ExpAI recruiting: make high_level_fraction parameter configurable

This also sets its default value to zero, in order to have consistent default behavior with versions from before this parameter was introduced.

It also provides a macro so that the ExpAI can be used with custom parameters in a scenario config, and adds high_level_fraction as an optional parameter to the Recruit Rushers Micro AI.

data/ai/lua/ca_recruit_rushers.lua

@@ -35,6 +35,7 @@ wesnoth.require("ai/lua/generic_recruit_engine.lua").init(dummy_engine, params)
 local ca_recruit_rushers = {}
 
 function ca_recruit_rushers:evaluation(cfg, data)
+    params.high_level_fraction = cfg.high_level_fraction
     return dummy_engine:recruit_rushers_eval()
 end
 

data/ai/lua/generic_recruit_engine.lua

@@ -785,7 +785,7 @@ return {
             local randomness = params.randomness or 0.1
 
             -- Bonus for higher-level units, as unit cost is penalized otherwise
-            local high_level_fraction = 0.33
+            local high_level_fraction = params.high_level_fraction or 0
             local all_units = AH.get_live_units {
                 side = wesnoth.current.side,
                 { "not", { canrecruit = "yes" }}

data/ai/micro_ais/cas/ca_recruit_rushers.lua

@@ -9,6 +9,7 @@ wesnoth.require("ai/lua/generic_recruit_engine.lua").init(internal_recruit_cas,
 local ca_recruit_rushers = {}
 
 function ca_recruit_rushers:evaluation(cfg)
+    internal_params.high_level_fraction = cfg.high_level_fraction
     internal_params.randomness = cfg.randomness
     internal_params.score_function = function() return cfg.ca_score end
     return internal_recruit_cas:recruit_rushers_eval()

data/ai/micro_ais/mai-defs/recruiting.lua

@@ -18,7 +18,7 @@ local function handle_default_recruitment(cfg)
 end
 
 function wesnoth.micro_ais.recruit_rushers(cfg)
-	local optional_keys = { "randomness" }
+	local optional_keys = { "high_level_fraction", "randomness" }
 	local CA_parms = {
 		ai_id = 'mai_rusher_recruit',
 		{ ca_id = "move", location = 'ca_recruit_rushers.lua', score = cfg.ca_score or 180000 }

data/core/macros/ai.cfg

@@ -590,3 +590,75 @@
         [/candidate_action]
     [/stage]
 #enddef
+
+#define CUSTOMIZABLE_EXPERIMENTAL_AI ARGS
+    # Use the Experimental AI with custom parameter setting
+    # Put this into the [side][ai] tag.
+    # Does not work in [modify_side][ai] or [modify_ai] at the moment.
+    [stage]
+        id=main_loop
+        name=ai_default_rca::candidate_action_evaluation_loop
+        {AI_CA_GOTO}
+        #{AI_CA_RECRUITMENT}
+        {AI_CA_MOVE_LEADER_TO_GOALS}
+        {AI_CA_MOVE_LEADER_TO_KEEP}
+        {AI_CA_HIGH_XP_ATTACK}
+        {AI_CA_COMBAT}
+        {AI_CA_HEALING}
+        {AI_CA_VILLAGES}
+        {AI_CA_RETREAT}
+        {AI_CA_MOVE_TO_TARGETS}
+        {AI_CA_LEADER_SHARES_KEEP}
+        [candidate_action]
+            engine=lua
+            name=recruit_rushers
+            max_score=300000
+            location="ai/lua/ca_recruit_rushers.lua"
+            [args]
+                {ARGS}
+            [/args]
+        [/candidate_action]
+        [candidate_action]
+            engine=lua
+            name=switch_castle
+            max_score=290000
+            location="ai/lua/ca_castle_switch.lua"
+        [/candidate_action]
+        [candidate_action]
+            engine=lua
+            name=retreat_injured
+            max_score=205000
+            location="ai/lua/ca_retreat_injured.lua"
+        [/candidate_action]
+        [candidate_action]
+            engine=lua
+            name=grab_villages
+            max_score=200000
+            location="ai/lua/ca_grab_villages.lua"
+        [/candidate_action]
+        [candidate_action]
+            engine=lua
+            name=spread_poison
+            max_score=190000
+            location="ai/lua/ca_spread_poison.lua"
+        [/candidate_action]
+        [candidate_action]
+            engine=lua
+            name=place_healers
+            max_score=95000
+            location="ai/lua/ca_place_healers.lua"
+        [/candidate_action]
+        [candidate_action]
+            engine=lua
+            name=village_hunt
+            max_score=30000
+            location="ai/lua/ca_village_hunt.lua"
+        [/candidate_action]
+        [candidate_action]
+            engine=lua
+            name=move_to_any_enemy
+            max_score=1
+            location="ai/lua/ca_move_to_any_enemy.lua"
+        [/candidate_action]
+    [/stage]
+#enddef