Improved performance of view by only updating when necessary

src/game/world/world_view.cpp

@@ -1,6 +1,6 @@
 #include "world_view.h"
 
-WorldView::WorldView() : view(nullptr)
+WorldView::WorldView() : view(nullptr), hasViewChanged(false)
 {
 }
 
@@ -15,27 +15,24 @@ void WorldView::draw(sf::RenderWindow *window) const
 
 void WorldView::update(Game *game)
 {
+    // Initialize if necessary
     if (view == nullptr)
     {
         initializeView(game);
     }
 
     // Update size
-    auto windowSize = game->window->getSize();
-    sf::Vector2f viewSize = sf::Vector2f(windowSize.x, windowSize.y);
-    view->setSize(viewSize);
+    setSize(game->window->getSize());
 
     // Update position
-    auto moveDirection = InputMapper::getInputDirection();
-    if (moveDirection != InputDirection::NONE)
-    {
-        float stepSize = 100.0f * FRAME_TIME.asSeconds();
-        auto delta = stepSize * Direction::getVector(moveDirection);
-        this->view->move(delta);
-    }
+    moveViewByControls();
 
-    // TODO: Only update if necessary
-    game->window->setView(*this->view);
+    // Update window if necessary
+    if (hasViewChanged)
+    {
+        game->window->setView(*this->view);
+        hasViewChanged = false;
+    }
 }
 
 void WorldView::initializeView(Game *game)
@@ -44,3 +41,24 @@ void WorldView::initializeView(Game *game)
     auto size = game->window->getView().getSize();
     view = new sf::View(center, size);
 }
+
+void WorldView::setSize(sf::Vector2u windowSize)
+{
+    sf::Vector2f viewSize = sf::Vector2f(windowSize.x, windowSize.y);
+    view->setSize(viewSize);
+    hasViewChanged = true;
+}
+
+void WorldView::moveViewByControls()
+{
+    auto moveDirection = InputMapper::getInputDirection();
+    if (moveDirection == InputDirection::NONE)
+    {
+        return;
+    }
+
+    float stepSize = 100.0f * FRAME_TIME.asSeconds();
+    auto delta = stepSize * Direction::getVector(moveDirection);
+    this->view->move(delta);
+    hasViewChanged = true;
+}

src/game/world/world_view.h

@@ -18,8 +18,13 @@ public:
 
 private:
     sf::View *view;
+    bool hasViewChanged;
 
     void initializeView(Game *game);
+
+    void setSize(sf::Vector2u windowSize);
+
+    void moveViewByControls();
 };