feat: DebugOverlay for rendering debug information

CMakeLists.txt

@@ -18,3 +18,9 @@ file(GLOB_RECURSE HEADERS CONFIGURE_DEPENDS src/*.hpp)
 add_executable(SFMLplayground ${SOURCES} ${HEADERS})
 target_compile_features(SFMLplayground PRIVATE cxx_std_17)
 target_link_libraries(SFMLplayground PRIVATE SFML::Graphics)
+
+add_custom_command(
+    TARGET SFMLplayground POST_BUILD
+    COMMAND ${CMAKE_COMMAND} -E copy_directory
+            ${CMAKE_SOURCE_DIR}/src/assets $<TARGET_FILE_DIR:SFMLplayground>/assets
+)

src/DebugOverlay.cpp

@@ -0,0 +1,29 @@
+#include "DebugOverlay.hpp"
+
+#include <sstream>
+
+DebugOverlay::DebugOverlay(const std::string& fontPath)
+    : m_font(fontPath), m_text(m_font) {
+    m_text.setCharacterSize(16);
+    m_text.setFillColor(sf::Color::White);
+    m_text.setPosition(sf::Vector2f(5.f, 5.f));
+}
+
+void DebugOverlay::update(int drawCalls, float timescale,
+                          const sf::RenderWindow& window) {
+    float elapsed = m_fpsClock.restart().asSeconds();
+    if (elapsed > 0.f) m_fps = static_cast<int>(1.f / elapsed);
+
+    sf::Vector2i mousePos = sf::Mouse::getPosition(window);
+
+    std::ostringstream oss;
+    oss << "Draw calls: " << drawCalls << "\n";
+    oss << "Framerate: " << m_fps << " FPS\n";
+    oss << "Frametime: " << (elapsed * 1000.f) << " ms\n";
+    oss << "Mouse: " << mousePos.x << ", " << mousePos.y << "\n";
+    oss << "Time scale: " << timescale << "\n";
+
+    m_text.setString(oss.str());
+}
+
+void DebugOverlay::draw(sf::RenderWindow& window) { window.draw(m_text); }

src/DebugOverlay.hpp

@@ -0,0 +1,20 @@
+#pragma once
+#include <SFML/Graphics/Font.hpp>
+#include <SFML/Graphics/RenderWindow.hpp>
+#include <SFML/Graphics/Text.hpp>
+#include <SFML/System/Clock.hpp>
+#include <string>
+
+class DebugOverlay {
+   public:
+    DebugOverlay(const std::string& fontPath);
+
+    void update(int drawCalls, float timescale, const sf::RenderWindow& window);
+    void draw(sf::RenderWindow& window);
+
+   private:
+    sf::Font m_font;
+    sf::Text m_text;
+    sf::Clock m_fpsClock;
+    float m_fps = 0.f;
+};

src/Game.cpp

@@ -12,7 +12,9 @@ Game::Game()
     : m_inputManager(
           std::bind(&Game::processKeyPressed, this, std::placeholders::_1),
           std::bind(&Game::processMousePressed, this, std::placeholders::_1)),
-      m_debugLines(sf::PrimitiveType::Lines) {
+      m_debugLines(sf::PrimitiveType::Lines),
+      m_drawCallCount(0),
+      m_debugOverlay("assets/consolas.ttf") {
     m_window.create(sf::VideoMode({Constants::WIDTH, Constants::HEIGHT}),
                     "SFML Playground");
     m_window.setVerticalSyncEnabled(true);
@@ -27,10 +29,11 @@ Game::Game()
 
 void Game::processKeyPressed(const sf::Event::KeyPressed &kP) {
     if (kP.code == sf::Keyboard::Key::Equal) {
-        m_timeScale *= 1.1f;
+        m_timeScale += 0.25f;
+        if (m_timeScale > 10.0f) m_timeScale = 10.0f;
     } else if (kP.code == sf::Keyboard::Key::Hyphen) {
-        m_timeScale /= 1.1f;
-        if (m_timeScale < 0.1f) m_timeScale = 0.1f;
+        m_timeScale -= 0.25f;
+        if (m_timeScale < 0.25f) m_timeScale = 0.25f;
     }
 }
 
@@ -60,9 +63,11 @@ void Game::render() {
     m_window.clear(sf::Color::Black);
 
     m_debugLines.clear();
+    m_drawCallCount = 0;
 
     for (const auto &object : m_objects) {
         object->draw(m_window);
+        m_drawCallCount++;
 
         auto *ball = dynamic_cast<Ball *>(object.get());
         if (!ball) continue;
@@ -72,6 +77,10 @@ void Game::render() {
     }
 
     DebugDraw::drawBatchedLines(m_window, m_debugLines);
+    m_drawCallCount++;
+
+    m_debugOverlay.update(m_drawCallCount, m_timeScale, m_window);
+    m_debugOverlay.draw(m_window);
 
     m_window.display();
 }

src/Game.hpp

@@ -1,5 +1,7 @@
 #pragma once
+#include <SFML/Graphics/Font.hpp>
 #include <SFML/Graphics/RenderWindow.hpp>
+#include <SFML/Graphics/Text.hpp>
 #include <SFML/Graphics/VertexArray.hpp>
 #include <SFML/System/Clock.hpp>
 #include <SFML/System/Vector2.hpp>
@@ -8,6 +10,7 @@
 #include <vector>
 
 #include "Ball.hpp"
+#include "DebugOverlay.hpp"
 #include "InputManager.hpp"
 #include "PhysicalObject.hpp"
 
@@ -22,6 +25,8 @@ class Game {
     sf::Clock m_clock;
     InputManager m_inputManager;
     sf::VertexArray m_debugLines;
+    int m_drawCallCount = 0;
+    DebugOverlay m_debugOverlay;
     void processKeyPressed(const sf::Event::KeyPressed& keyPressed);
     void processMousePressed(const sf::Event::MouseButtonPressed& mousePressed);
     void handleMouseClick(const sf::Vector2i& mousePos);