added rotation memory for facedir and colorfacedir nodes

README.md

@@ -14,6 +14,15 @@ A thin wrapper around a very useful library to deal with Matrices:
 
 [matrix] https://github.com/entuland/lua-matrix
 
+# Main features
+
+- for `facedir` and `colorfacedir` nodes:
+  - rotate any  node in a predictable manner regardless its current rotation
+  - **rotation memory**: optionally, place any new node with the same rotation as the last rotated node (see [Chat commands](#chat-commands) section)
+
+- for `wallmounted` and `colorwallmounted` nodes:
+  - cycle through valid rotations in the same way as the built-in screwdriver would
+
 # Why yet another screwdriver?
 
 The default screwdriver included in minetest_game, as well as any other screwdriver mod I have found, operate differently depending on the node's direction and rotation. This means that any given click on a node may produce different results which you cannot predict at a glance.
@@ -79,6 +88,13 @@ Rhotator Testing Cube: a Rhotator Screwdriver and any wool block
 
 ![Testing cube crafting](/screenshots/testcube-crafting.png)
 
+# Chat commands
+
+- `rhotator` shows available commands
+- `rhotator memory` shows current placement memory flag (on or off)
+- `rhotator memory on` enable placement memory
+- `rhotator memory off` disable placement memory
+
 # Usage feedback
 
 An HUD message will show usage feedback, in particular it will inform you about nodes that aren't currently supported.

init.lua

 rhotator = {}
 
 local mod_path = minetest.get_modpath(minetest.get_current_modname())
+local storage = minetest.get_mod_storage()
 
 -- constants
 
@@ -28,6 +29,8 @@ local dir_matrices = {}
 local huds = {}
 local hud_timeout_seconds = 3
 
+local facedir_memory = {}
+
 -- ============================================================
 -- init
 
@@ -277,6 +280,12 @@ function handlers.facedir(node, player, pointed_thing, click)
 	local remaining = node.param2 - rotation
 	local rotate_90deg_clockwise = 1
 	local rotation_result, message = rotate_main(rotation, player, pointed_thing, click, rotate_90deg_clockwise)
+	
+	local playername = player:get_player_name()
+	if storage:get_int("memory_" .. playername) == 1 then
+		facedir_memory[playername] = rotation_result
+	end
+	
 	return rotation_result + remaining, message
 end
 
@@ -323,9 +332,72 @@ end
 
 handlers.colorwallmounted = handlers.wallmounted
 
+-- ============================================================
+-- rotation memory
+
+local function command_memory(playername, params)
+	local player = minetest.get_player_by_name(playername)
+	local key = "memory_" .. playername
+	local memory = storage:get_int(key) == 1
+	if params[2] == "on" then
+		storage:set_int(key, 1)
+		memory = true
+	elseif params[2] == "off" then
+		storage:set_int(key, 0)
+		memory = false
+	elseif params[2] then
+		rhotator.command(playername, "")
+		return
+	end
+	minetest.chat_send_player(playername, "[rhotator] Memory is " .. (memory and "on" or "off"))
+end
+
+local function rhotator_on_placenode(pos, newnode, placer, oldnode, itemstack, pointed_thing)
+	if not placer or not placer.get_player_name then return end
+	
+	local playername = placer:get_player_name()
+	local key = "memory_" .. playername
+	local memory = storage:get_int(key) == 1
+	if not memory then return end
+
+	local new_rotation = facedir_memory[playername]
+	if not new_rotation then return end
+	
+	local nodedef = minetest.registered_nodes[newnode.name]
+	if not nodedef then return end
+	
+	local paramtype2 = nodedef.paramtype2
+
+	if paramtype2 ~= "facedir" and paramtype2 ~= "colorfacedir" then return end
+
+	local old_rotation = newnode.param2 % 32 -- get first 5 bits
+	local remaining = newnode.param2 - old_rotation
+	
+	newnode.param2 = new_rotation + remaining
+	minetest.swap_node(pos, newnode)
+	minetest.check_for_falling(pos)
+	
+	notify(placer, "Placed node according to previous rotation")
+end
+
 -- ============================================================
 -- interaction
 
+function rhotator.command(playername, param)
+	if param == "" then
+		minetest.chat_send_player(playername, "[rhotator] Usage: rhotator memory [on|off]")
+		return
+	end
+
+	local params = param:split(" ")
+	if params[1] == "memory" then
+		command_memory(playername, params)
+		return	
+	end
+
+	minetest.chat_send_player(playername, "[rhotator] unsupported param: " .. param)
+end
+
 local function interact(player, pointed_thing, click)
 	if pointed_thing.type ~= "node" then
 		return
@@ -422,3 +494,7 @@ minetest.register_craft({
 		{"rhotator:screwdriver"},
 	}
 })
+
+minetest.register_on_placenode(rhotator_on_placenode)
+
+minetest.register_chatcommand("rhotator", {func = rhotator.command})