From 08b4b10113496b9644cf3c71b6332cd191d5a99d Mon Sep 17 00:00:00 2001
From: Jan Mrna <mj370@protonmail.com>
Date: Fri, 10 Oct 2025 19:32:58 +0200
Subject: [PATCH] Selection rectangle

---
 cpp/src/pathfindingdemo.cpp | 30 ++++++++++++++++++++++++++++++
 cpp/src/pathfindingdemo.hpp |  8 ++++++++
 cpp/src/user_input.cpp      | 14 +++++++++++++-
 cpp/src/user_input.hpp      | 13 ++++++++++++-
 4 files changed, 63 insertions(+), 2 deletions(-)

diff --git a/cpp/src/pathfindingdemo.cpp b/cpp/src/pathfindingdemo.cpp
index 46ccd2b..7a1064c 100644
--- a/cpp/src/pathfindingdemo.cpp
+++ b/cpp/src/pathfindingdemo.cpp
@@ -203,5 +203,35 @@ void PathFindingDemo::HandleActions(const std::vector<UserAction> &actions)
       m_Camera.Zoom(action.Argument.float_number);
       LOG_INFO("Camera zoom: ", action.Argument.float_number);
     }
+    else if (action.type == UserAction::Type::SELECTION_START)
+    {
+      m_SelectionBox.active = true;
+      m_SelectionBox.start = action.Argument.position;
+    }
+    else if (action.type == UserAction::Type::SELECTION_END)
+    {
+      m_SelectionBox.end = action.Argument.position;
+      m_SelectionBox.active = false;
+      SelectEntitiesInRectangle(m_SelectionBox.start, m_SelectionBox.end);
+    }
   };
 }
+
+void PathFindingDemo::SelectEntitiesInRectangle(WindowPos A, WindowPos B)
+{
+  // TODO use colliders for this
+  m_SelectedEntities.clear();
+  auto [x_min, x_max] = std::minmax(A.x(), B.x());
+  auto [y_min, y_max] = std::minmax(A.y(), B.y());
+  for (const auto& entity : m_Entities)
+  {
+    const auto& pos = entity->GetPosition();
+    bool x_in_range = x_min < pos.x() && pos.x() < x_max;
+    bool y_in_range = y_min < pos.y() && pos.y() < y_max;
+    if (x_in_range && y_in_range)
+    {
+      m_SelectedEntities.push_back(std::weak_ptr(entity));
+    }
+  }
+}
+
diff --git a/cpp/src/pathfindingdemo.hpp b/cpp/src/pathfindingdemo.hpp
index ea34769..442716c 100644
--- a/cpp/src/pathfindingdemo.hpp
+++ b/cpp/src/pathfindingdemo.hpp
@@ -14,6 +14,12 @@
 
 using Collision = std::pair<std::weak_ptr<Entity>, std::weak_ptr<Entity>>;
 
+struct SelectionBox
+{
+  WindowPos start, end;
+  bool active;
+};
+
 class PathFindingDemo {
 public:
   PathFindingDemo(int width, int height);
@@ -35,6 +41,7 @@ public:
   void HandleActions(const std::vector<UserAction> &actions);
   WorldPos GetRandomPosition() const;
 
+  void SelectEntitiesInRectangle(WindowPos A, WindowPos B);
 
 private:
   const std::vector<Collision>& GetEntityCollisions();
@@ -45,4 +52,5 @@ private:
   std::vector<std::shared_ptr<Entity>> m_Entities;
   std::unique_ptr<pathfinder::PathFinderBase> m_PathFinder;
   std::vector<std::weak_ptr<Entity>> m_SelectedEntities;
+  SelectionBox m_SelectionBox;
 };
diff --git a/cpp/src/user_input.cpp b/cpp/src/user_input.cpp
index 1604f94..590924e 100644
--- a/cpp/src/user_input.cpp
+++ b/cpp/src/user_input.cpp
@@ -31,7 +31,13 @@ void UserInput::GetActions_mouse(const SDL_Event& event)
   {
     if (button == MouseButton::LEFT)
     {
-      LOG_DEBUG("Mouse down: ", mouse_event.x, ", ", mouse_event.y);
+      LOG_DEBUG("Selection start at ", mouse_event.x, ", ", mouse_event.y);
+      m_Actions.emplace_back(UserAction::Type::SELECTION_START,
+                             WindowPos{mouse_event.x, mouse_event.y});
+    }
+    else if (button == MouseButton::RIGHT)
+    {
+      LOG_DEBUG("Set move target to: ", mouse_event.x, ", ", mouse_event.y);
       m_Actions.emplace_back(UserAction::Type::SET_MOVE_TARGET,
                              WindowPos{mouse_event.x, mouse_event.y});
     }
@@ -42,6 +48,12 @@ void UserInput::GetActions_mouse(const SDL_Event& event)
   }
   else if (event.type == SDL_EVENT_MOUSE_BUTTON_UP)
   {
+    if (button == MouseButton::LEFT)
+    {
+      LOG_DEBUG("Selection end at ", mouse_event.x, ", ", mouse_event.y);
+      m_Actions.emplace_back(UserAction::Type::SELECTION_END,
+                             WindowPos{mouse_event.x, mouse_event.y});
+    }
     if (button == MouseButton::MIDDLE)
     {
       mouse_pan = false;
diff --git a/cpp/src/user_input.hpp b/cpp/src/user_input.hpp
index c32b071..de2c9f1 100644
--- a/cpp/src/user_input.hpp
+++ b/cpp/src/user_input.hpp
@@ -12,7 +12,18 @@ enum class MouseButton { LEFT = 1, MIDDLE, RIGHT };
 
 class UserAction {
 public:
-  enum class Type { NONE, EXIT, SET_MOVE_TARGET, SELECT_PATHFINDER, CAMERA_PAN, CAMERA_ZOOM };
+
+  enum class Type
+  {
+    NONE,
+    EXIT,
+    SET_MOVE_TARGET,
+    SELECT_PATHFINDER,
+    CAMERA_PAN,
+    CAMERA_ZOOM,
+    SELECTION_START,
+    SELECTION_END
+  };
 
   UserAction() : type(Type::NONE), Argument{.number = 0} {}
   UserAction(Type t) : type(t), Argument{.number = 0} {}