Debug placement (#11)

* return stack handler function

* defer item consumption until later

mainly after all checks have been done
otherwise items get used even if they
can't be placed

* pointed_thing rework

after this change, nodes don't skip to neighbour
coordinates anymore.
This commit also gives users the ability to define
direction of pointed_thing.

It leaves open the posibility of non-directional
pointed_thing, which could cause trouble but
from the experience with replacer:replacer, these
seem to be only few edge cases where a zero-orientation
pointed_thing causes trouble.

In my tests, all the facedir nodes I tried are positioned
correctly. Some of the wallmounted are still not working.

* improve item usage

items with metadata can alter the result:
a new technic:river_water_can is empty where as the
one in the inventory may contain water.

* improve return stack handling

some items return empty or less full containers

also snuck in ammendment to item usage in this commit

* enforce param2

again replacer:replacer experience:
enforce rotation.

In the case of replacer, we know that a node had that
setting, so we could assume this was legal.
Here user can set arbitrary param2, but the previous
checks seem to protect from e.g. building rotated water.

* comments about inventory check

* debug messages

* satisfy luacheck

* add a default pointed_thing.under

to avoid zero-orientation bugs

* add back the digtron-way of pointe_thing handling

but only when user does not specify a direction

* adds neutral orientation option

because that was what worked best before a default was
added back last two commits

* give fake player inventory

This enables using items such as seeds.

This commit also adds inventory scan for best item.
e.g. technic cans, look for fullest. Maybe in a later
commit we'll simplify and only check for next non-empty item.

Good news, placing river water on river water fails without consuming
any :)
Also seeds that couldn't be placed are returned.

* does this satisfy luacheck?

* adds examples of special nodes

- cable plates around a stone
- a box of slabs containing water

* update readme

explaining pointed_thing handling

* give fake player a position and look direction

Because this might help with some nodes.
Have no imperical data to support this yet.

* removes neutral field adds auto field

This commit makes neutral i.e. non directional pointed_thing the default
again.

It adds auto-field to allow digtron-style handling based on param2

* move predefined param2 override up

It makes more sense to check this before setting pointed_thing, am I
wrong?

* debug messages

* remove debug crud

* adjust for luacheck

digiline.lua

@@ -9,6 +9,46 @@ function digibuilder.get_node(pos)
 	return node
 end
 
+-- looks for index of item to pass to fake player
+-- while doing so, might as well look for best stack/item
+local function best_inventory_index(inv, itemname)
+	if not inv:contains_item("main", itemname) then
+		return nil
+	end
+
+	local best_stack, best_index, stack
+	local list = inv:get_list("main")
+	local index = #list
+	repeat
+		stack = list[index]
+		if not stack:is_empty() then
+			if itemname == stack:get_name() then
+				if not best_stack then
+					best_stack = stack
+					best_index = index
+				elseif (best_stack:get_wear() == 0 and stack:get_wear() > 0)
+					or (best_stack:get_wear() > stack:get_wear() and stack:get_wear() > 0) then
+					best_stack = stack
+					best_index = index
+				end
+			end
+		end
+		index = index - 1
+	until index == 0
+
+	return best_index
+end
+
+-- deals with returned stacks
+local function return_stack(pos, inv, stack)
+	if stack:is_empty() then return end
+	local overflow_stack = inv:add_item("main", stack)
+	if not overflow_stack:is_empty() then
+		-- TODO: discuss if items should be dropped at absolute_pos or pos
+		minetest.add_item(pos, overflow_stack)
+	end
+end
+
 function digibuilder.digiline_effector(pos, _, channel, msg)
 
 	-- only allow table message types
@@ -97,7 +137,7 @@ function digibuilder.digiline_effector(pos, _, channel, msg)
 
 		local is_creative = minetest.check_player_privs(owner, "creative")
 		local inv = meta:get_inventory()
-
+		local inv_best_index = best_inventory_index(inv, msg.name)
 
 		if not is_creative then
 			-- check if node is buildable to
@@ -111,7 +151,10 @@ function digibuilder.digiline_effector(pos, _, channel, msg)
 			end
 
 			-- check if node is in inventory
-			if not inv:contains_item("main", msg.name) then
+			-- this check does not work for items like technic:water_can
+			-- it may be in inventory but empty. Using an empty can with
+			-- digibuilder destroys it!
+			if not inv_best_index then
 				digilines.receptor_send(pos, digibuilder.digiline_rules, set_channel, {
 					pos = msg.pos,
 					error = true,
@@ -142,11 +185,6 @@ function digibuilder.digiline_effector(pos, _, channel, msg)
 			return
 		end
 
-		if not is_creative then
-			-- remove item
-			inv:remove_item("main", msg.name)
-		end
-
 		-- only allow param2 setting for "facedir" types
 		local param2 = tonumber(msg.param2) or 0
 		local enable_param2 = place_node_def.paramtype2 == "facedir" and param2 and param2 > 0 and param2 <= 255
@@ -160,7 +198,12 @@ function digibuilder.digiline_effector(pos, _, channel, msg)
 			place_node.param2 = param2
 		else
 			-- set default param2
-			param2 = 0
+			place_node.param2 = 0
+		end
+
+		if place_node_def.place_param2 ~= nil then
+			-- use predefined param2
+			place_node.param2 = place_node_def.place_param2
 		end
 
 		-- place node inworld
@@ -169,9 +212,38 @@ function digibuilder.digiline_effector(pos, _, channel, msg)
 			minetest.pos_to_string(absolute_pos)
 		)
 
+		local dir = minetest.facedir_to_dir(place_node.param2)
+		local pitch
+		local yaw
+		if dir.z < 0 then
+			yaw = 0
+			pitch = 0
+		elseif dir.z > 0 then
+			yaw = math.pi
+			pitch = 0
+		elseif dir.x < 0 then
+			yaw = 3*math.pi/2
+			pitch = 0
+		elseif dir.x > 0 then
+			yaw = math.pi/2
+			pitch = 0
+		elseif dir.y > 0 then
+			yaw = 0
+			pitch = -math.pi/2
+		else
+			yaw = 0
+			pitch = math.pi/2
+		end
 		-- create fake player for certain function arguments (after_place_node, etc)
 		local player = digibuilder.create_fake_player({
-			name = owner
+			name = owner,
+			inventory = inv,
+			wield_list = "main",
+			wield_index = inv_best_index,
+			position = vector.subtract(absolute_pos, vector.new(0, 1.5, 0)),
+			look_dir = vector.multiply(dir, -1),
+			look_pitch = pitch,
+			look_yaw = yaw
 		})
 
 		-- see:
@@ -179,27 +251,59 @@ function digibuilder.digiline_effector(pos, _, channel, msg)
 		local pointed_thing = {}
 		pointed_thing.type = "node"
 		pointed_thing.above = {x=absolute_pos.x, y=absolute_pos.y, z=absolute_pos.z}
-		pointed_thing.under = {x=absolute_pos.x, y=absolute_pos.y-1, z=absolute_pos.z}
+		pointed_thing.under = {x=absolute_pos.x, y=absolute_pos.y, z=absolute_pos.z}
-
+		-- Note: it is intentional that the default is a
+		-- neutral (non-directional) pointed_thing
+		if msg.up == true then
+			pointed_thing.under.y = absolute_pos.y + 1
+		elseif msg.down == true then
+			pointed_thing.under.y = absolute_pos.y - 1
+		elseif msg.west == true then
+			pointed_thing.under.x = absolute_pos.x - 1
+		elseif msg.east == true then
+			pointed_thing.under.x = absolute_pos.x + 1
+		elseif msg.south == true then
+			pointed_thing.under.z = absolute_pos.z - 1
+		elseif msg.north == true then
+			pointed_thing.under.z = absolute_pos.z + 1
+		elseif msg.auto == true then
 			if place_node_def.paramtype2 == "facedir" then
-			pointed_thing.under = vector.add(absolute_pos, minetest.facedir_to_dir(param2))
+				pointed_thing.under = vector.add(absolute_pos, minetest.facedir_to_dir(place_node.param2))
 			elseif place_node_def.paramtype2 == "wallmounted" then
-			pointed_thing.under = vector.add(absolute_pos, minetest.wallmounted_to_dir(param2))
+				pointed_thing.under = vector.add(absolute_pos, minetest.wallmounted_to_dir(place_node.param2))
+			else
+				pointed_thing.under.y = absolute_pos.y - 1
 			end
-
-		if place_node_def.place_param2 ~= nil then
-			-- use predefined param2
-			place_node.param2 = place_node_def.place_param2
 		end
 
 		if place_node_def.on_place ~= minetest.item_place then
 			-- non-default item placement, use custom function (crops, other items)
-			local itemstack = ItemStack(msg.name .. " 1")
+			-- taking an actual item instead of creating a new stack,
+			-- raises the chances that we get something useful
+			local itemstack
+			if is_creative and inv_best_index == nil then
+				itemstack = ItemStack(msg.name .. " 1")
+			else
+				-- get a copy (with metadata)
+				itemstack = inv:get_stack("main", inv_best_index)
+				-- delete slot
+				inv:set_stack("main", inv_best_index, ItemStack("")) --inv:remove_item("main", msg.name)
+			end
+
 			local returnstack, success = place_node_def.on_place(ItemStack(itemstack), player, pointed_thing)
-			if returnstack and returnstack:get_count() < itemstack:get_count() then
+			if returnstack then
+				return_stack(pos, inv, returnstack)
+				if returnstack:get_wear() ~= itemstack:get_wear()
+					or returnstack:get_name() ~= itemstack:get_name()
+					or returnstack:get_count() < itemstack:get_count() then
 						success = true
 				end
+			end
 			if not success then
+				if not returnstack then
+					-- some items aren't placed but don't return a stack
+					return_stack(pos, inv, itemstack)
+				end
 				digilines.receptor_send(pos, digibuilder.digiline_rules, set_channel, {
 					pos = msg.pos,
 					error = true,
@@ -210,6 +314,9 @@ function digibuilder.digiline_effector(pos, _, channel, msg)
 		else
 			-- default on_place, use `set_node` to avoid side-effects (on-place rotations)
 			minetest.set_node(absolute_pos, place_node)
+			if not is_creative then
+				inv:remove_item("main", msg.name)
+			end
 		end
 
 		-- check if "after_place_node" is defined
@@ -220,6 +327,18 @@ function digibuilder.digiline_effector(pos, _, channel, msg)
 		-- check if the node is falling
 		minetest.check_for_falling(absolute_pos)
 
+		-- checking if param2 actually is what was requested
+		if enable_param2 then
+			local check_node = digibuilder.get_node(absolute_pos)
+			-- it is not always a bad sign when name of placed node does
+			-- not match itemname, certain nodes change their name (or fall)
+			-- also itemname and nodename don't always match
+			if check_node.name == msg.name and check_node.param2 ~= place_node.param2 then
+				-- enforce param2
+				minetest.swap_node(absolute_pos, place_node)
+			end
+		end
+
 		digilines.receptor_send(pos, digibuilder.digiline_rules, set_channel, {
 			pos = msg.pos,
 			name = place_node.name,
@@ -228,3 +347,4 @@ function digibuilder.digiline_effector(pos, _, channel, msg)
 		})
 	end
 end
+

examples/cable_plates.lua

@@ -0,0 +1,44 @@
+-- places a stone above digibuilder, then surrounds it with
+-- cable-plates so that the big flat end lies against the stone
+
+-- list of setnode commands
+local s = "technic:hv_cable_plate_1"
+local data = {
+	{ name = "default:stone", pos = { x = 0, y = 2, z = 0 } },
+	{ name = s, up = true, pos = { x = 0, y = 1, z = 0 } },
+	{ name = s, down = true, pos = { x = 0, y = 3, z = 0 } },
+	{ name = s, north = true, pos = { x = 0, y = 2, z = -1 } },
+	{ name = s, south = true, pos = { x = 0, y = 2, z = 1 } },
+	{ name = s, west = true, pos = { x = 1, y = 2, z = 0 } },
+	{ name = s, east = true, pos = { x = -1, y = 2, z = 0 } }
+}
+
+-- initial start
+if event.type == "program" then
+	mem.pos = 1
+	interrupt(1)
+end
+
+-- timer interrupt
+if event.type == "interrupt" then
+	local entry = data[mem.pos]
+	if not entry then
+		-- done
+		return
+	end
+
+	entry.command = "setnode"
+	digiline_send("digibuilder", entry)
+end
+
+-- callback from digibuilder node
+if event.type == "digiline" and event.channel == "digibuilder" then
+	if event.error then
+		-- error state
+		error(event.message)
+	end
+
+	-- next command
+	mem.pos = mem.pos + 1
+	interrupt(1)
+end

examples/slabs_and_water.lua

@@ -0,0 +1,45 @@
+-- places a box of slabs and places water inside it
+
+local s = "moreblocks:slab_super_glow_glass_1"
+local w = "bucket:bucket_river_water"
+-- list of setnode commands
+local data = {
+	{ name = s, param2 = 21, pos = { x = 0, y = 1, z = 0 } },
+	{ name = s, param2 = 3, pos = { x = 0, y = 3, z = 0 } },
+	{ name = s, param2 = 11, pos = { x = 0, y = 2, z = -1 } },
+	{ name = s, param2 = 5, pos = { x = 0, y = 2, z = 1 } },
+	{ name = s, param2 = 12, pos = { x = 1, y = 2, z = 0 } },
+	{ name = s, param2 = 18, pos = { x = -1, y = 2, z = 0 } },
+	{ name = w, pos = { x = 0, y = 2, z = 0 }
+	}
+}
+
+-- initial start
+if event.type == "program" then
+	mem.pos = 1
+	interrupt(1)
+end
+
+-- timer interrupt
+if event.type == "interrupt" then
+	local entry = data[mem.pos]
+	if not entry then
+		-- done
+		return
+	end
+
+	entry.command = "setnode"
+	digiline_send("digibuilder", entry)
+end
+
+-- callback from digibuilder node
+if event.type == "digiline" and event.channel == "digibuilder" then
+	if event.error then
+		-- error state
+		error(event.message)
+	end
+
+	-- next command
+	mem.pos = mem.pos + 1
+	interrupt(1)
+end

readme.md

@@ -51,6 +51,15 @@ if event.type == "digiline" and event.channel == "digibuilder" then
 end
 ```
 
+### pointed_thing handling
+
+If none of the fields { up, down, north, south, west, east, auto } are set to true
+then a zero orientational pointed_thing is used. i.e. under == above coordinates.
+If auto field is set to true, then a direction is set based on the evaluated param2
+or falls back to downward direction.
+Some nodes need a support-node to be at under position or they will be placed in
+the resulting under-coordinate. e.g. technic:hv_cable_plate_1
+
 # Examples
 
 For code examples for the `luacontroller` see the "examples" directory