wesnoth/data/lua/helper.lua

395 lines
9.8 KiB
Lua

--! #textdomain wesnoth
local helper = {}
local wml_actions = wesnoth.wml_actions
--! Returns an iterator over all the sides matching a given filter that can be used in a for-in loop.
function helper.get_sides(cfg)
local function f(s)
local i = s.i
while i < #wesnoth.sides do
i = i + 1
if wesnoth.match_side(i, cfg) then
s.i = i
return wesnoth.sides[i], i
end
end
end
return f, { i = 0 }
end
--! Interrupts the current execution and displays a chat message that looks like a WML error.
function helper.wml_error(m)
error("~wml:" .. m, 0)
end
--! Returns an iterator over teams that can be used in a for-in loop.
function helper.all_teams()
local function f(s)
local i = s.i
local team = wesnoth.sides[i]
s.i = i + 1
return team
end
return f, { i = 1 }
end
--! Returns the first subtag of @a cfg with the given @a name.
--! If @a id is not nil, the "id" attribute of the subtag has to match too.
--! The function also returns the index of the subtag in the array.
function helper.get_child(cfg, name, id)
-- ipairs cannot be used on a vconfig object
for i = 1, #cfg do
local v = cfg[i]
if v[1] == name then
local w = v[2]
if not id or w.id == id then return w, i end
end
end
end
--! Returns an iterator over all the subtags of @a cfg with the given @a name.
function helper.child_range(cfg, tag)
local function f(s)
local c
repeat
local i = s.i
c = cfg[i]
if not c then return end
s.i = i + 1
until c[1] == tag
return c[2]
end
return f, { i = 1 }
end
--! Modifies all the units satisfying the given @a filter.
--! @param vars key/value pairs that need changing.
--! @note Usable only during WML actions.
function helper.modify_unit(filter, vars)
wml_actions.store_unit({
[1] = { "filter", filter },
variable = "LUA_modify_unit",
kill = true
})
for i = 0, wesnoth.get_variable("LUA_modify_unit.length") - 1 do
local u = "LUA_modify_unit[" .. i .. "]"
for k, v in pairs(vars) do
wesnoth.set_variable(u .. '.' .. k, v)
end
wml_actions.unstore_unit({
variable = u,
find_vacant = false
})
end
wesnoth.set_variable("LUA_modify_unit")
end
--! Fakes the move of a unit satisfying the given @a filter to position @a x, @a y.
--! @note Usable only during WML actions.
function helper.move_unit_fake(filter, to_x, to_y)
wml_actions.store_unit({
[1] = { "filter", filter },
variable = "LUA_move_unit",
kill = false
})
local from_x = wesnoth.get_variable("LUA_move_unit.x")
local from_y = wesnoth.get_variable("LUA_move_unit.y")
wml_actions.scroll_to({ x=from_x, y=from_y })
if to_x < from_x then
wesnoth.set_variable("LUA_move_unit.facing", "sw")
elseif to_x > from_x then
wesnoth.set_variable("LUA_move_unit.facing", "se")
end
wesnoth.set_variable("LUA_move_unit.x", to_x)
wesnoth.set_variable("LUA_move_unit.y", to_y)
wml_actions.kill({
x = from_x,
y = from_y,
animate = false,
fire_event = false
})
wml_actions.move_unit_fake({
type = "$LUA_move_unit.type",
gender = "$LUA_move_unit.gender",
variation = "$LUA_move_unit.variation",
side = "$LUA_move_unit.side",
x = from_x .. ',' .. to_x,
y = from_y .. ',' .. to_y
})
wml_actions.unstore_unit({ variable="LUA_move_unit", find_vacant=true })
wml_actions.redraw({})
wesnoth.set_variable("LUA_move_unit")
end
local variable_mt = {}
local function get_variable_proxy(k)
local v = wesnoth.get_variable(k, true)
if type(v) == "table" then
v = setmetatable({ __varname = k }, variable_mt)
end
return v
end
local function set_variable_proxy(k, v)
if getmetatable(v) == variable_mt then
v = wesnoth.get_variable(v.__varname)
end
wesnoth.set_variable(k, v)
end
function variable_mt.__index(t, k)
local i = tonumber(k)
if i then
k = t.__varname .. '[' .. i .. ']'
else
k = t.__varname .. '.' .. k
end
return get_variable_proxy(k)
end
function variable_mt.__newindex(t, k, v)
local i = tonumber(k)
if i then
k = t.__varname .. '[' .. i .. ']'
else
k = t.__varname .. '.' .. k
end
set_variable_proxy(k, v)
end
local root_variable_mt = {
__index = function(t, k) return get_variable_proxy(k) end,
__newindex = function(t, k, v)
if type(v) == "function" then
-- User-friendliness when _G is overloaded early.
-- FIXME: It should be disabled outside the "preload" event.
rawset(t, k, v)
else
set_variable_proxy(k, v)
end
end
}
--! Sets the metable of @a t so that it can be used to access WML variables.
--! @return @a t.
--! @code
--! helper.set_wml_var_metatable(_G)
--! my_persistent_variable = 42
--! @endcode
function helper.set_wml_var_metatable(t)
return setmetatable(t, root_variable_mt)
end
local fire_action_mt = {
__index = function(t, n)
return function(cfg) wesnoth.fire(n, cfg) end
end
}
--! Sets the metable of @a t so that it can be used to fire WML actions.
--! @return @a t.
--! @code
--! W = helper.set_wml_action_metatable {}
--! W.message { speaker = "narrator", message = "?" }
--! @endcode
function helper.set_wml_action_metatable(t)
return setmetatable(t, fire_action_mt)
end
local create_tag_mt = {
__index = function(t, n)
return function(cfg) return { n, cfg } end
end
}
--! Sets the metable of @a t so that it can be used to create subtags with less brackets.
--! @return @a t.
--! @code
--! T = helper.set_wml_tag_metatable {}
--! W.event { name = "new turn", T.message { speaker = "narrator", message = "?" } }
--! @endcode
function helper.set_wml_tag_metatable(t)
return setmetatable(t, create_tag_mt)
end
--! Fetches all the WML container variables with name @a var.
--! @returns a table containing all the variables (starting at index 1).
function helper.get_variable_array(var)
local result = {}
for i = 1, wesnoth.get_variable(var .. ".length") do
result[i] = wesnoth.get_variable(string.format("%s[%d]", var, i - 1))
end
return result
end
--! Puts all the elements of table @a t inside a WML container with name @a var.
function helper.set_variable_array(var, t)
wesnoth.set_variable(var)
for i, v in ipairs(t) do
wesnoth.set_variable(string.format("%s[%d]", var, i - 1), v)
end
end
--! Creates proxies for all the WML container variables with name @a var.
--! This is similar to helper.get_variable_array, except that the elements
--! can be used for writing too.
--! @returns a table containing all the variable proxies (starting at index 1).
function helper.get_variable_proxy_array(var)
local result = {}
for i = 1, wesnoth.get_variable(var .. ".length") do
result[i] = get_variable_proxy(string.format("%s[%d]", var, i - 1))
end
return result
end
--! Displays a WML message box with attributes from table @attr and options
--! from table @options.
--! @return the index of the selected option.
--! @code
--! local result = helper.get_user_choice({ speaker = "narrator" },
--! { "Choice 1", "Choice 2" })
--! @endcode
function helper.get_user_choice(attr, options)
local result = 0
function wesnoth.__user_choice_helper(i)
result = i
end
local msg = {}
for k,v in pairs(attr) do
msg[k] = attr[k]
end
for k,v in ipairs(options) do
table.insert(msg, { "option", { message = v,
{ "command", { { "lua", {
code = string.format("wesnoth.__user_choice_helper(%d)", k)
}}}}}})
end
wml_actions.message(msg)
wesnoth.__user_choice_helper = nil
return result
end
local function is_even(v) return v % 2 == 0 end
--! Returns the distance between two tiles given by their WML coordinates.
function helper.distance_between(x1, y1, x2, y2)
local hdist = math.abs(x1 - x2)
local vdist = math.abs(y1 - y2)
if (y1 < y2 and not is_even(x1) and is_even(x2)) or
(y2 < y1 and not is_even(x2) and is_even(x1))
then vdist = vdist + 1 end
return math.max(hdist, vdist + math.floor(hdist / 2))
end
local adjacent_offset = {
[false] = { {0,-1}, {1,-1}, {1,0}, {0,1}, {-1,0}, {-1,-1} },
[true] = { {0,-1}, {1,0}, {1,1}, {0,1}, {-1,1}, {-1,0} }
}
--! Returns an iterator over adjacent locations that can be used in a for-in loop.
function helper.adjacent_tiles(x, y, with_borders)
local x1,y1,x2,y2,b = 1,1,wesnoth.get_map_size()
if with_borders then
x1 = x1 - b
y1 = y1 - b
x2 = x2 + b
y2 = y2 + b
end
local offset = adjacent_offset[is_even(x)]
local i = 1
return function()
while i <= 6 do
local o = offset[i]
i = i + 1
local u, v = o[1] + x, o[2] + y
if u >= x1 and u <= x2 and v >= y1 and v <= y2 then
return u, v
end
end
return nil
end
end
function helper.literal(cfg)
if type(cfg) == "userdata" then
return cfg.__literal
else
return cfg or {}
end
end
function helper.parsed(cfg)
if type(cfg) == "userdata" then
return cfg.__parsed
else
return cfg or {}
end
end
function helper.shallow_literal(cfg)
if type(cfg) == "userdata" then
return cfg.__shallow_literal
else
return cfg or {}
end
end
function helper.shallow_parsed(cfg)
if type(cfg) == "userdata" then
return cfg.__shallow_parsed
else
return cfg or {}
end
end
function helper.rand (possible_values)
wml_actions.set_variable({ name = "LUA_rand", rand = possible_values })
local result = wesnoth.get_variable("LUA_rand")
wesnoth.set_variable("LUA_rand")
return result
end
function helper.deprecate(msg, f)
return function(...)
if msg then
wesnoth.message("warning", msg)
-- trigger the message only once
msg = nil
end
return f(...)
end
end
function helper.round( number )
-- code converted from util.hpp, round_portable function
-- round half away from zero method
if number >= 0 then
number = math.floor( number + 0.5 )
else
number = math.ceil ( number - 0.5 )
end
return number
end
function helper.shuffle( t )
-- since tables are passed by reference, this is an in-place shuffle
-- it uses the Fisher-Yates algorithm, also known as Knuth shuffle
assert( type( t ) == "table", string.format( "helper.shuffle expects a table as parameter, got %s instead", type( t ) ) )
local length = #t
for index = length, 2, -1 do
local random = math.random( 1, index )
t[index], t[random] = t[random], t[index]
end
end
return helper