Standardize engorged volume calculation

src/character.cpp

@@ -6386,6 +6386,11 @@ float Character::get_bmi_fat() const
             2 ) * get_cached_organic_size() );
 }
 
+bool Character::has_calorie_deficit() const
+{
+    return get_bmi_fat() < character_weight_category::normal;
+}
+
 units::mass Character::bodyweight() const
 {
     return bodyweight_fat() + bodyweight_lean();

src/character.h

@@ -3002,6 +3002,7 @@ class Character : public Creature, public visitable
         float get_bmi() const;
         float get_bmi_fat() const;
         float get_bmi_lean() const;
+        bool has_calorie_deficit() const;
         // returns amount of calories burned in a day given various metabolic factors
         int get_bmr() const;
         // add spent calories to calorie diary (if avatar)

src/character_body.cpp

@@ -1048,7 +1048,7 @@ void Character::update_stomach( const time_point &from, const time_point &to )
         set_thirst( 0 );
     }
 
-    const bool calorie_deficit = get_bmi_fat() < character_weight_category::normal;
+    const bool calorie_deficit = has_calorie_deficit();
     const units::volume contains = stomach.contains();
     const units::volume cap = stomach.capacity( *this );
 
@@ -1065,9 +1065,9 @@ void Character::update_stomach( const time_point &from, const time_point &to )
         // > 3/4 cap    full        full        full
         // > 1/2 cap    satisfied   v. hungry   famished/(near)starving
         // <= 1/2 cap   hungry      v. hungry   famished/(near)starving
-        if( contains >= cap ) {
+        if( stomach.would_be_engorged_with( *this, 0_ml, calorie_deficit ) ) {
             hunger_effect = effect_hunger_engorged;
-        } else if( contains > cap * 3 / 4 ) {
+        } else if( stomach.would_be_full_with( *this, 0_ml, calorie_deficit ) ) {
             hunger_effect = effect_hunger_full;
         } else if( just_ate && contains > cap / 2 ) {
             hunger_effect = effect_hunger_satisfied;
@@ -1090,9 +1090,9 @@ void Character::update_stomach( const time_point &from, const time_point &to )
         // >= 3/8 cap   satisfied   satisfied   blank
         // > 0          blank       blank       blank
         // 0            blank       blank       (v.) hungry
-        if( contains >= cap * 5 / 6 ) {
+        if( stomach.would_be_engorged_with( *this, 0_ml, calorie_deficit ) ) {
             hunger_effect = effect_hunger_engorged;
-        } else if( contains > cap * 11 / 20 ) {
+        } else if( stomach.would_be_full_with( *this, 0_ml, calorie_deficit ) ) {
             hunger_effect = effect_hunger_full;
         } else if( recently_ate && contains >= cap * 3 / 8 ) {
             hunger_effect = effect_hunger_satisfied;

src/consumption.cpp

@@ -992,8 +992,9 @@ ret_val<edible_rating> Character::will_eat( const item &food, bool interactive )
         add_consequence( _( "Your stomach won't be happy (not rotten enough)." ), ALLERGY_WEAK );
     }
 
+    units::volume in_stomach_volume = food.volume() * compute_effective_food_volume_ratio( food );
     if( food.is_food() &&
-        ( food.charges_per_volume( stomach.stomach_remaining( *this ) ) < 1 ||
+        ( stomach.would_be_engorged_with( *this, in_stomach_volume, has_calorie_deficit() ) ||
           has_effect( effect_hunger_full ) || has_effect( effect_hunger_engorged ) ) ) {
         if( edible ) {
             add_consequence( _( "You're full already and will be forcing yourself to eat." ), TOO_FULL );

src/stomach.cpp

@@ -313,6 +313,30 @@ units::volume stomach_contents::stomach_remaining( const Character &owner ) cons
     return capacity( owner ) - contents - water;
 }
 
+bool stomach_contents::would_be_engorged_with( const Character &owner, units::volume intake,
+        bool calorie_deficit ) const
+{
+    const double fullness_ratio = ( contains() + intake ) / capacity( owner );
+    if( calorie_deficit && fullness_ratio >= 1.0 ) {
+        return true;
+    } else if( fullness_ratio >= 5.0 / 6.0 ) {
+        return true;
+    }
+    return false;
+}
+
+bool stomach_contents::would_be_full_with( const Character &owner, units::volume intake,
+        bool calorie_deficit ) const
+{
+    const double fullness_ratio = ( contains() + intake ) / capacity( owner );
+    if( calorie_deficit && fullness_ratio >= 11.0 / 20.0 ) {
+        return true;
+    } else if( fullness_ratio >= 3.0 / 4.0 ) {
+        return true;
+    }
+    return false;
+}
+
 units::volume stomach_contents::contains() const
 {
     return contents + water;

src/stomach.h

@@ -164,6 +164,10 @@ class stomach_contents
          * @return This stomach's capacity, in units::volume
          */
         units::volume capacity( const Character &owner ) const;
+        // These functions need a ref to the stomach's owner because capacity() does
+        bool would_be_engorged_with( const Character &owner, units::volume intake,
+                                     bool calorie_deficit ) const;
+        bool would_be_full_with( const Character &owner, units::volume intake, bool calorie_deficit ) const;
         // how much stomach capacity you have left before you puke from stuffing your gob
         units::volume stomach_remaining( const Character &owner ) const;
         // how much volume is in the stomach_contents