Minetest-WorldEditAdditions/worldeditadditions/lib/noise/params_apply_default.lua

local wea = worldeditadditions
local wea_c = worldeditadditions_core
local Vector3 = wea_c.Vector3

--- Makes sure that the default settings are all present in the given params table.
-- This way not all params have to be specified by the user.
-- @param	params	table	The params table generated from the user's input.
-- @return	table	A NEW table with all the missing properties filled in with the default values.
function worldeditadditions.noise.params_apply_default(params)
	local params_default = {
		-- How to apply the noise to the heightmap. Different values result in
		-- different effects:
		-- - The exact string "add": Noise values are added to each heightmap pixel.
		-- - The exact string "multiply": Each heightmap pixel is multiplied by the corresponding noise value.
		-- - A string in the form of digits followed, then the noise will is remapped from the range 0 - 1 to the range -1 - +1 and multiplied by this number / 2, and then for each pixel in the heightmap the corresponding noise value will be added to it.
		apply = 5,
		-- The backend noise algorithm to use
		algorithm = "perlinmt",
		-- Zooms in and out
		scale = Vector3.new(1, 1, 1),
		-- Offset the generated noise by this vector.
		offset = Vector3.new(0, 0, 0),
		-- Apply this exponent to the resulting noise value
		exponent = 1,
		-- Multiply the resulting noise value by this number. Changes the "strength" of the noise
		multiply = 1,
		-- Add this number to the resulting noise value
		add = 0
		-- The seed to generate the noise with. nil = randomly chosen
		-- The perlin generator isn't currently seedable :-/
		-- seed = nil
	}
	
	if not params[1] then params = { params } end
	
	-- If params[1] is thing, this is a list of params
	-- This might be a thing if we're dealing with multiple octaves
	for i,params_el in ipairs(params) do
		local default_copy = wea_c.table.shallowcopy(params_default)
		
		-- Keyword support
		for _i, keyword in ipairs(wea.noise.engines.available) do
			if params_el[keyword] ~= nil then
				params_el.algorithm = keyword
			end
		end
		
		-- Apply this table to fill in the gaps
		wea_c.table.apply(
			params_el,
			default_copy
		)
		params[i] = default_copy
	end
	
	return params
end