ComfyFactorio/modules/dynamic_landfill.lua

-- changes placed landfill tiles, adapting the new tile to adjecant tiles -- by mewmew

local regenerate_decoratives_value = true
local Event = require 'utils.event'
local math_random = math.random
local table_insert = table.insert
local water_tile_whitelist = {
    ['water'] = true,
    ['deepwater'] = true,
    ['water-green'] = true,
    ['water-mud'] = true,
    ['water-shallow'] = true,
    ['deepwater-green'] = true
}

local spiral_coords = {}
for r = 1, 96, 1 do
    for x = r * -1, r - 1, 1 do
        table_insert(spiral_coords, {x = x, y = r * -1})
    end
    for y = r * -1, r - 1, 1 do
        table_insert(spiral_coords, {x = r, y = y})
    end
    for x = r, r * -1 + 1, -1 do
        table_insert(spiral_coords, {x = x, y = r})
    end
    for y = r, r * -1 + 1, -1 do
        table_insert(spiral_coords, {x = r * -1, y = y})
    end
end

local function get_chunk_position(position)
    local chunk_position = {}
    position.x = math.floor(position.x, 0)
    position.y = math.floor(position.y, 0)
    for x = 0, 31, 1 do
        if (position.x - x) % 32 == 0 then
            chunk_position.x = (position.x - x) / 32
        end
    end
    for y = 0, 31, 1 do
        if (position.y - y) % 32 == 0 then
            chunk_position.y = (position.y - y) / 32
        end
    end
    return chunk_position
end

local function regenerate_decoratives(surface, position)
    local chunk = get_chunk_position(position)
    if not chunk then
        return
    end
    surface.destroy_decoratives({area = {{chunk.x * 32, chunk.y * 32}, {chunk.x * 32 + 32, chunk.y * 32 + 32}}})
    local decorative_names = {}
    for k, v in pairs(game.decorative_prototypes) do
        if v.autoplace_specification then
            decorative_names[#decorative_names + 1] = k
        end
    end
    surface.regenerate_decorative(decorative_names, {chunk})
end

local function is_this_a_valid_source_tile(pos, tiles)
    for _, tile in pairs(tiles) do
        if tile.position.x == pos.x and tile.position.y == pos.y then
            return false
        end
    end
    return true
end

local function place_fitting_tile(position, surface, tiles_placed)
    for _, coord in pairs(spiral_coords) do
        local tile = surface.get_tile({position.x + coord.x, position.y + coord.y})
        if not tile.collides_with('player-layer') then
            local valid_source_tile = is_this_a_valid_source_tile(tile.position, tiles_placed)
            if tile.name == 'out-of-map' then
                valid_source_tile = false
            end

            if valid_source_tile then
                if tile.hidden_tile then
                    surface.set_tiles({{name = tile.hidden_tile, position = position}}, true)
                else
                    surface.set_tiles({{name = tile.name, position = position}}, true)
                end
                return
            end
        end
    end
end

local function on_player_built_tile(event)
    if not event.item then
        return
    end
    if event.item.name ~= 'landfill' then
        return
    end
    local surface = game.surfaces[event.surface_index]

    for _, placed_tile in pairs(event.tiles) do
        if water_tile_whitelist[placed_tile.old_tile.name] then
            place_fitting_tile(placed_tile.position, surface, event.tiles)
            if regenerate_decoratives_value then
                if math_random(1, 5) == 1 then
                    regenerate_decoratives(surface, placed_tile.position)
                end
            end
        end
    end
end

local function on_robot_built_tile(event)
    if event.item.name ~= 'landfill' then
        return
    end
    local surface = event.robot.surface

    for _, placed_tile in pairs(event.tiles) do
        if water_tile_whitelist[placed_tile.old_tile.name] then
            place_fitting_tile(placed_tile.position, surface, event.tiles)
            if regenerate_decoratives then
                if math_random(1, 4) == 1 then
                    regenerate_decoratives(surface, placed_tile.position)
                end
            end
        end
    end
end

Event.add(defines.events.on_player_built_tile, on_player_built_tile)
Event.add(defines.events.on_robot_built_tile, on_robot_built_tile)