Update for Knockback_follow attribute

data/json/techniques.json

@@ -1458,7 +1458,7 @@
     "unarmed_allowed": true,
     "knockback_dist": 1,
     "knockback_spread": 1,
-    "knockback_follow": 1,
+    "knockback_follow": true,
     "mult_bonuses": [ [ "movecost", 0.5 ], [ "damage", "bash", 0.66 ], [ "damage", "cut", 0.66 ], [ "damage", "stab", 0.66 ] ],
     "messages": [ "You chain strike %s", "<npcname> chain strikes %s" ],
     "description": "50% moves, 66% damage, knockback and follow"

src/game.cpp

@@ -8927,7 +8927,29 @@ bool game::disable_robot( const tripoint &p )
     return false;
 }
 
+bool game::is_dangerous_tile( const tripoint &dest_loc ) const
+{
+    return !( get_dangerous_tile( dest_loc ).empty() );
+}
+
 bool game::prompt_dangerous_tile( const tripoint &dest_loc ) const
+{
+    std::vector<std::string> harmful_stuff = get_dangerous_tile( dest_loc );
+
+    if( !harmful_stuff.empty() &&
+        !query_yn( _( "Really step into %s?" ), enumerate_as_string( harmful_stuff ) ) ) {
+        return false;
+    }
+    if( !harmful_stuff.empty() && u.is_mounted() &&
+        m.tr_at( dest_loc ).loadid == tr_ledge ) {
+        add_msg( m_warning, _( "Your %s refuses to move over that ledge!" ),
+                 u.mounted_creature->get_name() );
+        return false;
+    }
+    return true;
+}
+
+std::vector<std::string> game::get_dangerous_tile( const tripoint &dest_loc ) const
 {
     std::vector<std::string> harmful_stuff;
     const auto fields_here = m.field_at( u.pos() );
@@ -8972,17 +8994,7 @@ bool game::prompt_dangerous_tile( const tripoint &dest_loc ) const
 
     }
 
-    if( !harmful_stuff.empty() &&
-        !query_yn( _( "Really step into %s?" ), enumerate_as_string( harmful_stuff ) ) ) {
-        return false;
-    }
-    if( !harmful_stuff.empty() && u.is_mounted() &&
-        m.tr_at( dest_loc ).loadid == tr_ledge ) {
-        add_msg( m_warning, _( "Your %s refuses to move over that ledge!" ),
-                 u.mounted_creature->get_name() );
-        return false;
-    }
-    return true;
+    return harmful_stuff;
 }
 
 bool game::walk_move( const tripoint &dest_loc )

src/game.h

@@ -794,6 +794,8 @@ class game
         void mon_info( const catacurses::window &,
                        int hor_padding = 0 ); // Prints a list of nearby monsters
         void cleanup_dead();     // Delete any dead NPCs/monsters
+        bool is_dangerous_tile( const tripoint &dest_loc ) const;
+        std::vector<std::string> get_dangerous_tile( const tripoint &dest_loc ) const;
         bool prompt_dangerous_tile( const tripoint &dest_loc ) const;
     private:
         void wield();

src/martialarts.cpp

@@ -130,7 +130,7 @@ void ma_technique::load( JsonObject &jo, const std::string &src )
     optional( jo, was_loaded, "knockback_dist", knockback_dist, 0 );
     optional( jo, was_loaded, "knockback_spread", knockback_spread, 0 );
     optional( jo, was_loaded, "powerful_knockback", powerful_knockback, false );
-    optional( jo, was_loaded, "knockback_follow", knockback_follow, 0 );
+    optional( jo, was_loaded, "knockback_follow", knockback_follow, false );
 
     optional( jo, was_loaded, "aoe", aoe, "" );
     optional( jo, was_loaded, "flags", flags, auto_flags_reader<> {} );
@@ -512,7 +512,7 @@ ma_technique::ma_technique()
     knockback_dist = 0;
     knockback_spread = 0; // adding randomness to knockback, like tec_throw
     powerful_knockback = false;
-    knockback_follow = 0; // player follows the knocked-back party into their former tile
+    knockback_follow = false; // player follows the knocked-back party into their former tile
 
     // offensive
     disarms = false; // like tec_disarm

src/martialarts.h

@@ -98,7 +98,7 @@ class ma_technique
         float knockback_spread; // adding randomness to knockback, like tec_throw
         bool powerful_knockback;
         std::string aoe; // corresponds to an aoe shape, defaults to just the target
-        int knockback_follow; // player follows the knocked-back party into their former tile
+        bool knockback_follow; // player follows the knocked-back party into their former tile
 
         // offensive
         bool disarms; // like tec_disarm

src/melee.cpp

@@ -53,6 +53,9 @@
 #include "material.h"
 #include "type_id.h"
 #include "point.h"
+#include "vehicle.h"
+#include "vpart_position.h"
+#include "mapdata.h"
 
 static const bionic_id bio_cqb( "bio_cqb" );
 static const bionic_id bio_memory( "bio_memory" );
@@ -102,6 +105,8 @@ static const trait_id trait_SLIME_HANDS( "SLIME_HANDS" );
 static const trait_id trait_TALONS( "TALONS" );
 static const trait_id trait_THORNS( "THORNS" );
 
+static const efftype_id effect_amigara( "amigara" );
+
 const species_id HUMAN( "HUMAN" );
 
 void player_hit_message( player *attacker, const std::string &message,
@@ -1318,28 +1323,34 @@ void player::perform_technique( const ma_technique &technique, Creature &t, dama
         t.add_effect( effect_stunned, rng( 1_turns, time_duration::from_turns( technique.stun_dur ) ) );
     }
 
-    if( technique.knockback_dist > 0 ) {
+    if( technique.knockback_dist ) {
         const tripoint prev_pos = t.pos(); // track target startpoint for knockback_follow
         const int kb_offset_x = rng( -technique.knockback_spread, technique.knockback_spread );
         const int kb_offset_y = rng( -technique.knockback_spread, technique.knockback_spread );
         tripoint kb_point( posx() + kb_offset_x, posy() + kb_offset_y, posz() );
-
-        if( !technique.powerful_knockback ) {
-            for( int dist = rng( 1, technique.knockback_dist ); dist > 0; dist-- ) {
-                t.knock_back_from( kb_point );
-            }
-        } else {
-            g->knockback( pos(), t.pos(), technique.knockback_dist, technique.stun_dur, 1 );
+        for( int dist = rng( 1, technique.knockback_dist ); dist > 0; dist-- ) {
+            t.knock_back_from( kb_point );
         }
-
         // This technique makes the player follow into the tile the target was knocked from
-        if( technique.knockback_follow > 0 ) {
-            // Check if terrain there is safe then if a critter's still there - if clear, move player there
-            if( !g->prompt_dangerous_tile( prev_pos ) ) {
-                return;
-            } else {
+        if( technique.knockback_follow ) {
+            const optional_vpart_position vp0 = g->m.veh_at( pos() );
+            vehicle *const veh0 = veh_pointer_or_null( vp0 );
+            bool to_swimmable = g->m.has_flag( "SWIMMABLE", prev_pos );
+            bool to_deepwater = g->m.has_flag( TFLAG_DEEP_WATER, prev_pos );
+
+            // Check if it's possible to move to the new tile
+            bool move_issue =
+                g->is_dangerous_tile( prev_pos ) || // Tile contains fire, etc
+                ( to_swimmable && to_deepwater ) || // Dive into deep water
+                is_mounted() ||
+                ( veh0 != nullptr && abs( veh0->velocity ) > 100 ) || // Diving from moving vehicle
+                ( veh0 != nullptr && veh0->player_in_control( g->u ) ) || // Player is driving
+                has_effect( effect_amigara );
+
+            if( !move_issue ) {
                 if( t.pos() != prev_pos ) {
                     g->place_player( prev_pos );
+                    g->on_move_effects();
                 }
             }
         }