kingdoms_game/mods/utils/mapmanipulator.lua

--[[
Copyright (c) 2014, Robert 'Bobby' Zenz
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--- The MapManipulator is a thin wrapper around the VoxelManip object
-- provided by minetest. It only capsules the VoxelManip and VoxelArea behind
-- a few functions to minimize code.
MapManipulator = {}


--- Creates a new instance of MapManipulator.
--
-- The parameters only need to be used if you want to read from a certain
-- area of the map. They are not needed if called from on_generated function.
--
-- @param minp Optional. The minimum point to read the data from.
-- @param maxp Optional. The maximum point to read the data from.
-- @return A new instance.
function MapManipulator:new(minp, maxp)
	local instance = {
		area = nil,
		data = nil,
		emax = nil,
		emin = nil,
		param2_data = nil,
		voxelmanip = nil
	}
	
	if minp == nil and maxp == nil then
		instance.voxelmanip, instance.emin, instance.emax = minetest.get_mapgen_object("voxelmanip")
	else
		instance.voxelmanip = minetest.get_voxel_manip()
		instance.emin = minp
		instance.emax = maxp
		instance.voxelmanip:read_from_map(instance.emin, instance.emax)
	end
	
	instance.area = VoxelArea:new({
		MinEdge = instance.emin,
		MaxEdge = instance.emax
	})
	
	setmetatable(instance, self)
	self.__index = self
	
	return instance
end


--- Gets the VoxelArea for the current VoxelManip.
--
-- @return The VoxelArea.
function MapManipulator:get_area()
	return self.area
end

--- Gets the data from the VoxelManip object.
-- The data is an array that can be accessed by using the VoxelArea object.
--
-- @return Two values, the data and the param2 data.
function MapManipulator:get_data()
	if self.data == nil then
		self.data = self.voxelmanip:get_data()
		self.param2_data = self.voxelmanip:get_param2_data()
	end
	
	return self.data, self.param2_data
end

--- Gets the node and param2 at the given location.
--
-- @param x The x coordinate (width).
-- @param z the z coordinate (depth).
-- @param y The y coordinate (height).
-- @return Two values, the node at the given location and the param2 value.
function MapManipulator:get_node(x, z, y)
	if self.data == nil then
		self.data = self.voxelmanip:get_data()
		self.param2_data = self.voxelmanip:get_param2_data()
	end
	
	local index = self.area:index(x, y, z)
	
	return self.data[index], self.param2_data[index]
end

--- Sets the data into the VoxelManip object.
-- Will also correct and update the lighting, the liquids and flush the map.
--
-- @param data Optional. The data to set. If nil the cached data will be used.
-- @param param2_data Optional. The param2 data to set. If nil the cached data
--                    will be used.
function MapManipulator:set_data(data, param2_data)
	if data == nil and self.data == nil then
		return
	end
	
	self.voxelmanip:set_data(data or self.data)
	self.voxelmanip:set_param2_data(param2_data or self.param2_data)
	
	self.voxelmanip:set_lighting({
		day = 1,
		night = 0
	})
	self.voxelmanip:calc_lighting()
	self.voxelmanip:update_liquids()
	self.voxelmanip:write_to_map()
	self.voxelmanip:update_map()
	
	self.data = nil
	self.param2_data = nil
end

--- Sets the node at the given location.
--
-- @param x The x coordinate (width).
-- @param z the z coordinate (depth).
-- @param y The y coordinate (height).
-- @param node The node to set.
-- @param param2 Optional. The param2 data to set for this node.
function MapManipulator:set_node(x, z, y, node, param2)
	if self.data == nil then
		self.data = self.voxelmanip:get_data()
		self.param2_data = self.voxelmanip:get_param2_data()
	end
	
	local index = self.area:index(x, y, z)
	
	self.data[index] = node
	self.param2_data[index] = param2
end