Weakpoints (part 2): Let the player know if they hit a weakpoint (#51372

)

* Plumb hit source into the weakpoint hit_chance calculation

* Make absorb_hit return the name of the weakpoint, if any

* Add weakpoint printing to ranged attacks

* Add message to non-tech melee attacks

* Run astyle

* style json

* Add messages for weakspots and melee techniques.

* Add translator comments

* Convert string_format to positional and modify translator comments.

* Adjust weak point technique message

* Adjust technique message again.

data/json/monsters/misc.json

@@ -18,7 +18,10 @@
     "melee_cut": 0,
     "vision_day": 1,
     "armor_bullet": 100,
-    "weakpoints": [ { "name": "knee", "armor_mult": { "bullet": 0.5 }, "armor_penalty": { "bullet": 25 }, "coverage": 50 } ],
+    "weakpoints": [
+      { "name": "the knee", "armor_mult": { "bullet": 0.5 }, "armor_penalty": { "bullet": 25 }, "coverage": 25 },
+      { "name": "the bugs", "armor_mult": { "bullet": 0.0 }, "armor_penalty": { "bullet": 0 }, "coverage": 25 }
+    ],
     "harvest": "exempt",
     "death_function": { "corpse_type": "NO_CORPSE", "message": "The %s melts away." },
     "regenerates": 50,

src/character.cpp

@@ -6781,7 +6781,7 @@ static void armor_enchantment_adjust( Character &guy, damage_unit &du )
     du.amount = std::max( 0.0f, du.amount );
 }
 
-void Character::absorb_hit( const bodypart_id &bp, damage_instance &dam )
+std::string Character::absorb_hit( Creature *, const bodypart_id &bp, damage_instance &dam )
 {
     std::list<item> worn_remains;
     bool armor_destroyed = false;
@@ -6886,6 +6886,7 @@ void Character::absorb_hit( const bodypart_id &bp, damage_instance &dam )
     if( armor_destroyed ) {
         drop_invalid_inventory();
     }
+    return {};
 }
 
 bool Character::armor_absorb( damage_unit &du, item &armor, const bodypart_id &bp )

src/character.h

@@ -996,7 +996,7 @@ class Character : public Creature, public visitable
          */
         void passive_absorb_hit( const bodypart_id &bp, damage_unit &du ) const;
         /** Runs through all bionics and armor on a part and reduces damage through their armor_absorb */
-        void absorb_hit( const bodypart_id &bp, damage_instance &dam ) override;
+        std::string absorb_hit( Creature *source, const bodypart_id &bp, damage_instance &dam ) override;
         /**
          * Reduces and mutates du, prints messages about armor taking damage.
          * @return true if the armor was completely destroyed (and the item must be deleted).

src/creature.cpp

@@ -826,6 +826,7 @@ struct projectile_attack_results {
     game_message_type gmtSCTcolor = m_neutral;
     double damage_mult = 1.0;
     bodypart_id bp_hit;
+    std::string wp_hit;
 
     explicit projectile_attack_results( const projectile &proj ) {
         max_damage = proj.impact.total_damage();
@@ -928,14 +929,25 @@ void Creature::messaging_projectile_attack( const Creature *source,
                 } else {
                     SCT.removeCreatureHP();
                 }
-
-                //~ %1$s: creature name, %2$d: damage value
-                add_msg( m_good, _( "You hit %1$s for %2$d damage." ),
-                         disp_name(), total_damage );
+                if( hit_selection.wp_hit.empty() ) {
+                    //~ %1$s: creature name, %2$d: damage value
+                    add_msg( m_good, _( "You hit %1$s for %2$d damage." ),
+                             disp_name(), total_damage );
+                } else {
+                    //~ %1$s: creature name, %2$s: weakpoint hit, %3$d: damage value
+                    add_msg( m_good, _( "You hit %1$s in %2$s for %3$d damage." ),
+                             disp_name(), hit_selection.wp_hit, total_damage );
+                }
             } else if( u_see_this ) {
-                //~ 1$ - shooter, 2$ - target
-                add_msg( _( "%1$s shoots %2$s." ),
-                         source->disp_name(), disp_name() );
+                if( hit_selection.wp_hit.empty() ) {
+                    //~ 1$ - shooter, 2$ - target
+                    add_msg( _( "%1$s shoots %2$s." ),
+                             source->disp_name(), disp_name() );
+                } else {
+                    //~ 1$ - shooter, 2$ - target, 3$ - weakpoint
+                    add_msg( _( "%1$s shoots %2$s in %3$s." ),
+                             source->disp_name(), disp_name(), hit_selection.wp_hit );
+                }
             }
         }
     }
@@ -1026,7 +1038,10 @@ void Creature::deal_projectile_attack( Creature *source, dealt_projectile_attack
     }
 
     dealt_dam = deal_damage( source, hit_selection.bp_hit, impact );
+    // Force damage instance to match the selected body point
     dealt_dam.bp_hit = hit_selection.bp_hit;
+    // Retrieve the selected weakpoint from the damage instance.
+    hit_selection.wp_hit = dealt_dam.wp_hit;
 
     proj.apply_effects_damage( *this, source, dealt_dam, goodhit < accuracy_critical );
 
@@ -1050,7 +1065,7 @@ dealt_damage_instance Creature::deal_damage( Creature *source, bodypart_id bp,
     damage_instance d = dam; // copy, since we will mutate in absorb_hit
 
     dealt_damage_instance dealt_dams;
-    absorb_hit( bp, d );
+    dealt_dams.wp_hit = absorb_hit( source, bp, d );
 
     // Add up all the damage units dealt
     for( const auto &it : d.damage_units ) {

src/creature.h

@@ -391,8 +391,8 @@ class Creature : public viewer
                                 damage_instance &dam ) = 0;
 
         // handles armor absorption (including clothing damage etc)
-        // of damage instance. mutates &dam
-        virtual void absorb_hit( const bodypart_id &bp, damage_instance &dam ) = 0;
+        // of damage instance. returns name of weakpoint hit, if any. mutates &dam.
+        virtual std::string absorb_hit( Creature *source, const bodypart_id &bp, damage_instance &dam ) = 0;
 
         // TODO: this is just a shim so knockbacks work
         void knock_back_from( const tripoint &p );

src/damage.h

@@ -111,6 +111,7 @@ class damage_over_time_data
 struct dealt_damage_instance {
     std::array<int, static_cast<int>( damage_type::NUM )> dealt_dams;
     bodypart_id bp_hit;
+    std::string wp_hit;
 
     dealt_damage_instance();
     void set_damage( damage_type dt, int amount );

src/item.cpp

@@ -1649,7 +1649,8 @@ double item::effective_dps( const Character &guy, Creature &mon ) const
         damage_instance base_damage;
         guy.roll_all_damage( crit, base_damage, true, *this );
         damage_instance dealt_damage = base_damage;
-        temp_mon->absorb_hit( bodypart_id( "torso" ), dealt_damage );
+        // TODO: Modify DPS calculation to consider weakpoints.
+        temp_mon->absorb_hit( nullptr, bodypart_id( "torso" ), dealt_damage );
         dealt_damage_instance dealt_dams;
         for( const damage_unit &dmg_unit : dealt_damage.damage_units ) {
             int cur_damage = 0;
@@ -1672,7 +1673,8 @@ double item::effective_dps( const Character &guy, Creature &mon ) const
             for( damage_unit &dmg_unit : dealt_rs_damage.damage_units ) {
                 dmg_unit.damage_multiplier *= 0.66;
             }
-            temp_rs_mon->absorb_hit( bodypart_id( "torso" ), dealt_rs_damage );
+            // TODO: Modify DPS calculation to consider weakpoints.
+            temp_rs_mon->absorb_hit( nullptr, bodypart_id( "torso" ), dealt_rs_damage );
             dealt_damage_instance rs_dealt_dams;
             for( const damage_unit &dmg_unit : dealt_rs_damage.damage_units ) {
                 int cur_damage = 0;

src/melee.cpp

@@ -129,7 +129,7 @@ static const efftype_id effect_amigara( "amigara" );
 static const species_id species_HUMAN( "HUMAN" );
 
 static void player_hit_message( Character *attacker, const std::string &message,
-                                Creature &t, int dam, bool crit = false );
+                                Creature &t, int dam, bool crit = false, bool technique = false, std::string wp_hit = {} );
 static int  stumble( Character &u, const item &weap );
 static std::string melee_message( const ma_technique &tec, Character &p,
                                   const dealt_damage_instance &ddi );
@@ -763,7 +763,8 @@ bool Character::melee_attack_abstract( Creature &t, bool allow_special,
             // Treat monster as seen if we see it before or after the attack
             if( seen || player_character.sees( t ) ) {
                 std::string message = melee_message( technique, *this, dealt_dam );
-                player_hit_message( this, message, t, dam, critical_hit );
+                player_hit_message( this, message, t, dam, critical_hit, technique.id != tec_none,
+                                    dealt_dam.wp_hit );
             } else {
                 add_msg_player_or_npc( m_good, _( "You hit something." ),
                                        _( "<npcname> hits something." ) );
@@ -2369,20 +2370,27 @@ std::string melee_message( const ma_technique &tec, Character &p, const dealt_da
         index = cutting ? 8 : 5;
     }
 
+    std::string message;
     if( dominant_type == damage_type::STAB ) {
-        return npc ? _( npc_stab[index] ) : _( player_stab[index] );
+        message = npc ? _( npc_stab[index] ) : _( player_stab[index] );
     } else if( dominant_type == damage_type::CUT ) {
-        return npc ? _( npc_cut[index] ) : _( player_cut[index] );
+        message = npc ? _( npc_cut[index] ) : _( player_cut[index] );
     } else if( dominant_type == damage_type::BASH ) {
-        return npc ? _( npc_bash[index] ) : _( player_bash[index] );
+        message = npc ? _( npc_bash[index] ) : _( player_bash[index] );
+    }
+    if( ddi.wp_hit.empty() ) {
+        return message;
+    } else {
+        //~ %1$s: "Somone hit something", %2$s: the weakpoint that was hit
+        return string_format( _( "%1$s in %2$s" ), message, ddi.wp_hit );
     }
 
     return _( "The bugs attack %s" );
 }
 
 // display the hit message for an attack
 void player_hit_message( Character *attacker, const std::string &message,
-                         Creature &t, int dam, bool crit )
+                         Creature &t, int dam, bool crit, bool technique, std::string wp_hit )
 {
     std::string msg;
     game_message_type msgtype = m_good;
@@ -2404,6 +2412,10 @@ void player_hit_message( Character *attacker, const std::string &message,
         if( attacker->is_npc() && !player_character.has_trait( trait_DEBUG_NIGHTVISION ) ) {
             //~ NPC hits something (critical)
             msg = string_format( _( "%s. Critical!" ), message );
+        } else if( technique && !wp_hit.empty() ) {
+            //~ %1$s: "someone hits something", %2$d: damage dealt, %3$s: the weakpoint hit
+            msg = string_format( _( "%1$s for %2$d damage, and hit it in %3$s.  Critical!" ), message, dam,
+                                 wp_hit );
         } else {
             //~ someone hits something for %d damage (critical)
             msg = string_format( _( "%s for %d damage.  Critical!" ), message, dam );
@@ -2414,6 +2426,9 @@ void player_hit_message( Character *attacker, const std::string &message,
         if( attacker->is_npc() && !player_character.has_trait( trait_DEBUG_NIGHTVISION ) ) {
             //~ NPC hits something
             msg = string_format( _( "%s." ), message );
+        } else if( technique && !wp_hit.empty() ) {
+            //~ %1$s: "someone hits something", %2$d: damage dealt, %3$s: the weakpoint hit
+            msg = string_format( _( "%1$s for %2$d damage, and hit it in %3$s." ), message, dam, wp_hit );
         } else {
             //~ someone hits something for %d damage
             msg = string_format( _( "%s for %d damage." ), message, dam );

src/monster.cpp

@@ -1502,22 +1502,23 @@ bool monster::block_hit( Creature *, bodypart_id &, damage_instance & )
     return false;
 }
 
-void monster::absorb_hit( const bodypart_id &, damage_instance &dam )
+std::string monster::absorb_hit( Creature *source, const bodypart_id &, damage_instance &dam )
 {
     resistances r = resistances( *this );
-    const weakpoint *weakpoint = type->weakpoints.select_weakpoint();
-    weakpoint->apply_to( r );
+    const weakpoint *wp = type->weakpoints.select_weakpoint( source );
+    wp->apply_to( r );
     for( auto &elem : dam.damage_units ) {
         add_msg_debug( debugmode::DF_MONSTER, "Dam Type: %s :: Ar Pen: %.1f :: Armor Mult: %.1f",
                        name_by_dt( elem.type ), elem.res_pen, elem.res_mult );
         add_msg_debug( debugmode::DF_MONSTER,
                        "Weakpoint: %s :: Armor Mult: %.1f :: Armor Penalty: %.1f :: Resist: %.1f",
-                       weakpoint->id, weakpoint->armor_mult[static_cast<int>( elem.type )],
-                       weakpoint->armor_penalty[static_cast<int>( elem.type )],
+                       wp->id, wp->armor_mult[static_cast<int>( elem.type )],
+                       wp->armor_penalty[static_cast<int>( elem.type )],
                        r.get_effective_resist( elem ) );
         elem.amount -= std::min( r.get_effective_resist( elem ) +
                                  get_worn_armor_val( elem.type ), elem.amount );
     }
+    return wp->name;
 }
 
 bool monster::melee_attack( Creature &target )

src/monster.h

@@ -319,7 +319,7 @@ class monster : public Creature
         void make_bleed( const effect_source &source, const bodypart_id &bp, time_duration duration,
                          int intensity = 1, bool permanent = false, bool force = false, bool defferred = false ) override;
 
-        void absorb_hit( const bodypart_id &bp, damage_instance &dam ) override;
+        std::string absorb_hit( Creature *source, const bodypart_id &bp, damage_instance &dam ) override;
         bool block_hit( Creature *source, bodypart_id &bp_hit, damage_instance &d ) override;
         bool melee_attack( Creature &target );
         bool melee_attack( Creature &target, float accuracy );

src/weakpoint.cpp

@@ -44,16 +44,17 @@ void weakpoint::apply_to( resistances &resistances ) const
     }
 }
 
-float weakpoint::hit_chance() const
+float weakpoint::hit_chance( Creature * ) const
 {
+    // TODO: scale the hit chance based on the source's skill / stats
     return coverage;
 }
 
-const weakpoint *weakpoints::select_weakpoint() const
+const weakpoint *weakpoints::select_weakpoint( Creature *source ) const
 {
     float idx = rng_float( 0.0f, 100.0f );
     for( const weakpoint &weakpoint : weakpoint_list ) {
-        float hit_chance = weakpoint.hit_chance( );
+        float hit_chance = weakpoint.hit_chance( source );
         if( idx < hit_chance ) {
             return &weakpoint;
         }

src/weakpoint.h

@@ -28,7 +28,7 @@ struct weakpoint {
     // Apply the armor multipliers and offsets to a set of resistances.
     void apply_to( resistances &resistances ) const;
     // Return the change of the creature hitting the weakpoint.
-    float hit_chance( ) const;
+    float hit_chance( Creature *source ) const;
     void load( const JsonObject &jo );
 };
 
@@ -39,7 +39,7 @@ struct weakpoints {
     weakpoint default_weakpoint;
 
     // Selects a weakpoint to hit.
-    const weakpoint *select_weakpoint( ) const;
+    const weakpoint *select_weakpoint( Creature *source ) const;
 
     void clear();
     void load( const JsonArray &ja );