added tile_picker feature for better dirt generation in diggy

map_gen/maps/diggy/config.lua

@@ -448,6 +448,17 @@ local Config = {
                 ['behemoth-spitter'] = 7,
             },
         },
+        -- perlin noise for dirt generation
+        tile_picker = {
+            -- uses perlin noise when true, random when false
+            enabled = true,
+
+            -- tiles to pick from
+            tiles = {'dirt-1', 'dirt-2', 'dirt-3', 'dirt-4', 'dirt-5', 'dirt-6', 'dirt-7'},
+
+            -- value between 0 and 1, higher values means smaller areas with same tile
+            noise_variance = 0.03
+        }
     },
 }
 

map_gen/maps/diggy/feature/diggy_hole.lua

@@ -11,6 +11,7 @@ local ScoreTable = require 'map_gen.maps.diggy.score_table'
 local Command = require 'utils.command'
 local CreateParticles = require 'features.create_particles'
 local Ranks = require 'resources.ranks'
+local TilePicker = require 'map_gen.maps.diggy.feature.tile_picker'
 
 local random = math.random
 local tonumber = tonumber
@@ -89,7 +90,8 @@ local function diggy_hole(entity)
 
     for i = #out_of_map_found, 1, -1 do
         local void_position = out_of_map_found[i]
-        tiles[i] = {name = 'dirt-' .. random(1, 7), position = void_position}
+        local tile_name = TilePicker.get_tile(void_position.x, void_position.y)
+        tiles[i] = {name = tile_name, position = void_position}
         local predicted = random()
         if predicted < 0.2 then
             rocks[i] = {name = 'rock-huge', position = void_position}
@@ -120,7 +122,8 @@ local function on_mined_tile(surface, tiles)
     for _, tile in pairs(tiles) do
         if (artificial_tiles[tile.old_tile.name]) then
             count = count + 1
-            new_tiles[count] = {name = 'dirt-' .. random(1, 7), position = tile.position}
+            local tile_name = TilePicker.get_tile(tile.position.x, tile.position.y)
+            new_tiles[count] = {name = tile_name, position = tile.position}
         end
     end
 
@@ -141,7 +144,8 @@ Command.add('diggy-clear-void', {
     for x = 0, width do
         for y = 0, height do
             count = count + 1
-            tiles[count] = {name = 'dirt-' .. random(1, 7), position = {x = x + left_top_x, y = y + left_top_y}}
+            local tile_name = TilePicker.get_tile(x + left_top_x, y + left_top_y)
+            tiles[count] = {name = tile_name, position = {x = x + left_top_x, y = y + left_top_y}}
         end
     end
 

map_gen/maps/diggy/feature/starting_zone.lua

@@ -8,9 +8,9 @@ local Template = require 'map_gen.maps.diggy.template'
 local Retailer = require 'features.retailer'
 local DiggyCaveCollapse = require 'map_gen.maps.diggy.feature.diggy_cave_collapse'
 local RS = require 'map_gen.shared.redmew_surface'
+local TilePicker = require 'map_gen.maps.diggy.feature.tile_picker'
 
 local insert = table.insert
-local random = math.random
 local sqrt = math.sqrt
 local floor = math.floor
 local pairs = pairs
@@ -51,13 +51,18 @@ function StartingZone.register(config)
         local rock_range = starting_zone_size - 2
         local stress_hack = floor(starting_zone_size * 0.1)
 
+        -- init tile picker
+        local seed = surface.map_gen_settings.seed + surface.index + 300
+        TilePicker.set_seed(seed)
+
         for x = -starting_zone_size, starting_zone_size do
             for y = -starting_zone_size, starting_zone_size do
                 local distance = floor(sqrt(x * x + y * y))
 
                 if (distance < starting_zone_size) then
                     if (distance > dirt_range) then
-                        insert(tiles, {name = 'dirt-' .. random(1, 7), position = {x = x, y = y}})
+                        local tile_name = TilePicker.get_tile(x, y)
+                        insert(tiles, {name = tile_name, position = {x = x, y = y}})
                     else
                         insert(tiles, {name = 'stone-path', position = {x = x, y = y}})
                     end

map_gen/maps/diggy/feature/tile_picker.lua

@@ -0,0 +1,78 @@
+--[[-- info
+    Provides nicer tile picking
+]]
+
+-- dependencies
+local Event = require 'utils.event'
+local perlin_noise = require 'map_gen.shared.perlin_noise'.noise
+
+-- this
+local Picker = {}
+
+local floor = math.floor
+local random = math.random
+
+local enabled = false
+local replacement_tiles
+local tile_count
+local noise_variance
+local seed
+
+-- should be called once before calling get_tile
+function Picker.set_seed(new_seed)
+    seed = new_seed
+end
+
+-- returns tile generated by perlin noise from coordinates
+function Picker.get_tile(x, y)
+    if not enabled then
+        return 'dirt-' .. random(1, 7)
+    end
+
+    -- value in range [-1, 1]
+    local noise
+    if seed then
+        noise = perlin_noise(x * noise_variance, y * noise_variance, seed)
+    else
+        noise = perlin_noise(x * noise_variance, y * noise_variance)
+    end
+
+    -- value in range [0, 1]
+    local corrected_noise = (noise + 1) / 2
+
+    -- value in range [1, tile_count]
+    local tile_number = floor(corrected_noise * tile_count) + 1
+
+    -- just in case perlin_noise() returns '1', not even sure if it can
+    if tile_number > tile_count then
+        tile_number = tile_count
+    end
+
+    return replacement_tiles[tile_number]
+end
+
+function Picker.register(config)
+    enabled = true
+    replacement_tiles = config.tiles or {'dirt-1', 'dirt-2', 'dirt-3', 'dirt-4', 'dirt-5', 'dirt-6', 'dirt-7'}
+    tile_count = #replacement_tiles
+    noise_variance = config.noise_variance or 0.03
+
+    -- add landfill event
+    Event.add(defines.events.on_player_built_tile, function(event)
+        local item = event.item
+        if not item or item.name ~= 'landfill' then
+            return
+        end
+
+        local tiles = event.tiles
+        for i = 1, #tiles do
+            local tile_name = Picker.get_tile(tiles[i].position.x, tiles[i].position.y)
+            tiles[i].name = tile_name
+        end
+
+        local surface = game.surfaces[event.surface_index]
+        surface.set_tiles(tiles)
+    end)
+end
+
+return Picker

map_gen/maps/diggy/scenario.lua

@@ -73,8 +73,11 @@ function Scenario.register()
         end
     )
 
-    local landfill_tiles = {'dirt-1','dirt-2','dirt-3','dirt-4','dirt-5','dirt-6','dirt-7'}
-    require ('map_gen.shared.change_landfill_tile')(landfill_tiles)
+    -- tile_picker adds its own landfill event
+    if not Config.features.tile_picker.enabled then
+        local landfill_tiles = {'dirt-1','dirt-2','dirt-3','dirt-4','dirt-5','dirt-6','dirt-7'}
+        require ('map_gen.shared.change_landfill_tile')(landfill_tiles)
+    end
 
     ScenarioInfo.set_map_name('Diggy')
     ScenarioInfo.set_map_description('Dig your way through!')