Major rewrite of items in tubes

common.lua

@@ -0,0 +1,144 @@
+----------------------
+-- Vector functions --
+----------------------
+
+function vector.cross(a, b)
+	return {
+		x = a.y * b.z - a.z * b.y,
+		y = a.z * b.x - a.x * b.z,
+		z = a.x * b.y - a.y * b.x
+	}
+end
+
+function vector.dot(a, b)
+	return a.x * b.x + a.y * b.y + a.z * b.z
+end
+
+-----------------------
+-- Facedir functions --
+-----------------------
+
+function minetest.facedir_to_top_dir(facedir)
+	return 	({[0] = {x =  0, y =  1, z =  0},
+	                {x =  0, y =  0, z =  1},
+	                {x =  0, y =  0, z = -1},
+	                {x =  1, y =  0, z =  0},
+	                {x = -1, y =  0, z =  0},
+	                {x =  0, y = -1, z =  0}})
+		[math.floor(facedir / 4)]
+end
+
+function minetest.facedir_to_right_dir(facedir)
+	return vector.cross(
+		minetest.facedir_to_top_dir(facedir),
+		minetest.facedir_to_dir(facedir)
+	)
+end
+
+directions = {}
+function directions.side_to_dir(side)
+	return ({[0] = vector.new(),
+		vector.new( 0,  1,  0),
+		vector.new( 0, -1,  0),
+		vector.new( 1,  0,  0),
+		vector.new(-1,  0,  0),
+		vector.new( 0,  0,  1),
+		vector.new( 0,  0, -1)
+	})[side]
+end
+
+function directions.dir_to_side(dir)
+	local c = vector.dot(dir, vector.new(1, 2, 3)) + 4
+	return ({6, 2, 4, 0, 3, 1, 5})[c]
+end
+
+----------------------
+-- String functions --
+----------------------
+
+--[[function string.split(str, sep)
+	local fields = {}
+	local index = 1
+	local expr = "([^"..sep.."])+"
+	string.gsub(str, expr, function(substring)
+		fields[index] = substring
+		index = index + 1
+	end)
+	return fields
+end]]
+
+function string.startswith(str, substr)
+	return str:sub(1, substr:len()) == substr
+end
+
+---------------------
+-- Table functions --
+---------------------
+
+function table.contains(tbl, element)
+	for _, elt in pairs(tbl) do
+		if elt == element then
+			return true
+		end
+	end
+	return false
+end
+
+function table.extend(tbl, tbl2)
+	local index = #tbl + 1
+	for _, elt in ipairs(tbl2) do
+		tbl[index] = elt
+		index = index + 1
+	end
+end
+
+function table.recursive_replace(tbl, pattern, replace_with)
+	if type(tbl) == "table" then
+		local tbl2 = {}
+		for key, value in pairs(tbl) do
+			tbl2[key] = table.recursive_replace(value, pattern, replace_with)
+		end
+		return tbl2
+	elseif type(tbl) == "string" then
+		return tbl:gsub(pattern, replace_with)
+	else
+		return tbl
+	end
+end
+
+------------------------
+-- Formspec functions --
+------------------------
+
+fs_helpers = {}
+function fs_helpers.on_receive_fields(pos, fields)
+	local meta = minetest.get_meta(pos)
+	for field, value in pairs(fields) do
+		if field:startswith("fs_helpers_cycling:") then
+			local l = field:split(":")
+			local new_value = tonumber(l[2])
+			local meta_name = l[3]
+			meta:set_int(meta_name, new_value)
+		end
+	end
+end
+
+function fs_helpers.cycling_button(meta, base, meta_name, values)
+	local current_value = meta:get_int(meta_name)
+	local new_value = (current_value + 1) % (#values)
+	local text = values[current_value + 1]
+	local field = "fs_helpers_cycling:"..new_value..":"..meta_name
+	return base..";"..field..";"..text.."]"
+end
+
+---------
+-- Env --
+---------
+
+function minetest.load_position(pos)
+	if minetest.get_node_or_nil(pos) then
+		return
+	end
+	local vm = minetest.get_voxel_manip()
+	vm:read_from_map(pos, pos)
+end