Tinkered with strafing but I too dumb.

raycaster.cpp

@@ -130,6 +130,13 @@ void draw_everything(sf::RenderWindow &window) {
   window.display();
 }
 
+bool collision(float x, float y) {
+  int col = int(x / TILE_SIZE);
+  int row = int(y / TILE_SIZE);
+
+  return MAP[row][col] == 1;
+}
+
 int main() {
   using KB = sf::Keyboard;
   sf::RenderWindow window(sf::VideoMode(SCREEN_WIDTH, SCREEN_HEIGHT), "Raycaster");
@@ -138,6 +145,9 @@ int main() {
   while(window.isOpen()) {
     draw_everything(window);
 
+    float x = player_x;
+    float y = player_y;
+
     if(KB::isKeyPressed(KB::A)) {
       player_angle -= 0.1;
     } else if(KB::isKeyPressed(KB::D)) {
@@ -145,11 +155,16 @@ int main() {
     }
 
     if(KB::isKeyPressed(KB::W)) {
-      player_x += -1 * std::sin(player_angle) * 5;
-      player_y += std::cos(player_angle) * 5;
+      x += -1 * std::sin(player_angle) * 5;
+      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;
+      x -= -1 * std::sin(player_angle) * 5;
+      y -= std::cos(player_angle) * 5;
+    }
+
+    if(!collision(x, y)) {
+      player_x = x;
+      player_y = y;
     }
 
     sf::Event event;