EI S8 (Training the Ogres): add custom AI for the ogres

data/campaigns/Eastern_Invasion/ai/ca_ogres_flee.lua

@@ -0,0 +1,97 @@
+local H = wesnoth.require "lua/helper.lua"
+local AH = wesnoth.require "ai/lua/ai_helper.lua"
+local BC = wesnoth.require "ai/lua/battle_calcs.lua"
+--local LS = wesnoth.require "lua/location_set.lua"
+
+local ca_ogres_flee = {}
+
+function ca_ogres_flee:evaluation(ai, cfg, self)
+    local units = wesnoth.get_units { side = wesnoth.current.side,
+        formula = '$this_unit.moves > 0'
+    }
+
+    if (not units[1]) then return 0 end
+    return 110000
+end
+
+function ca_ogres_flee:execution(ai, cfg, self)
+    local units = wesnoth.get_units { side = wesnoth.current.side,
+        formula = '$this_unit.moves > 0'
+    }
+
+    local units_noMP = wesnoth.get_units { side = wesnoth.current.side,
+        formula = '$this_unit.moves = 0'
+    }
+
+    local width, height = wesnoth.get_map_size()
+
+    -- Need the enemy map and enemy attack map if avoid_enemies is set
+    local enemies = wesnoth.get_units {  { "filter_side", { {"enemy_of", {side = wesnoth.current.side} } } } }
+    local enemy_attack_map = BC.get_attack_map(enemies)
+
+    local best_hex, best_unit, max_rating = {}, nil, -9e99
+    for i,u in ipairs(units) do
+        local reach = wesnoth.find_reach(u)
+
+        --local rating_map = LS.create()
+
+        for j,r in ipairs(reach) do
+            local unit_in_way = wesnoth.get_unit(r[1], r[2])
+
+            if (not unit_in_way) or (unit_in_way == u) then
+
+                -- First rating is distance from a map edge
+                local dist_left = r[1] - 1
+                local dist_right = width - r[1]
+                local dist_top = r[2] - 1
+                local dist_bottom = height - r[2]
+                local dist = math.min(dist_left, dist_right, dist_top, dist_bottom)
+
+                local rating = - dist
+
+                -- If we can reach the edge, we do so
+                if (dist == 0) then rating = rating + 1000 end
+
+                local enemy_weight = 0.5
+                local enemy_rating = - (enemy_attack_map.units:get(r[1], r[2]) or 0) * enemy_weight
+
+                local enemy_rating = 0
+                for k,e in ipairs(enemies) do
+                    local dist = H.distance_between(r[1], r[2], e.x, e.y)
+                    enemy_rating = enemy_rating + math.sqrt(dist)
+                end
+
+                rating = rating + enemy_rating
+
+                -- Also, maximize distance from own units that have already moved
+                local own_unit_weight = 0.5
+                local own_unit_rating = 0
+                for k,u_noMP in ipairs(units_noMP) do
+                    local dist = H.distance_between(r[1], r[2], u_noMP.x, u_noMP.y)
+                    own_unit_rating = own_unit_rating + math.sqrt(dist)
+                end
+
+                rating = rating + own_unit_rating * own_unit_weight
+
+                --rating_map:insert(r[1], r[2], rating)
+
+                if (rating > max_rating) then
+                    best_hex = { r[1], r[2] }
+                    best_unit = u
+                    max_rating = rating
+                end
+            end
+        end
+
+        --AH.put_labels(rating_map)
+    end
+    --print(best_unit.id, best_unit.x, best_unit.y, best_hex[1], best_hex[2], max_rating)
+
+    if best_hex then
+        AH.movefull_outofway_stopunit(ai, best_unit, best_hex[1], best_hex[2])
+    else
+        ai.stopunit_moves(best_unit)
+    end
+end
+
+return ca_ogres_flee

data/campaigns/Eastern_Invasion/scenarios/08_Training_the_Ogres.cfg

@@ -46,15 +46,17 @@
         team_name=ogres
         user_team_name=_"Ogres"
         [ai]
-            {AI_SIMPLE_ALWAYS_ASPECT aggression 0.0}
-            [goal]
-                # This ought to make the ogres run for the map edges
-                name=target_location
-                [criteria]
-                    {MAP_EDGES_SLF}
-                [/criteria]
-                value=99
-            [/goal]
+            aggression=1.0
+
+            {MODIFY_AI_ADD_CANDIDATE_ACTION 2 main_loop (
+                [candidate_action]
+                    engine=lua
+                    name=ogres_flee
+                    id=ogres_flee
+                    max_score=110000
+                    location="campaigns/Eastern_Invasion/ai/ca_ogres_flee.lua"
+                [/candidate_action]
+            )}
         [/ai]
     [/side]