Add exclusive unit traits handling similar to require_amla (#7109)

data/schema/units/modifications.cfg

@@ -217,6 +217,8 @@
 	{SIMPLE_KEY male_name t_string}
 	{SIMPLE_KEY female_name t_string}
 	{SIMPLE_KEY description t_string}
+	{SIMPLE_KEY exclude_traits string_list}
+	{SIMPLE_KEY require_traits string_list}
 	{SIMPLE_KEY help_text t_string}
 [/tag]
 

data/test/_main.cfg

@@ -73,6 +73,9 @@
 {test/scenarios/wml_tests/UnitsWML/AbilitiesWML}
 {test/scenarios/wml_tests/WesnothFormulaLanguage}
 
+# Load test unit wml
+{test/units.cfg}
+
 #endif
 
 #ifndef DONT_RELOAD_CORE

data/test/scenarios/wml_tests/UnitsWML/traits_exclude_include.cfg

@@ -0,0 +1,77 @@
+# wmllint: no translatables
+
+#####
+# API(s) being tested: [trait]exclude_traits=
+##
+# Actions:
+# Bob is told to generate special random traits.
+##
+# Expected end state:
+# One of the two special traits excludes another trait to be already had by Bob.
+# Bob should either not have the trait or have only the excluded one.
+#####
+
+{GENERIC_UNIT_TEST "trait_exclusion_test" (
+	[event]
+		name=start
+		{UNIT 1 (Test Unit Exclude) 1 1 (id=excluder1)}
+	[/event]
+	[event]
+		name=side 1 turn 1
+		[store_unit]
+			[filter]
+				side=1
+				id=excluder1
+			[/filter]
+			variable=excluded
+			kill=no
+		[/store_unit]
+		[if]
+			# Check if the first randomly generated trait is the excluded one, then the
+			# next trait slot should be empty
+			{VARIABLE_CONDITIONAL excluded.modifications.trait[0].id equals "test_excluded"}
+			[then]
+				{ASSERT ({VARIABLE_CONDITIONAL excluded.modifications.trait[1].id equals $nil})}
+			[/then]
+			[else]
+				# Otherwise if it is "test_exclude" then the next slot should be empty as well
+				{ASSERT ({VARIABLE_CONDITIONAL excluded.modifications.trait[0].id equals "test_exclude"})}
+				{ASSERT ({VARIABLE_CONDITIONAL excluded.modifications.trait[1].id equals $nil})}
+			[/else]
+		[/if]
+		{SUCCEED}
+	[/event]
+)}
+
+#####
+# API(s) being tested: [trait]require_traits=
+##
+# Actions:
+# Bob is told to generate special random traits.
+##
+# Expected end state:
+# One of the two special traits needs another trait to be already had by Bob.
+# Bob only have the trait if it also has the one it requires one.
+#####
+
+
+{GENERIC_UNIT_TEST "trait_requirement_test" (
+	[event]
+		name=start
+		{UNIT 1 (Test Unit Require) 1 1 (id=requirer1)}
+	[/event]
+	[event]
+		name=side 1 turn 1
+		[store_unit]
+			[filter]
+				side=1
+				id=requirer1
+			[/filter]
+			variable=required
+			kill=no
+		[/store_unit]
+		# Check if the second randomly generated trait is the one requiring the other one
+		{ASSERT ({VARIABLE_CONDITIONAL required.modifications.trait[1].id equals "test_require"})}
+		{SUCCEED}
+	[/event]
+)}

data/test/units.cfg

@@ -0,0 +1,36 @@
+#textdomain wesnoth-test
+
+[units]
+	{test/units/}
+	
+		[race]
+		id=test
+		name= _ "test"
+		female_name= _ "test"
+		plural_name= _ "tests"
+		description= _ "test race"
+		num_traits=2
+		undead_variation=wolf
+		{ORCISH_NAMES}
+	[/race]
+	
+	[movetype]
+		name=fly
+		flying=yes
+		[movement_costs]
+			{FLY_MOVE}
+			cave=3
+			fungus=3
+		[/movement_costs]
+		[defense]
+			{FLY_DEFENSE 50}
+			cave=80
+			fungus=-70
+		[/defense]
+		{FLY_RESISTANCE}
+		[special_note]
+			note={INTERNAL:SPECIAL_NOTES_DEFENSE_CAP}
+		[/special_note]
+	[/movetype]
+	
+[/units]

data/test/units/test_unit_exclude.cfg

@@ -0,0 +1,56 @@
+#textdomain wesnoth-test
+
+#define TRAIT_TEST_EXCLUDE
+    # Test for exclude trait
+    [trait]
+        id=test_exclude
+        male_name= _ "test_exclude"
+        female_name= _ "female^test_exclude"
+        help_text= _ "Test exclude"
+        exclude_traits=test_excluded,strong,quick,intelligent,resilient
+        [effect]
+            apply_to=hitpoints
+            increase_total=1
+        [/effect]
+    [/trait]
+#enddef
+
+#define TRAIT_TEST_EXCLUDED
+    # Test for require trait
+    [trait]
+        id=test_excluded
+        male_name= _ "test_excluded"
+        female_name= _ "female^test_excluded"
+        help_text= _ "Test excluded"
+        [effect]
+            apply_to=hitpoints
+            increase_total=1
+        [/effect]
+    [/trait]
+#enddef
+
+# This unit is used for testing the exclude traits functionality.
+
+[unit_type]
+	id=Test Unit Exclude
+	name=_ "dummy_unit^Test Unit Exclude"
+	race=test
+	image="misc/blank-hex.png"
+	ignore_race_traits=yes
+	{TRAIT_TEST_EXCLUDE}
+	{TRAIT_TEST_EXCLUDED}
+	hitpoints=1
+	movement_type=fly
+	movement=1
+	experience=1
+	level=1
+	alignment=neutral
+	advances_to=null
+	cost=1
+	usage=scout
+	hide_help=yes
+	do_not_list=yes
+[/unit_type]
+
+#undef TRAIT_TEST_EXCLUDE
+#undef TRAIT_TEST_EXCLUDED

data/test/units/test_unit_require.cfg

@@ -0,0 +1,56 @@
+#textdomain wesnoth-test
+
+#define TRAIT_TEST_REQUIRE
+    # Test for require trait
+    [trait]
+        id=test_require
+        male_name= _ "test_require"
+        female_name= _ "female^test_require"
+        help_text= _ "Test require"
+        require_traits=test_required
+        [effect]
+            apply_to=hitpoints
+            increase_total=1
+        [/effect]
+    [/trait]
+#enddef
+
+#define TRAIT_TEST_REQUIRED
+    # Test for require trait
+    [trait]
+        id=test_required
+        male_name= _ "test_required"
+        female_name= _ "female^test_required"
+        help_text= _ "Test required"
+        [effect]
+            apply_to=hitpoints
+            increase_total=1
+        [/effect]
+    [/trait]
+#enddef
+
+# This unit is used for testing the require traits functionality.
+
+[unit_type]
+	id=Test Unit Require
+	name=_ "dummy_unit^Test Unit Require"
+	race=test
+	image="misc/blank-hex.png"
+	ignore_race_traits=yes
+	{TRAIT_TEST_REQUIRE}
+	{TRAIT_TEST_REQUIRED}
+	hitpoints=1
+	movement_type=fly
+	movement=1
+	experience=1
+	level=1
+	alignment=neutral
+	advances_to=null
+	cost=1
+	usage=scout
+	hide_help=yes
+	do_not_list=yes
+[/unit_type]
+
+#undef TRAIT_TEST_REQUIRE
+#undef TRAIT_TEST_REQUIRED

src/units/unit.cpp

@@ -806,10 +806,9 @@ void unit::generate_traits(bool must_have_only)
 	LOG_UT << "Generating a trait for unit type " << type().log_id() << " with must_have_only " << must_have_only;
 	const unit_type& u_type = type();
 
-	// Calculate the unit's traits
 	config::const_child_itors current_traits = modifications_.child_range("trait");
-	std::vector<const config*> candidate_traits;
 
+	// Handle must-have only at the beginning
 	for(const config& t : u_type.possible_traits()) {
 		// Skip the trait if the unit already has it.
 		const std::string& tid = t["id"];
@@ -820,11 +819,9 @@ void unit::generate_traits(bool must_have_only)
 				break;
 			}
 		}
-
 		if(already) {
 			continue;
 		}
-
 		// Add the trait if it is mandatory.
 		const std::string& avl = t["availability"];
 		if(avl == "musthave") {
@@ -832,27 +829,106 @@ void unit::generate_traits(bool must_have_only)
 			current_traits = modifications_.child_range("trait");
 			continue;
 		}
-
-		// The trait is still available, mark it as a candidate for randomizing.
-		// For leaders, only traits with availability "any" are considered.
-		if(!must_have_only && (!can_recruit() || avl == "any")) {
-			candidate_traits.push_back(&t);
-		}
 	}
 
-	if(must_have_only) return;
+	if(must_have_only) {
+		return;
+	}
+
+	std::vector<const config*> candidate_traits;
+	std::vector<std::string> temp_require_traits;
+	std::vector<std::string> temp_exclude_traits;
 
 	// Now randomly fill out to the number of traits required or until
 	// there aren't any more traits.
 	int nb_traits = current_traits.size();
 	int max_traits = u_type.num_traits();
-	for(; nb_traits < max_traits && !candidate_traits.empty(); ++nb_traits)
+	for(; nb_traits < max_traits; ++nb_traits)
 	{
+		current_traits = modifications_.child_range("trait");
+		candidate_traits.clear();
+		for(const config& t : u_type.possible_traits()) {
+			// Skip the trait if the unit already has it.
+			const std::string& tid = t["id"];
+			bool already = false;
+			for(const config& mod : current_traits) {
+				if(mod["id"] == tid) {
+					already = true;
+					break;
+				}
+			}
+
+			if(already) {
+				continue;
+			}
+			// Skip trait if trait requirements are not met
+			// or trait exclusions are present
+			temp_require_traits = utils::split(t["require_traits"]);
+			temp_exclude_traits = utils::split(t["exclude_traits"]);
+
+			// See if the unit already has a trait that excludes the current one
+			for(const config& mod : current_traits) {
+				if (mod["exclude_traits"] != "") {
+					for (const auto& c: utils::split(mod["exclude_traits"])) {
+						temp_exclude_traits.push_back(c);
+					}
+				}
+			}
+
+			// First check for requirements
+			bool trait_req_met = true;
+			for(const std::string& s : temp_require_traits) {
+				bool has_trait = false;
+				for(const config& mod : current_traits) {
+					if (mod["id"] == s)
+						has_trait = true;
+				}
+				if(!has_trait) {
+					trait_req_met = false;
+					break;
+				}
+			}
+			if(!trait_req_met) {
+				continue;
+			}
+
+			// Now check for exclusionary traits
+			bool trait_exc_met = true;
+
+			for(const std::string& s : temp_exclude_traits) {
+				bool has_exclusionary_trait = false;
+				for(const config& mod : current_traits) {
+					if (mod["id"] == s)
+						has_exclusionary_trait = true;
+				}
+				if (tid == s) {
+					has_exclusionary_trait = true;
+				}
+				if(has_exclusionary_trait) {
+					trait_exc_met = false;
+					break;
+				}
+			}
+			if(!trait_exc_met) {
+				continue;
+			}
+
+			const std::string& avl = t["availability"];
+			// The trait is still available, mark it as a candidate for randomizing.
+			// For leaders, only traits with availability "any" are considered.
+			if(!must_have_only && (!can_recruit() || avl == "any")) {
+				candidate_traits.push_back(&t);
+			}
+		}
+		// No traits available anymore? Break
+		if(candidate_traits.empty()) {
+			break;
+		}
+
 		int num = randomness::generator->get_random_int(0,candidate_traits.size()-1);
 		modifications_.add_child("trait", *candidate_traits[num]);
 		candidate_traits.erase(candidate_traits.begin() + num);
 	}
-
 	// Once random traits are added, don't do it again.
 	// Such as when restoring a saved character.
 	random_traits_ = false;

wml_test_schedule

@@ -309,6 +309,8 @@
 0 unslowable_status_test
 0 unpetrifiable_status_test
 0 test_force_chance_to_hit_macro
+0 trait_exclusion_test
+0 trait_requirement_test
 0 swarms_filter_student_by_type
 0 swarms_effects_not_checkable
 0 filter_special_id_active