AI configuration: new optional parameter mp_rank=

This parameter determines in which order the available AIs are shown in the MP computer player selection menu. This can be used for eras, modifications or cores to change which AI is first in the list.

data/ai/ais/ai_default_rca.cfg

@@ -7,6 +7,7 @@
 [ai]
     id=ai_default_rca
     description=_"Multiplayer_AI^Default AI (RCA)" # wmllint: no spellcheck
+    mp_rank=1010
     # RCA := Register Candidate Action; more info at http://forums.wesnoth.org/viewtopic.php?p=419625#p419625
     [stage]
         id=main_loop

data/ai/ais/ai_experimental.cfg

@@ -7,6 +7,7 @@
 [ai]
     id=experimental_ai
     description=_"Multiplayer_AI^Experimental AI" # wmllint: no spellcheck
+    mp_rank=1000
 
     [stage]
         id=main_loop

data/ai/dev/ai_default_rca_alternate_recruiting.cfg

@@ -8,6 +8,7 @@
 [ai]
     id=ai_default_rca_alternate_recruiting
     description=_"Multiplayer_AI^Dev AI: Default AI (RCA) with Alternate Recruiting" # wmllint: no spellcheck
+    mp_rank=100
     # RCA := Register Candidate Action; more info at http://forums.wesnoth.org/viewtopic.php?p=419625#p419625
     [stage]
         id=main_loop

data/ai/dev/formula_ai.cfg

@@ -8,6 +8,7 @@
 [ai]
     id=formula_ai # id is needed to uniquely identify a MP AI, it is not needed in the scenario AI
     description=_"Multiplayer_AI^Dev AI: Default + Experimental Recruitment (Formula AI)" # wmllint: no spellcheck
+    mp_rank=100
     # this description is, again, needed for MP AI (it shows in AI list under this description
 
     [stage]

data/ai/dev/formula_ai_poisoning.cfg

@@ -7,6 +7,7 @@
 [ai]
     id=formula_ai_poisoning
     description=_"Multiplayer_AI^Dev AI: Default + Poisoning (Formula AI)" # wmllint: no spellcheck
+    mp_rank=100
     [stage]
         id=main_loop
         name=ai_default_rca::candidate_action_evaluation_loop

src/ai/configuration.cpp

@@ -69,6 +69,7 @@ void configuration::init(const config &game_config)
 
 		description desc;
 		desc.id=id;
+		desc.mp_rank=ai_configuration["mp_rank"].to_int(0);
 		desc.text = ai_configuration["description"].t_str();
 		desc.cfg=ai_configuration;
 
@@ -95,6 +96,7 @@ void extract_ai_configurations(std::map<std::string, description> &storage, cons
 		description desc;
 		desc.id=id;
 		desc.text = ai_configuration["description"].t_str();
+		desc.mp_rank = ai_configuration["mp_rank"].to_int(0);
 		desc.cfg=ai_configuration;
 
 		storage.emplace(id, desc);
@@ -143,6 +145,13 @@ std::vector<description*> configuration::get_available_ais()
 		add_if_not_hidden(&m_config.second);
 	}
 
+	// Sort by mp_rank. For same mp_rank, keep alphabetical order.
+	std::stable_sort(ais_list.begin(), ais_list.end(),
+        [](const description* a, const description* b) {
+			return a->mp_rank > b->mp_rank;
+		}
+    );
+
 	return ais_list;
 }
 

src/ai/configuration.hpp

@@ -46,12 +46,14 @@ public:
 	description()
 		: text()
 		, id()
+		, mp_rank()
 		, cfg()
 	{
 	}
 
 	t_string text;
 	std::string id;
+	int mp_rank;
 	config cfg;
 };