Fix invalid calculation of "short" object passability

src/fheroes2/maps/maps_tiles.cpp

@@ -248,48 +248,6 @@ namespace
     }
 #endif
 
-    bool isShortObject( const MP2::MapObjectType objectType )
-    {
-        // Some objects allow middle moves even being attached to the bottom.
-        // These object actually don't have any sprites on tiles above them within addon 2 level objects.
-        // TODO: find a better way to do not hardcode values here.
-
-        switch ( objectType ) {
-        case MP2::OBJ_HALFLING_HOLE:
-        case MP2::OBJ_NON_ACTION_HALFLING_HOLE:
-        case MP2::OBJ_LEAN_TO:
-        case MP2::OBJ_WATER_LAKE:
-        case MP2::OBJ_TAR_PIT:
-        case MP2::OBJ_MERCENARY_CAMP:
-        case MP2::OBJ_NON_ACTION_MERCENARY_CAMP:
-        case MP2::OBJ_STANDING_STONES:
-        case MP2::OBJ_SHRINE_FIRST_CIRCLE:
-        case MP2::OBJ_SHRINE_SECOND_CIRCLE:
-        case MP2::OBJ_SHRINE_THIRD_CIRCLE:
-        case MP2::OBJ_MAGIC_GARDEN:
-        case MP2::OBJ_RUINS:
-        case MP2::OBJ_NON_ACTION_RUINS:
-        case MP2::OBJ_SIGN:
-        case MP2::OBJ_IDOL:
-        case MP2::OBJ_STONE_LITHS:
-        case MP2::OBJ_NON_ACTION_STONE_LITHS:
-        case MP2::OBJ_WAGON:
-        case MP2::OBJ_WAGON_CAMP:
-        case MP2::OBJ_NON_ACTION_WAGON_CAMP:
-        case MP2::OBJ_GOBLIN_HUT:
-        case MP2::OBJ_FAERIE_RING:
-        case MP2::OBJ_NON_ACTION_FAERIE_RING:
-        case MP2::OBJ_BARRIER:
-        case MP2::OBJ_MAGIC_WELL:
-        case MP2::OBJ_NOTHING_SPECIAL:
-            return true;
-        default:
-            break;
-        }
-
-        return false;
-    }
-
     bool isDetachedObjectType( const MP2::MapObjectType objectType )
     {
         // Some objects do not take into account other objects below them.
@@ -507,7 +465,7 @@ void Maps::Tiles::Init( int32_t index, const MP2::mp2tile_t & mp2 )
         _isTileMarkedAsRoad = true;
     }
 
-    if ( mp2.mapObjectType == MP2::OBJ_NONE && ( layerType == Maps::ObjectLayerType::SHADOW_LAYER || layerType == Maps::ObjectLayerType::TERRAIN_LAYER ) ) {
+    if ( _mainObjectType == MP2::OBJ_NONE && ( layerType == Maps::ObjectLayerType::SHADOW_LAYER || layerType == Maps::ObjectLayerType::TERRAIN_LAYER ) ) {
         // If an object sits on shadow or terrain layer then we should put it as a bottom layer add-on.
         if ( bottomObjectIcnType != MP2::ObjectIcnType::OBJ_ICN_TYPE_UNKNOWN ) {
             _addonBottomLayer.emplace_back( layerType, mp2.level1ObjectUID, bottomObjectIcnType, mp2.bottomIcnImageIndex );
@@ -693,6 +651,17 @@ int Maps::Tiles::getBoatDirection() const
 
 int Maps::Tiles::getOriginalPassability() const
 {
+    // Run through all objects in this tile and calculate the passability based on all of them.
+    if ( isValidReefsSprite( _mainAddon._objectIcnType, _mainAddon._imageIndex ) ) {
+        return 0;
+    }
+
+    for ( const TilesAddon & addon : _addonBottomLayer ) {
+        if ( isValidReefsSprite( addon._objectIcnType, addon._imageIndex ) ) {
+            return 0;
+        }
+    }
+
     const MP2::MapObjectType objectType = GetObject( false );
 
     if ( MP2::isActionObject( objectType ) ) {
@@ -704,16 +673,6 @@ int Maps::Tiles::getOriginalPassability() const
         return DIRECTION_ALL;
     }
 
-    if ( isValidReefsSprite( _mainAddon._objectIcnType, _mainAddon._imageIndex ) ) {
-        return 0;
-    }
-
-    for ( const TilesAddon & addon : _addonBottomLayer ) {
-        if ( isValidReefsSprite( addon._objectIcnType, addon._imageIndex ) ) {
-            return 0;
-        }
-    }
-
     // Objects have fixed passability.
     return DIRECTION_CENTER_ROW | DIRECTION_BOTTOM_ROW;
 }
@@ -790,9 +749,11 @@ void Maps::Tiles::updatePassability()
             const MP2::MapObjectType bottomTileObjectType = bottomTile.GetObject( false );
             const MP2::MapObjectType correctedObjectType = MP2::getBaseActionObjectType( bottomTileObjectType );
 
+            const bool isBottomObjectShort = isMainObjectShort( bottomTile );
+
             if ( MP2::isActionObject( bottomTileObjectType ) ) {
                 if ( ( MP2::getActionObjectDirection( bottomTileObjectType ) & Direction::TOP ) == 0 ) {
-                    if ( isShortObject( bottomTileObjectType ) ) {
+                    if ( isBottomObjectShort ) {
                         _tilePassabilityDirections &= ~Direction::BOTTOM;
                     }
                     else {
@@ -802,10 +763,10 @@ void Maps::Tiles::updatePassability()
                 }
             }
             else if ( bottomTile._mainObjectType != MP2::OBJ_NONE && correctedObjectType != bottomTileObjectType && MP2::isActionObject( correctedObjectType )
-                      && isShortObject( correctedObjectType ) && ( bottomTile.getOriginalPassability() & Direction::TOP ) == 0 ) {
+                      && isBottomObjectShort && ( bottomTile.getOriginalPassability() & Direction::TOP ) == 0 ) {
                 _tilePassabilityDirections &= ~Direction::BOTTOM;
             }
-            else if ( isShortObject( bottomTileObjectType )
+            else if ( isBottomObjectShort
                       || ( !bottomTile.containsAnyObjectIcnType( getValidObjectIcnTypes() )
                            && ( isCombinedObject( objectType ) || isCombinedObject( bottomTileObjectType ) ) ) ) {
                 _tilePassabilityDirections &= ~Direction::BOTTOM;

src/fheroes2/maps/maps_tiles.h

@@ -1,6 +1,6 @@
 /***************************************************************************
  *   fheroes2: https://github.com/ihhub/fheroes2                           *
- *   Copyright (C) 2019 - 2023                                             *
+ *   Copyright (C) 2019 - 2024                                             *
  *                                                                         *
  *   Free Heroes2 Engine: http://sourceforge.net/projects/fheroes2         *
  *   Copyright (C) 2009 by Andrey Afletdinov <fheroes2@gmail.com>          *
@@ -42,12 +42,17 @@ class StreamBase;
 
 namespace Maps
 {
+    // Layer types. They affect passability and also rendering. Rendering must be in the following order:
+    // - terrain objects (they have no shadows)
+    // - shadows
+    // - background objects
+    // - objects
     enum ObjectLayerType : uint8_t
     {
-        OBJECT_LAYER = 0, // main and action objects like mines, forest, mountains, castles and etc.
-        BACKGROUND_LAYER = 1, // background objects like lakes or bushes.
-        SHADOW_LAYER = 2, // shadows and some special objects like castle's entrance road.
-        TERRAIN_LAYER = 3 // roads, water flaws and cracks. Essentially everything what is a part of terrain.
+        OBJECT_LAYER = 0, // Common objects like mines, forest, mountains, castles and etc. They affect passability.
+        BACKGROUND_LAYER = 1, // Objects that still affect passability but they must be rendered as background. Such objects are lakes, bushes and etc.
+        SHADOW_LAYER = 2, // Shadows and some special objects like castle's entrance road. No passability changes.
+        TERRAIN_LAYER = 3 // Roads, water flaws and cracks. Essentially everything what is a part of terrain. No passability changes.
     };
 
     struct TilesAddon

src/fheroes2/maps/maps_tiles_helper.cpp

@@ -25,6 +25,7 @@
 #include <cassert>
 #include <cstdint>
 #include <cstdlib>
+#include <deque>
 #include <initializer_list>
 #include <limits>
 #include <list>
@@ -3120,6 +3121,65 @@ namespace Maps
         }
     }
 
+    bool doesTileHaveObjectUID( const Tiles & tile, const uint32_t uid )
+    {
+        if ( tile.GetObjectUID() == uid ) {
+            return true;
+        }
+
+        for ( const TilesAddon & addon : tile.getBottomLayerAddons() ) {
+            if ( addon._uid == uid ) {
+                return true;
+            }
+        }
+
+        for ( const TilesAddon & addon : tile.getTopLayerAddons() ) {
+            if ( addon._uid == uid ) {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
+    bool isMainObjectShort( const Tiles & tile )
+    {
+        const uint32_t uid = tile.GetObjectUID();
+        const int32_t startIndex = tile.GetIndex();
+
+        const int32_t startY = startIndex / world.w();
+
+        std::deque<int32_t> indexToTraverse{ startIndex };
+        std::set<int32_t> traversedIndex;
+
+        const Directions & directions = Direction::All();
+
+        while ( !indexToTraverse.empty() ) {
+            traversedIndex.emplace( indexToTraverse.front() );
+
+            for ( const int direction : directions ) {
+                if ( !isValidDirection( indexToTraverse.front(), direction ) ) {
+                    continue;
+                }
+
+                const int32_t newIndex = Maps::GetDirectionIndex( indexToTraverse.front(), direction );
+                const Tiles & newTile = world.GetTiles( newIndex );
+
+                if ( doesTileHaveObjectUID( newTile, uid ) && traversedIndex.count( newIndex ) == 0 ) {
+                    if ( ( newIndex / world.w() ) != startY ) {
+                        return false;
+                    }
+
+                    indexToTraverse.emplace_back( newIndex );
+                }
+            }
+
+            indexToTraverse.pop_front();
+        }
+
+        return true;
+    }
+
     bool removeObjectTypeFromTile( Tiles & tile, const MP2::ObjectIcnType objectIcnType )
     {
         if ( tile.getObjectIdByObjectIcnType( objectIcnType ) == 0 ) {

src/fheroes2/maps/maps_tiles_helper.h

@@ -176,6 +176,11 @@ namespace Maps
     // Determine the fog direction in the area between min and max positions for given player(s) color code and store it in corresponding tile data.
     void updateFogDirectionsInArea( const fheroes2::Point & minPos, const fheroes2::Point & maxPos, const int32_t color );
 
+    bool doesTileHaveObjectUID( const Tiles & tile, const uint32_t uid );
+
+    // An object is considered as short if its height is no more than 1 tile.
+    bool isMainObjectShort( const Tiles & tile );
+
     // The functions below are used only in the map Editor.
 
     void setTerrainOnTiles( const int32_t startTileId, const int32_t endTileId, const int groundId );