Add copper, and the beginnings of a machine system.

mods/rgt_machines/rgt_alloy_furnace/mod.conf

@@ -0,0 +1,2 @@
+name = rgt_alloy_furnace
+depends = rgt_machines

mods/rgt_machines/rgt_arc_furnace/init.lua

@@ -5,8 +5,9 @@ local function can_work(node, m, inv)
     if input:get_count() > 0 then
         -- Would melting this item exceed our fluid capacity?
         local fluid = m:get_float "fluid"
-        local capacity = m:get_int "fluid_capacity"
-        if capacity -fluid >= 1 then
+        local fluid_type = m:get "fluid_type"
+        local capacity = m:get_float "fluid_capacity"
+        if capacity -fluid >= 1 and (fluid == 0 or input:get_definition().material == fluid_type) then
             return true
         end
     end
@@ -16,7 +17,7 @@ end
 local function update_formspec(m, progress)
     progress = progress or m:get_int "progress"
     local fluid = m:get_float "fluid"
-    local capacity = m:get_int "fluid_capacity"
+    local capacity = m:get_float "fluid_capacity"
     local progressbar = progress == 0 and "rgt_progress_bg.png^[transformR270" or "rgt_progress_bg.png^[lowpart:"..progress..":rgt_progress_bg_active.png^[transformR270"
     local fluidcontainer = fluid == 0 and "rgt_fluid_container_bg.png" or "rgt_fluid_container_bg.png^[lowpart:"..(fluid /capacity *100)..":rgt_fluid_container_bg_filled.png"
     local fs = {"\
@@ -57,11 +58,14 @@ local function update(pos, elapsed)
             minetest.swap_node(pos, node)
         end
         
-        local progress = m:get_int("progress") +20
+        local progress = m:get_int("progress") +50
         
         if progress >= 100 then
             local fluid = m:get_float "fluid"
             fluid = fluid +1
+            if fluid >= 2 then
+                fluid = fluid -rgt_machines.push_fluid(pos, m:get "fluid_type", fluid)
+            end
             m:set_float("fluid", fluid)
             
             -- Consume an item.
@@ -69,6 +73,8 @@ local function update(pos, elapsed)
             s:take_item()
             inv:set_stack("input", 1, s)
             
+            m:set_string("fluid_type", s:get_definition().material)
+            
             progress = 0
         end
         m:set_int("progress", progress)
@@ -90,7 +96,7 @@ rgt_machines.register_machine("arc_furnace", {
         },
         active = {
             tiles = {"rgt_iron_block.png", "rgt_iron_block.png", "rgt_iron_block.png", "rgt_iron_block.png", "rgt_iron_block.png", "rgt_arc_furnace_front_active.png"},
-            drop = "arc_furnace_idle"
+            drop = "arc_furnace_idle",
         }
     },
     paramtype2 = "4dir",
@@ -100,7 +106,7 @@ rgt_machines.register_machine("arc_furnace", {
         local inv = m:get_inventory()
         inv:set_size("input", 1)
         
-        m:set_int("fluid_capacity", 10)
+        m:set_float("fluid_capacity", 10)
         m:set_string("active", "false")
         
         update_formspec(m)

mods/rgt_machines/rgt_arc_furnace/mod.conf

@@ -1,2 +1,2 @@
 name = rgt_arc_furnace
-depends = rgt_machines_core
+depends = rgt_machines

mods/rgt_machines/rgt_casting_basin/init.lua

@@ -0,0 +1,167 @@
+local ns = rgt_machines
+
+ns.casting_recipes = {
+    {
+        name = "plate",
+        label = "Plate"
+    },
+    {
+        name = "rod",
+        label = "Rod"
+    },
+    {
+        name = "gear",
+        label = "Gear"
+    },
+}
+
+local function can_work(node, m, inv)
+    -- Do we have an input item?
+    local fluid = m:get_float "fluid"
+    if m:contains "recipe" and m:contains "fluid_type" and fluid > 0 and inv:get_stack("output", 1):get_free_space() > 0 then
+        return true
+    end
+    return false
+end
+
+local function update_formspec(m, progress)
+    progress = progress or m:get_int "progress"
+    local fluid_type = m:get_string "fluid_type"
+    local fluid = m:get_float "fluid"
+    local capacity = m:get_int "fluid_capacity"
+    local progressbar = progress == 0 and "rgt_progress_bg.png^[transformR270" or "rgt_progress_bg.png^[lowpart:"..progress..":rgt_progress_bg_active.png^[transformR270"
+    local fluidcontainer = fluid == 0 and "rgt_fluid_container_bg.png" or "rgt_fluid_container_bg.png^[lowpart:"..(fluid /capacity *100)..":rgt_fluid_container_bg_filled.png"
+    local fs = {"\
+        formspec_version[10]\
+        size[12,12]\
+        image[3.5,2;1,1;", progressbar, "]\
+        image[2,1;1,3;", minetest.formspec_escape(fluidcontainer), "]\
+        label[0.5,0.5;", fluid, " / ", capacity, "]\
+        ", ui.list("context", "output", 5, 2, 1, 1), "\
+    "}
+    fs[#fs +1] = ui.list("current_player", "main", 1.125, 6.5, 8, 4)
+    fs[#fs +1] = "\
+    listring[]"
+    
+    local recipe = m:get "recipe"
+    
+    local x = 0
+    local y = 0
+    for _, r in ipairs(ns.casting_recipes) do
+        if r.name == recipe then
+            fs[#fs +1] = "style[select_recipe_"..r.name..";bgimg=rgt_other_button_bg.png]"
+        end
+        fs[#fs +1] = "image_button["..(x *1.1 +7)..","..(y +1.5)..";1,1;rgt_cast_"..r.name..".png;select_recipe_"..r.name..";]\
+        tooltip[select_recipe_"..r.name..";"..(r.label or r.name).."]\
+        "
+        x = x +1
+    end
+    
+    m:set_string("formspec", table.concat(fs))
+end
+
+local function activate(pos, node, m)
+    m:set_string("active", "true")
+    node.name = "casting_basin_active"
+    minetest.swap_node(pos, node)
+end
+
+local function deactivate(pos, node, m)
+    m:set_string("active", "false")
+    m:set_int("progress", 0)
+    update_formspec(m)
+    node.name = "casting_basin_idle"
+    minetest.swap_node(pos, node)
+end
+
+local function update(pos, elapsed)
+    local node = minetest.get_node(pos)
+    local m = minetest.get_meta(pos)
+    local inv = m:get_inventory()
+    
+    local active = m:get_string("active") == "true"
+    
+    if can_work(node, m, inv) then
+        if not active then
+            active = true
+            activate(pos, node, m)
+        end
+        
+        local progress = m:get_int("progress") +20
+        
+        if progress >= 100 then
+            local fluid = m:get_float "fluid"
+            fluid = fluid -1
+            m:set_float("fluid", fluid)
+            
+            local s = inv:get_stack("output", 1)
+            if s and s:get_count() > 0 then
+                s:set_count(s:get_count() +1)
+            else
+                s = ItemStack(m:get_string("fluid_type").."_"..m:get_string("recipe"))
+            end
+            inv:set_stack("output", 1, s)
+            
+            progress = 0
+        end
+        m:set_int("progress", progress)
+        
+        update_formspec(m, progress)
+        
+    elseif active then
+        active = false
+        deactivate(pos, node, m)
+    end
+    
+    return true
+end
+
+rgt_machines.register_machine("casting_basin", {
+    states = {
+        idle = {
+            tiles = {"rgt_iron_block.png", "rgt_iron_block.png", "rgt_iron_block.png", "rgt_iron_block.png", "rgt_iron_block.png", "rgt_casting_basin_front.png"}
+        },
+        active = {
+            tiles = {"rgt_iron_block.png", "rgt_iron_block.png", "rgt_iron_block.png", "rgt_iron_block.png", "rgt_iron_block.png", "rgt_casting_basin_front_active.png"},
+            drop = "casting_basin_idle",
+        }
+    },
+    paramtype2 = "4dir",
+    groups = {dig_immediate = 3, fluid_sink = 1},
+    on_construct = function(pos)
+        local m = minetest.get_meta(pos)
+        local inv = m:get_inventory()
+        inv:set_size("output", 1)
+        
+        m:set_int("fluid_capacity", 10)
+        m:set_string("active", "false")
+        
+        update_formspec(m)
+        
+        minetest.get_node_timer(pos):start(1)
+    end,
+    on_destruct = function(pos)
+        local m = minetest.get_meta(pos)
+        local inv = m:get_inventory()
+        for i = 1, inv:get_size("input") do
+            local item = minetest.add_item(pos, inv:get_stack("input", i))
+            if item then
+                item:set_velocity(vector.random_direction() *math.random(2, 3))
+            end
+        end
+    end,
+    allow_metadata_inventory_put = function(pos, list, idx, s, p)
+        return 0
+    end,
+    on_receive_fields = function(pos, form, data, p)
+        for k, v in pairs(data) do
+            if k:find "^select_recipe_" then
+                local m = minetest.get_meta(pos)
+                local recipe = k:match "^select_recipe_(.*)"
+                m:set_string("recipe", recipe)
+                update_formspec(m)
+            end
+        end
+    end,
+    on_timer = update
+})

mods/rgt_machines/rgt_casting_basin/mod.conf

@@ -0,0 +1,2 @@
+name = rgt_casting_basin
+depends = rgt_machines

mods/rgt_machines/rgt_furnace/init.lua

@@ -33,7 +33,7 @@ rgt_machines.register_machine("fuel_furnace", {
         local inv = m:get_inventory()
         inv:set_size("input", 1)
         inv:set_size("output", 1)
-        -- Dummy list handle Shift-adding properly.
+        -- Dummy list to handle Shift-adding properly.
         inv:set_size("sort", 1)
         inv:set_size("fuel", 1)
         

mods/rgt_machines/rgt_furnace/mod.conf

@@ -1,2 +1,2 @@
 name = rgt_furnace
-depends = rgt_machines_core
+depends = rgt_machines

mods/rgt_machines/rgt_machines/cables.lua

@@ -0,0 +1,38 @@
+local ns = rgt_machines
+
+local nodebox = {
+    type = "connected",
+    disconnected = {1/8, 1/8, 1/8, -1/8, -1/8, -1/8},
+    connect_top = {1/8, 1/2, 1/8, -1/8, -1/8, -1/8},
+    connect_bottom = {1/8, 1/8, 1/8, -1/8, -1/2, -1/8},
+    connect_front = {1/8, 1/8, 1/8, -1/8, -1/8, -1/2},
+    connect_left = {1/8, 1/8, 1/8, -1/2, -1/8, -1/8},
+    connect_back = {1/8, 1/8, 1/2, -1/8, -1/8, -1/8},
+    connect_right = {1/2, 1/8, 1/8, -1/8, -1/8, -1/8}
+}
+
+
+function ns.register_cable(type, def)
+    rgt.register_node("cable_"..type, {
+        drawtype = "nodebox",
+        node_box = nodebox,
+        connects_to = {"group:cable", "group:machine"},
+        tiles = {"rgt_cable_"..type..".png"},
+        groups = {cable = 1, dig_immediate = 3, network_component = 1},
+        paramtype = "light",
+        sunlight_propagates = true,
+        on_construct = function(pos)
+            ns.update_network(pos)
+        end,
+        after_destruct = function(pos)
+            ns.update_network(pos)
+        end,
+        cable_def = def
+    })
+end
+
+ns.register_cable("copper", {
+    resistance = 0,
+    max_transference = 200
+})
+-- //lua say(dump(minetest.get_meta(rgt.players.singleplayer.pos:round()):to_table()))

mods/rgt_machines/rgt_machines/fluids.lua

@@ -0,0 +1,74 @@
+local ns = rgt_machines
+
+-- The recursive funtion that executes a request to push fluid to a network.
+local function push_fluid(pos, node, ctx)
+    -- Indicate that this node has now been checked.
+    ctx.ignore[minetest.hash_node_position(pos)] = true
+    
+    -- If the node is a sink, add as much fluid to it as we can.
+    if minetest.get_item_group(node, "fluid_sink") > 0 then
+        local m = minetest.get_meta(pos)
+        local fluid = m:get_float "fluid"
+        local fluid_type = m:get "fluid_type"
+        local space = m:get_float "fluid_capacity" -fluid
+        
+        -- If possible, cast the type of an empty tank to that of  the fluid we're pushing; if, however, the tank already contains some amount of a different fluid type, we should not push anything.
+        if ctx.type ~= fluid_type then
+            if not fluid_type or fluid == 0 then
+                m:set_string("fluid_type", ctx.type)
+            else
+                return
+            end
+        end
+        
+        -- Push as much fluid into the receiver's tank as we can, and decrement the amount awaiting transfer appropriately.
+        if space >= ctx.amount then
+            m:set_float("fluid", fluid +ctx.amount)
+            ctx.amount = 0
+        else
+            m:set_float("fluid", fluid +space)
+            ctx.amount = ctx.amount -space
+        end
+    -- If the node is a pipe, continue pushing to its neighbors.
+    elseif minetest.get_item_group(node, "pipe") > 0 then
+        for _, x in ipairs(rgt.adjacent_neighbor_offests) do
+            -- If we've no fluid left to push, we can just stop.
+            if ctx.amount <= 0 then break end
+            
+            if not ctx.ignore[minetest.hash_node_position(pos +x)] then
+                push_fluid(pos +x, node, ctx)
+            end
+        end
+    end
+end
+
+-- Pushes fluid from `pos` to any connected fluid network.
+-- Returns the amount of fluid that was successfully pushed.
+function ns.push_fluid(pos, type, amount)
+    -- Create a master storage table for this push request.
+    local ctx = {
+        ignore = {minetest.hash_node_position(pos)}, -- Nodes we have already checked.
+        type = type, -- The type of the fluid we are sending.
+        amount = amount -- How much fluid remains to be sent.
+    }
+    -- Recursively dispatch the request to all neighbors in sequence.
+    for _, x in ipairs(rgt.adjacent_neighbor_offests) do
+        if ctx.amount > 0 and not ctx.ignore[minetest.hash_node_position(pos +x)] then
+            push_fluid(pos +x, minetest.get_node(pos +x).name, ctx)
+        end
+    end
+    -- Return the amount we were able to transfer (amount requested minus amount left).
+    return amount -ctx.amount
+end
+
+-- Pulls fluid into `pos` from any connected fluid network.
+-- Returns false if no fluid could be pulled, and the amount pulled otherwise.
+function ns.pull_fluid(pos)
+    
+end
+
+function ns.register_fluid_tank(name, def)
+    rgt.register_node("fluid_tank_"..name, {
+        
+    })
+end

mods/rgt_machines/rgt_machines/init.lua

@@ -0,0 +1,171 @@
+--[[
+    List of machines:
+    - Arc furnace: Melts materials into their liquid form
+--]]
+
+
+rgt_machines = {
+    registered_machines = {},
+    networks = {}
+}
+local ns = rgt_machines
+
+local db = minetest.get_mod_storage()
+function ns.get_network(id)
+    return minetest.deserialize(db:get(id) or "return nil") or {supply = 0, demand = 0}
+end
+
+-- This abstracts away the use of multiple nodes for visual state feedback by
+-- copying all node callbacks into each node, so that by default the machine
+-- behaves exactly the same regardless of the underlying node type.
+--[[
+    {
+        states = { ... }, -- Alternate visual states for this node. All properties of the resultant node may be overriden.
+        ...
+    }
+--]]
+function ns.register_machine(name, def)
+    if not def.groups then
+        def.groups = {}
+    end
+    def.groups.machine = 1
+    def.groups.network_component = 1
+    def.groups.run_on_activate = 1
+    def.groups[name] = 1
+    
+    -- Ensure that we update the network when a machine is placed or removed.
+    local _on_construct = def.on_construct
+    def.on_construct = function(pos)
+        ns.update_network(pos)
+        if _on_construct then _on_construct(pos) end
+    end
+    local _after_destruct = def.after_destruct
+    def.after_destruct = function(pos)
+        ns.update_network(pos)
+        if _after_destruct then _after_destruct(pos) end
+    end
+    
+    ns.registered_machines[name] = def
+    for state, x in pairs(def.states) do
+        rgt.register_node(name.."_"..state, extend(table.copy(def), x))
+    end
+end
+
+-- Recursively propagate a network reassignment to all connected nodes (ignoring positions in `ignore`).
+local function propagate_network_update(pos, net, ignore)
+    ignore[minetest.hash_node_position(pos)] = true
+    -- Store the network to the target node.
+    minetest.get_meta(pos):set_string("network", net)
+    -- Check each neighboring node for further propagation.
+    for _, x in ipairs(rgt.adjacent_neighbor_offests) do
+        -- If we already checked this node, we shouldn't consider it to avoid infinite recursion.
+        if not ignore[minetest.hash_node_position(pos +x)] then
+            local cid = minetest.get_node_raw(pos.x +x.x, pos.y +x.y, pos.z +x.z)
+            -- Ensure that this node can belong to a network and thus is a valid propagation target.
+            if minetest.get_item_group(rgt.content_ids_to_nodes[cid], "network_component") > 0 then
+                propagate_network_update(pos +x, net, ignore)
+            end
+        end
+    end
+end
+
+-- Called when a pos is added to or removed from a network.
+-- Whether an addition or deletion is being performed depends on whether the node at `pos` belongs to the `network_component` group.
+function ns.update_network(pos)
+    -- We're adding a node.
+    if minetest.get_item_group(minetest.get_node(pos).name, "network_component") > 0 then
+        -- Find all adjacent networks.
+        local net
+        local nets = {}
+        local num_nets = 0
+        for _, x in ipairs(rgt.adjacent_neighbor_offests) do
+            -- Ensure that this is a node that should have a network field.
+            if minetest.get_item_group(minetest.get_node(pos +x).name, "network_component") > 0 then
+                local n = minetest.get_meta(pos +x):get("network")
+                -- If the node doesn't have a network for some reason, we should give it one.
+                if not n or table.indexof(nets, n) == -1 then
+                    -- Set our network to the first one we find.
+                    if not net then
+                        net = n
+                    -- Store the positions of any other adjacent networks, so we can merge them with ours.
+                    elseif net ~= n then
+                        nets[#nets +1] = x
+                    end
+                    num_nets = num_nets +1
+                end
+            end
+        end
+        
+        -- Propagate our chosen network to adjacent networks with different IDs.
+        -- If we didn't find any adjacent networks, this will just do nothing.
+        local ignore = {[minetest.hash_node_position(pos)] = true}
+        for _, x in ipairs(nets) do
+            propagate_network_update(pos +x, net, ignore)
+        end
+
+        -- Create a new unique network ID if none of our neighbors have one.
+        if not net then
+            net = string.format("net_%d_%06d", minetest.get_us_time(), math.random(100000, 999999))
+        end
+        
+        -- Save our chosen network ID.
+        minetest.get_meta(pos):set_string("network", net)
+    -- We're removing a node.
+    else
+        -- Find all adjacent networks.
+        local net
+        local nets = {}
+        for _, x in ipairs(rgt.adjacent_neighbor_offests) do
+            -- Ensure that this is a node that should have a network field.
+            if minetest.get_item_group(minetest.get_node(pos +x).name, "network_component") > 0 then
+                local n = minetest.get_meta(pos +x):get("network")
+                nets[#nets +1] = x
+            end
+        end
+        -- We only need to ensure that these networks are unique, thus one of them can keep its original ID.
+        if #nets > 1 then table.remove(nets, 1) end
+
+        -- Create a new ID for each network and propagate it.
+        local pos_hash = minetest.hash_node_position(pos)
+        for _, x in ipairs(nets) do
+            net = string.format("net_%d_%06d", minetest.get_us_time(), math.random(100000, 999999))
+            -- Provide a different ignore table each time, to ensure that when the same network abuts this node on multiple edges, all touching nodes get the same network in the end.
+            propagate_network_update(pos +x, net, {[pos_hash] = true})
+        end
+    end
+    return true
+end
+
+function ns.add_network_supply(id, amount)
+    local net = ns.get_network(id)
+    net.supply = net.supply +amount
+    db:set_string(id, minetest.serialize(net))
+end
+
+function ns.remove_network_supply(id, amount)
+    ns.add_network_supply(id, -amount)
+end
+
+function ns.change_network_supply(id, from, to)
+    ns.add_network_supply(id, to -from)
+end
+
+function ns.add_network_demand(id, amount)
+    local net = ns.get_network(id)
+    net.demand = net.demand +amount
+    db:set_string(id, minetest.serialize(net))
+end
+
+function ns.remove_network_demand(id, amount)
+    ns.add_network_demand(id, -amount)
+end
+
+function ns.change_network_demand(id, from, to)
+    ns.add_network_demand(id, to -from)
+end
+
+include "fluids.lua"
+
+include "cables.lua"
+include "pipes.lua"
+

mods/rgt_machines/rgt_machines/mod.conf

@@ -0,0 +1,2 @@
+name = rgt_machines
+depends = rgt_world, rgt_player

mods/rgt_machines/rgt_machines/pipes.lua

@@ -6,7 +6,7 @@ local function update_pipe(pos, leaf)
     local dir
     local pipe
     
-    for _, offset in ipairs(rgt.adjacent_horizontal_neighbor_offests) do
+    for _, offset in ipairs(rgt.adjacent_neighbor_offests) do
         pipe = minetest.get_node(pos +offset)
         if minetest.get_item_group(pipe.name, "pipe_straight") > 0 then
             neighbors[#neighbors +1] = offset
@@ -48,7 +48,7 @@ rgt.register_node("pipe_straight", {
         update_pipe(pos)
     end,
     after_destruct = function(pos)
-        for _, offset in ipairs(rgt.adjacent_horizontal_neighbor_offests) do
+        for _, offset in ipairs(rgt.adjacent_neighbor_offests) do
             pipe = minetest.get_node(pos +offset)
             if minetest.get_item_group(pipe.name, "pipe_straight") > 0 then
                 update_pipe(pos +offset, true)
@@ -70,7 +70,7 @@ rgt.register_node("pipe_straight_single_cap", {
         update_pipe(pos)
     end,
     after_destruct = function(pos)
-        for _, offset in ipairs(rgt.adjacent_horizontal_neighbor_offests) do
+        for _, offset in ipairs(rgt.adjacent_neighbor_offests) do
             pipe = minetest.get_node(pos +offset)
             if minetest.get_item_group(pipe.name, "pipe_straight") > 0 then
                 update_pipe(pos +offset, true)
@@ -92,7 +92,7 @@ rgt.register_node("pipe_straight_double_cap", {
         update_pipe(pos)
     end,
     after_destruct = function(pos)
-        for _, offset in ipairs(rgt.adjacent_horizontal_neighbor_offests) do
+        for _, offset in ipairs(rgt.adjacent_neighbor_offests) do
             pipe = minetest.get_node(pos +offset)
             if minetest.get_item_group(pipe.name, "pipe_straight") > 0 then
                 update_pipe(pos +offset, true)

mods/rgt_machines/rgt_machines_core/fluids.lua

@@ -1,11 +0,0 @@
-local ns = rgt_machines
-
-function ns.create_fluid_tank(m)
-    
-end
-
-function ns.make_fluid_display(x, y, fliud, max, amount)
-    local fs = {}
-    
-    return table.concat(fs)
-end

mods/rgt_machines/rgt_machines_core/init.lua

@@ -1,36 +0,0 @@
---[[
-    List of machines:
-    - Arc furnace: Melts materials into their liquid form
---]]
-
-
-rgt_machines = {
-    registered_machines = {}
-}
-local ns = rgt_machines
-
--- This abstracts away the use of multiple nodes for visual state feedback by
--- copying all node callbacks into each node, so that by default the machine
--- behaves exactly the same regardless of the underlying node type.
---[[
-    {
-        states = { ... }, -- Alternate visual states for this node. All properties of the resultant node may be overriden.
-        ...
-    }
---]]
-function ns.register_machine(name, def)
-    if not def.groups then
-        def.groups = {}
-    end
-    def.groups.rgt_machine = 1
-    def.groups.run_on_activate = 1
-    def.groups[name] = 1
-    ns.registered_machines[name] = def
-    for state, x in pairs(def.states) do
-        rgt.register_node(name.."_"..state, extend(table.copy(def), x))
-    end
-end
-
-include "fluids.lua"
-
-include "pipes.lua"

mods/rgt_machines/rgt_machines_core/mod.conf

@@ -1,2 +0,0 @@
-name = rgt_machines_core
-depends = rgt_world, rgt_player

mods/rgt_machines/rgt_steam_generator/init.lua

@@ -0,0 +1,132 @@
+
+local function can_work(node, m, inv)
+    -- Do we have an input item?
+    local input = inv:get_stack("input", 1)
+    if input:get_count() > 0 then
+        return true
+    end
+    return false
+end
+
+local function update_formspec(m, progress)
+    progress = progress or m:get_int "progress"
+    local fluid = m:get_float "fluid"
+    local capacity = m:get_int "fluid_capacity"
+    local progressbar = progress == 0 and "rgt_progress_bg.png^[transformR270" or "rgt_progress_bg.png^[lowpart:"..progress..":rgt_progress_bg_active.png^[transformR270"
+    local fluidcontainer = fluid == 0 and "rgt_fluid_container_bg.png" or "rgt_fluid_container_bg.png^[lowpart:"..(fluid /capacity *100)..":rgt_fluid_container_bg_filled.png"
+    local fs = {"\
+        formspec_version[10]\
+        size[12,12]\
+        ", ui.list("context", "input", 2, 2, 1, 1), "\
+        image[4,2;1,1;", progressbar, "]\
+        image[7,1;1,3;", minetest.formspec_escape(fluidcontainer), "]\
+        label[0.5,0.5;", fluid, " / ", capacity, "]\
+    "}
+    fs[#fs +1] = ui.list("current_player", "main", 1.125, 6.5, 8, 4)
+    fs[#fs +1] = "\
+    listring[]"
+    
+    m:set_string("formspec", table.concat(fs))
+end
+
+local function activate(pos, node, m)
+    m:set_string("active", "true")
+    node.name = "steam_generator_active"
+    minetest.swap_node(pos, node)
+end
+
+local function deactivate(pos, node, m)
+    m:set_string("active", "false")
+    m:set_int("progress", 0)
+    update_formspec(m)
+    node.name = "steam_generator_idle"
+    minetest.swap_node(pos, node)
+end
+
+local function update(pos, elapsed)
+    local node = minetest.get_node(pos)
+    local m = minetest.get_meta(pos)
+    local inv = m:get_inventory()
+    
+    local active = m:get_string("active") == "true"
+    
+    if can_work(node, m, inv) then
+        if not active then
+            active = true
+            activate(pos, node, m)
+        end
+        
+        local progress = m:get_int("progress") +20
+        
+        if progress >= 100 then
+            local fluid = m:get_float "fluid"
+            fluid = fluid +1
+            m:set_float("fluid", fluid)
+            
+            -- Consume an item.
+            local s = inv:get_stack("input", 1)
+            s:take_item()
+            inv:set_stack("input", 1, s)
+            
+            progress = 0
+        end
+        m:set_int("progress", progress)
+        
+        update_formspec(m, progress)
+        
+    elseif active then
+        active = false
+        deactivate(pos, node, m)
+    end
+    
+    return true
+end
+
+rgt_machines.register_machine("steam_generator", {
+    states = {
+        idle = {
+            tiles = {"rgt_iron_block.png", "rgt_iron_block.png", "rgt_iron_block.png", "rgt_iron_block.png", "rgt_iron_block.png", "rgt_steam_generator_front.png"}
+        },
+        active = {
+            tiles = {"rgt_iron_block.png", "rgt_iron_block.png", "rgt_iron_block.png", "rgt_iron_block.png", "rgt_iron_block.png", "rgt_steam_generator_front_active.png"},
+            drop = "steam_generator_idle",
+        }
+    },
+    paramtype2 = "4dir",
+    groups = {dig_immediate = 3},
+    on_construct = function(pos)
+        local m = minetest.get_meta(pos)
+        local inv = m:get_inventory()
+        inv:set_size("input", 1)
+        
+        m:set_int("fluid_capacity", 10)
+        m:set_string("active", "false")
+        
+        update_formspec(m)
+        
+        minetest.get_node_timer(pos):start(1)
+    end,
+    on_destruct = function(pos)
+        local m = minetest.get_meta(pos)
+        local inv = m:get_inventory()
+        for i = 1, inv:get_size("input") do
+            local item = minetest.add_item(pos, inv:get_stack("input", i))
+            if item then
+                item:set_velocity(vector.random_direction() *math.random(2, 3))
+            end
+        end
+    end,
+    allow_metadata_inventory_put = function(pos, list, idx, s, p)
+        local inv = minetest.get_meta(pos):get_inventory()
+        local meltable = minetest.registered_items[s:get_name()].groups.arc_furnace_meltable
+        if meltable then
+            if inv:room_for_item("input", s) then
+                return s:get_count()
+            elseif inv:room_for_item("input", s:take_item()) then
+                return s:get_stack_max() -inv:get_stack("input", 1):get_count()
+            end
+        end
+        return 0
+    end,
+    on_timer = update
+})

mods/rgt_machines/rgt_steam_generator/mod.conf

@@ -0,0 +1,2 @@
+name = rgt_steam_generator
+depends = rgt_machines