10:
+      -- claimed flat so the drawing does not ALSO fold up as a building
+      -- behind the modelled tower (see topRows above)
+      {
+        id = "pokemon_tower_top",
+        claimOnly = true,
+        tiles = {
+          {  5,  6, 83, 83, 83, 83, 83, 83, 83, 83,  8,  9 },
+          { 21, 56, 18, 18, 18, 18, 18, 18, 18, 18, 56, 25 },
+          { 21, 56, 18, 18, 18, 18, 18, 18, 18, 18, 56, 25 },
+          { 21, 22, 23, 23, 23, 23, 23, 23, 23, 23, 24, 25 },
+          { 21, 56, 18, 18, 18, 18, 18, 18, 18, 18, 56, 25 },
+          { 21, 56, 18, 18, 18, 18, 18, 18, 18, 18, 56, 25 },
+          { 21, 22, 23, 23, 23, 23, 23, 23, 23, 23, 24, 25 },
+          { 37, 38, 34, 34, 34, 34, 34, 34, 34, 34, 40, 41 },
+          { 15, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 31 },
+          { 15, 75, 75, 75, 75, 75, 75, 75, 75, 75, 75, 31 },
+          { 15, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 31 },
+          { 15, 75, 75, 75, 75, 75, 75, 75, 75, 75, 75, 31 },
+        },
+      },
       -- assets/docs/buildings/B07: the two-storey gabled house.  Coursed cap over
       -- a gable wall, an awning with its double black underline, then the
       -- ground floor with the door.  7 placements, Red's and Blue's among
@@ -2731,75 +2810,6 @@ return {
         roofRows = 64, roofBack = 8, roofFront = 8, roofCycle = { 8, 31 },
         slab = 4, frontEave = 4, ledge = nil, seal = "s",
       },
-      -- assets/docs/buildings/B30: the POKEMON TOWER.  The one drawing
-      -- in the catalogue that STRADDLES A MAP BOUNDARY: its purple roof
-      -- band and top two window courses stand in ROUTE_10's last eight
-      -- tile rows, and only the lower eight rows -- six more courses and
-      -- the base with the door -- are on LAVENDER_TOWN, where the
-      -- building begins at tile row 0.  Modelled per map it came out as
-      -- two half-buildings: Lavender's half wearing a fabricated flat
-      -- cap (art row 0 stretched into a yellow slab), Route 10's half a
-      -- low volume of roof drawing folded at ground level behind it.
-      --
-      -- `topRows` is the fix, built for this template: the eight
-      -- ROUTE_10 rows are composited ABOVE the matched grid, so the
-      -- model is the COMPLETE 16-row drawing -- 96px of facade under a
-      -- real 32px roof band -- while placement still matches only the
-      -- Lavender rows.  Its twin `pokemon_tower_top` below claims the
-      -- Route 10 rows and stamps nothing, so the roof half no longer
-      -- also stands as its own building behind the tower.
-      --
-      -- The old silhouette problem is gone with the roof back: the band
-      -- closes the drawing's north outline the way it does on every
-      -- sibling, so no `seal` is needed.  The 13-id last row survives
-      -- from the first attempt: the bare 12-wide grid is B14's lower
-      -- two-thirds tile for tile, and the extra id keeps this template
-      -- from stamping inside flat_block_6x6's three placements
-      -- (`matches` walks a row to its own length; `read` composites
-      -- only #tiles[1] columns, so the 13th id constrains placement
-      -- without entering the drawing).
-      {
-        id = "pokemon_tower",
-        topRows = {
-          { 21, 56, 18, 18, 18, 18, 18, 18, 18, 18, 56, 25 },
-          { 21, 56, 18, 18, 18, 18, 18, 18, 18, 18, 56, 25 },
-          { 21, 22, 23, 23, 23, 23, 23, 23, 23, 23, 24, 25 },
-          { 37, 38, 34, 34, 34, 34, 34, 34, 34, 34, 40, 41 },
-          { 15, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 31 },
-          { 15, 75, 75, 75, 75, 75, 75, 75, 75, 75, 75, 31 },
-          { 15, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 31 },
-          { 15, 75, 75, 75, 75, 75, 75, 75, 75, 75, 75, 31 },
-        },
-        tiles = {
-          { 15, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 31 },
-          { 15, 75, 75, 75, 75, 75, 75, 75, 75, 75, 75, 31 },
-          { 15, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 31 },
-          { 15, 75, 75, 75, 75, 75, 75, 75, 75, 75, 75, 31 },
-          { 15, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 31 },
-          { 15, 75, 75, 75, 75, 75, 75, 75, 75, 75, 75, 31 },
-          { 15, 75, 75, 75, 75, 75, 75, 75, 75, 75, 75, 31 },
-          { 78, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 79, 17 },
-        },
-        roofRows = 32, roofBack = 7, roofFront = 8, roofCycle = { 5, 12 },
-        slab = 4, frontEave = 4, ledge = nil,
-      },
-      -- the tower's roof half, where it actually stands on ROUTE_10:
-      -- claimed flat so the drawing does not ALSO fold up as a second
-      -- building behind the modelled tower (see topRows above)
-      {
-        id = "pokemon_tower_top",
-        claimOnly = true,
-        tiles = {
-          { 21, 56, 18, 18, 18, 18, 18, 18, 18, 18, 56, 25 },
-          { 21, 56, 18, 18, 18, 18, 18, 18, 18, 18, 56, 25 },
-          { 21, 22, 23, 23, 23, 23, 23, 23, 23, 23, 24, 25 },
-          { 37, 38, 34, 34, 34, 34, 34, 34, 34, 34, 40, 41 },
-          { 15, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 31 },
-          { 15, 75, 75, 75, 75, 75, 75, 75, 75, 75, 75, 31 },
-          { 15, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 31 },
-          { 15, 75, 75, 75, 75, 75, 75, 75, 75, 75, 75, 31 },
-        },
-      },
     },
 
     FOREST = {

lib/Buildings.lua

@@ -627,7 +627,27 @@ function Buildings.build(S, map, data, perRow)
       for ty = 0, th - bh do
         Budget.tick()
         for tx = 0, tw - bw do
-          if S.tileAt[keyOf(tx, ty)] == first and matches(S, t, tx, ty) then
+          -- A placement never stamps into cells another template already
+          -- claimed. Templates are matched independently, and one
+          -- drawing can satisfy two grids: the Pokemon Tower's upper
+          -- twelve rows on ROUTE_10 are a standard 6-cell block tile for
+          -- tile, so `gabled_block_6x6` matched there and stood a whole
+          -- second building behind the tower. First claim wins, so the
+          -- list order below is the priority order -- the tower's own
+          -- templates come first precisely so they take those cells.
+          local free = S.tileAt[keyOf(tx, ty)] == first
+          if free then
+            for r = 0, bh - 1 do
+              for c = 0, bw - 1 do
+                if S.skip[keyOf(tx + c, ty + r)] then
+                  free = false
+                  break
+                end
+              end
+              if not free then break end
+            end
+          end
+          if free and matches(S, t, tx, ty) then
             if not built then
               local key = tileset.id .. ":" .. index
               if not models[key] then

tests/voxel_mound_probe.lua

@@ -30,7 +30,8 @@ return function(game)
   Pipelines.setLevel("tiltshift", 0)
   U.teleport(game, mapId, tonumber(sx), tonumber(sy), facing)
   U.wait(20)
-  Pipelines.setLevel("voxel", 3)
+  Pipelines.setLevel("voxel",
+    math.floor(tonumber(os.getenv("MOUND_LEVEL")) or 3))
   U.wait(30)
 
   local V = game.mods.exports["DRAMATIC_SHAPE"]