Raycaster is smoother without changing much. Big debate is should left-right and forward-back at the same time cancel out motion or should they be exclusive since you can't do both.

raycaster.cpp

@@ -112,47 +112,50 @@ void ray_casting(sf::RenderWindow &window, Matrix& map) {
   }
 }
 
+void draw_ceiling_floor(sf::RenderWindow &window) {
+  draw_rect(window,
+      {SCREEN_HEIGHT, SCREEN_HEIGHT /2},
+      {SCREEN_HEIGHT, SCREEN_HEIGHT},
+      100);
+  draw_rect(window,
+      {SCREEN_HEIGHT, (SCREEN_HEIGHT * -1) / 2},
+      {SCREEN_HEIGHT, SCREEN_HEIGHT},
+      200);
+}
+
+void draw_everything(sf::RenderWindow &window) {
+  draw_map(window, MAP);
+  draw_ceiling_floor(window);
+  ray_casting(window, MAP);
+  window.display();
+}
+
 int main() {
+  using KB = sf::Keyboard;
   sf::RenderWindow window(sf::VideoMode(SCREEN_WIDTH, SCREEN_HEIGHT), "Raycaster");
   window.setVerticalSyncEnabled(true);
 
   while(window.isOpen()) {
-    sf::Event event;
+    draw_everything(window);
 
-    draw_map(window, MAP);
-
-    draw_rect(window,
-        {480, SCREEN_HEIGHT /2},
-        {SCREEN_HEIGHT, SCREEN_HEIGHT},
-        100);
-
-    draw_rect(window,
-        {480, (SCREEN_HEIGHT * -1) / 2},
-        {SCREEN_HEIGHT, SCREEN_HEIGHT},
-        200);
-
-    ray_casting(window, MAP);
+    if(KB::isKeyPressed(KB::A)) {
+      player_angle -= 0.1;
+    } else if(KB::isKeyPressed(KB::D)) {
+      player_angle += 0.1;
+    }
 
-    window.display();
+    if(KB::isKeyPressed(KB::W)) {
+      player_x += -1 * std::sin(player_angle) * 5;
+      player_y += std::cos(player_angle) * 5;
+    } else if(KB::isKeyPressed(KB::S)) {
+      player_x -= -1 * std::sin(player_angle) * 5;
+      player_y -= std::cos(player_angle) * 5;
+    }
 
+    sf::Event event;
     while(window.pollEvent(event)) {
-      using KB = sf::Keyboard;
-
       if(event.type == sf::Event::Closed) {
         window.close();
-      } else if(event.type == sf::Event::KeyPressed) {
-        if(KB::isKeyPressed(KB::Left)) {
-          player_angle -= 0.1;
-        } else if(KB::isKeyPressed(KB::Right)) {
-          player_angle += 0.1;
-        } else if(KB::isKeyPressed(KB::Up)) {
-          player_x += -1 * std::sin(player_angle) * 5;
-          player_y += std::cos(player_angle) * 5;
-        } else if(KB::isKeyPressed(KB::Down)) {
-          player_x -= -1 * std::sin(player_angle) * 5;
-          player_y -= std::cos(player_angle) * 5;
-
-        }
       }
     }
   }