Pong: Only paint areas that needs to be updated

Userland/Games/Pong/Game.cpp

@@ -21,15 +21,21 @@ Game::~Game()
 
 void Game::reset_paddles()
 {
+    if (m_cursor_paddle_target_y.has_value())
+        update(cursor_paddle_target_rect());
     m_cursor_paddle_target_y.clear();
 
+    update(enclosing_int_rect(m_player1_paddle.rect));
     m_player1_paddle.moving_up = m_up_key_held;
     m_player1_paddle.moving_down = m_down_key_held;
     m_player1_paddle.rect = { game_width - 12, game_height / 2 - 40, m_player1_paddle.width, m_player1_paddle.height };
+    update(enclosing_int_rect(m_player1_paddle.rect));
 
+    update(enclosing_int_rect(m_player2_paddle.rect));
     m_player2_paddle.moving_up = false;
     m_player2_paddle.moving_down = false;
     m_player2_paddle.rect = { 4, game_height / 2 - 40, m_player2_paddle.width, m_player2_paddle.height };
+    update(enclosing_int_rect(m_player2_paddle.rect));
 }
 
 void Game::reset()
@@ -56,12 +62,8 @@ void Game::paint_event(GUI::PaintEvent& event)
     painter.fill_rect(enclosing_int_rect(m_player1_paddle.rect), m_player1_paddle.color);
     painter.fill_rect(enclosing_int_rect(m_player2_paddle.rect), m_player2_paddle.color);
 
-    if (m_cursor_paddle_target_y.has_value()) {
-        int radius = 3;
-        int center_x = m_player1_paddle.rect.center().x();
-        int center_y = *m_cursor_paddle_target_y + m_player1_paddle.rect.height() / 2;
-        painter.fill_ellipse(Gfx::IntRect { center_x - radius, center_y - radius, 2 * radius, 2 * radius }, Color::Blue);
-    }
+    if (m_cursor_paddle_target_y.has_value())
+        painter.fill_ellipse(cursor_paddle_target_rect(), Color::Blue);
 
     painter.draw_text(player_1_score_rect(), String::formatted("{}", m_player_1_score), Gfx::TextAlignment::TopLeft, Color::White);
     painter.draw_text(player_2_score_rect(), String::formatted("{}", m_player_2_score), Gfx::TextAlignment::TopLeft, Color::White);
@@ -113,6 +115,9 @@ void Game::mousemove_event(GUI::MouseEvent& event)
         return;
     }
 
+    if (m_cursor_paddle_target_y.has_value())
+        update(cursor_paddle_target_rect());
+
     m_cursor_paddle_target_y = clamp(event.y() - m_player1_paddle.rect.height() / 2, 0.f, game_height - m_player1_paddle.rect.height());
     if (m_player1_paddle.rect.y() > *m_cursor_paddle_target_y) {
         m_player1_paddle.moving_up = true;
@@ -121,6 +126,7 @@ void Game::mousemove_event(GUI::MouseEvent& event)
         m_player1_paddle.moving_up = false;
         m_player1_paddle.moving_down = true;
     }
+    update(cursor_paddle_target_rect());
 }
 
 void Game::reset_ball(int serve_to_player)
@@ -149,11 +155,17 @@ void Game::game_over(int winner)
 void Game::round_over(int winner)
 {
     stop_timer();
-    if (winner == 1)
+    if (winner == 1) {
+        update(player_1_score_rect());
         m_player_1_score++;
+        update(player_1_score_rect());
+    }
 
-    if (winner == 2)
+    if (winner == 2) {
+        update(player_2_score_rect());
         m_player_2_score++;
+        update(player_2_score_rect());
+    }
 
     if (m_player_1_score == m_score_to_win || m_player_2_score == m_score_to_win) {
         game_over(winner);
@@ -207,6 +219,8 @@ void Game::tick()
     auto new_ball = m_ball;
     new_ball.position += new_ball.velocity;
 
+    update(enclosing_int_rect(m_ball.rect()));
+
     if (new_ball.y() < new_ball.radius || new_ball.y() > game_height - new_ball.radius) {
         new_ball.position.set_y(m_ball.y());
         new_ball.velocity.set_y(new_ball.velocity.y() * -1);
@@ -222,6 +236,8 @@ void Game::tick()
         return;
     }
 
+    update(enclosing_int_rect(new_ball.rect()));
+
     if (new_ball.rect().intersects(m_player1_paddle.rect)) {
         new_ball.position.set_x(m_ball.x());
         new_ball.velocity.set_x(new_ball.velocity.x() * -1);
@@ -241,32 +257,38 @@ void Game::tick()
     }
 
     if (m_player1_paddle.moving_up) {
+        update(enclosing_int_rect(m_player1_paddle.rect));
         m_player1_paddle.rect.set_y(max(0.0f, m_player1_paddle.rect.y() - m_player1_paddle.speed));
         if (m_cursor_paddle_target_y.has_value() && m_player1_paddle.rect.y() <= *m_cursor_paddle_target_y) {
             m_cursor_paddle_target_y.clear();
             m_player1_paddle.moving_up = false;
         }
+        update(enclosing_int_rect(m_player1_paddle.rect));
     }
     if (m_player1_paddle.moving_down) {
+        update(enclosing_int_rect(m_player1_paddle.rect));
         m_player1_paddle.rect.set_y(min(game_height - m_player1_paddle.rect.height(), m_player1_paddle.rect.y() + m_player1_paddle.speed));
         if (m_cursor_paddle_target_y.has_value() && m_player1_paddle.rect.y() >= *m_cursor_paddle_target_y) {
             m_cursor_paddle_target_y.clear();
             m_player1_paddle.moving_down = false;
         }
+        update(enclosing_int_rect(m_player1_paddle.rect));
     }
 
     calculate_move();
 
     if (m_player2_paddle.moving_up) {
+        update(enclosing_int_rect(m_player2_paddle.rect));
         m_player2_paddle.rect.set_y(max(0.0f, m_player2_paddle.rect.y() - m_player2_paddle.speed));
+        update(enclosing_int_rect(m_player2_paddle.rect));
     }
     if (m_player2_paddle.moving_down) {
+        update(enclosing_int_rect(m_player2_paddle.rect));
         m_player2_paddle.rect.set_y(min(game_height - m_player2_paddle.rect.height(), m_player2_paddle.rect.y() + m_player2_paddle.speed));
+        update(enclosing_int_rect(m_player2_paddle.rect));
     }
 
     m_ball = new_ball;
-
-    update();
 }
 
 }

Userland/Games/Pong/Game.h

@@ -90,6 +90,14 @@ private:
         return { (game_width / 2) - score_width - score_margin, score_margin, score_width, font().glyph_height() };
     }
 
+    Gfx::IntRect cursor_paddle_target_rect() const
+    {
+        int radius = 3;
+        int center_x = m_player1_paddle.rect.center().x();
+        int center_y = *m_cursor_paddle_target_y + m_player1_paddle.rect.height() / 2;
+        return { center_x - radius, center_y - radius, 2 * radius, 2 * radius };
+    }
+
     Net m_net;
     Ball m_ball;
     Paddle m_player1_paddle;