Add decoration engine

This commit still has an unexplained bug where it fails to place schematics underground, and this is to be investigated.

init.lua

@@ -704,12 +704,13 @@ function internal.generate_caves(data, minp, maxp)
     )
 
     local air = minetest.get_content_id("air")
+    local schems = {}
 
     -- Place blocks where necessary
     internal.iter_3d_area(bminp, bmaxp, function (i, pos)
         
-        local function place(name)
         local vi = vmanip:pos_to_index(pos)
+        local function place(name)
 
             if vmanip:get_index(vi) == air then
             elseif type(name) == "string" then
@@ -726,14 +727,6 @@ function internal.generate_caves(data, minp, maxp)
         elseif nt == internal.node_types.stick_edge then
         elseif nt == internal.node_types.air then
             place("air")
-        elseif nt == internal.node_types.floor_deco then
-            for _, deco in ipairs(noordstar_caves.registered_decorations) do
-                if deco.place_on ~= "floor" then
-                elseif math.random() > deco.fill_ratio then
-                else
-                    -- TODO: Check for biome
-                end
-            end
         else
             -- Find appropriate biome
             local heat = heat_points:get_index(i)
@@ -747,6 +740,32 @@ function internal.generate_caves(data, minp, maxp)
                 place(def.node_wall)
             elseif nt == internal.node_types.ceiling then
                 place(def.node_roof)
+            elseif nt == internal.node_types.floor_deco then
+                local schem_placed = false
+
+                if not schem_placed then
+                    -- Prevent decorations from spawning in the air
+                    if vmanip:get_index(vi) == air then
+                        schem_placed = true
+                    end
+                end
+
+                if not schem_placed then
+                    for _, deco in ipairs(noordstar_caves.registered_decorations) do
+                        if deco.place_on ~= "floor" then
+                        elseif math.random() > deco.fill_ratio then
+                        elseif not internal.is_deco_biome(deco, def.name) then
+                        else
+                            table.insert(schems, { pos = pos, deco = deco })
+                            schem_placed = true
+                            break
+                        end
+                    end
+                end
+
+                if not schem_placed then
+                    place(def.node_dust or "air")
+                end
             else
                 error(
                     table.concat(
@@ -763,7 +782,7 @@ function internal.generate_caves(data, minp, maxp)
         end
     end)
 
-    return vmanip.arr
+    return vmanip.arr, schems
 end
 
 -- Get the noise params for the cave biome temperature.
@@ -799,6 +818,23 @@ function internal.is_cave_node(noise, vastness)
     return noise > 1 - vastness
 end
 
+-- Return whether a given decoration definition can spawn in a given biome name
+function internal.is_deco_biome(def, biome_name)
+    if type(def.biomes) == "nil" then
+        return true
+    elseif type(def.biomes) == "string" then
+        return def.biomes == biome_name
+    elseif type(def.biomes) == "table" then
+        for _, name in pairs(def.biomes) do
+            if name == biome_name then
+                return true
+            end
+        end
+    end
+
+    return false
+end
+
 -- Return a bool whether a position is within a given volume
 function internal.is_valid_pos(pos, minp, maxp)
     if minp.x <= pos.x and pos.x <= maxp.x then
@@ -869,6 +905,80 @@ end
 --     minetest.chat_send_all(os.time() .. " - " .. text)
 -- end
 
+-- Place a table full of schematics into the world
+function internal.place_schematics(schems)
+    for _, schem in ipairs(schems) do
+        local pos  = schem.pos
+        local deco = schem.deco
+
+        if deco.deco_type == "simple" then
+            local h_min = deco.height
+            local h_max = math.max(deco.height_max, deco.height)
+            local dy = deco.place_offset_y - 1
+
+            if deco.place_on == "floor" then
+                for y = 1, math.random(h_min, h_max), 1 do
+
+                    minetest.set_node(
+                        { x = pos.x, y = pos.y + y + dy, z = pos.z },
+                        { name = deco.decoration }
+                    )
+                end
+            elseif deco.place_on == "ceiling" then
+                for y = 1, math.random(h_min, h_max), 1 do
+
+                    minetest.set_node(
+                        { x = pos.x, y = pos.y - y - dy, z = pos.z },
+                        { name = deco.decoration }
+                    )
+                end
+            else
+                error("Unknown place_on parameter `" .. deco.place_on .. "` for simple decoration!")
+            end
+        elseif deco.deco_type == "schematic" then
+            local name = deco.schematic
+            local force_placement = true
+            if string.find("force_placement", deco.flags) then
+                force_placement = true
+            end
+
+            if deco.place_on == "floor" then
+                local n = minetest.place_schematic(
+                    pos, name, deco.rotation, deco.replacements,
+                    force_placement, deco.flags
+                )
+
+                if type(n) == "nil" then
+                    minetest.chat_send_all("Squeak could not load!")
+                else
+                    minetest.chat_send_all("Placed a Squeak!")
+                    if not tpd_yet then
+                        minetest.get_player_by_name("singleplayer"):move_to(pos)
+                        tpd_yet = true
+                        minetest.chat_send_all(internal.pos_to_str(pos))
+                    end
+                end
+            elseif deco.place_on == "ceiling" then
+                -- Aim to place schematic against the ceiling, not through it
+                local h = minetest.read_schematic(name).size.y
+                local c_pos = { x = pos.x, y = pos.y - h, z = pos.z }
+                if string.find("place_center_y", deco.flags) then
+                    c_pos = pos
+                end
+
+                minetest.place_schematic(
+                    pos, name, deco.rotation, deco.replacements,
+                    force_placement, deco.flags
+                )
+            else
+                error("Unknown place_on parameter `" .. deco.place_on .. "` for simple decoration!")
+            end
+        else
+            error("Unknown decoration type `" .. deco.deco_type .. "`")
+        end
+    end
+end
+
 -- Helper function to convert a set of coordinates to a readable string
 function internal.pos_to_str(pos)
     return "(" .. pos.x .. ", " .. pos.y .. ", " .. pos.z .. " )"
@@ -1090,13 +1200,17 @@ end
 -------------------------------------------------------------------------------
 -------------------------------------------------------------------------------
 minetest.register_on_generated(function(minp, maxp, blockseed)
+    math.randomseed(blockseed)
+
     local vm = minetest.get_mapgen_object("voxelmanip")
     local data = vm:get_data()
 
-    data = internal.generate_caves(data, minp, maxp)
+    data, schems = internal.generate_caves(data, minp, maxp)
 
     vm:set_data(data)
     vm:write_to_map()
+
+    internal.place_schematics(schems)
 end)
 -------------------------------------------------------------------------------
 -------------------------------------------------------------------------------
@@ -1202,6 +1316,7 @@ noordstar_caves.register_biome({
     node_floor = "mcl_core:crying_obsidian",
     node_wall = "mcl_core:sand",
     node_roof = "mcl_ocean:sea_lantern",
+    node_dust = "mcl_core:snow",
     heat_point = 0,
     humidity_point = 0,
 })
@@ -1213,3 +1328,21 @@ noordstar_caves.register_biome({
     heat_point = 100,
     humidity_point = 100,
 })
+
+noordstar_caves.register_decoration({
+    deco_type = "simple",
+    place_on = "floor",
+    fill_ratio = 0.01,
+    decoration = "mcl_core:cactus",
+    height = 3,
+    height_max = 8,
+    biomes = { "test" },
+})
+noordstar_caves.register_decoration({
+    deco_type = "schematic",
+    place_on = "floor",
+    fill_ratio = 0.005,
+    schematic = "test.mts",
+    rotation = "random",
+    place_offset_y = 5,
+})