Jsonify water boiling and other temperature effects on the item

data/json/items/comestibles/drink.json

@@ -1500,6 +1500,7 @@
     "container": "bottle_plastic",
     "sealed": false,
     "delete": { "flags": [ "DECAYS_IN_AIR" ] },
+    "temperature_effects": [ { "temperature_above": "373 K", "transform": "water_clean", "remove_poison": true } ],
     "contamination": [ { "disease": "highly_contaminated_food", "probability": 0.1 }, { "disease": "bad_food", "probability": 1 } ]
   },
   {
@@ -1508,6 +1509,7 @@
     "copy-from": "water",
     "name": { "str_sp": "murky water" },
     "description": "Water, the stuff of life.  This water looks like it has quite a bit of life in it in fact, and not the good kind.  You should filter and sterilize it if you want to drink it.",
+    "temperature_effects": [  ],
     "quench": 30,
     "parasites": 5,
     "contamination": [ { "disease": "highly_contaminated_food", "probability": 100 } ]

doc/JSON_INFO.md

@@ -3502,6 +3502,14 @@ Weakpoints only match if they share the same id, so it's important to define the
   "recipe": "paste_nut_mill_10_1"            // Reference to the recipe that performs the task. The syntax is <product name>_mill_<source amount>_<product amount>. The recipe is then defined as a normal recipe for the source with the product as its result and an id_suffix of "mill_X_Y". 
                                              // See data/json/recipes/food/milling.json for such recipes. Can also use "milling": { "into": "null", "recipe": "" } to override milling from a copied base item.
 },
+"temperature_effects": [{           // Optional. Specifies certain effects happening to the item when it reaches certain internal temperature thresholds.
+                                    // Holds an array of objects
+    "temperature_above": "373 K",   // Temperature needs to be at least this high for the effect to happen.
+    "temperature_below": "0 K",     // Temperature needs to be at least this low for the effect to happen.
+                                    // Exactly one of temperature_above and temperature_below must be set.
+    "transform": "water_clean",     // The item id that we transform into upon reaching the temperature. Boiling water gives clean water, as an example.
+    "remove_poison": true           // Whether we should remove poison from comestible item. Defaults to false.
+}],
 "explode_in_fire": true,                     // Should the item explode if set on fire
 "nanofab_template_group": "nanofab_recipes", // This item is nanofabricator recipe, and point to itemgroup with items, that it could possibly contain; require nanofab_template_group
 "template_requirements": "nanofabricator",   // `requirement`, that needed to craft any of this templates; used as "one full requirememt per 250 ml of item's volume" - item with volume 750 ml would require three times of `requirement`, item of 2L - eight times of `requirement`

src/game_constants.h

@@ -109,9 +109,6 @@ constexpr units::temperature freezer = units::from_celsius( -5 ); // -5 Celsius
 
 // Temperature in which water freezes.
 constexpr units::temperature freezing = units::from_celsius( 0 ); // 0 Celsius
-
-// Temperature in which water boils.
-constexpr units::temperature boiling = units::from_celsius( 100 ); // 100 Celsius
 } // namespace temperatures
 
 // Slowest speed at which a gun can be aimed.

src/item.cpp

@@ -182,8 +182,6 @@ static const itype_id itype_rad_badge( "rad_badge" );
 static const itype_id itype_rm13_armor( "rm13_armor" );
 static const itype_id itype_stock_none( "stock_none" );
 static const itype_id itype_tuned_mechanism( "tuned_mechanism" );
-static const itype_id itype_water( "water" );
-static const itype_id itype_water_clean( "water_clean" );
 static const itype_id itype_waterproof_gunmod( "waterproof_gunmod" );
 
 static const json_character_flag json_flag_CANNIBAL( "CANNIBAL" );
@@ -13222,9 +13220,22 @@ void item::set_temp_flags( units::temperature new_temperature, float freeze_perc
         set_flag( flag_COLD );
     }
 
-    // Convert water into clean water if it starts boiling
-    if( typeId() == itype_water && new_temperature > temperatures::boiling ) {
-        convert( itype_water_clean ).poison = 0;
+    // Execute temperature effects if a new threshold is reached.
+    // Water turning into clean water when boiling is a canonical example.
+    const islot_temperature_effects *te_data = type->temperature_effects_data.get();
+    if( te_data != nullptr ) {
+        for( const temperature_effect &eff : te_data->effects ) {
+            if( ( eff.temperature_above.has_value() && eff.temperature_above.value() <= new_temperature ) ||
+                ( eff.temperature_below.has_value() && eff.temperature_below.value() >= new_temperature )
+              ) {
+                if( eff.transform_into ) {
+                    convert( eff.transform_into );
+                }
+                if( eff.remove_poison ) {
+                    poison = 0;
+                }
+            }
+        }
     }
 }
 

src/item_factory.cpp

@@ -825,6 +825,20 @@
             }
         }
     }
+
+    // temperature_effects consistency
+    if( obj.temperature_effects_data ) {
+        for( const temperature_effect &eff : obj.temperature_effects_data->effects ) {
+            if( eff.temperature_above.has_value() == eff.temperature_below.has_value() ) {
+                debugmsg( "Exactly one of temperature_above and temperature_above must be set in %s temperature_effects",
+                          obj.id.str() );
+            }
+            if( eff.transform_into.is_null() || !eff.transform_into.is_valid() ) {
+                debugmsg( "'%s' is not a valid item id (in %s temperature_effects)",
+                          eff.transform_into.c_str(), obj.id.str() );
+            }
+        }
+    }
 }
 
 void Item_factory::finalize_post_armor( itype &obj )
@@ -2667,6 +2681,29 @@
     load( jo );
 }
 
+void temperature_effect::load( const JsonObject &jo )
+{
+    optional( jo, was_loaded, "temperature_above", temperature_above );
+    optional( jo, was_loaded, "temperature_below", temperature_below );
+    optional( jo, was_loaded, "transform", transform_into );
+    optional( jo, was_loaded, "remove_poison", remove_poison );
+}
+
+static void load_temperature_effects(
+    const JsonObject &jo, const std::string_view member,
+    cata::value_ptr<islot_temperature_effects> &slotptr, const std::string &src )
+{
+    if( !jo.has_member( member ) ) {
+        return;
+    }
+    slotptr = cata::make_value<islot_temperature_effects>();
+    for( const JsonObject &tejo : jo.get_array( member ) ) {
+        temperature_effect eff;
+        eff.load( tejo );
+        slotptr->effects.push_back( eff );
+    }
+}
+
 static void load_memory_card_data( memory_card_info &mcd, const JsonObject &jo )
 {
     mcd.data_chance = jo.get_float( "data_chance", 1.0f );
@@ -4494,6 +4531,8 @@
     assign( jo, "compostable", def.compostable, src == "dda" );
     load_slot_optional( def.relic_data, jo, "relic_data", src );
     assign( jo, "milling", def.milling_data, src == "dda" );
+    load_temperature_effects( jo, "temperature_effects", def.temperature_effects_data, src );
+
 
     // optional gunmod slot may also specify mod data
     if( jo.has_member( "gunmod_data" ) ) {

src/itype.h

@@ -1204,6 +1204,21 @@ class islot_milling
         void deserialize( const JsonObject &jo );
 };
 
+struct temperature_effect {
+    std::optional<units::temperature> temperature_above;
+    std::optional<units::temperature> temperature_below;
+
+    itype_id transform_into;
+    bool remove_poison = false;
+
+    bool was_loaded = false;
+    void load( const JsonObject &jo );
+};
+
+struct islot_temperature_effects {
+    std::vector<temperature_effect> effects;
+};
+
 struct memory_card_info {
     float data_chance;
     itype_id on_read_convert_to;
@@ -1228,6 +1243,14 @@ struct itype {
 
         using FlagsSetType = std::set<flag_id>;
 
+    protected:
+        // private because it should only be accessed through itype::nname!
+        // nname() is used for display purposes
+        translation name = no_translation( "none" );
+
+    public:
+        translation description; // Flavor text
+
         /**
          * Slots for various item type properties. Each slot may contain a valid pointer or null, check
          * this before using it.
@@ -1252,6 +1275,7 @@ struct itype {
         cata::value_ptr<islot_seed> seed;
         cata::value_ptr<relic> relic_data;
         cata::value_ptr<islot_milling> milling_data;
+        cata::value_ptr<islot_temperature_effects> temperature_effects_data;
         /*@}*/
 
         /** Action to take BEFORE the item is placed on map. If it returns non-zero, item won't be placed. */
@@ -1390,14 +1414,6 @@ struct itype {
         // How should the item explode
         explosion_data explosion;
 
-        translation description; // Flavor text
-
-    protected:
-        // private because is should only be accessed through itype::nname!
-        // nname() is used for display purposes
-        translation name = no_translation( "none" );
-
-    public:
         // Total of item's material portions (materials->second)
         int mat_portion_total = 0;