wesnoth/data/ai/lua/ai_helper.lua
2021-03-14 08:59:42 -07:00

1951 lines
73 KiB
Lua

local H = wesnoth.require "helper"
local W = H.set_wml_action_metatable {}
local LS = wesnoth.require "location_set"
local F = wesnoth.require "functional"
local M = wesnoth.map
-- This is a collection of Lua functions used for custom AI development.
-- Note that this is still work in progress with significant changes occurring
-- frequently. Backward compatibility cannot be guaranteed at this time in
-- development releases, but it is of course easily possible to copy a function
-- from a previous release directly into an add-on if it is needed there.
--
-- Invisible units ('viewing_side' parameter):
-- With their default settings, the ai_helper functions use the vision a player of
-- the respective side would see, that is, they assume no knowledge of invisible
-- units. This can be influenced with the 'viewing_side' parameter, which works
-- in the same way as it does in wesnoth.find_reach() and wesnoth.find_path():
-- - If set to a valid side number, vision for that side is used
-- - If set to an invalid side number (e.g. 0), all units on the map are seen
-- - If omitted and a function takes a a parameter linked to a specific side,
-- such as a side number or a unit, as input, vision of that side is used. In
-- this case, viewing_side is passed as part of the optional @cfg configuration
-- table and can be passed from function to function.
-- - If omitted and the function takes no such input, viewing_side is made a
-- required parameter in order to avoid mismatches between the default values
-- of different functions.
--
-- Path finding:
-- All ai_helper functions disregard shroud for path finding (while still ignoring
-- hidden units correctly) as of Wesnoth 1.13.7. This is consistent with default
-- Wesnoth AI behavior and ensures that Lua AIs, including the Micro AIs, can be
-- used for AI sides with shroud=yes. It is accomplished by using
-- ai_helper.find_path_with_shroud() instead of wesnoth.find_path().
local ai_helper = {}
----- Debugging helper functions ------
function ai_helper.show_messages()
-- Returns true or false (hard-coded). To be used to
-- show messages if in debug mode.
-- Just edit the following line (easier than trying to set WML variable)
local show_messages_flag = false
if wesnoth.game_config.debug then return show_messages_flag end
return false
end
function ai_helper.print_exec()
-- Returns true or false (hard-coded). To be used to
-- show which CA is being executed if in debug mode.
-- Just edit the following line (easier than trying to set WML variable)
local print_exec_flag = false
if wesnoth.game_config.debug then return print_exec_flag end
return false
end
function ai_helper.print_eval()
-- Returns true or false (hard-coded). To be used to
-- show which CA is being evaluated if in debug mode.
-- Just edit the following line (easier than trying to set WML variable)
local print_eval_flag = false
if wesnoth.game_config.debug then return print_eval_flag end
return false
end
function ai_helper.done_eval_messages(start_time, ca_name)
ca_name = ca_name or 'unknown'
local dt = wesnoth.get_time_stamp() / 1000. - start_time
if ai_helper.print_eval() then
ai_helper.print_ts_delta(start_time, ' - Done evaluating ' .. ca_name .. ':')
end
end
function ai_helper.clear_labels()
-- Clear all labels on a map
local width, height = wesnoth.get_map_size()
for x = 1,width do
for y = 1,height do
W.label { x = x, y = y, text = "" }
end
end
end
function ai_helper.put_labels(map, cfg)
-- Take @map (location set) and put label containing 'value' onto the map.
-- Print 'nan' if element exists but is not a number.
-- @cfg: table with optional configuration parameters:
-- - show_coords: (boolean) use hex coordinates as labels instead of value
-- - factor=1: (number) if value is a number, multiply by this factor
-- - keys: (array) if the value to be displayed is a subelement of the LS data,
-- use these keys to access it. For example, if we want to display data[3]
-- set keys = { 3 }, if it's data.arg[3], set keys = { 'arg', 3 }
cfg = cfg or {}
local factor = cfg.factor or 1
ai_helper.clear_labels()
map:iter(function(x, y, data)
local out
if cfg.show_coords then
out = x .. ',' .. y
else
if cfg.keys then
for _,key in ipairs(cfg.keys) do data = data[key] end
end
if (type(data) == 'string') then
out = data
else
out = tonumber(data) or 'nan'
end
end
if (type(out) == 'number') then out = out * factor end
W.label { x = x, y = y, text = out }
end)
end
function ai_helper.print_ts(...)
-- Print arguments preceded by a time stamp in seconds
-- Also return that time stamp
local ts = wesnoth.get_time_stamp() / 1000.
local arg = { ... }
arg[#arg+1] = string.format('[ t = %.3f ]', ts)
std_print(table.unpack(arg))
return ts
end
function ai_helper.print_ts_delta(start_time, ...)
-- @start_time: time stamp in seconds as returned by wesnoth.get_time_stamp / 1000.
-- Same as ai_helper.print_ts(), but also adds time elapsed since
-- the time given in the first argument (in seconds)
-- Returns time stamp as well as time elapsed
local ts = wesnoth.get_time_stamp() / 1000.
local delta = ts - start_time
local arg = { ... }
arg[#arg+1] = string.format('[ t = %.3f, dt = %.3f ]', ts, delta)
std_print(table.unpack(arg))
return ts, delta
end
----- AI execution helper functions ------
function ai_helper.is_incomplete_move(check)
if (not check.ok) then
-- Legitimately interrupted moves have the following error codes:
-- E_AMBUSHED = 2005
-- E_FAILED_TELEPORT = 2006,
-- E_NOT_REACHED_DESTINATION = 2007
if (check.status == 2005) or (check.status == 2006) or (check.status == 2007) then
return check.status
end
end
return false
end
function ai_helper.is_incomplete_or_empty_move(check)
if (not check.ok) then
-- Empty moves have the following error code:
-- E_EMPTY_MOVE = 2001
if ai_helper.is_incomplete_move(check) or (check.status == 2001) then
return check.status
end
end
return false
end
function ai_helper.dummy_check_action(gamestate_changed, ok, result, status)
return {
gamestate_changed = gamestate_changed or false,
ok = ok or false,
result = result or 'ai_helper::DUMMY_FAILED_ACTION',
status = status or 99999
}
end
function ai_helper.checked_action_error(action, error_code)
if wesnoth.game_config.debug then
error(action .. ' could not be executed. Error code: ' .. error_code, 3)
end
end
function ai_helper.checked_attack(ai, attacker, defender, weapon)
local check = ai.check_attack(attacker, defender, weapon)
if (not check.ok) then
ai.stopunit_attacks(attacker)
ai_helper.checked_action_error('ai.attack from ' .. attacker.x .. ',' .. attacker.y .. ' to ' .. defender.x .. ',' .. defender.y, check.status .. ' (' .. check.result .. ')')
return check
end
return ai.attack(attacker, defender, weapon)
end
function ai_helper.checked_move_core(ai, unit, x, y, move_type)
local check = ai.check_move(unit, x, y)
if (not check.ok) then
if (not ai_helper.is_incomplete_or_empty_move(check)) then
ai.stopunit_moves(unit)
ai_helper.checked_action_error(move_type .. ' from ' .. unit.x .. ',' .. unit.y .. ' to ' .. x .. ',' .. y, check.status .. ' (' .. check.result .. ')')
return check
end
end
if (move_type == 'ai.move_full') then
return ai.move_full(unit, x, y)
else
return ai.move(unit, x, y)
end
end
function ai_helper.checked_move_full(ai, unit, x, y)
return ai_helper.checked_move_core(ai, unit, x, y, 'ai.move_full')
end
function ai_helper.checked_move(ai, unit, x, y)
return ai_helper.checked_move_core(ai, unit, x, y, 'ai.move')
end
function ai_helper.checked_recruit(ai, unit_type, x, y)
local check = ai.check_recruit(unit_type, x, y)
if (not check.ok) then
ai_helper.checked_action_error('ai.recruit of ' .. unit_type .. ' at ' .. x .. ',' .. y, check.status .. ' (' .. check.result .. ')')
return check
end
return ai.recruit(unit_type, x, y)
end
function ai_helper.checked_stopunit_all(ai, unit)
local check = ai.check_stopunit(unit)
if (not check.ok) then
ai_helper.checked_action_error('ai.stopunit_all of ' .. unit.x .. ',' .. unit.y, check.status .. ' (' .. check.result .. ')')
return check
end
return ai.stopunit_all(unit)
end
function ai_helper.checked_stopunit_attacks(ai, unit)
local check = ai.check_stopunit(unit)
if (not check.ok) then
ai_helper.checked_action_error('ai.stopunit_attacks of ' .. unit.x .. ',' .. unit.y, check.status .. ' (' .. check.result .. ')')
return check
end
return ai.stopunit_attacks(unit)
end
function ai_helper.checked_stopunit_moves(ai, unit)
local check = ai.check_stopunit(unit)
if (not check.ok) then
ai_helper.checked_action_error('ai.stopunit_moves of ' .. unit.x .. ',' .. unit.y, check.status .. ' (' .. check.result .. ')')
return check
end
return ai.stopunit_moves(unit)
end
function ai_helper.robust_move_and_attack(ai, src, dst, target_loc, cfg)
-- Perform a move and/or attack with an AI unit in a way that is robust against
-- unexpected outcomes such as being ambushed or changes caused by WML events.
-- As much as possible, this function also tries to ensure that the gamestate
-- is changed in case an action turns out to be impossible due to such an
-- unexpected outcome.
--
-- Required input parameters:
-- @ai: the Lua ai table
-- @src: current coordinates of the AI unit to be used
-- @dst: coordinates to which the unit should move. This does not have to be
-- different from @src. In fact, the unit does not even need to have moves
-- left, as long as an attack is specified in the latter case. If another
-- AI unit is at @dst, it is moved out of the way.
--
-- Optional parameters:
-- @target_loc: coordinates of the enemy unit to be attacked. If not given, no
-- attack is attempted.
-- @cfg: table with optional configuration parameters:
-- partial_move: By default, this function performs full moves. If this
-- parameter is true, a partial move is done instead.
-- weapon: The number (starting at 1) of the attack weapon to be used.
-- If omitted, the best weapon is automatically selected.
-- all optional parameters for ai_helper.move_unit_out_of_way()
-- Notes:
-- - @src, @dst and @target_loc can be any table (including proxy units) that contains
-- the coordinates of the respective locations using either indices .x/.y or [1]/[2].
-- If both are given, .x/.y takes precedence over [1]/[2].
-- - This function only safeguards AI moves against outcomes that the AI cannot know
-- about, such as hidden units and WML events. It is assumed that the potential
-- move was tested for general feasibility (units are on AI side and have moves
-- left, terrain is passable, etc.) beforehand. If that is not done, it might
-- lead to very undesirable behavior, incl. the CA being blacklisted or even the
-- entire AI turn being ended.
local src_x, src_y = src.x or src[1], src.y or src[2] -- this works with units or locations
local dst_x, dst_y = dst.x or dst[1], dst.y or dst[2]
local unit = wesnoth.get_unit(src_x, src_y)
if (not unit) then
return ai_helper.dummy_check_action(false, false, 'robust_move_and_attack::NO_UNIT')
end
-- Getting target at beginning also, in case events mess up things along the way
local target, target_x, target_y
if target_loc then
target_x, target_y = target_loc.x or target_loc[1], target_loc.y or target_loc[2]
target = wesnoth.get_unit(target_x, target_y)
if (not target) then
return ai_helper.dummy_check_action(false, false, 'robust_move_and_attack::NO_TARGET')
end
end
local gamestate_changed = false
local move_result = ai_helper.dummy_check_action(false, false, 'robust_move_and_attack::NO_ACTION')
if (unit.moves > 0) then
if (src_x == dst_x) and (src_y == dst_y) then
move_result = ai.stopunit_moves(unit)
-- The only possible failure modes are non-recoverable (such as E_NOT_OWN_UNIT)
if (not move_result.ok) then return move_result end
if (not unit) or (not unit.valid) then
return ai_helper.dummy_check_action(true, false, 'robust_move_and_attack::UNIT_DISAPPEARED')
end
gamestate_changed = true
else
local unit_old_moves = unit.moves
local unit_in_way = wesnoth.get_unit(dst_x, dst_y)
if unit_in_way and (unit_in_way.side == wesnoth.current.side) and (unit_in_way.moves > 0) then
local uiw_old_moves = unit_in_way.moves
ai_helper.move_unit_out_of_way(ai, unit_in_way, cfg)
if (not unit_in_way) or (not unit_in_way.valid) then
return ai_helper.dummy_check_action(true, false, 'robust_move_and_attack::UNIT_IN_WAY_DISAPPEARED')
end
-- Failed move out of way: abandon remaining actions
if (unit_in_way.x == dst_x) and (unit_in_way.y == dst_y) then
if (unit_in_way.moves == uiw_old_moves) then
-- Forcing a gamestate change, if necessary
ai.stopunit_moves(unit_in_way)
end
return ai_helper.dummy_check_action(true, false, 'robust_move_and_attack::UNIT_IN_WAY_EMPTY_MOVE')
end
-- Check whether dst hex is free now (an event could have done something funny)
local unit_in_way = wesnoth.get_unit(dst_x, dst_y)
if unit_in_way then
return ai_helper.dummy_check_action(true, false, 'robust_move_and_attack::ANOTHER_UNIT_IN_WAY')
end
gamestate_changed = true
end
if (not unit) or (not unit.valid) or (unit.x ~= src_x) or (unit.y ~= src_y) then
return ai_helper.dummy_check_action(true, false, 'robust_move_and_attack::UNIT_DISAPPEARED')
end
local check_result = ai.check_move(unit, dst_x, dst_y)
if (not check_result.ok) then
if (not ai_helper.is_incomplete_or_empty_move(check_result)) then
if (not gamestate_changed) then
ai.stopunit_moves(unit)
end
return check_result
end
end
if cfg and cfg.partial_move then
move_result = ai.move(unit, dst_x, dst_y)
else
move_result = ai.move_full(unit, dst_x, dst_y)
end
if (not move_result.ok) then return move_result end
if (not unit) or (not unit.valid) then
return ai_helper.dummy_check_action(true, false, 'robust_move_and_attack::UNIT_DISAPPEARED')
end
-- Failed move: abandon rest of actions
if (unit.x == src_x) and (unit.y == src_y) then
if (not gamestate_changed) and (unit.moves == unit_old_moves) then
-- Forcing a gamestate change, if necessary
ai.stopunit_moves(unit)
end
return ai_helper.dummy_check_action(true, false, 'robust_move_and_attack::UNPLANNED_EMPTY_MOVE')
end
gamestate_changed = true
end
end
-- Tests after the move, before continuing to attack, to ensure WML events
-- did not do something funny
if (not unit) or (not unit.valid) then
return ai_helper.dummy_check_action(true, false, 'robust_move_and_attack::UNIT_DISAPPEARED')
end
if (unit.x ~= dst_x) or (unit.y ~= dst_y) then
return ai_helper.dummy_check_action(true, false, 'robust_move_and_attack::UNIT_NOT_AT_DESTINATION')
end
-- In case all went well and there's no attack to be done
if (not target_x) then return move_result end
if (not target) or (not target.valid) then
return ai_helper.dummy_check_action(true, false, 'robust_move_and_attack::TARGET_DISAPPEARED')
end
if (target.x ~= target_x) or (target.y ~= target_y) then
return ai_helper.dummy_check_action(true, false, 'robust_move_and_attack::TARGET_MOVED')
end
local weapon = cfg and cfg.weapon
local old_attacks_left = unit.attacks_left
local check_result = ai.check_attack(unit, target, weapon)
if (not check_result.ok) then
if (not gamestate_changed) then
ai.stopunit_all(unit)
end
return check_result
end
move_result = ai.attack(unit, target, weapon)
-- This should not happen, given that we just checked, but just in case
if (not move_result.ok) then return move_result end
if (not unit) or (not unit.valid) then
return ai_helper.dummy_check_action(true, false, 'robust_move_and_attack::UNIT_DISAPPEARED')
end
if (unit.attacks_left == old_attacks_left) and (not gamestate_changed) then
ai.stopunit_all(unit)
return ai_helper.dummy_check_action(true, false, 'robust_move_and_attack::NO_ATTACK')
end
return move_result
end
----- General functionality and maths helper functions ------
function ai_helper.filter(input, condition)
return F.filter(input, condition)
end
function ai_helper.choose(input, value)
return F.choose(input, value)
end
function ai_helper.table_copy(t)
-- Make a copy of a table (rather than just another pointer to the same table)
local copy = {}
for k,v in pairs(t) do copy[k] = v end
return copy
end
function ai_helper.array_merge(a1, a2)
-- Merge two arrays without overwriting @a1 or @a2 -> create a new table
-- This only works with arrays, not general tables
local merger = {}
for _,a in pairs(a1) do table.insert(merger, a) end
for _,a in pairs(a2) do table.insert(merger, a) end
return merger
end
function ai_helper.serialize(input)
-- Convert @input to a string in a format corresponding to the type of @input
-- The string is all put into one line
local str = ''
if (type(input) == "number") or (type(input) == "boolean") then
str = tostring(input)
elseif type(input) == "string" then
str = string.format("%q", input)
elseif type(input) == "table" then
str = str .. "{ "
for k,v in pairs(input) do
str = str .. "[" .. ai_helper.serialize(k) .. "] = "
str = str .. ai_helper.serialize(v)
str = str .. ", "
end
str = str .. "}"
else
error("cannot serialize a " .. type(input), 2)
end
return str
end
function ai_helper.split(str, sep)
-- Split string @str into a table using the delimiter @sep (default: ',')
local sep, fields = sep or ",", {}
local pattern = string.format("([^%s]+)", sep)
string.gsub(str, pattern, function(c) fields[#fields+1] = c end)
return fields
end
--------- Location set related helper functions ----------
function ai_helper.get_LS_xy(index)
-- Get the x,y coordinates for the index of a location set
-- For some reason, there doesn't seem to be a LS function for this
local tmp_set = LS.create()
tmp_set.values[index] = 1
local xy = tmp_set:to_pairs()[1]
return xy[1], xy[2]
end
--------- Location, position or hex related helper functions ----------
function ai_helper.cartesian_coords(x, y)
-- Converts coordinates from hex geometry to cartesian coordinates,
-- meaning that y coordinates are offset by 0.5 every other hex
-- Example: (1,1) stays (1,1) and (3,1) remains (3,1), but (2,1) -> (2,1.5) etc.
return x, y + ((x + 1) % 2) / 2.
end
function ai_helper.get_angle(from_hex, to_hex)
-- Returns the angle of the direction from @from_hex to @to_hex
-- Angle is in radians and goes from -pi to pi. 0 is toward east.
-- Input hex tables can be of form { x, y } or { x = x, y = y }, which
-- means that it is also possible to pass a unit table
local x1, y1 = from_hex.x or from_hex[1], from_hex.y or from_hex[2]
local x2, y2 = to_hex.x or to_hex[1], to_hex.y or to_hex[2]
local _, y1cart = ai_helper.cartesian_coords(x1, y1)
local _, y2cart = ai_helper.cartesian_coords(x2, y2)
return math.atan(y2cart - y1cart, x2 - x1)
end
function ai_helper.get_direction_index(from_hex, to_hex, n, center_on_east)
-- Returns an integer index for the direction from @from_hex to @to_hex
-- with the full circle divided into @n slices
-- 1 is always to the east, with indices increasing clockwise
-- Input hex tables can be of form { x, y } or { x = x, y = y }, which
-- means that it is also possible to pass a unit table
--
-- Optional input:
-- @center_on_east (false): boolean. By default, the eastern direction is the
-- northern border of the first slice. If this parameter is set, east will
-- instead be the center direction of the first slice
local d_east = 0
if center_on_east then d_east = 0.5 end
local angle = ai_helper.get_angle(from_hex, to_hex)
local index = math.floor((angle / math.pi * n/2 + d_east) % n ) + 1
return index
end
function ai_helper.get_cardinal_directions(from_hex, to_hex)
local dirs = { "E", "S", "W", "N" }
return dirs[ai_helper.get_direction_index(from_hex, to_hex, 4, true)]
end
function ai_helper.get_intercardinal_directions(from_hex, to_hex)
local dirs = { "E", "SE", "S", "SW", "W", "NW", "N", "NE" }
return dirs[ai_helper.get_direction_index(from_hex, to_hex, 8, true)]
end
function ai_helper.get_hex_facing(from_hex, to_hex)
local dirs = { "se", "s", "sw", "nw", "n", "ne" }
return dirs[ai_helper.get_direction_index(from_hex, to_hex, 6)]
end
function ai_helper.find_opposite_hex_adjacent(hex, center_hex)
-- Find the hex that is opposite of @hex with respect to @center_hex
-- Both input hexes are of format { x, y }
-- Output: {opp_x, opp_y} -- or nil if @hex and @center_hex are not adjacent
-- (or no opposite hex is found, e.g. for hexes on border)
-- If the two input hexes are not adjacent, return nil
if (M.distance_between(hex[1], hex[2], center_hex[1], center_hex[2]) ~= 1) then return nil end
-- Finding the opposite x position is easy
local opp_x = center_hex[1] + (center_hex[1] - hex[1])
-- y is slightly more tricky, because of the hexagonal shape, but there's a trick
-- that saves us from having to build in a lot of if statements
-- Among the adjacent hexes, it is the one with the correct x, and y _different_ from hex[2]
for xa,ya in H.adjacent_tiles(center_hex[1], center_hex[2]) do
if (xa == opp_x) and (ya ~= hex[2]) then return { xa, ya } end
end
return nil
end
function ai_helper.find_opposite_hex(hex, center_hex)
-- Find the hex that is opposite of @hex with respect to @center_hex
-- Using "square coordinate" method by JaMiT
-- Note: this also works for non-adjacent hexes, but might return hexes that are not on the map!
-- Both input hexes are of format { x, y }
-- Output: { opp_x, opp_y }
-- Finding the opposite x position is easy
local opp_x = center_hex[1] + (center_hex[1] - hex[1])
-- Going to "square geometry" for y coordinate
local y_sq = hex[2] * 2 - (hex[1] % 2)
local yc_sq = center_hex[2] * 2 - (center_hex[1] % 2)
-- Now the same equation as for x can be used for y
local opp_y = yc_sq + (yc_sq - y_sq)
opp_y = math.floor((opp_y + 1) / 2)
return {opp_x, opp_y}
end
function ai_helper.is_opposite_adjacent(hex1, hex2, center_hex)
-- Returns true if @hex1 and @hex2 are opposite from each other with respect to @center_hex
local opp_hex = ai_helper.find_opposite_hex_adjacent(hex1, center_hex)
if opp_hex and (opp_hex[1] == hex2[1]) and (opp_hex[2] == hex2[2]) then return true end
return false
end
function ai_helper.get_closest_location(hex, location_filter, unit)
-- Get the location closest to @hex (in format { x, y })
-- that matches @location_filter (in WML table format)
-- @unit can be passed as an optional third parameter, in which case the
-- terrain needs to be passable for that unit
-- Returns nil if no terrain matching the filter was found
-- Find the maximum distance from 'hex' that's possible on the map
local max_distance = 0
local width, height = wesnoth.get_map_size()
local to_top_left = M.distance_between(hex[1], hex[2], 0, 0)
if (to_top_left > max_distance) then max_distance = to_top_left end
local to_top_right = M.distance_between(hex[1], hex[2], width+1, 0)
if (to_top_right > max_distance) then max_distance = to_top_right end
local to_bottom_left = M.distance_between(hex[1], hex[2], 0, height+1)
if (to_bottom_left > max_distance) then max_distance = to_bottom_left end
local to_bottom_right = M.distance_between(hex[1], hex[2], width+1, height+1)
if (to_bottom_right > max_distance) then max_distance = to_bottom_right end
-- If the hex is supposed to be passable for a unit, it cannot be on the map border
local include_borders
if unit then include_borders = 'no' end
local radius = 0
while (radius <= max_distance) do
local loc_filter = {}
if (radius == 0) then
loc_filter = {
{ "and", { x = hex[1], y = hex[2], include_borders = include_borders, radius = radius } },
{ "and", location_filter }
}
else
loc_filter = {
{ "and", { x = hex[1], y = hex[2], include_borders = include_borders, radius = radius } },
{ "not", { x = hex[1], y = hex[2], radius = radius - 1 } },
{ "and", location_filter }
}
end
local locs = wesnoth.get_locations(loc_filter)
if unit then
for _,loc in ipairs(locs) do
local movecost = wesnoth.unit_movement_cost(unit, wesnoth.get_terrain(loc[1], loc[2]))
if (movecost <= unit.max_moves) then return loc end
end
else
if locs[1] then return locs[1] end
end
radius = radius + 1
end
return nil
end
function ai_helper.get_passable_locations(location_filter, unit)
-- Finds all locations matching @location_filter that are passable for
-- @unit. This also excludes hexes on the map border.
-- @unit is optional: if omitted, all hexes matching the filter, but
-- excluding border hexes are returned
-- All hexes that are not on the map border
local width, height = wesnoth.get_map_size()
local all_locs = wesnoth.get_locations{
x = '1-' .. width,
y = '1-' .. height,
{ "and", location_filter }
}
-- If @unit is provided, exclude terrain that's impassable for the unit
if unit then
local locs = {}
for _,loc in ipairs(all_locs) do
local movecost = wesnoth.unit_movement_cost(unit, wesnoth.get_terrain(loc[1], loc[2]))
if (movecost <= unit.max_moves) then table.insert(locs, loc) end
end
return locs
end
return all_locs
end
function ai_helper.distance_map(units, map)
-- Get the distance map DM for all units in @units (as a location set)
-- DM = sum ( distance_from_unit )
-- This is done for all elements of @map (a locations set), or for the entire map if @map is not given
local DM = LS.create()
if map then
map:iter(function(x, y, data)
local dist = 0
for _,unit in ipairs(units) do
dist = dist + M.distance_between(unit.x, unit.y, x, y)
end
DM:insert(x, y, dist)
end)
else
local width, height = wesnoth.get_map_size()
for x = 1,width do
for y = 1,height do
local dist = 0
for _,unit in ipairs(units) do
dist = dist + M.distance_between(unit.x, unit.y, x, y)
end
DM:insert(x, y, dist)
end
end
end
return DM
end
function ai_helper.inverse_distance_map(units, map)
-- Get the inverse distance map IDM for all units in @units (as a location set)
-- IDM = sum ( 1 / (distance_from_unit+1) )
-- This is done for all elements of @map (a locations set), or for the entire map if @map is not given
local IDM = LS.create()
if map then
map:iter(function(x, y, data)
local dist = 0
for _,unit in ipairs(units) do
dist = dist + 1. / (M.distance_between(unit.x, unit.y, x, y) + 1)
end
IDM:insert(x, y, dist)
end)
else
local width, height = wesnoth.get_map_size()
for x = 1,width do
for y = 1,height do
local dist = 0
for _,unit in ipairs(units) do
dist = dist + 1. / (M.distance_between(unit.x, unit.y, x, y) + 1)
end
IDM:insert(x, y, dist)
end
end
end
return IDM
end
function ai_helper.generalized_distance(x1, y1, x2, y2)
-- Determines distance of (@x1,@y1) from (@x2,@y2) even if
-- @x2 and @y2 are not necessarily both given (or not numbers)
-- Return 0 if neither is given
if (not x2) and (not y2) then return 0 end
-- If only one of the parameters is set
if (not x2) then return math.abs(y1 - y2) end
if (not y2) then return math.abs(x1 - x2) end
-- Otherwise, return standard distance
return M.distance_between(x1, y1, x2, y2)
end
function ai_helper.xyoff(x, y, ori, hex)
-- Finds hexes at a certain offset from @x,@y
-- @ori: direction/orientation: north (0), ne (1), se (2), s (3), sw (4), nw (5)
-- @hex: string for the hex to be queried. Possible values:
-- 's': self, 'u': up, 'lu': left up, 'ld': left down, 'ru': right up, 'rd': right down
-- This is all relative "looking" in the direction of 'ori'
-- returns x,y for the queried hex
-- Unlike Lua default, we count 'ori' from 0 (north) to 5 (nw), so that modulo operator can be used
ori = ori % 6
if (hex == 's') then return x, y end
-- This is all done with ifs, to keep it as fast as possible
if (ori == 0) then -- "north"
if (hex == 'u') then return x, y-1 end
if (hex == 'd') then return x, y+1 end
local dy = 0
if (x % 2) == 1 then dy=1 end
if (hex == 'lu') then return x-1, y-dy end
if (hex == 'ld') then return x-1, y+1-dy end
if (hex == 'ru') then return x+1, y-dy end
if (hex == 'rd') then return x+1, y+1-dy end
end
if (ori == 1) then -- "north-east"
local dy = 0
if (x % 2) == 1 then dy=1 end
if (hex == 'u') then return x+1, y-dy end
if (hex == 'd') then return x-1, y+1-dy end
if (hex == 'lu') then return x, y-1 end
if (hex == 'ld') then return x-1, y-dy end
if (hex == 'ru') then return x+1, y+1-dy end
if (hex == 'rd') then return x, y+1 end
end
if (ori == 2) then -- "south-east"
local dy = 0
if (x % 2) == 1 then dy=1 end
if (hex == 'u') then return x+1, y+1-dy end
if (hex == 'd') then return x-1, y-dy end
if (hex == 'lu') then return x+1, y-dy end
if (hex == 'ld') then return x, y-1 end
if (hex == 'ru') then return x, y+1 end
if (hex == 'rd') then return x-1, y+1-dy end
end
if (ori == 3) then -- "south"
if (hex == 'u') then return x, y+1 end
if (hex == 'd') then return x, y-1 end
local dy = 0
if (x % 2) == 1 then dy=1 end
if (hex == 'lu') then return x+1, y+1-dy end
if (hex == 'ld') then return x+1, y-dy end
if (hex == 'ru') then return x-1, y+1-dy end
if (hex == 'rd') then return x-1, y-dy end
end
if (ori == 4) then -- "south-west"
local dy = 0
if (x % 2) == 1 then dy=1 end
if (hex == 'u') then return x-1, y+1-dy end
if (hex == 'd') then return x+1, y-dy end
if (hex == 'lu') then return x, y+1 end
if (hex == 'ld') then return x+1, y+1-dy end
if (hex == 'ru') then return x-1, y-dy end
if (hex == 'rd') then return x, y-1 end
end
if (ori == 5) then -- "north-west"
local dy = 0
if (x % 2) == 1 then dy=1 end
if (hex == 'u') then return x-1, y-dy end
if (hex == 'd') then return x+1, y+1-dy end
if (hex == 'lu') then return x-1, y+1-dy end
if (hex == 'ld') then return x, y+1 end
if (hex == 'ru') then return x, y-1 end
if (hex == 'rd') then return x+1, y-dy end
end
return
end
function ai_helper.split_location_list_to_strings(list)
-- Convert a list of locations @list as returned by wesnoth.get_locations into a pair of strings
-- suitable for passing in as x,y coordinate lists to wesnoth.get_locations.
-- Could alternatively convert to a WML table and use the find_in argument, but this is simpler.
local locsx, locsy = {}, {}
for i,loc in ipairs(list) do
locsx[i] = loc[1]
locsy[i] = loc[2]
end
locsx = table.concat(locsx, ",")
locsy = table.concat(locsy, ",")
return locsx, locsy
end
--------- Unit related helper functions ----------
function ai_helper.get_live_units(filter)
-- Note: the order of the filters and the [and] tags are important for speed reasons
return wesnoth.get_units { { "not", { status = "petrified" } }, { "and", filter } }
end
function ai_helper.get_units_with_moves(filter, exclude_guardians)
-- Optional input: @exclude_guardians: set to 'true' to exclude units with ai_special=guardian
-- Note: the order of the filters and the [and] tags are important for speed reasons
local exclude_status = 'petrified'
if exclude_guardians then
exclude_status = exclude_status .. ',guardian'
end
return wesnoth.get_units {
{ "and", { formula = "moves > 0" } },
{ "not", { status = exclude_status } },
{ "and", filter }
}
end
function ai_helper.get_units_with_attacks(filter)
-- Note: the order of the filters and the [and] tags are important for speed reasons
return wesnoth.get_units {
{ "and", { formula = "attacks_left > 0 and size(attacks) > 0" } },
{ "not", { status = "petrified" } },
{ "and", filter }
}
end
function ai_helper.get_visible_units(viewing_side, filter)
-- Get units that are visible to side @viewing_side
--
-- Required parameters:
-- @viewing_side: see comments at beginning of this file
--
-- Optional parameters:
-- @filter: Standard unit filter WML table for the units
-- Example 1: { type = 'Orcish Grunt' }
-- Example 2: { { "filter_location", { x = 10, y = 12, radius = 5 } } }
if (not viewing_side) then
error('ai_helper.get_visible_units() is missing required parameter viewing_side.', 2)
end
if (type(viewing_side) ~= 'number') then
error('ai_helper.get_visible_units(): parameter viewing_side must be a number., 2')
end
local filter_plus_vision = {}
if filter then filter_plus_vision = ai_helper.table_copy(filter) end
if wesnoth.sides[viewing_side] then
table.insert(filter_plus_vision, { "filter_vision", { side = viewing_side, visible = 'yes' } })
end
local units = {}
local all_units = wesnoth.get_units()
for _,unit in ipairs(all_units) do
if unit:matches(filter_plus_vision) then
table.insert(units, unit)
end
end
return units
end
function ai_helper.is_visible_unit(viewing_side, unit)
-- Check whether @unit exists and is visible to side @viewing_side.
--
-- Required parameters:
-- @viewing_side: see comments at beginning of this file.
-- @unit: unit proxy table
if (not viewing_side) then
error('ai_helper.is_visible_unit() is missing required parameter viewing_side.', 2)
end
if (type(viewing_side) ~= 'number') then
error('ai_helper.is_visible_unit(): parameter viewing_side must be a number.', 2)
end
if (not unit) then return false end
if wesnoth.sides[viewing_side]
and unit:matches({ { "filter_vision", { side = viewing_side, visible = 'no' } } })
then
return false
end
return true
end
function ai_helper.get_attackable_enemies(filter, side, cfg)
-- Attackable enemies are defined as being being
-- - enemies of the side defined in @side,
-- - not petrified
-- - and visible to the side defined in @cfg.viewing_side.
-- For speed reasons, this is done separately, rather than calling ai_helper.get_visible_units().
--
-- Optional parameters:
-- @filter: Standard unit filter WML table for the enemies
-- Example 1: { type = 'Orcish Grunt' }
-- Example 2: { { "filter_location", { x = 10, y = 12, radius = 5 } } }
-- @side: side number, if side other than current side is to be considered
-- @cfg: table with optional configuration parameters:
-- viewing_side: see comments at beginning of this file. Defaults to @side.
side = side or wesnoth.current.side
local viewing_side = cfg and cfg.viewing_side or side
local filter_plus_vision = {}
if filter then filter_plus_vision = ai_helper.table_copy(filter) end
if wesnoth.sides[viewing_side] then
table.insert(filter_plus_vision, { "filter_vision", { side = viewing_side, visible = 'yes' } })
end
local enemies = {}
local all_units = wesnoth.get_units()
for _,unit in ipairs(all_units) do
if wesnoth.is_enemy(side, unit.side)
and (not unit.status.petrified)
and unit:matches(filter_plus_vision)
then
table.insert(enemies, unit)
end
end
return enemies
end
function ai_helper.is_attackable_enemy(unit, side, cfg)
-- Check if @unit exists, is an enemy of @side, is visible to the side defined
-- in @cfg.viewing_side and is not petrified.
--
-- Optional parameters:
-- @side: side number, defaults to current side.
-- @cfg: table with optional configuration parameters:
-- viewing_side: see comments at beginning of this file. Defaults to @side.
side = side or wesnoth.current.side
local viewing_side = cfg and cfg.viewing_side or side
if (not unit)
or (not wesnoth.is_enemy(side, unit.side))
or unit.status.petrified
or (not ai_helper.is_visible_unit(viewing_side, unit))
then
return false
end
return true
end
function ai_helper.get_closest_enemy(loc, side, cfg)
-- Return distance to and location of the enemy closest to @loc, or to the
-- leader of side with number @side if @loc is not specified
--
-- Optional parameters:
-- @loc: location in format { x , y }
-- @side: number of side for which to find enemy; defaults to current side
-- @cfg: table with optional configuration parameters:
-- viewing_side: see comments at beginning of this file. Defaults to @side.
side = side or wesnoth.current.side
local enemies = ai_helper.get_attackable_enemies({}, side, cfg)
local x, y
if not loc then
local leader = wesnoth.get_units { side = side, canrecruit = 'yes' }[1]
x, y = leader.x, leader.y
else
x, y = loc[1], loc[2]
end
local closest_distance, location = 9e99
for _,enemy in ipairs(enemies) do
enemy_distance = M.distance_between(x, y, enemy.x, enemy.y)
if (enemy_distance < closest_distance) then
closest_distance = enemy_distance
location = { x = enemy.x, y = enemy.y}
end
end
return closest_distance, location
end
function ai_helper.has_ability(unit, ability)
-- Returns true/false depending on whether unit has the given ability
local has_ability = false
local abilities = wml.get_child(unit.__cfg, "abilities")
if abilities then
if wml.get_child(abilities, ability) then has_ability = true end
end
return has_ability
end
function ai_helper.has_weapon_special(unit, special)
-- Returns true/false depending on whether @unit has a weapon with special @special
-- Also returns the number of the first weapon with this special
for weapon_number,att in ipairs(unit.attacks) do
for _,sp in ipairs(att.specials) do
if (sp[1] == special) then
return true, weapon_number
end
end
end
return false
end
function ai_helper.get_cheapest_recruit_cost()
local cheapest_unit_cost = 9e99
for _,recruit_id in ipairs(wesnoth.sides[wesnoth.current.side].recruit) do
if wesnoth.unit_types[recruit_id].cost < cheapest_unit_cost then
cheapest_unit_cost = wesnoth.unit_types[recruit_id].cost
end
end
return cheapest_unit_cost
end
--------- Move related helper functions ----------
ai_helper.no_path = 42424242 -- Value returned by C++ engine for distance when no path is found
function ai_helper.get_dst_src_units(units, cfg)
-- Get the dst_src location set for @units
-- @cfg: table with optional configuration parameters:
-- moves: if set to 'max' use max_moves of units, rather than current moves
-- all parameters for wesnoth.find_reach
local max_moves = false
if cfg then
if (cfg['moves'] == 'max') then max_moves = true end
end
local dstsrc = LS.create()
for _,unit in ipairs(units) do
local tmp = unit.moves
if max_moves then
unit.moves = unit.max_moves
end
local reach = wesnoth.find_reach(unit, cfg)
if max_moves then
unit.moves = tmp
end
for _,loc in ipairs(reach) do
local tmp = dstsrc:get(loc[1], loc[2]) or {}
table.insert(tmp, { x = unit.x, y = unit.y })
dstsrc:insert(loc[1], loc[2], tmp)
end
end
return dstsrc
end
function ai_helper.get_dst_src(units, cfg)
-- If @units table is given use it, otherwise use all units on the current side
-- @cfg: table with optional configuration parameters:
-- moves: if set to 'max' use max_moves of units, rather than current moves
-- all parameters for wesnoth.find_reach
if (not units) then
units = wesnoth.get_units { side = wesnoth.current.side }
end
return ai_helper.get_dst_src_units(units, cfg)
end
function ai_helper.get_enemy_dst_src(enemies, cfg)
-- If @enemies table is given use it, otherwise use all enemy units
-- @cfg: table with optional configuration parameters:
-- all parameters for wesnoth.find_reach
if (not enemies) then
enemies = wesnoth.get_units {
{ "filter_side", { { "enemy_of", { side = wesnoth.current.side} } } }
}
end
local cfg_copy = {}
if cfg then cfg_copy = ai_helper.table_copy(cfg) end
cfg_copy.moves = 'max'
return ai_helper.get_dst_src_units(enemies, cfg_copy)
end
function ai_helper.my_moves()
-- Produces an array with each field of form:
-- [1] = { dst = { x = 7, y = 16 },
-- src = { x = 6, y = 16 } }
local dstsrc = ai.get_dstsrc()
local my_moves = {}
for key,value in pairs(dstsrc) do
table.insert( my_moves,
{ src = { x = value[1].x , y = value[1].y },
dst = { x = key.x , y = key.y }
}
)
end
return my_moves
end
function ai_helper.enemy_moves()
-- Produces an array with each field of form:
-- [1] = { dst = { x = 7, y = 16 },
-- src = { x = 6, y = 16 } }
local dstsrc = ai.get_enemy_dstsrc()
local enemy_moves = {}
for key,value in pairs(dstsrc) do
table.insert( enemy_moves,
{ src = { x = value[1].x , y = value[1].y },
dst = { x = key.x , y = key.y }
}
)
end
return enemy_moves
end
function ai_helper.next_hop(unit, x, y, cfg)
-- Finds the next "hop" of @unit on its way to (@x,@y)
-- Returns coordinates of the endpoint of the hop (or nil if no path to
-- (x,y) is found for the unit), and movement cost to get there.
-- Only unoccupied hexes are considered
-- @cfg: standard extra options for wesnoth.find_path()
-- including:
-- viewing_side: see comments at beginning of this file. Defaults to side of @unit
-- plus:
-- ignore_own_units: if set to true, then own units that can move out of the way are ignored
local path, cost = ai_helper.find_path_with_shroud(unit, x, y, cfg)
if cost >= ai_helper.no_path then return nil, cost end
-- If none of the hexes are unoccupied, use current position as default
local next_hop, nh_cost = { unit.x, unit.y }, 0
-- Go through loop to find reachable, unoccupied hex along the path
-- Start at second index, as first is just the unit position itself
for i = 2,#path do
local sub_path, sub_cost = ai_helper.find_path_with_shroud(unit, path[i][1], path[i][2], cfg)
if sub_cost <= unit.moves then
-- Check for unit in way only if cfg.ignore_units is not set
local unit_in_way
if (not cfg) or (not cfg.ignore_units) then
unit_in_way = wesnoth.get_unit(path[i][1], path[i][2])
-- If ignore_own_units is set, ignore own side units that can move out of the way
if cfg and cfg.ignore_own_units then
if unit_in_way and (unit_in_way.side == unit.side) then
local reach = ai_helper.get_reachable_unocc(unit_in_way, cfg)
if (reach:size() > 1) then unit_in_way = nil end
end
end
end
if not unit_in_way then
next_hop, nh_cost = path[i], sub_cost
end
else
break
end
end
return next_hop, nh_cost
end
function ai_helper.can_reach(unit, x, y, cfg)
-- Returns true if hex (@x, @y) is unoccupied (by a visible unit), or
-- at most occupied by unit on same side as @unit that can move away
-- (can be modified with options below)
--
-- @cfg: table with optional configuration parameters:
-- moves = 'max' use max_moves instead of current moves
-- ignore_units: if true, ignore both own and enemy units
-- exclude_occupied: if true, exclude hex if there's a unit there, irrespective of value of 'ignore_units'
-- viewing_side: see comments at beginning of this file. Defaults to side of @unit
cfg = cfg or {}
local viewing_side = cfg.viewing_side or unit.side
-- Is there a unit at the goal hex?
local unit_in_way = wesnoth.get_unit(x, y)
if (cfg.exclude_occupied)
and unit_in_way and ai_helper.is_visible_unit(viewing_side, unit_in_way)
then
return false
end
-- Otherwise, if 'ignore_units' is not set, return false if there's a unit of other side,
-- or a unit of own side that cannot move away (this might be slow, don't know)
if (not cfg.ignore_units) then
-- If there's a unit at the goal that's not on own side (even ally), return false
if unit_in_way
and (unit_in_way.side ~= unit.side)
and ai_helper.is_visible_unit(viewing_side, unit_in_way)
then
return false
end
-- If the unit in the way is on 'unit's' side and cannot move away, also return false
if unit_in_way and (unit_in_way.side == unit.side) then
-- need to pass the cfg here so that it works for enemy units (generally with no moves left) also
local move_away = ai_helper.get_reachable_unocc(unit_in_way, cfg)
if (move_away:size() <= 1) then return false end
end
end
-- After all that, test whether our unit can actually get there
local old_moves = unit.moves
if (cfg.moves == 'max') then unit.moves = unit.max_moves end
local can_reach = false
local path, cost = ai_helper.find_path_with_shroud(unit, x, y, cfg)
if (cost <= unit.moves) then can_reach = true end
unit.moves = old_moves
return can_reach
end
function ai_helper.get_reachable_unocc(unit, cfg)
-- Get all reachable hexes for @unit that are (or appear) unoccupied, taking
-- vision into account as specified by the @cfg.viewing_side parameter.
-- Returned array is a location set, with value = 1 for each reachable hex
--
-- @cfg: table with optional configuration parameters:
-- moves: if set to 'max', unit MP is set to max_moves before calculation
-- viewing_side: see comments at beginning of this file. Defaults to side of @unit
-- plus all other parameters to wesnoth.find_reach
local viewing_side = cfg and cfg.viewing_side or unit.side
local old_moves = unit.moves
if cfg then
if (cfg.moves == 'max') then unit.moves = unit.max_moves end
end
local reach = LS.create()
local initial_reach = wesnoth.find_reach(unit, cfg)
for _,loc in ipairs(initial_reach) do
local unit_in_way = wesnoth.get_unit(loc[1], loc[2])
if (not unit_in_way) or (not ai_helper.is_visible_unit(viewing_side, unit_in_way)) then
reach:insert(loc[1], loc[2], 1)
end
end
-- Also need to include the hex the unit is on itself
reach:insert(unit.x, unit.y, 1)
unit.moves = old_moves
return reach
end
function ai_helper.find_path_with_shroud(unit, x, y, cfg)
-- Same as wesnoth.find_path, just that it works under shroud as well while still
-- ignoring invisible units. It does this by using viewing_side=0 and taking
-- invisible units off the map for the path finding process.
--
-- Notes on some of the optional parameters that can be passed in @cfg:
-- - viewing_side: If not given, use side of the unit (not the current side!)
-- for determining which units are hidden and need to be extracted, as that
-- is what the path_finder code uses. If set to an invalid side, we can use
-- default path finding as shroud is ignored then anyway.
-- - ignore_units: if true, hidden units do not need to be extracted because
-- all units are ignored anyway
local viewing_side = (cfg and cfg.viewing_side) or unit.side
local path, cost
if wesnoth.sides[viewing_side] and wesnoth.sides[viewing_side].shroud then
local extracted_units = {}
if (not cfg) or (not cfg.ignore_units) then
local all_units = wesnoth.get_units()
for _,u in ipairs(all_units) do
if (u.side ~= viewing_side)
and (not ai_helper.is_visible_unit(viewing_side, u))
then
wesnoth.extract_unit(u)
table.insert(extracted_units, u)
end
end
end
local cfg_copy = {}
if cfg then cfg_copy = ai_helper.table_copy(cfg) end
cfg_copy.viewing_side = 0
path, cost = wesnoth.find_path(unit, x, y, cfg_copy)
for _,extracted_unit in ipairs(extracted_units) do
wesnoth.put_unit(extracted_unit)
end
else
path, cost = wesnoth.find_path(unit, x, y, cfg)
end
return path, cost
end
function ai_helper.find_best_move(units, rating_function, cfg)
-- Find the best move and best unit based on @rating_function
-- INPUTS:
-- @units: (required) single unit or table of units
-- @rating_function: (required) function(x, y) with rating function for the hexes the unit can reach
-- @cfg: table with optional configuration parameters:
-- labels: if set, put labels with ratings onto map
-- no_random: if set, do not add random value between 0.0001 and 0.0099 to each hex
-- plus all the possible parameters for ai_helper.get_reachable_unocc()
--
-- OUTPUTS:
-- best_hex: format { x, y }
-- best_unit: unit for which this rating function produced the maximum value
-- max_rating: the rating found for this hex/unit combination
-- If no valid moves were found, best_unit and best_hex are empty arrays
-- TODO: change return value to nil if no unit/hex is found later in 1.13., but keep as is in 1.12
cfg = cfg or {}
-- If this is an individual unit, turn it into an array
if units.hitpoints then units = { units } end
local max_rating, best_hex, best_unit = -9e99, {}, {}
for _,unit in ipairs(units) do
-- Hexes each unit can reach
local reach_map = ai_helper.get_reachable_unocc(unit, cfg)
reach_map:iter( function(x, y, v)
-- Rate based on rating_function argument
local rating = rating_function(x, y)
-- If cfg.random is set, add some randomness (on 0.0001 - 0.0099 level)
if (not cfg.no_random) then rating = rating + math.random(99) / 10000. end
-- If cfg.labels is set: insert values for label map
if cfg.labels then reach_map:insert(x, y, rating) end
if rating > max_rating then
max_rating, best_hex, best_unit = rating, { x, y }, unit
end
end)
if cfg.labels then ai_helper.put_labels(reach_map) end
end
return best_hex, best_unit, max_rating
end
function ai_helper.move_unit_out_of_way(ai, unit, cfg)
-- Move @unit to the best close location.
-- Main rating is the moves the unit still has left after that
-- Other, configurable, parameters are given to function in @cfg:
-- dx, dy: the direction in which moving out of the way is preferred
-- labels: if set, display labels of the rating for each hex the unit can reach
-- viewing_side: see comments at beginning of this file. Defaults to side of @unit.
-- all other optional parameters to wesnoth.find_reach()
cfg = cfg or {}
local viewing_side = cfg.viewing_side or unit.side
local dx, dy
if cfg.dx and cfg.dy then
local r = math.sqrt(cfg.dx * cfg.dx + cfg.dy * cfg.dy)
if (r ~= 0) then dx, dy = cfg.dx / r, cfg.dy / r end
end
local reach = wesnoth.find_reach(unit, cfg)
local reach_map = LS.create()
local max_rating, best_hex = -9e99
for _,loc in ipairs(reach) do
local unit_in_way = wesnoth.get_unit(loc[1], loc[2])
if (not unit_in_way) -- also excludes current hex
or (not ai_helper.is_visible_unit(viewing_side, unit_in_way))
then
local rating = loc[3] -- also disfavors hexes next to visible enemy units for which loc[3] = 0
if dx then
rating = rating + (loc[1] - unit.x) * dx * 0.01
rating = rating + (loc[2] - unit.y) * dy * 0.01
end
if cfg.labels then reach_map:insert(loc[1], loc[2], rating) end
if (rating > max_rating) then
max_rating, best_hex = rating, { loc[1], loc[2] }
end
end
end
if cfg.labels then ai_helper.put_labels(reach_map) end
if best_hex then
ai_helper.checked_move(ai, unit, best_hex[1], best_hex[2])
end
end
function ai_helper.movefull_stopunit(ai, unit, x, y)
-- Does ai.move_full for @unit if not at (@x,@y), otherwise ai.stopunit_moves
-- Uses ai_helper.next_hop(), so that it works if unit cannot get there in one move
-- Coordinates can be given as x and y components, or as a 2-element table { x, y } or { x = x, y = y }
if (type(x) ~= 'number') then
if x[1] then
x, y = x[1], x[2]
else
x, y = x.x, x.y
end
end
local next_hop = ai_helper.next_hop(unit, x, y)
if next_hop and ((next_hop[1] ~= unit.x) or (next_hop[2] ~= unit.y)) then
return ai_helper.checked_move_full(ai, unit, next_hop[1], next_hop[2])
else
return ai_helper.checked_stopunit_moves(ai, unit)
end
end
function ai_helper.movefull_outofway_stopunit(ai, unit, x, y, cfg)
-- Same as ai_help.movefull_stopunit(), but also moves a unit out of the way if there is one
--
-- @cfg: table with optional configuration parameters:
-- viewing_side: see comments at beginning of this file. Defaults to side of @unit
-- all other optional parameters to ai_helper.move_unit_out_of_way() and wesnoth.find_path()
local viewing_side = cfg and cfg.viewing_side or unit.side
if (type(x) ~= 'number') then
if x[1] then
x, y = x[1], x[2]
else
x, y = x.x, x.y
end
end
-- Only move unit out of way if the main unit can get there
local path, cost = ai_helper.find_path_with_shroud(unit, x, y, cfg)
if (cost <= unit.moves) then
local unit_in_way = wesnoth.get_unit(x, y)
if unit_in_way and (unit_in_way ~= unit)
and ai_helper.is_visible_unit(viewing_side, unit_in_way)
then
--W.message { speaker = 'narrator', message = 'Moving out of way' }
ai_helper.move_unit_out_of_way(ai, unit_in_way, cfg)
end
end
local next_hop = ai_helper.next_hop(unit, x, y)
if next_hop and ((next_hop[1] ~= unit.x) or (next_hop[2] ~= unit.y)) then
ai_helper.checked_move_full(ai, unit, next_hop[1], next_hop[2])
else
ai_helper.checked_stopunit_moves(ai, unit)
end
end
---------- Attack related helper functions --------------
function ai_helper.get_attacks(units, cfg)
-- Get all attacks the units stored in @units can do. Invisible enemies are
-- excluded unless option @cfg.viewing_side=0 is used.
--
-- This includes a variety of configurable options, passed in the @cfg table
-- @cfg: table with optional configuration parameters:
-- moves: "current" (default for units on current side) or "max" (always used for units on other sides)
-- include_occupied (false): if set, also include hexes occupied by own-side units that can move away
-- simulate_combat (false): if set, also simulate the combat and return result (this is slow; only set if needed)
-- viewing_side: see comments at beginning of this file. Defaults to side of @units
-- all other optional parameters to wesnoth.find_reach()
--
-- Returns {} if no attacks can be done, otherwise table with fields:
-- dst: { x = x, y = y } of attack position
-- src: { x = x, y = y } of attacking unit (don't use id, could be ambiguous)
-- target: { x = x, y = y } of defending unit
-- att_stats, def_stats: as returned by wesnoth.simulate_combat (if cfg.simulate_combat is set)
-- attack_hex_occupied: boolean storing whether an own unit that can move away is on the attack hex
cfg = cfg or {}
local attacks = {}
if (not units[1]) then return attacks end
local side = units[1].side -- all units need to be on same side
local viewing_side = cfg and cfg.viewing_side or side
-- 'moves' can be either "current" or "max"
-- For unit on current side: use "current" by default, or override by cfg.moves
local moves = cfg.moves or "current"
-- For unit on any other side, only moves="max" makes sense
if (side ~= wesnoth.current.side) then moves = "max" end
local old_moves = {}
if (moves == "max") then
for i,unit in ipairs(units) do
old_moves[i] = unit.moves
unit.moves = unit.max_moves
end
end
-- Note: the remainder is optimized for speed, so we only get_units once,
-- do not use WML filters, etc.
local all_units = wesnoth.get_units()
local enemy_map, my_unit_map, other_unit_map = LS.create(), LS.create(), LS.create()
for i,unit in ipairs(all_units) do
-- The value of all the location sets is the index of the
-- unit in the all_units array
if ai_helper.is_attackable_enemy(unit, side, cfg) then
enemy_map:insert(unit.x, unit.y, i)
end
if (unit.side == side) then
my_unit_map:insert(unit.x, unit.y, i)
else
if ai_helper.is_visible_unit(viewing_side, unit) then
other_unit_map:insert(unit.x, unit.y, i)
end
end
end
local attack_hex_map = LS.create()
enemy_map:iter(function(e_x, e_y, i)
for xa,ya in H.adjacent_tiles(e_x, e_y) do
-- If there's no unit of another side on this hex, include it
-- as possible attack location (this includes hexes occupied
-- by own units at this time)
if (not other_unit_map:get(xa, ya)) then
local target_table = attack_hex_map:get(xa, ya) or {}
table.insert(target_table, { x = e_x, y = e_y, i = i })
attack_hex_map:insert(xa, ya, target_table)
end
end
end)
-- The following is done so that we at most need to do find_reach() once per unit
-- It is needed for all units in @units and for testing whether units can move out of the way
local reaches = LS.create()
for _,unit in ipairs(units) do
local reach
if reaches:get(unit.x, unit.y) then
reach = reaches:get(unit.x, unit.y)
else
reach = wesnoth.find_reach(unit, cfg)
reaches:insert(unit.x, unit.y, reach)
end
for _,loc in ipairs(reach) do
if attack_hex_map:get(loc[1], loc[2]) then
local add_target = true
local attack_hex_occupied = false
-- If another unit of same side is on this hex:
if my_unit_map:get(loc[1], loc[2]) and ((loc[1] ~= unit.x) or (loc[2] ~= unit.y)) then
attack_hex_occupied = true
add_target = false
if cfg.include_occupied then -- Test whether it can move out of the way
local unit_in_way = all_units[my_unit_map:get(loc[1], loc[2])]
local uiw_reach
if reaches:get(unit_in_way.x, unit_in_way.y) then
uiw_reach = reaches:get(unit_in_way.x, unit_in_way.y)
else
uiw_reach = wesnoth.find_reach(unit_in_way, cfg)
reaches:insert(unit_in_way.x, unit_in_way.y, uiw_reach)
end
-- Check whether the unit to move out of the way has an unoccupied hex to move to.
-- We do not deal with cases where a unit can move out of the way for a
-- unit that is moving out of the way of the initial unit (etc.).
for _,uiw_loc in ipairs(uiw_reach) do
-- Unit in the way of the unit in the way
local uiw_uiw = wesnoth.get_unit(uiw_loc[1], uiw_loc[2])
if (not uiw_uiw) or (not ai_helper.is_visible_unit(viewing_side, uiw_uiw)) then
add_target = true
break
end
end
end
end
if add_target then
for _,target in ipairs(attack_hex_map:get(loc[1], loc[2])) do
local att_stats, def_stats
if cfg.simulate_combat then
local unit_dst = wesnoth.copy_unit(unit)
unit_dst.x, unit_dst.y = loc[1], loc[2]
local enemy = all_units[target.i]
att_stats, def_stats = wesnoth.simulate_combat(unit_dst, enemy)
end
table.insert(attacks, {
src = { x = unit.x, y = unit.y },
dst = { x = loc[1], y = loc[2] },
target = { x = target.x, y = target.y },
att_stats = att_stats,
def_stats = def_stats,
attack_hex_occupied = attack_hex_occupied
})
end
end
end
end
end
if (moves == "max") then
for i,unit in ipairs(units) do
unit.moves = old_moves[i]
end
end
return attacks
end
function ai_helper.add_next_attack_combo_level(combos, attacks)
-- This is called from ai_helper.get_attack_combos_full() and
-- builds up the combos for the next recursion level.
-- It also calls the next recursion level, if possible
-- Important: function needs to make a copy of the input array, otherwise original is changed
-- Set up the array, if this is the first recursion level
if (not combos) then combos = {} end
-- Array to hold combinations for this recursion level only
local combos_this_level = {}
for _,attack in ipairs(attacks) do
local dst = attack.dst.y + attack.dst.x * 1000. -- attack hex (src)
local src = attack.src.y + attack.src.x * 1000. -- attacker hex (dst)
if (not combos[1]) then -- if this is the first recursion level, set up new combos for this level
local move = {}
move[dst] = src
table.insert(combos_this_level, move)
else
-- Otherwise, we need to go through the already existing elements in 'combos'
-- to see if either hex, or attacker is already used; and then add new attack to each
for _,combo in ipairs(combos) do
local this_combo = {} -- needed because tables are pointers, need to create a separate one
local add_combo = true
for d,s in pairs(combo) do
if (d == dst) or (s == src) then
add_combo = false
break
end
this_combo[d] = s -- insert individual moves to a combo
end
if add_combo then -- and add it into the array, if it contains only unique moves
this_combo[dst] = src
table.insert(combos_this_level, this_combo)
end
end
end
end
local combos_next_level = {}
if combos_this_level[1] then -- If moves were found for this level, also find those for the next level
combos_next_level = ai_helper.add_next_attack_combo_level(combos_this_level, attacks)
end
-- Finally, combine this level and next level combos
combos_this_level = ai_helper.array_merge(combos_this_level, combos_next_level)
return combos_this_level
end
function ai_helper.get_attack_combos_full(units, enemy, cfg)
-- Calculate attack combination result by @units on @enemy
-- All combinations of all units are taken into account, as well as their order
-- This can result in a _very_ large number of possible combinations
-- Use ai_helper.get_attack_combos() instead if order does not matter
--
-- Optional inputs:
-- @cfg: Configuration table to be passed on to ai_helper.get_attacks()
--
-- Return value:
-- 1. Attack combinations in form { dst = src }
local all_attacks = ai_helper.get_attacks(units, cfg)
-- Eliminate those that are not on @enemy
local attacks = {}
for _,attack in ipairs(all_attacks) do
if (attack.target.x == enemy.x) and (attack.target.y == enemy.y) then
table.insert(attacks, attack)
end
end
if (not attacks[1]) then return {} end
-- This recursive function does all the work:
local combos = ai_helper.add_next_attack_combo_level(combos, attacks)
return combos
end
function ai_helper.get_attack_combos(units, enemy, cfg)
-- Calculate attack combination result by @units on @enemy
-- All the unit/hex combinations are considered, but without specifying the order of the
-- attacks. Use ai_helper.get_attack_combos_full() if order matters.
--
-- Optional inputs:
-- @cfg: Configuration table to be passed on to wesnoth.find_path()
--
-- Return values:
-- 1. Attack combinations in form { dst = src }
-- 2. All the attacks indexed by [dst][src]
-- We don't need the full attacks here, just the coordinates,
-- so for speed reasons, we do not use ai_helper.get_attacks()
-- For units on the current side, we need to make sure that
-- there isn't a unit in the way that cannot move any more
-- TODO: generalize it so that it works not only for units with moves=0, but blocked units etc.
local blocked_hexes = LS.create()
if units[1] and (units[1].side == wesnoth.current.side) then
local all_units = wesnoth.get_units { side = wesnoth.current.side }
for _,unit in ipairs(all_units) do
if (unit.moves == 0) then
blocked_hexes:insert(unit.x, unit.y)
end
end
end
-- For sides other than the current, we always use max_moves,
-- for the current side we always use current moves
local old_moves = {}
for i,unit in ipairs(units) do
if (unit.side ~= wesnoth.current.side) then
old_moves[i] = unit.moves
unit.moves = unit.max_moves
end
end
-- Find which units in @units can get to hexes next to the enemy
local attacks_dst_src = {}
local found_attacks = false
for xa,ya in H.adjacent_tiles(enemy.x, enemy.y) do
-- Make sure the hex is not occupied by unit that cannot move out of the way
local dst = xa * 1000 + ya
for _,unit in ipairs(units) do
if ((unit.x == xa) and (unit.y == ya)) or (not blocked_hexes:get(xa, ya)) then
-- wesnoth.map.distance_between() is much faster than wesnoth.find_path()
--> pre-filter using the former
local cost = M.distance_between(unit.x, unit.y, xa, ya)
-- If the distance is <= the unit's MP, then see if it can actually get there
-- This also means that only short paths have to be evaluated (in most situations)
if (cost <= unit.moves) then
local path -- since cost is already defined outside this block
path, cost = ai_helper.find_path_with_shroud(unit, xa, ya, cfg)
end
if (cost <= unit.moves) then
-- for attack by no unit on this hex
if (not attacks_dst_src[dst]) then
attacks_dst_src[dst] = { 0, unit.x * 1000 + unit.y }
found_attacks = true -- since attacks_dst_src is not a simple array, this is easier
else
table.insert(attacks_dst_src[dst], unit.x * 1000 + unit.y )
end
end
end
end
end
for i,unit in ipairs(units) do
if (unit.side ~= wesnoth.current.side) then
unit.moves = old_moves[i]
end
end
if (not found_attacks) then return {}, {} end
-- Now we set up an array of all attack combinations
-- at this time, this includes all the 'no unit attacks this hex' elements
-- which have a value of 0 for 'src'
-- They need to be kept in this part, so that we get the combos that do not
-- use the maximum amount of units possible. They will be eliminated below.
local attack_array = {}
-- For all values of 'dst'
for dst,ads in pairs(attacks_dst_src) do
local org_array = ai_helper.table_copy(attack_array)
attack_array = {}
-- Go through all the values of 'src'
for _,src in ipairs(ads) do
-- If the array does not exist, set it up
if (not org_array[1]) then
local tmp = {}
tmp[dst] = src
table.insert(attack_array, tmp)
else -- otherwise, add the new dst-src pair to each element of the existing array
for _,org in ipairs(org_array) do
-- but only do so if that 'src' value does not exist already
-- except for 0's those all need to be kept
local add_attack = true
for _,s in pairs(org) do
if (s == src) and (src ~=0) then
add_attack = false
break
end
end
-- Finally, add it to the array
if add_attack then
local tmp = ai_helper.table_copy(org)
tmp[dst] = src
table.insert(attack_array, tmp)
end
end
end
end
end
-- Now eliminate all the 0s
-- Also eliminate the combo that has no attacks on any hex (all zeros)
local i_empty = 0
for i,att in ipairs(attack_array) do
local count = 0
for dst,src in pairs(att) do
if (src == 0) then
att[dst] = nil
else
count = count + 1
end
end
if (count == 0) then i_empty = i end
end
-- This last step eliminates the "empty attack combo" (the one with all zeros)
-- Since this is only one, it's okay to use table.remove (even though it's slow)
table.remove(attack_array, i_empty)
return attack_array
end
function ai_helper.get_unit_time_of_day_bonus(alignment, lawful_bonus)
local multiplier = 1
if (lawful_bonus ~= 0) then
if (alignment == 'lawful') then
multiplier = (1 + lawful_bonus / 100.)
elseif (alignment == 'chaotic') then
multiplier = (1 - lawful_bonus / 100.)
elseif (alignment == 'liminal') then
multipler = (1 - math.abs(lawful_bonus) / 100.)
end
end
return multiplier
end
return ai_helper