feat: stack comestibles regardless of rot (#4320)

* feat: stack comestibles regardless of rot

* feat: configurable merge strategy

* perf: cache option

* fix: take account of liquid only option

* feat: display item content freshness

* fix: averaged rot in liquid transfer

* test: test legacy and all merging

* fix: fallthrough in switch statement

* fix: explicit fallthrough

* feat: change to similarity based merging

src/cached_item_options.cpp

@@ -0,0 +1,5 @@
+#include "cached_item_options.h"
+
+merge_comestible_t merge_comestible_mode = merge_comestible_t::merge_legacy;
+
+float similarity_threshold;

src/cached_item_options.h

@@ -0,0 +1,24 @@
+#pragma once
+#ifndef CATA_SRC_CACHED_ITEM_OPTIONS_H
+#define CATA_SRC_CACHED_ITEM_OPTIONS_H
+
+enum class merge_comestible_t {
+    merge_legacy,
+    merge_liquid,
+    merge_all,
+};
+
+/**
+ * Merge similar comestibles.  Legacy: default behavior.  Liquid: Merge only liquid comestibles.  All: Merge all comestibles.
+ */
+extern merge_comestible_t merge_comestible_mode;
+
+/**
+ * Limit maximum allowed staleness difference when merging comestibles.
+ * The lower the value, the more similar the items must be to merge.
+ * 0.0: Only merge identical items.
+ * 1.0: Merge comestibles regardless of its freshness.
+ */
+extern float similarity_threshold;
+
+#endif // CATA_SRC_CACHED_ITEM_OPTIONS_H

src/item.cpp

@@ -25,6 +25,7 @@
 #include "bodypart.h"
 #include "cata_utility.h"
 #include "catacharset.h"
+#include "cached_item_options.h"
 #include "character.h"
 #include "character_id.h"
 #include "character_encumbrance.h"
@@ -1003,13 +1004,28 @@ bool item::stacks_with( const item &rhs, bool check_components, bool skip_type_c
     if( goes_bad() && rhs.goes_bad() ) {
         // Stack items that fall into the same "bucket" of freshness.
         // Distant buckets are larger than near ones.
-        std::pair<int, clipped_unit> my_clipped_time_to_rot =
-            clipped_time( get_shelf_life() - rot );
-        std::pair<int, clipped_unit> other_clipped_time_to_rot =
-            clipped_time( rhs.get_shelf_life() - rhs.rot );
-        if( my_clipped_time_to_rot != other_clipped_time_to_rot ) {
-            return false;
+
+        switch( merge_comestible_mode ) {
+            case merge_comestible_t::merge_legacy: {
+                std::pair<int, clipped_unit> my_clipped_time_to_rot =
+                    clipped_time( get_shelf_life() - rot );
+                std::pair<int, clipped_unit> other_clipped_time_to_rot =
+                    clipped_time( rhs.get_shelf_life() - rhs.rot );
+                if( my_clipped_time_to_rot != other_clipped_time_to_rot ) {
+                    return false;
+                }
+            }
+            break;
+            case merge_comestible_t::merge_liquid: {
+                if( !made_of( LIQUID ) || !rhs.made_of( LIQUID ) ) {
+                    return false;
+                }
+            }
+            [[fallthrough]];
+            default:
+                return std::abs( get_relative_rot() - rhs.get_relative_rot() ) <= similarity_threshold;
         }
+
         if( rotten() != rhs.rotten() ) {
             // just to be safe that rotten and unrotten food is *never* stacked.
             return false;
@@ -1046,6 +1062,20 @@ bool item::stacks_with( const item &rhs, bool check_components, bool skip_type_c
     return contents.stacks_with( rhs.contents );
 }
 
+namespace
+{
+
+time_duration weighted_averaged_rot( const item *a, const item *b )
+{
+    const int base_charges = a->charges + b->charges;
+
+    return base_charges > 0
+           ? ( a->get_rot() * a->charges + b->get_rot() * b->charges ) / base_charges
+           : 0_seconds;
+}
+
+} // namespace
+
 bool item::merge_charges( detached_ptr<item> &&rhs, bool force )
 {
     if( this == &*rhs ) {
@@ -1059,6 +1089,8 @@ bool item::merge_charges( detached_ptr<item> &&rhs, bool force )
     safe_reference<item>::merge( this, &*rhs );
     detached_ptr<item> del = std::move( rhs );
 
+    const auto new_rot = weighted_averaged_rot( this, &obj );
+
     // Prevent overflow when either item has "near infinite" charges.
     if( charges >= INFINITE_CHARGES / 2 || obj.charges >= INFINITE_CHARGES / 2 ) {
         charges = INFINITE_CHARGES;
@@ -1070,6 +1102,10 @@ bool item::merge_charges( detached_ptr<item> &&rhs, bool force )
                          ( obj.item_counter ) * obj.charges ) / ( charges + obj.charges );
     }
     charges += obj.charges;
+
+    rot = new_rot;
+    set_age( std::max( age(), obj.age() ) );
+
     return true;
 }
 
@@ -1720,7 +1756,7 @@ void item::basic_info( std::vector<iteminfo> &info, const iteminfo_query *parts,
                 info.emplace_back( "BASE", _( "rot (turns): " ),
                                    "", iteminfo::lower_is_better,
                                    to_turns<int>( food->rot ) );
-                info.emplace_back( "BASE", space + _( "max rot (turns): " ),
+                info.emplace_back( "BASE", space + _( "shelf life (turns): " ),
                                    "", iteminfo::lower_is_better,
                                    to_turns<int>( food->get_shelf_life() ) );
                 info.emplace_back( "BASE", _( "last rot: " ),
@@ -3494,7 +3530,7 @@ void item::combat_info( std::vector<iteminfo> &info, const iteminfo_query *parts
 }
 
 void item::contents_info( std::vector<iteminfo> &info, const iteminfo_query *parts, int batch,
-                          bool /*debug*/ ) const
+                          bool debug ) const
 {
     if( contents.empty() || !parts->test( iteminfo_parts::DESCRIPTION_CONTENTS ) ) {
         return;
@@ -3572,6 +3608,22 @@ void item::contents_info( std::vector<iteminfo> &info, const iteminfo_query *par
                 }
                 info.emplace_back( "DESCRIPTION", description.translated() );
             }
+
+            if( debug && contents_item && contents_item->goes_bad() ) {
+                info.emplace_back( "CONTAINER", space );
+                info.emplace_back( "CONTAINER", _( "age (turns): " ),
+                                   "", iteminfo::lower_is_better,
+                                   to_turns<int>( contents_item->age() ) );
+                info.emplace_back( "CONTAINER", _( "rot (turns): " ),
+                                   "", iteminfo::lower_is_better,
+                                   to_turns<int>( contents_item->rot ) );
+                info.emplace_back( "CONTAINER", space + _( "shelf life (turns): " ),
+                                   "", iteminfo::lower_is_better,
+                                   to_turns<int>( contents_item->get_shelf_life() ) );
+                info.emplace_back( "CONTAINER", _( "last rot: " ),
+                                   "", iteminfo::lower_is_better,
+                                   to_turn<int>( contents_item->last_rot_check ) );
+            }
         }
     }
 }
@@ -8646,9 +8698,8 @@ detached_ptr<item> item::fill_with( detached_ptr<item> &&liquid, int amount )
         ammo_set( liquid->typeId(), ammo_remaining() + amount );
     } else if( is_food_container() ) {
         item &cts = contents.front();
-        // Use maximum rot between the two
-        cts.set_relative_rot( std::max( cts.get_relative_rot(),
-                                        liquid->get_relative_rot() ) );
+
+        cts.set_rot( weighted_averaged_rot( &cts, &*liquid ) );
         cts.mod_charges( amount );
     } else if( !is_container_empty() ) {
         // if container already has liquid we need to set the amount

src/options.cpp

@@ -7,6 +7,7 @@
 #include <stdexcept>
 
 #include "calendar.h"
+#include "cached_item_options.h"
 #include "cata_utility.h"
 #include "catacharset.h"
 #include "color.h"
@@ -1234,6 +1235,30 @@ void options_manager::add_options_general()
 
     add_empty_line();
 
+    add_option_group( general, Group( "comestible_merging",
+                                      to_translation( "Merge similar comestibles" ),
+                                      to_translation( "Configure how similar items are stacked." ) ),
+    [&]( auto & page_id ) {
+        add( "MERGE_COMESTIBLES", page_id, translate_marker( "Merging Mode" ),
+        translate_marker( "Merge similar comestibles.  Legacy: default behavior.  Liquid: Merge only liquid comestibles.  All: Merge all comestibles." ), {
+            { "legacy", to_translation( "Legacy" ) },
+            { "liquid", to_translation( "Liquid" ) },
+            { "all", to_translation( "All" ) }
+        }, "all" );
+
+        add( "MERGE_COMESTIBLES_THRESHOLD", general, translate_marker( "Freshness similarity threshold" ),
+             translate_marker( "Limit maximum allowed staleness difference when merging comestibles."
+                               "  The lower the value, the more similar the items must be to merge."
+                               "  0.0: Only merge identical items."
+                               "  1.0: Merge comestibles regardless of its freshness."
+                             ),
+             0.0, 1.0, 0.25, 0.05 );
+
+        get_option( "MERGE_COMESTIBLES_THRESHOLD" ).setPrerequisites( "MERGE_COMESTIBLES", {"liquid", "all"} );
+    } );
+
+    add_empty_line();
+
     add( "AUTO_PICKUP", general, translate_marker( "Auto pickup enabled" ),
          translate_marker( "Enable item auto pickup.  Change pickup rules with the Auto Pickup Manager." ),
          false
@@ -3369,6 +3394,16 @@ void options_manager::cache_to_globals()
     fov_3d_z_range = ::get_option<int>( "FOV_3D_Z_RANGE" );
     static_z_effect = ::get_option<bool>( "STATICZEFFECT" );
     PICKUP_RANGE = ::get_option<int>( "PICKUP_RANGE" );
+
+    merge_comestible_mode = ( [] {
+        const auto opt = ::get_option<std::string>( "MERGE_COMESTIBLES" );
+        return opt == "legacy" ? merge_comestible_t::merge_legacy
+        : opt == "liquid" ? merge_comestible_t::merge_liquid
+        : merge_comestible_t::merge_all;
+    } )();
+
+    similarity_threshold = ::get_option<float>( "MERGE_COMESTIBLES_THRESHOLD" );
+
 #if defined(SDL_SOUND)
     sounds::sound_enabled = ::get_option<bool>( "SOUND_ENABLED" );
 #endif

tests/item_test.cpp

@@ -12,6 +12,7 @@
 #include "math_defines.h"
 #include "units.h"
 #include "value_ptr.h"
+#include "cached_item_options.h"
 
 TEST_CASE( "item_volume", "[item]" )
 {
@@ -69,7 +70,9 @@ TEST_CASE( "stacking_over_time", "[item]" )
     item &A = *item::spawn_temporary( "bologna" );
     item &B = *item::spawn_temporary( "bologna" );
 
-    GIVEN( "Two items with the same birthday" ) {
+    GIVEN( "Two items with the same birthday (stack mode: legacy)" ) {
+        merge_comestible_mode = merge_comestible_t::merge_legacy;
+
         REQUIRE( A.stacks_with( B ) );
         WHEN( "the items are aged different numbers of seconds" ) {
             A.mod_rot( A.type->comestible->spoils - 1_turns );
@@ -159,8 +162,103 @@ TEST_CASE( "stacking_over_time", "[item]" )
             }
         }
     }
+
+    GIVEN( "Two items with the same birthday (stack mode: all)" ) {
+        merge_comestible_mode = merge_comestible_t::merge_all;
+        similarity_threshold = 1.0f;
+
+        REQUIRE( A.stacks_with( B ) );
+        WHEN( "the items are aged different numbers of seconds" ) {
+            A.mod_rot( A.type->comestible->spoils - 1_turns );
+            B.mod_rot( B.type->comestible->spoils - 3_turns );
+            THEN( "they stack" ) {
+                CHECK( A.stacks_with( B ) );
+            }
+        }
+        WHEN( "the items are aged the same to the minute but different numbers of seconds" ) {
+            A.mod_rot( A.type->comestible->spoils - 5_minutes );
+            B.mod_rot( B.type->comestible->spoils - 5_minutes );
+            B.mod_rot( -5_turns );
+            THEN( "they stack" ) {
+                CHECK( A.stacks_with( B ) );
+            }
+        }
+        WHEN( "the items are aged a few seconds different but different minutes" ) {
+            A.mod_rot( A.type->comestible->spoils - 5_minutes );
+            B.mod_rot( B.type->comestible->spoils - 5_minutes );
+            B.mod_rot( 5_turns );
+            THEN( "they stack" ) {
+                CHECK( A.stacks_with( B ) );
+            }
+        }
+        WHEN( "the items are aged the same to the hour but different numbers of minutes" ) {
+            A.mod_rot( A.type->comestible->spoils - 5_hours );
+            B.mod_rot( B.type->comestible->spoils - 5_hours );
+            B.mod_rot( -5_minutes );
+            THEN( "they stack" ) {
+                CHECK( A.stacks_with( B ) );
+            }
+        }
+        WHEN( "the items are aged a few seconds different but different hours" ) {
+            A.mod_rot( A.type->comestible->spoils - 5_hours );
+            B.mod_rot( B.type->comestible->spoils - 5_hours );
+            B.mod_rot( 5_turns );
+            THEN( "they stack" ) {
+                CHECK( A.stacks_with( B ) );
+            }
+        }
+        WHEN( "the items are aged the same to the day but different numbers of seconds" ) {
+            A.mod_rot( A.type->comestible->spoils - 3_days );
+            B.mod_rot( B.type->comestible->spoils - 3_days );
+            B.mod_rot( -5_turns );
+            THEN( "they stack" ) {
+                CHECK( A.stacks_with( B ) );
+            }
+        }
+        WHEN( "the items are aged a few seconds different but different days" ) {
+            A.mod_rot( A.type->comestible->spoils - 3_days );
+            B.mod_rot( B.type->comestible->spoils - 3_days );
+            B.mod_rot( 5_turns );
+            THEN( "they stack" ) {
+                CHECK( A.stacks_with( B ) );
+            }
+        }
+        WHEN( "the items are aged the same to the week but different numbers of seconds" ) {
+            A.mod_rot( A.type->comestible->spoils - 7_days );
+            B.mod_rot( B.type->comestible->spoils - 7_days );
+            B.mod_rot( -5_turns );
+            THEN( "they stack" ) {
+                CHECK( A.stacks_with( B ) );
+            }
+        }
+        WHEN( "the items are aged a few seconds different but different weeks" ) {
+            A.mod_rot( A.type->comestible->spoils - 7_days );
+            B.mod_rot( B.type->comestible->spoils - 7_days );
+            B.mod_rot( 5_turns );
+            THEN( "they stack" ) {
+                CHECK( A.stacks_with( B ) );
+            }
+        }
+        WHEN( "the items are aged the same to the season but different numbers of seconds" ) {
+            A.mod_rot( A.type->comestible->spoils - calendar::season_length() );
+            B.mod_rot( B.type->comestible->spoils - calendar::season_length() );
+            B.mod_rot( -5_turns );
+            THEN( "they stack" ) {
+                CHECK( A.stacks_with( B ) );
+            }
+        }
+        WHEN( "the items are aged a few seconds different but different seasons" ) {
+            A.mod_rot( A.type->comestible->spoils - calendar::season_length() );
+            B.mod_rot( B.type->comestible->spoils - calendar::season_length() );
+            B.mod_rot( 5_turns );
+            THEN( "they stack" ) {
+                CHECK( A.stacks_with( B ) );
+            }
+        }
+    }
 }
 
+
 TEST_CASE( "magazine_copyfrom_extends", "[item]" )
 {
     item gun( "glock_19" );