board: automatic create a bridge if two straight tile are placed on top of each other

server/src/board/board.cpp

@@ -45,8 +45,31 @@ Board::Board(const std::weak_ptr<World>& world, std::string_view _id) :
         return false;
 
       if(auto it = m_tiles.find(l); it != m_tiles.end())
-        if(!replace || !deleteTile(x, y))
+      {
+        if(!replace && classId == StraightRailTile::classId && std::dynamic_pointer_cast<StraightRailTile>(it->second)) // merge to bridge
+        {
+          const TileRotate tileRotate = it->second->rotate;
+          if((tileRotate == rotate + TileRotate::Deg90 || tileRotate == rotate - TileRotate::Deg90) && deleteTile(x, y))
+          {
+            classId = Bridge90RailTile::classId;
+            rotate = tileRotate;
+          }
+          else if((tileRotate == rotate + TileRotate::Deg45 || tileRotate == rotate + TileRotate::Deg225) && deleteTile(x, y))
+          {
+            classId = Bridge45LeftRailTile::classId;
+            rotate = tileRotate;
+          }
+          else if((tileRotate == rotate - TileRotate::Deg45 || tileRotate == rotate - TileRotate::Deg225) && deleteTile(x, y))
+          {
+            classId = Bridge45RightRailTile::classId;
+            rotate = tileRotate;
+          }
+          else
+            return false;
+        }
+        else if(!replace || !deleteTile(x, y))
           return false;
+      }
 
       auto tile = Tiles::create(w, classId);
       if(!tile)

server/test/board/mergetile.cpp

@@ -0,0 +1,104 @@
+/**
+ * server/test/board/addtile.cpp
+ *
+ * This file is part of the traintastic test suite.
+ *
+ * Copyright (C) 2021 Reinder Feenstra
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+
+#include <catch2/catch.hpp>
+#include "../src/world/world.hpp"
+#include "../src/board/board.hpp"
+#include "../src/board/tile/rail/straightrailtile.hpp"
+#include "../src/board/tile/rail/bridge90railtile.hpp"
+#include "../src/board/tile/rail/bridge45leftrailtile.hpp"
+#include "../src/board/tile/rail/bridge45rightrailtile.hpp"
+
+TEST_CASE("Board: Merge tile, brigde 90", "[board][board-merge]")
+{
+  auto world = World::create();
+  auto board = world->boards->add();
+
+  int16_t x = 0;
+  const int16_t y = 0;
+  for(auto r : {TileRotate::Deg0, TileRotate::Deg45, TileRotate::Deg90, TileRotate::Deg135})
+  {
+    REQUIRE(board->addTile(x, y, r, StraightRailTile::classId, false));
+    std::weak_ptr<Tile> straight = board->getTile({x, y});
+    REQUIRE_FALSE(straight.expired());
+    REQUIRE(straight.lock()->rotate == r);
+
+    REQUIRE(board->addTile(x, y, r + TileRotate::Deg90, StraightRailTile::classId, false));
+    REQUIRE(straight.expired());
+    std::weak_ptr<Tile> bridge = board->getTile({x, y});
+    REQUIRE_FALSE(bridge.expired());
+    REQUIRE(bridge.lock()->getClassId() == Bridge90RailTile::classId);
+    REQUIRE(bridge.lock()->rotate == r);
+
+    x++;
+  }
+}
+
+TEST_CASE("Board: Merge tile, brigde 45 left", "[board][board-merge]")
+{
+  auto world = World::create();
+  auto board = world->boards->add();
+
+  int16_t x = 0;
+  const int16_t y = 0;
+  for(auto r : {TileRotate::Deg0, TileRotate::Deg45, TileRotate::Deg90, TileRotate::Deg135})
+  {
+    REQUIRE(board->addTile(x, y, r, StraightRailTile::classId, false));
+    std::weak_ptr<Tile> straight = board->getTile({x, y});
+    REQUIRE_FALSE(straight.expired());
+    REQUIRE(straight.lock()->rotate == r);
+
+    REQUIRE(board->addTile(x, y, r - TileRotate::Deg45, StraightRailTile::classId, false));
+    REQUIRE(straight.expired());
+    std::weak_ptr<Tile> bridge = board->getTile({x, y});
+    REQUIRE_FALSE(bridge.expired());
+    REQUIRE(bridge.lock()->getClassId() == Bridge45LeftRailTile::classId);
+    REQUIRE(bridge.lock()->rotate == r);
+
+    x++;
+  }
+}
+
+TEST_CASE("Board: Merge tile, brigde 45 right", "[board][board-merge]")
+{
+  auto world = World::create();
+  auto board = world->boards->add();
+
+  int16_t x = 0;
+  const int16_t y = 0;
+  for(auto r : {TileRotate::Deg0, TileRotate::Deg45, TileRotate::Deg90, TileRotate::Deg135})
+  {
+    REQUIRE(board->addTile(x, y, r, StraightRailTile::classId, false));
+    std::weak_ptr<Tile> straight = board->getTile({x, y});
+    REQUIRE_FALSE(straight.expired());
+    REQUIRE(straight.lock()->rotate == r);
+
+    REQUIRE(board->addTile(x, y, r + TileRotate::Deg45, StraightRailTile::classId, false));
+    REQUIRE(straight.expired());
+    std::weak_ptr<Tile> bridge = board->getTile({x, y});
+    REQUIRE_FALSE(bridge.expired());
+    REQUIRE(bridge.lock()->getClassId() == Bridge45RightRailTile::classId);
+    REQUIRE(bridge.lock()->rotate == r);
+
+    x++;
+  }
+}