205 lines
8 KiB
Lua
205 lines
8 KiB
Lua
--[=[
|
|
Functions to support the retreat of injured units
|
|
]=]
|
|
|
|
local H = wesnoth.require "helper"
|
|
local AH = wesnoth.require "ai/lua/ai_helper.lua"
|
|
local BC = wesnoth.require "ai/lua/battle_calcs.lua"
|
|
local LS = wesnoth.require "location_set"
|
|
|
|
local retreat_functions = {}
|
|
|
|
function retreat_functions.min_hp(unit)
|
|
-- The minimum hp to retreat is a function of level and terrain defense
|
|
-- We want to stay longer on good terrain and leave early on very bad terrain
|
|
local hp_per_level = unit:defense(wesnoth.get_terrain(unit.x, unit.y))/15
|
|
local level = unit.level
|
|
|
|
-- Leaders are considered to be higher level because of their value
|
|
if unit.canrecruit then level = level+2 end
|
|
|
|
local min_hp = hp_per_level*(level+2)
|
|
|
|
-- Account for poison damage on next turn
|
|
if unit.status.poisoned then min_hp = min_hp + 8 end
|
|
|
|
-- Make sure that units are actually injured
|
|
if min_hp > unit.max_hitpoints - 4 then
|
|
min_hp = unit.max_hitpoints - 4
|
|
end
|
|
|
|
return min_hp
|
|
end
|
|
|
|
-- Given a set of units, return one from the set that should retreat and the location to retreat to
|
|
-- Return nil if no unit needs to retreat
|
|
function retreat_functions.retreat_injured_units(units)
|
|
-- Split units into those that regenerate and those that do not
|
|
local regen, non_regen = {}, {}
|
|
for i,u in ipairs(units) do
|
|
if u.hitpoints < retreat_functions.min_hp(u) then
|
|
if u:ability('regenerate') then
|
|
table.insert(regen, u)
|
|
else
|
|
table.insert(non_regen, u)
|
|
end
|
|
end
|
|
end
|
|
|
|
-- First we retreat non-regenerating units to healing terrain, if they can get to a safe location
|
|
local unit_nr, loc_nr, threat_nr
|
|
if non_regen[1] then
|
|
unit_nr, loc_nr, threat_nr = retreat_functions.get_retreat_injured_units(non_regen, false)
|
|
if unit_nr and (threat_nr == 0) then
|
|
return unit_nr, loc_nr, threat_nr
|
|
end
|
|
end
|
|
|
|
-- Then we retreat regenerating units to terrain with high defense, if they can get to a safe location
|
|
local unit_r, loc_r, threat_r
|
|
if regen[1] then
|
|
unit_r, loc_r, threat_r = retreat_functions.get_retreat_injured_units(regen, true)
|
|
if unit_r and (threat_r == 0) then
|
|
return unit_r, loc_r, threat_r
|
|
end
|
|
end
|
|
|
|
-- The we retreat those that cannot get to a safe location (non-regenerating units first again)
|
|
if unit_nr then
|
|
return unit_nr, loc_nr, threat_nr
|
|
end
|
|
if unit_r then
|
|
return unit_r, loc_r, threat_r
|
|
end
|
|
end
|
|
|
|
function retreat_functions.get_healing_locations()
|
|
local possible_healers = AH.get_live_units {
|
|
{ "filter_side", {{"allied_with", {side = wesnoth.current.side} }} }
|
|
}
|
|
|
|
local healing_locs = LS.create()
|
|
for i,u in ipairs(possible_healers) do
|
|
-- Only consider healers that cannot move this turn
|
|
if u.moves == 0 or u.side ~= wesnoth.current.side then
|
|
local heal_amount = 0
|
|
local cure = 0
|
|
local abilities = wml.get_child(u.__cfg, "abilities") or {}
|
|
for ability in wml.child_range(abilities, "heals") do
|
|
heal_amount = ability.value
|
|
if ability.poison == "slowed" then
|
|
cure = 1
|
|
elseif ability.poison == "cured" then
|
|
cure = 2
|
|
end
|
|
end
|
|
if heal_amount + cure > 0 then
|
|
for x, y in H.adjacent_tiles(u.x, u.y) do
|
|
local old_values = healing_locs:get(x, y) or {0, 0}
|
|
local best_heal = math.max(old_values[0] or heal_amount)
|
|
local best_cure = math.max(old_values[1] or cure)
|
|
healing_locs:insert(u.x, u.y, {best_heal, best_cure})
|
|
end
|
|
end
|
|
end
|
|
end
|
|
|
|
return healing_locs
|
|
end
|
|
|
|
function retreat_functions.get_retreat_injured_units(healees, regenerates)
|
|
-- Only retreat to safe locations
|
|
local enemies = AH.get_attackable_enemies()
|
|
local enemy_attack_map = BC.get_attack_map(enemies)
|
|
|
|
local healing_locs = retreat_functions.get_healing_locations()
|
|
|
|
local max_rating, best_loc, best_unit = - math.huge
|
|
for i,u in ipairs(healees) do
|
|
local possible_locations = wesnoth.find_reach(u)
|
|
-- TODO: avoid ally's villages (may be preferable to lower rating so they will
|
|
-- be used if unit is very injured)
|
|
if not regenerates then
|
|
-- Unit cannot self heal, make the terrain do it for us if possible
|
|
local location_subset = {}
|
|
for j,loc in ipairs(possible_locations) do
|
|
local heal_amount = wesnoth.get_terrain_info(wesnoth.get_terrain(loc[1], loc[2])).healing or 0
|
|
if heal_amount == true then
|
|
-- handle deprecated syntax
|
|
-- TODO: remove this when removed from game
|
|
heal_amount = 8
|
|
end
|
|
local curing = 0
|
|
if heal_amount > 0 then
|
|
curing = 2
|
|
end
|
|
local healer_values = healing_locs:get(loc[1], loc[2]) or {0, 0}
|
|
heal_amount = math.max(heal_amount, healer_values[1])
|
|
curing = math.max(curing, healer_values[2])
|
|
table.insert(location_subset, {loc[1], loc[2], heal_amount, curing})
|
|
end
|
|
|
|
possible_locations = location_subset
|
|
end
|
|
|
|
local base_rating = - u.hitpoints + u.max_hitpoints / 2.
|
|
if u.status.poisoned then base_rating = base_rating + 8 end
|
|
if u.status.slowed then base_rating = base_rating + 4 end
|
|
base_rating = base_rating * 1000
|
|
|
|
for j,loc in ipairs(possible_locations) do
|
|
local unit_in_way = wesnoth.get_unit(loc[1], loc[2])
|
|
if (not AH.is_visible_unit(wesnoth.current.side, unit_in_way))
|
|
or ((unit_in_way.moves > 0) and (unit_in_way.side == wesnoth.current.side))
|
|
then
|
|
local rating = base_rating
|
|
local heal_score = 0
|
|
if regenerates then
|
|
heal_score = math.min(8, u.max_hitpoints - u.hitpoints)
|
|
else
|
|
if u.status.poisoned then
|
|
if loc[4] > 0 then
|
|
heal_score = math.min(8, u.hitpoints - 1)
|
|
if loc[4] == 2 then
|
|
-- This value is arbitrary, it just represents the ability to heal on the turn after
|
|
heal_score = heal_score + 1
|
|
end
|
|
end
|
|
else
|
|
heal_score = math.min(loc[3], u.max_hitpoints - u.hitpoints)
|
|
end
|
|
end
|
|
|
|
-- Huge penalty for each enemy that can reach location,
|
|
-- this is the single most important point (and non-linear)
|
|
local enemy_count = enemy_attack_map.units:get(loc[1], loc[2]) or 0
|
|
rating = rating - enemy_count * 100000
|
|
|
|
-- Penalty based on terrain defense for unit
|
|
rating = rating - u:defense(wesnoth.get_terrain(loc[1], loc[2]))/10
|
|
|
|
if (loc[1] == u.x) and (loc[2] == u.y) and (not u.status.poisoned) then
|
|
if enemy_count == 0 then
|
|
-- Bonus if we can rest heal
|
|
-- TODO: Always apply bonus if unit has healthy trait
|
|
heal_score = heal_score + 2
|
|
end
|
|
elseif unit_in_way then
|
|
-- Penalty if a unit has to move out of the way
|
|
-- (based on hp of moving unit)
|
|
rating = rating + unit_in_way.hitpoints - unit_in_way.max_hitpoints
|
|
end
|
|
|
|
rating = rating + heal_score^2
|
|
|
|
if (rating > max_rating) then
|
|
max_rating, best_loc, best_unit = rating, loc, u
|
|
end
|
|
end
|
|
end
|
|
end
|
|
|
|
return best_unit, best_loc, enemy_attack_map.units:get(best_loc[1], best_loc[2]) or 0
|
|
end
|
|
|
|
return retreat_functions
|