StagedVoxelRegion: initial save() implementation.

....but it's untested, as usual.

worldeditadditions_core/init.lua

@@ -9,6 +9,7 @@
 local modpath = minetest.get_modpath("worldeditadditions_core")
 
 worldeditadditions_core = {
+	version = "1.15-dev",
 	modpath = modpath,
 	registered_commands = {},
 	-- Storage for per-player node limits before safe_region kicks in.

worldeditadditions_core/utils/io/StagedVoxelRegion.lua

@@ -1,7 +1,7 @@
 local weac = worldeditadditions_core
 
 local weaschem = weac.parse.file.weaschem
-
+local voxeltools = dofile(weac.modpath.."utils/io/voxeltools.lua")
 
 --- A region of the world that is to be or has been saved to/from disk.
 -- This class exists to make moving things to/from disk easier and less complicated.
@@ -38,13 +38,15 @@ end
 -- To save data, you probably want to call the save() method.
 -- @param	pos1		Vector3				The position in WORLD SPACE of pos1 of the defined region to stage for saving.
 -- @param	pos2		Vector3				The position in WORLD SPACE of pos2 of the defined region to stage for saving.
+-- @param	offset		Vector3		Apply this offset before placing in the world. e.g. if you have a schematic of a tree, and want it to place centred on the base thereof.
 -- @param	voxelmanip	VoxelManipulator	The voxel manipulator to take data from and save to disk.
 -- @returns	bool,StagedVoxelRegion	A success boolean, followed by the new StagedVoxelRegion instance.
-function StagedVoxelRegion.NewFromVoxelManip(pos1, pos2, voxelmanip)
+function StagedVoxelRegion.NewFromVoxelManip(pos1, pos2, offset, voxelmanip)
-	
+	local data, param2 = voxeltools.voxelmanip2raw(voxelmanip, pos1, pos2)
+	return StagedVoxelRegion.NewFromRaw(pos1, pos2, offset, data, param2)
 end
 
---- Creates a new StagedVoxelRegion from the given VoxelManipulator data.
+-- Creates a new StagedVoxelRegion from the given VoxelManipulator data.
 -- To save data, you probably want to call the save() method.
 -- @param	pos1		Vector3				The position in WORLD SPACE of pos1 of the defined region to stage for saving.
 -- @param	pos2		Vector3				The position in WORLD SPACE of pos2 of the defined region to stage for saving.
@@ -52,23 +54,25 @@ end
 -- @param	data	number[]	A table of numbers representing the node ids.
 -- @param	param2	number[]	A table of numbers representing the param2 data. Should exactly match the data number[] in size.
 -- @returns	bool,StagedVoxelRegion	A success boolean, followed by the new StagedVoxelRegion instance.
-function StagedVoxelRegion.NewFromTable(pos1, pos2, area, data, param2)
+-- function StagedVoxelRegion.NewFromTable(pos1, pos2, area, data, param2)
 	
-end
+-- end
 
 --- Creates a new StagedVoxelRegion from raw data/param2 tables.
 -- @static
--- @param	pos1		Vector3				The position in WORLD SPACE of pos1 of the defined region to stage for saving.
+-- @param	pos1		Vector3		The position in WORLD SPACE of pos1 of the defined region to stage for saving.
--- @param	pos2		Vector3				The position in WORLD SPACE of pos2 of the defined region to stage for saving.
+-- @param	pos2		Vector3		The position in WORLD SPACE of pos2 of the defined region to stage for saving.
--- @param	data	number[]	A table of numbers representing the node ids. Must be ALREADY TRIMMED, NOT just taken straight from a VoxelManip!
+-- @param	offset		Vector3		Apply this offset before placing in the world. e.g. if you have a schematic of a tree, and want it to place centred on the base thereof.
--- @param	param2	number[]	A table of numbers representing the param2 data. Should exactly match the data number[] in size. Must be ALREADY TRIMMED, NOT just taken straight from a VoxelManip!
+-- @param	data	number[]		A table of numbers representing the node ids. Must be ALREADY TRIMMED, NOT just taken straight from a VoxelManip!
+-- @param	param2	number[]		A table of numbers representing the param2 data. Should exactly match the data number[] in size. Must be ALREADY TRIMMED, NOT just taken straight from a VoxelManip!
 -- @returns	bool,StagedVoxelRegion	A success boolean, followed by the new StagedVoxelRegion instance.
-function StagedVoxelRegion.NewFromRaw(pos1, pos2, data, param2)
+function StagedVoxelRegion.NewFromRaw(pos1, pos2, offset, data, param2)
 	return make_instance({
 		name = "untitled",
 		description = "",
 		pos1 = pos1:clone(),
 		pos2 = pos2:clone(),
+		offset = offset,
 		tables = {
 			data = data,
 			param2 = param2
@@ -136,8 +140,59 @@ end
 -- @param	filepath		string	The filepath to save the StagedVoxelRegion to.
 -- @param	format="auto"	string	The format to save in. Default: automatic, determine from file extension. See worldeditadditions_core.io.FileFormats for more information.
 -- @returns	bool			Whether the operation was successful or not.
-function StagedVoxelRegion.save(filepath, format)
+function StagedVoxelRegion.save(svr, filepath, format)
+	local handle = io.open(filepath, "w")
+	if handle == nil then return false, "Failed to open handle to filepath '"..filepath.."'" end
 	
+	local parts = {}
+	
+	---
+	-- Magic bytes
+	---
+	table.insert(parts, "WEASCHEM 1\n")
+	
+	---
+	-- Header
+	---
+	local header = {
+		name = svr.name,
+		size = (svr.pos2 - svr.pos1):abs(),
+		offset = svr.offset,
+		
+		type = "full", -- TODO: Add delta support later
+		generator = "WorldEditAdditions/"..weac.version.." "..minetest.get_version().project.."/"..minetest.get_version().string,
+	}
+	if svr.description then header.description = svr.description end
+	table.insert(parts, minetest.write_json(header, false).."\n")
+	
+	---
+	-- ID map
+	---
+	local id_map, wid2sid = voxeltools.make_id_maps(svr.tables.data)
+	table.insert(parts, minetest.write_json(id_map, false).."\n")
+	
+	---
+	-- Data tables
+	---
+	local data, param2 = weac.table.map(svr.tables.data, function(val)
+		return wid2sid[data]
+	end), svr.tables.param2
+	
+	table.insert(parts, table.concat(voxeltools.runlength_encode(data), ","))
+	table.insert(parts, "\n")
+	table.insert(parts, table.concat(voxeltools.runlength_encode(param2), ","))
+	table.insert(parts, "\n")
+	
+	
+	---
+	-- Writing
+	---
+	
+	-- TODO: Implement compression here - maybe via minetest.compress(data, method, ...)
+	local schematic = table.concat(parts, "")
+	
+	handle:write(schematic)
+	handle:close()
 end
 
 --- Loads a file of the an array.

worldeditadditions_core/utils/io/voxeltools.lua

@@ -42,3 +42,80 @@ local function voxelmanip2raw(voxelmanip, pos1, pos2)
 	
 	return result_data, result_param2
 end
+
+--- Makes a node id map for saving to disk based on a given RAW data array of node ids.
+-- Also sequentially packs node ids to save space and potentially improve compression ratio, though this is unproven.
+-- @param	data	table	The RAW data table to read ids from to build the map.
+-- @returns table,table	A pair of maps to transform node ids from the world to the schematic file.
+-- 
+-- 1. The sID: number → node_name: string map to be saved in the schematic. sID stands for *schematic* id, which is NOT the same as the node id in the world.
+-- 2. The wID → sID node id map. wID = the node id in the current Minetest world, and sID = the *schematic* id as in #1. All world node ids MUST be pushed through this map before being saved to the schematic file.
+local function make_id_maps(data)
+	local map = {}
+	local id2id = {}
+	local next_id = 0
+	for _, wid in pairs(data) do
+		if id2id[wid] == nil then
+			id2id[wid] = next_id
+			next_id = next_id + 1
+			local sid = id2id[wid]
+			map[sid] = minetest.get_name_from_content_id(wid)
+		end
+	end
+	return map, id2id
+end
+
+--- Encodes a table of numbers (ZERO INDEXED) with run-length encoding.
+-- The reason for the existence of this function is avoiding very long strings when serialising / deserialising. Long strings can be a problem in more ways than one.
+-- @param	tbl		number[]	The table of numbers to runlength encode.
+local function runlength_encode(tbl)
+	local result = {}
+	local next = 0
+	local prev, count = nil, 0
+	for i, val in pairs(tbl) do
+		if prev ~= val then
+			local msg = tostring(prev)
+			if count > 1 then msg = tostring(count).."x"..msg end
+			result[next] = msg
+			next = next + 1
+			count = 0
+		end
+		prev = val
+		count = count + 1
+	end
+	local msg_last = tostring(prev)
+	if count > 1 then msg_last = tostring(count) .. "x" .. msg_last end
+	result[next] = msg_last
+	
+	return result
+end
+
+
+local function runlength_decode(tbl)
+	local unpacked = {}
+	local next = 0
+	
+	for i, val in pairs(tbl) do
+		local count, sid = string.match(val, "(%d+)x(%d+)")
+		if count == nil then
+			unpacked[next] = tonumber(val)
+			next = next + 1
+		else
+			sid = tonumber(sid)
+			for _ = 1, count do
+				unpacked[next] = sid
+				next = next + 1
+			end
+		end
+	end
+	
+	return unpacked
+end
+
+return {
+	voxelmanip2raw,
+	make_id_maps,
+	
+	runlength_encode,
+	runlength_decode
+}

worldeditadditions_core/utils/parse/file/init.lua

@@ -1,6 +1,7 @@
+local weac = worldeditadditions_core
 
 
-local localpath = wea_c.modpath.."/utils/parse/file/"
+local localpath = weac.modpath.."/utils/parse/file/"
 
 --- Parsers specifically for file formats.
 -- @namespace worldeditadditions_core.parse.file

worldeditadditions_core/utils/parse/file/weaschem.lua

@@ -3,7 +3,7 @@ local Vector3
 local parse_json, split
 if worldeditadditions_core then
 	Vector3 = weac.Vector3
-	parse_json = weac.parse.json
+	parse_json = dofile(weac.modpath.."/utils/parse/json.lua")
 	split = weac.split
 else
 	Vector3 = require("worldeditadditions_core.utils.vector3")