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) {
   }
 }
 
-int main() {
-  sf::RenderWindow window(sf::VideoMode(SCREEN_WIDTH, SCREEN_HEIGHT), "Raycaster");
-  window.setVerticalSyncEnabled(true);
-
-  while(window.isOpen()) {
-    sf::Event event;
-
-    draw_map(window, MAP);
-
+void draw_ceiling_floor(sf::RenderWindow &window) {
   draw_rect(window,
-        {480, SCREEN_HEIGHT /2},
+      {SCREEN_HEIGHT, SCREEN_HEIGHT /2},
       {SCREEN_HEIGHT, SCREEN_HEIGHT},
       100);
-
   draw_rect(window,
-        {480, (SCREEN_HEIGHT * -1) / 2},
+      {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();
+}
 
-    while(window.pollEvent(event)) {
+int main() {
   using KB = sf::Keyboard;
+  sf::RenderWindow window(sf::VideoMode(SCREEN_WIDTH, SCREEN_HEIGHT), "Raycaster");
+  window.setVerticalSyncEnabled(true);
 
-      if(event.type == sf::Event::Closed) {
-        window.close();
-      } else if(event.type == sf::Event::KeyPressed) {
-        if(KB::isKeyPressed(KB::Left)) {
+  while(window.isOpen()) {
+    draw_everything(window);
+
+    if(KB::isKeyPressed(KB::A)) {
       player_angle -= 0.1;
-        } else if(KB::isKeyPressed(KB::Right)) {
+    } else if(KB::isKeyPressed(KB::D)) {
       player_angle += 0.1;
-        } else if(KB::isKeyPressed(KB::Up)) {
+    }
+
+    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::Down)) {
+    } 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)) {
+      if(event.type == sf::Event::Closed) {
+        window.close();
       }
     }
   }