feat(balance): mutations can modify power value of mutant toxins, adding a vanilla use for Robust Genetics

data/json/mutations/mutations.json

@@ -1227,6 +1227,17 @@
     "prereqs": [ "FLIMSY2" ],
     "hp_modifier": -0.75
   },
+  {
+    "type": "mutation",
+    "id": "ROBUST",
+    "name": { "str": "Robust Genetics" },
+    "points": 3,
+    "description": "You have a very strong genetic base.  Mutations gained from eating mutant flesh will balance out at a higher number of positive mutations.",
+    "starting_trait": true,
+    "cancels": [ "CHAOTIC_BAD" ],
+    "category": [ "FISH", "SLIME", "ALPHA", "MEDICAL" ],
+    "mutagen_target_modifier": 8
+  },
   {
     "type": "mutation",
     "id": "CHAOTIC_BAD",
@@ -1236,7 +1247,8 @@
     "description": "The events of the Cataclysm have damaged your DNA beyond repair.  You mutate frequently, and all mutations you receive (from any source) are negative.",
     "starting_trait": true,
     "cancels": [ "ROBUST" ],
-    "valid": false
+    "valid": false,
+    "mutagen_target_modifier": -50
   },
   {
     "type": "mutation",
@@ -5640,7 +5652,9 @@
     "description": "You sometimes look back on your days before your tail came in.  But you're better now.",
     "valid": false,
     "purifiable": false,
-    "threshold": true
+    "threshold": true,
+    "//": "Based on highest of category's iv_hunger, iv_thirst, or iv_fatigue.  Most default to 10+10+5 so default value of 10",
+    "mutagen_target_modifier": 10
   },
   {
     "type": "mutation",
@@ -5650,7 +5664,8 @@
     "description": "You're sure you'll fly someday.  In the meantime, there are still nests to build.",
     "valid": false,
     "purifiable": false,
-    "threshold": true
+    "threshold": true,
+    "mutagen_target_modifier": 10
   },
   {
     "type": "mutation",
@@ -5660,7 +5675,8 @@
     "description": "Ninety percent of the planet, and it's yours to explore.  And colonize.  And enjoy.  What was that about a surface?",
     "valid": false,
     "purifiable": false,
-    "threshold": true
+    "threshold": true,
+    "mutagen_target_modifier": 10
   },
   {
     "type": "mutation",
@@ -5670,7 +5686,8 @@
     "description": "It's about time you grew out.  Now that you've matured, it is time to make something of yourself.",
     "valid": false,
     "purifiable": false,
-    "threshold": true
+    "threshold": true,
+    "mutagen_target_modifier": 10
   },
   {
     "type": "mutation",
@@ -5680,7 +5697,8 @@
     "description": "Stalking prey, eating well, and lying in the sun.  Mmm, all you could ever desire.",
     "valid": false,
     "purifiable": false,
-    "threshold": true
+    "threshold": true,
+    "mutagen_target_modifier": 10
   },
   {
     "type": "mutation",
@@ -5690,7 +5708,8 @@
     "description": "You're the perfect candidate to lead a pack.",
     "valid": false,
     "purifiable": false,
-    "threshold": true
+    "threshold": true,
+    "mutagen_target_modifier": 10
   },
   {
     "type": "mutation",
@@ -5701,7 +5720,8 @@
     "cancels": [ "CARNIVORE" ],
     "valid": false,
     "purifiable": false,
-    "threshold": true
+    "threshold": true,
+    "mutagen_target_modifier": 10
   },
   {
     "type": "mutation",
@@ -5711,7 +5731,8 @@
     "description": "Civilization collapsed?  Great!  You and your kin will never have to worry about a slaughterhouse again.",
     "valid": false,
     "purifiable": false,
-    "threshold": true
+    "threshold": true,
+    "mutagen_target_modifier": 10
   },
   {
     "type": "mutation",
@@ -5721,7 +5742,8 @@
     "description": "It would be good to be a Queen, having workers constantly servicing your every need… but how would you keep them in line?",
     "valid": false,
     "purifiable": false,
-    "threshold": true
+    "threshold": true,
+    "mutagen_target_modifier": 10
   },
   {
     "type": "mutation",
@@ -5731,7 +5753,8 @@
     "description": "Well, you still have those other walking flowers-and the mushrooms too-to deal with.  But you'll manage.",
     "valid": false,
     "purifiable": false,
-    "threshold": true
+    "threshold": true,
+    "mutagen_target_modifier": 10
   },
   {
     "type": "mutation",
@@ -5741,7 +5764,8 @@
     "description": "What was that old advertisement?  'Paint the planet'?  That might be a good long-term goal, but for now…",
     "valid": false,
     "purifiable": false,
-    "threshold": true
+    "threshold": true,
+    "mutagen_target_modifier": 10
   },
   {
     "type": "mutation",
@@ -5751,7 +5775,8 @@
     "description": "Not much point to rebuilding up in that horribly bright roofless wasteland.  Now that you've become accustomed to your new digs, there's the beginning of a great empire right here, underground.",
     "valid": false,
     "purifiable": false,
-    "threshold": true
+    "threshold": true,
+    "mutagen_target_modifier": 10
   },
   {
     "type": "mutation",
@@ -5761,7 +5786,8 @@
     "description": "Strange aeons, true, but Death seems to be slacking, and you are doing just fine.",
     "valid": false,
     "purifiable": false,
-    "threshold": true
+    "threshold": true,
+    "mutagen_target_modifier": 10
   },
   {
     "type": "mutation",
@@ -5771,7 +5797,8 @@
     "description": "Well, maybe you'll just have to make your own worldwide web.",
     "valid": false,
     "purifiable": false,
-    "threshold": true
+    "threshold": true,
+    "mutagen_target_modifier": 10
   },
   {
     "type": "mutation",
@@ -5781,7 +5808,8 @@
     "description": "Hey.  Civilization fell.  You're still around.  'Rat' just isn't respectful.",
     "valid": false,
     "purifiable": false,
-    "threshold": true
+    "threshold": true,
+    "mutagen_target_modifier": 10
   },
   {
     "type": "mutation",
@@ -5791,7 +5819,9 @@
     "description": "After all those experiments, what's a few more, hmm?",
     "valid": false,
     "purifiable": false,
-    "threshold": true
+    "threshold": true,
+    "//": "iv_fatigue of 5, other values are lower",
+    "mutagen_target_modifier": 5
   },
   {
     "type": "mutation",
@@ -5801,7 +5831,9 @@
     "description": "You're the perfect candidate to tidy this mess.",
     "valid": false,
     "purifiable": false,
-    "threshold": true
+    "threshold": true,
+    "//": "iv_fatigue of 5, other values are lower",
+    "mutagen_target_modifier": 5
   },
   {
     "type": "mutation",
@@ -5811,7 +5843,8 @@
     "description": "You are the tree under which humankind will shelter during these dark times.",
     "valid": false,
     "purifiable": false,
-    "threshold": true
+    "threshold": true,
+    "mutagen_target_modifier": 10
   },
   {
     "type": "mutation",
@@ -5821,7 +5854,9 @@
     "description": "You can't tell what you are anymore.  Everything and yet nothing, like you weren't meant to exist.  But you do, and you're a force, no matter what happens.",
     "valid": false,
     "purifiable": false,
-    "threshold": true
+    "threshold": true,
+    "//": "iv_hunger, iv_thirst, and iv_fatigue are all at 20",
+    "mutagen_target_modifier": 20
   },
   {
     "type": "mutation",
@@ -5831,7 +5866,8 @@
     "description": "The chance to undo not one but TWO extinction events.  You're confident you'll do fine.",
     "valid": false,
     "purifiable": false,
-    "threshold": true
+    "threshold": true,
+    "mutagen_target_modifier": 10
   },
   {
     "type": "mutation",
@@ -5841,7 +5877,8 @@
     "description": "So much food, everywhere!  And nobody's even guarding it anymore!  These are good times.",
     "valid": false,
     "purifiable": false,
-    "threshold": true
+    "threshold": true,
+    "mutagen_target_modifier": 10
   },
   {
     "type": "mutation",

data/json/obsoletion/mutations.json

@@ -1,13 +1,4 @@
 [
-  {
-    "type": "mutation",
-    "id": "ROBUST",
-    "name": { "str": "Robust Genetics" },
-    "points": 0,
-    "description": "Genetics?  Doesn't excuse not eating healthy, though.",
-    "valid": false,
-    "player_display": false
-  },
   {
     "type": "mutation",
     "id": "TRUTHTELLER",

doc/src/content/docs/en/mod/json/reference/json_info.md

@@ -1283,6 +1283,7 @@ wake up for the first time after 24 hours into the game.
                "active": false , // Will the target mutation start powered ( turn ON ).
                "moves": 100 // how many moves this costs. (default: 0)
 "enchantments": [ "MEP_INK_GLAND_SPRAY" ], // Applies this enchantment to the player. See magic.md and effects_json.md
+"mutagen_target_modifier": 5         // Increases or decreases how mutations prefer to balance out when mutating from mutant toxins, negative values push the target value lower (default: 0)
 }
 ```
 

src/character.cpp

@@ -7125,6 +7125,7 @@ mutation_value_map = {
     { "mana_modifier", calc_mutation_value_additive<&mutation_branch::mana_modifier> },
     { "mana_multiplier", calc_mutation_value_multiplicative<&mutation_branch::mana_multiplier> },
     { "mana_regen_multiplier", calc_mutation_value_multiplicative<&mutation_branch::mana_regen_multiplier> },
+    { "mutagen_target_modifier", calc_mutation_value_additive<&mutation_branch::mutagen_target_modifier> },
     { "speed_modifier", calc_mutation_value_multiplicative<&mutation_branch::speed_modifier> },
     { "movecost_modifier", calc_mutation_value_multiplicative<&mutation_branch::movecost_modifier> },
     { "movecost_flatground_modifier", calc_mutation_value_multiplicative<&mutation_branch::movecost_flatground_modifier> },

src/mutation.cpp

@@ -731,7 +731,8 @@ std::map<trait_id, float> Character::mutation_chances() const
     int current_score = genetic_score( *this );
     // 10/10/10/10 in stats, balanced traits, plus tip
     int expected_score = 4 * 10 + 6;
-    int direction = expected_score - current_score;
+    int direction = expected_score - current_score + mutation_value( "mutagen_target_modifier" );
+    add_msg_if_player( m_debug, "Mutation target value: %s", direction );
 
     // Duplicates allowed - they'll increase chances of change
     std::vector<potential_mutation> potential;

src/mutation.h

@@ -233,6 +233,8 @@ struct mutation_branch {
         float mana_modifier = 0.0f;
         float mana_multiplier = 1.0f;
         float mana_regen_multiplier = 1.0f;
+        // Bonus or penalty when mutating from toxins, see Character::mutation_chances
+        float mutagen_target_modifier = 0;
         // spells learned and their associated level when gaining the mutation
         std::map<spell_id, int> spells_learned;
         /** mutation enchantments */

src/mutation_data.cpp

@@ -403,6 +403,8 @@ void mutation_branch::load( const JsonObject &jo, const std::string & )
     optional( jo, was_loaded, "mana_multiplier", mana_multiplier, 1.0f );
     optional( jo, was_loaded, "mana_regen_multiplier", mana_regen_multiplier, 1.0f );
 
+    optional( jo, was_loaded, "mutagen_target_modifier", mutagen_target_modifier, 0 );
+
     if( jo.has_object( "rand_cut_bonus" ) ) {
         JsonObject sm = jo.get_object( "rand_cut_bonus" );
         rand_cut_bonus.first = sm.get_int( "min" );