1 files changed, 127 insertions, 53 deletions
diff --git a/Tools/BlockTypePaletteGenerator/Generator.lua b/Tools/BlockTypePaletteGenerator/Generator.lua
index f33f2b789..b052ffa92 100644
--- a/Tools/BlockTypePaletteGenerator/Generator.lua
+++ b/Tools/BlockTypePaletteGenerator/Generator.lua
@@ -1,14 +1,33 @@
--- lib/lunajson/src/ is not in default Lua package paths
+-- Generator.lua
+
+--[[
+Crafts an intermediate block palette format to be read by Cuberite.
+It processes the blocks.json report file (https://wiki.vg/Data_Generators)
+into a file that can be loaded into a BlockTypePalette (and is to be stored
+as Server/Protocol/<version>/base.btp.txt).
+
+The output format is the regular TSV BlockTypePalette, described in the
+$/src/BlockTypePalette.h file.
+--]]
+
+
+
+
+-- Allow Lua to load libraries in our subfolder:
 package.path = 'lib/lunajson/src/?.lua;' .. package.path;
 
 
+
+
+
+
 --- Prints usage instructions to stdout.
--- If the optional `message` is passed, output is prepended by message _and_
+-- If the optional `aMessage` is passed, output is prepended by message _and_
 -- redirected to stderr.
-function usage(message)
-	if message then
+local function usage(aMessage)
+	if aMessage then
 		io.output(io.stderr);
-		io.write(message, "\n\n");
+		io.write(aMessage, "\n\n");
 	end
 	io.write(
 		"Usage: lua Generator.lua INPUTFILE OUTPUTFILE\n"..
@@ -22,70 +41,125 @@ function usage(message)
 end
 
 
--- Test whether the script is run in a path where it can load it's libraries
-if not pcall(function() require("lunajson.decoder") end) then
-	usage("Could not load required libraries, please run `Generator.lua` "..
-		"within its directory and make sure to run `git submodule update`.");
-end
 
 
--- Check/Prepare CLI arguments
-local inpath, outpath = ...;
-io.input(io.stdin);
-io.output(io.stdout);
 
-if select("#", ...) ~= 2 then
-	usage("Incorrect number of arguments.");
+--- Parses the JSON registry into a Lua table
+--[[ The returned array-table has the following format:
+{
+	{ id = 1, blockTypeName = "minecraft:stone", properties = {key = value, ...} },
+	...
+}
+--]]
+local function parseRegistry(aBlockRegistryJsonStr)
+	assert(type(aBlockRegistryJsonStr) == "string")
+
+	local lj = require("lunajson")
+	local input = lj.decode(aBlockRegistryJsonStr)
+	local registry = {}
+	local idx = 1
+	for blockTypeName, blockData in pairs(input) do
+		for _, state in pairs(blockData.states) do
+			registry[idx] = {
+				id = state.id,
+				blockTypeName = blockTypeName,
+				properties = state.properties,
+			}
+			idx = idx + 1
+		end
+	end
+	return registry
 end
 
-if inpath ~= "-" then
-	local handle, err = io.open(inpath, "r");
-	io.input(handle or usage(err));
-end
 
-if outpath ~= "-" then
-	local handle, err = io.open(outpath, "w");
-	io.output(handle or usage(err));
-end
 
 
--- Main program starts here
-local decode = (require("lunajson.decoder"))();
-local encode = (require("lunajson.encoder"))();
 
-local input = decode(io.input():read("*a"));
-local registry = {};
-local max_id = -1;
+--- Serializes the properties from the JSON / array table format into a single output string
+-- Concatenates all properties with \t as the delimiting character
+local function serializeProperties(aProperties)
+	local res = {}
+	local idx = 1
+	for k, v in pairs(aProperties or {}) do
+		res[idx] = k
+		res[idx + 1] = v
+		idx = idx + 2
+	end
+	return table.concat(res, "\t")
+end
+
 
 
-for blockname, blockdata in pairs(input) do
-	for i = 1, #(blockdata.states or {}) do
-		local state = blockdata.states[i];
-		assert(registry[state.id + 1] == nil, "Ensure no duplicate IDs");
 
-		-- needed in the end to verify we got no holes in the array:
-		max_id = math.max(max_id, state.id);
 
-		registry[state.id + 1] = {
-			id = assert(state.id, "id is required."),
-			name = assert(blockname, "Block type name is required."),
-			-- default = state.default or nil,  -- may need this later
-			props = state.properties,
-		};
+--- Returns the prefix that is common for all block type names in the registry
+-- aRegistry is the parsed registry, as returned from parseRegistry()
+local function findCommonPrefix(aRegistryTable)
+	local prefix = aRegistryTable[1].blockTypeName
+	local len = string.len(prefix)
+	local sub = string.sub
+	for _, block in ipairs(aRegistryTable) do
+		while (sub(block.blockTypeName, 1, len) ~= prefix) do
+			len = len - 1
+			if (len == 0) then
+				return ""
+			end
+			prefix = sub(prefix, 1, len)
+		end
 	end
+	return prefix
 end
 
 
--- The following assertion is not necessary by the current spec, but is required
--- by how lunajson distinguishes objects from arrays. Also if this fails, it is
--- _very_ likely that the input file is faulty.
-assert(#registry == max_id + 1, "Ensure that registry has contiguous keys");
 
-local out = {
-	Metadata = {
-		ProtocolBlockTypePaletteVersion = 1
-	},
-	Palette = registry
-};
 
-io.write(encode(out), "\n");
+
+-- Test whether the script is run in a path where it can load it's libraries
+if not(pcall(function() require("lunajson") end)) then
+	usage(
+		"Could not load required libraries, please run `Generator.lua` " ..
+		"within its directory and make sure to run `git submodule update`."
+	)
+end
+
+-- Check/Prepare CLI arguments
+local inpath, outpath = ...;
+inpath = inpath or "blocks.json"
+outpath = outpath or "base.btp.txt"
+if (inpath ~= "-") then
+	local handle, err = io.open(inpath, "r")
+	io.input(handle or usage(err))
+end
+if (outpath ~= "-") then
+	local handle, err = io.open(outpath, "w")
+	io.output(handle or usage(err))
+end
+
+-- Parse the registry:
+local registry = parseRegistry(io.input():read("*a"))
+local commonPrefix = findCommonPrefix(registry)
+
+-- Sort the entries:
+table.sort(registry,
+	function (entry1, entry2)
+		return (entry1.id < entry2.id)
+	end
+)
+
+-- Write out the output format:
+io.write("BlockTypePalette\n")
+io.write("FileVersion\t1\n")
+io.write("CommonPrefix\t", commonPrefix, "\n")
+io.write("\n")
+local prefixLen = string.len(commonPrefix) + 1
+for _, entry in ipairs(registry) do
+	local props = serializeProperties(entry.properties)
+	if (props ~= "") then
+		props = "\t" .. props
+	end
+	io.write(
+		entry.id, "\t",
+		string.sub(entry.blockTypeName, prefixLen),
+		props, "\n"
+	)
+end