ethereal_rebalance/init.lua

--[[
Copyright 2024 Andrey Stepanov

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
]]--

local decor_to_exclude = {}
decor_to_exclude["default:cactus"] = { "desert", }

local function has_value(tab, value)
    for _, v in pairs(tab) do
        if v == value then
            return true
        end
    end
    return false
end

local function is_empty(tab)
    if next(tab) == nil then
        return true
    else
        return false
    end
end

local decorations_backup = table.copy(minetest.registered_decorations)
minetest.clear_registered_decorations()
for _, decoration in pairs(decorations_backup) do
    local biomes_to_exclude = decor_to_exclude[decoration.decoration]
    if biomes_to_exclude == nil then
        minetest.register_decoration(decoration)
    else
        local biomes_backup = table.copy(decoration.biomes)
        decoration.biomes = {}
        for _, biome in pairs(biomes_backup) do
            if not has_value(biomes_to_exclude, biome) then
                table.insert(decoration.biomes, biome)
            end
        end
        if not is_empty(decoration.biomes) then
            minetest.register_decoration(decoration)
        end
    end
end

-- cactus
minetest.register_decoration(
    {
        decoration = "default:cactus",
        deco_type = "simple",
        biomes = { "desert" },
        sidelen = 80,
        y_min = 1,
        y_max = 100,
        place_on = { "default:desert_sand" },
        fill_ratio = 0.001,
        height_max = 4
    }
)