commit 216bf4adf320f6b336ee198d94e6dbaa9371ad1a
Author: rnd1 <rnd@rnd.com>
Date:   Tue Nov 8 10:32:58 2016 +0100

    init

diff --git a/README.txt b/README.txt
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+++ b/README.txt
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+BASIC_ROBOT: lightweight robot mod for multiplayer
+minetest 0.4.14
+(c) 2016 rnd
+
+MANUAL:
+	1. ingame help: right click spawner and click help button
+
+---------------------------------------------------------------------
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+----------------------------------------------------------------------
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diff --git a/commands.lua b/commands.lua
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+++ b/commands.lua
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+basic_robot.commands = {};
+
+local pi = math.pi;
+
+local function pos_in_dir(obj, dir) -- position after we move in specified direction
+	local yaw = obj:getyaw();
+	local pos = obj:getpos();
+	
+	if dir == 1 then
+		yaw = yaw + pi/2;
+		elseif dir == 2 then
+			yaw = yaw - pi/2;
+		elseif dir == 3 then
+		elseif dir == 4 then
+			yaw = yaw+pi;
+		elseif dir ==  5 then
+			pos.y=pos.y+1
+		elseif dir ==  6 then
+			pos.y=pos.y-1
+	end
+	
+	if dir<5 then
+		pos.x = pos.x+math.cos(yaw)
+		pos.z = pos.z+math.sin(yaw)
+	end
+	return pos
+end
+
+basic_robot.commands.move = function(obj,dir)
+	local pos = pos_in_dir(obj, dir)
+	
+	if minetest.get_node(pos).name ~= "air" then return end
+	-- up; no levitation!
+	if minetest.get_node({x=pos.x,y=pos.y-1,z=pos.z}).name == "air" and
+		minetest.get_node({x=pos.x,y=pos.y-2,z=pos.z}).name == "air" then 
+		return 
+	end
+	
+	obj:moveto(pos, true)
+end
+
+
+basic_robot.commands.turn = function (obj, angle)
+	local yaw = obj:getyaw()+angle;
+	obj:setyaw(yaw);
+end
+
+
+basic_robot.commands.dig = function(obj,dir)
+	local pos = pos_in_dir(obj, dir)	
+	local luaent = obj:get_luaentity();
+	if minetest.is_protected(pos,luaent.owner ) then return end
+	minetest.set_node(pos,{name = "air"})
+end
+
+basic_robot.commands.read_node = function(obj,dir)
+	local pos = pos_in_dir(obj, dir)	
+	return minetest.get_node(pos).name or ""
+end
+
+
+basic_robot.commands.place = function(obj,nodename, dir)
+	local pos = pos_in_dir(obj, dir)	
+	local luaent = obj:get_luaentity();
+	if minetest.is_protected(pos,luaent.owner ) then return end
+	if minetest.get_node(pos).name~="air" then return end
+	minetest.set_node(pos,{name = nodename})
+end
\ No newline at end of file
diff --git a/init.lua b/init.lua
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index 0000000..26da0e5
--- /dev/null
+++ b/init.lua
@@ -0,0 +1,443 @@
+-- basic_robot by rnd, 2016
+basic_robot = {};
+
+basic_robot.data = {}; 
+--[[
+[name] = {sandbox= .., bytecode = ..., ram = ..., obj = robot object} 
+robot object = object of entity, used to manipulate movements and more
+--]]
+
+
+
+dofile(minetest.get_modpath("basic_robot").."/commands.lua")
+
+-- SANDBOX for running lua code isolated and safely
+
+function getSandboxEnv (name)
+	local obj = basic_robot.data[name].obj;
+	local commands = basic_robot.commands;
+	return 
+	{
+		pcall=pcall,
+		ram = basic_robot.data[name].ram, -- "ram" - used to store variables
+		move = { -- changes position of robot
+			left = function() commands.move(obj, 1) end,
+			right = function() commands.move(obj, 2) end,
+			forward = function() commands.move(obj, 3) end,
+			backward = function() commands.move(obj, 4) end,
+			up = function() commands.move(obj,5) end,
+			down = function() commands.move(obj,6) end,
+		},
+		
+		turn = {
+			left = function() commands.turn(obj,math.pi/2) end,
+			right = function() commands.turn(obj,-math.pi/2) end,
+			angle = function(angle) commands.turn(obj,angle*math.pi/180) end,
+		},
+		
+		dig = {
+			left = function() commands.dig(obj, 1) end,
+			right = function() commands.dig(obj, 2) end,
+			forward = function() commands.dig(obj, 3) end,
+			backward = function() commands.dig(obj, 4) end,
+			down = function() commands.dig(obj, 6) end,
+			up = function() commands.dig(obj, 5) end,
+		},
+		
+		place = {
+			left = function(nodename) commands.place(obj, nodename, 1) end,
+			right = function(nodename) commands.place(obj,nodename, 2) end,
+			forward = function(nodename) commands.place(obj,nodename, 3) end,
+			backward = function(nodename) commands.place(obj,nodename, 4) end,
+			down = function(nodename) commands.place(obj,nodename, 6) end,
+			up = function(nodename) commands.place(obj,nodename, 5) end,
+		},
+		
+		insert = { -- insert item from inventory into another inventory TODO
+			forward = function(item, inventory) robot_insert(obj, item, inventory,1) end,
+			backward = function(item, inventory) robot_insert(obj, item, inventory,2) end,
+			down = function(item, inventory) robot_insert(obj, item, inventory,3) end,
+			up = function(item, inventory) robot_insert(obj, item, inventory,4) end,
+		},
+		
+		take = {}, -- take item from inventory TODO
+
+		selfpos = function() return obj:getpos() end,
+		
+		find_nodes = 
+			function(nodename,r) 
+				if r>8 then return false end
+				return (minetest.find_node_near(obj:getpos(), r, nodename)~=nil)
+			end, -- in radius around position
+		
+		
+		read_node = { -- returns node name
+			left = function() return commands.read_node(obj, 1) end,
+			right = function() return commands.read_node(obj, 2) end,
+			forward = function() return commands.read_node(obj, 3) end,
+			backward = function() return commands.read_node(obj, 4) end,
+			down = function() return commands.read_node(obj, 6) end,
+			up = function() return commands.read_node(obj, 5) end,
+		},
+		
+		say  = function(text)
+			minetest.chat_send_all("<robot ".. name .. "> " .. text)
+		end,
+
+		
+		string = {
+			byte = string.byte,	char = string.char,
+			find = string.find,
+			format = string.format,	gsub = string.gsub,
+			len = string.len, lower = string.lower,
+			upper = string.upper, rep = string.rep,
+			reverse = string.reverse, sub = string.sub,
+		},
+		math = {
+			abs = math.abs,	acos = math.acos,
+			asin = math.asin, atan = math.atan,
+			atan2 = math.atan2,	ceil = math.ceil,
+			cos = math.cos,	cosh = math.cosh,
+			deg = math.deg,	exp = math.exp,
+			floor = math.floor,	fmod = math.fmod,
+			frexp = math.frexp,	huge = math.huge,
+			ldexp = math.ldexp,	log = math.log,
+			log10 = math.log10,	max = math.max,
+			min = math.min,	modf = math.modf,
+			pi = math.pi, pow = math.pow,
+			rad = math.rad,	random = math.random,
+			sin = math.sin,	sinh = math.sinh,
+			sqrt = math.sqrt, tan = math.tan,
+			tanh = math.tanh,
+			},
+		table = {
+			concat = table.concat,
+			insert = table.insert,
+			maxn = table.maxn,
+			remove = table.remove,
+			sort = table.sort,
+		},
+		os = {
+			clock = os.clock,
+			difftime = os.difftime,
+			time = os.time,
+			
+		},
+	}
+end
+
+
+local function check_code(code)
+  
+  local bad_code = {"while ", "for ", "do ", "repeat ", "until ", "goto "}
+	
+  for _, v in pairs(bad_code) do
+    if string.find(code, v) then
+      return v .. " is not allowed!";
+    end
+  end
+
+end
+
+local function CompileCode ( script )
+	local ScriptFunc, CompileError = loadstring( script )
+    if CompileError then
+        return nil, CompileError
+    end
+	return ScriptFunc, nil
+end
+
+local function initSandbox ( name )
+	basic_robot.data[name].sandbox = getSandboxEnv (name);
+end
+
+local function setCode( name, script ) -- to run script: 1. initSandbox 2. setCode 3. runSandbox
+	local err;
+	err = check_code(script);
+	if err then return err end
+	local bytecode, err = CompileCode ( script );
+	if err then return err end
+	basic_robot.data[name].bytecode = bytecode;
+	return nil
+end
+
+
+local function runSandbox( name)
+    
+	local ScriptFunc = basic_robot.data[name].bytecode;
+	if not ScriptFunc then 
+		return "Bytecode missing."
+	end	
+	
+    setfenv( ScriptFunc, basic_robot.data[name].sandbox )
+
+    local Result, RuntimeError = pcall( ScriptFunc )
+    if RuntimeError then
+        return RuntimeError
+    end
+
+    return nil
+end
+
+
+
+-- note: to see memory used by lua in kbytes: collectgarbage("count")
+-- /spawnentity basic_robot:robot
+
+-- TODO.. display form when right click robot
+local function update_formspec_robot(self)
+	
+end
+
+minetest.register_entity("basic_robot:robot",{
+	energy = 1, 
+	owner = "",
+	hp_max = 10,
+	code = "",
+	timer = 0,
+	timestep = 1,
+	spawnpos = "",
+	visual="cube",
+	visual_size={x=1,y=1},
+	running = 0,
+	collisionbox = {-0.5,-0.5,-0.5, 0.5,0.5,0.5},
+	physical=true,
+
+	textures={"arrow.png","basic_machine_side.png","face.png","basic_machine_side.png","basic_machine_side.png","basic_machine_side.png"},
+		
+	on_activate = function(self, staticdata)
+		
+		-- how to make it remember owner when it reactivates ?? staticdata seems to be empty
+		
+		if staticdata~="" then -- reactivate robot
+			
+			self.owner = staticdata; -- remember its owner
+			if not basic_robot.data[self.owner] then
+				self.object:remove(); 
+				minetest.chat_send_player(self.owner, "#ROBOT INIT:  error. spawn robot again.")
+				return;
+			end
+			
+			basic_robot.data[self.owner].obj = self.object;
+			initSandbox ( self.owner )
+			self.running = 1;
+
+			return
+		end
+		
+		-- init robot
+		minetest.after(0, 
+		function() 
+			if not basic_robot.data[self.owner] then
+				basic_robot.data[self.owner] = {};
+			end
+			basic_robot.data[self.owner].obj = self.object;
+			
+			initSandbox ( self.owner )
+			local err = setCode( self.owner, self.code );
+			if err then
+				minetest.chat_send_player(self.owner,"#ROBOT CODE COMPILATION ERROR : " .. err) 
+				self.running = 0; -- stop execution
+			end
+			
+			self.running = 1
+		end
+		)
+		
+		self.object:setyaw(0);
+		
+	end,
+	
+	get_staticdata = function(self)
+		return self.owner;
+	end,
+	
+	on_punch = function (self, puncher, time_from_last_punch, tool_capabilities, dir)
+		
+	end,
+	
+	on_step = function(self, dtime)
+		self.timer=self.timer+dtime
+		if self.timer>self.timestep and self.running ~= 0 then 
+			self.timer = 0;
+			local err = runSandbox(self.owner);
+			if err then 
+				minetest.chat_send_player(self.owner,"#ROBOT ERROR : " .. err) 
+				self.running = 0; -- stop execution
+			end
+			
+			return 
+		end
+		
+		return
+	end,
+	
+	 on_rightclick = function(self, clicker)
+		-- TODO
+	 end,
+})
+
+
+local robot_spawner_update_form = function (pos)
+	
+		local meta = minetest.get_meta(pos);
+		local x0,y0,z0;
+		x0=meta:get_int("x0");y0=meta:get_int("y0");z0=meta:get_int("z0"); -- direction of velocity
+		local code = minetest.formspec_escape(meta:get_string("code"));
+		
+		local form  = 
+		"size[8,6]" ..  -- width, height
+		"textarea[0.1,0.75;8.4,6.5;code;code;".. code.."]"..
+		"button_exit[-0.25,-0.25;2,1;spawn;SPAWN]"..
+		"button[1.75,-0.25;2,1;despawn;REMOVE]"..
+		"button[5.25,-0.25;1,1;help;help]"..
+		"button_exit[6.25,-0.25;1,1;reset;reset]"..
+		"button_exit[7.25,-0.25;1,1;OK;OK]";
+
+		meta:set_string("formspec",form);
+
+end
+
+local spawn_robot = function(pos,node,ttl)
+	if ttl<0 then return end
+	
+	local meta = minetest.get_meta(pos);
+	local t0 = meta:get_int("t");
+	local t1 = minetest.get_gametime(); 
+	local T = meta:get_int("T"); -- temperature
+	
+	if t0>t1-2 then -- activated before natural time
+		T=T+1;
+	else
+		if T>0 then 
+			T=T-1 
+			if t1-t0>5 then T = 0 end
+		end
+	end
+	meta:set_int("T",T);
+	meta:set_int("t",t1); -- update last activation time
+	
+	if T > 2 then -- overheat
+			minetest.sound_play("default_cool_lava",{pos = pos, max_hear_distance = 16, gain = 0.25})
+			meta:set_string("infotext","overheat: temperature ".. T)
+			return
+	end
+
+	-- spawn robot on top
+	pos.y=pos.y+1;
+	local owner = meta:get_string("owner")
+	-- if robot already exists do nothing
+	if basic_robot.data[owner] and basic_robot.data[owner].obj then
+		if basic_robot.data[owner].obj:getpos() then 
+			minetest.chat_send_player(owner,"#ROBOT ERROR : robot already active")
+			return 
+		end
+	end
+	
+	local obj = minetest.add_entity(pos,"basic_robot:robot");
+	local luaent = obj:get_luaentity();
+	luaent.owner = meta:get_string("owner");
+	luaent.code = meta:get_string("code");
+	luaent.spawnpos = minetest.pos_to_string({x=pos.x,y=pos.y-1,z=pos.z});
+end
+
+minetest.register_node("basic_robot:spawner", {
+	description = "Spawns robot",
+	tiles = {"cpu.png"},
+	groups = {oddly_breakable_by_hand=2,mesecon_effector_on = 1},
+	drawtype = "allfaces",
+	paramtype = "light",
+	param1=1,
+	walkable = true,
+	alpha = 150,
+	after_place_node = function(pos, placer)
+		local meta = minetest.env:get_meta(pos)
+		meta:set_string("owner", placer:get_player_name()); 
+		local privs = minetest.get_player_privs(placer:get_player_name()); if privs.privs then meta:set_int("admin",1) end
+	
+		meta:set_string("code","");
+		robot_spawner_update_form(pos);
+		
+	end,
+
+	mesecons = {effector = {
+		action_on = spawn_robot 
+		}
+	},
+	
+	on_receive_fields = function(pos, formname, fields, sender)
+		
+		local name = sender:get_player_name();
+		if minetest.is_protected(pos,name) then return end
+		
+		if fields.reset then
+			local meta = minetest.get_meta(pos);
+			meta:set_string("code","");
+			robot_spawner_update_form(pos);
+			return
+		end
+		
+		if fields.OK then
+			local privs = minetest.get_player_privs(sender:get_player_name());
+			local meta = minetest.get_meta(pos);
+			--minetest.chat_send_all("form at " .. dump(pos) .. " fields " .. dump(fields))
+			
+			if fields.code then 
+				local code = fields.code or "";
+				meta:set_string("code", code)
+			end
+	
+			robot_spawner_update_form(pos);
+			return
+		end
+		
+		if fields.help then 
+			
+			local text =  "BASIC LUA SYNTAX\n \nif CONDITION then BLOCK1 else BLOCK2 end \nmyTable1 = {1,2,3},  myTable2 = {[\"entry1\"]=5, [\"entry2\"]=1}\n"..
+			"access table entries with myTable1[1] or myTable2.entry1 or myTable2[\"entry1\"]\n"..
+			"\nROBOT COMMANDS\n\n"..
+			"move.direction(), where direction is forward, backward, left,right, up, down\n"..
+			"turn.left(), turn.right(), turn.angle(45)\n"..
+			"dig.direction(), place.direction(\"default:dirt\")\nread_node.direction() tells you names of nodes\n"..
+			"find_nodes(3,\"default:dirt\") is true if node can be found at radius 3 around robot, otherwise false\n"..
+			"selfpos() returns table {x=pos.x,y=pos.y,z=pos.z}\n"..
+			"say(\"hello\") will speak";
+			
+		
+			text = minetest.formspec_escape(text);
+			
+			local form = "size [8,7] textarea[0,0;8.5,8.5;help;HELP;".. text.."]"
+			minetest.show_formspec(sender:get_player_name(), "robot_help", form);
+			
+			return
+		end
+		
+		if fields.spawn then
+			spawn_robot(pos,0,0);
+			return
+		end
+		
+		if fields.despawn then
+			local meta = minetest.get_meta(pos);
+			local owner = meta:get_string("owner");
+			
+			if not basic_robot.data[owner] then return end
+			if basic_robot.data[owner].obj then
+				basic_robot.data[owner].obj:remove();
+			end
+			return
+		end
+		
+	end,
+	
+})
+
+
+minetest.register_craft({
+	output = "basic_robot:spawner",
+	recipe = {
+		{"default:mese_crystal", "default:mese_crystal","default:mese_crystal"},
+		{"default:mese_crystal", "default:mese_crystal","default:mese_crystal"},
+		{"default:stone", "default:steel_ingot", "default:stone"}
+	}
+})
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diff --git a/textures/arrow.png b/textures/arrow.png
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diff --git a/textures/basic_machine_side.png b/textures/basic_machine_side.png
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diff --git a/textures/cpu.png b/textures/cpu.png
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diff --git a/textures/face.png b/textures/face.png
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