From 49751ea09e2148ddc8f0762bcde5fdaa1a6b7a39 Mon Sep 17 00:00:00 2001
From: Grant Horner <h.grant.horner@gmail.com>
Date: Sun, 30 Nov 2025 21:00:04 -0500
Subject: [PATCH] refactor spawner

---
 main.cpp | 101 ++++++++++++++++++++++++++++++++-----------------------
 1 file changed, 58 insertions(+), 43 deletions(-)

diff --git a/main.cpp b/main.cpp
index ccd9abb..02b3e40 100644
--- a/main.cpp
+++ b/main.cpp
@@ -9,9 +9,7 @@
 
 float screen_width = 800;
 float screen_height = 600;
-Rectangle walls[] = {
-    // {.x = 100, .y = 100, .width = 5, .height = 100}
-};
+Rectangle walls[] = {};
 
 Player player;
 auto player_speed = 5.0f;
@@ -29,7 +27,6 @@ double fire_rate = .5;
 std::mutex enemy_mutex;
 float enemy_max_speed = 3.0;
 float enemy_radius = 25.0;
-Enemy enemies[100] = {};
 
 struct Rng {
     static std::random_device dev;
@@ -94,18 +91,22 @@ void Player::move(const float delta_x, const float delta_y) {
     }
 }
 
-struct EnemySpawner {
-    std::mutex m;
+template <typename T, size_t N>
+struct Spawner {
+    std::mutex mutex;
     std::condition_variable cv;
     std::atomic<bool> running;
     std::atomic<bool> paused;
-    std::thread timer;
+    std::optional<std::thread> timer;
     long long rate_secs;
+    T values[N];
 
-    explicit EnemySpawner(const long long rate_secs)
+    explicit Spawner(const long long rate_secs)
         : rate_secs(rate_secs) {
     }
 
+    virtual void spawn() {}
+
     void start() {
         running.store(true);
         timer = std::thread([&] {
@@ -113,50 +114,64 @@ struct EnemySpawner {
                 const auto start = std::chrono::steady_clock::now();
 
                 if (!paused.load()) {
-                    std::lock_guard lock(enemy_mutex);
+                    std::lock_guard lock(mutex);
 
-                    const auto num = Rng::generate();
-                    const auto starting_x = Rng::generate(static_cast<uint32_t>(screen_width));
-                    const auto starting_y = Rng::generate(static_cast<uint32_t>(screen_height));
-
-                    for (auto &[center, radius, speed, alive]: enemies) {
-                        if (alive) continue;
-                        alive = true;
-                        radius = enemy_radius;
-                        if (num < 0.25) {
-                            center = {.x = starting_x, .y = 0};
-                        } else if (0.25 <= num && num < 0.5) {
-                            center = {
-                                .x = starting_x, .y = (screen_height)
-                            };
-                        } else if (0.5 <= num && num < 0.75) {
-                            center = {.x = 0, .y = starting_y};
-                        } else {
-                            center = {
-                                .x = (screen_width), .y = starting_y
-                            };
-                        }
-
-                        speed = Rng::generate(static_cast<uint32_t>(enemy_max_speed));
-
-                        break;
-                    }
+                    spawn();
                 }
 
                 auto next = start + std::chrono::seconds(rate_secs);
-                std::unique_lock lock{m};
+                std::unique_lock lock{mutex};
                 cv.wait_until(lock, next, [&] { return !running.load(); });
             }
         });
     }
 
-    ~EnemySpawner() {
+    virtual ~Spawner() {
         running.store(false);
         cv.notify_all();
-        timer.join();
+        if (timer) {
+            timer.value().join();
+        }
     }
 };
 
+struct EnemySpawner final : Spawner<Enemy, 100> {
+    explicit EnemySpawner(const long long rate_secs)
+        : Spawner<Enemy, 100>(rate_secs) {
+    }
+
+    void spawn() override {
+        const auto num = Rng::generate();
+        const auto starting_x = Rng::generate(static_cast<uint32_t>(screen_width));
+        const auto starting_y = Rng::generate(static_cast<uint32_t>(screen_height));
+
+        for (auto &[center, radius, speed, alive]: this->values) {
+            if (alive) continue;
+            alive = true;
+            radius = enemy_radius;
+            if (num < 0.25) {
+                center = {.x = starting_x, .y = 0};
+            } else if (0.25 <= num && num < 0.5) {
+                center = {
+                    .x = starting_x, .y = (screen_height)
+                };
+            } else if (0.5 <= num && num < 0.75) {
+                center = {.x = 0, .y = starting_y};
+            } else {
+                center = {
+                    .x = (screen_width), .y = starting_y
+                };
+            }
+
+            speed = Rng::generate(static_cast<uint32_t>(enemy_max_speed));
+
+            break;
+        }
+    }
+};
+
+EnemySpawner enemy_spawner{2};
+
 void spawn_tear(const Vector2 center, const Direction direction) {
     for (auto &[tear_center, tear_direction, tear_active, starting_center]: tears) {
         if (!tear_active) {
@@ -179,8 +194,8 @@ void update_tears() {
                 }
             }
 
-            for (auto &enemy: enemies) {
-                if (CheckCollisionCircles(center, tear_radius, enemy.center, enemy.radius)) {
+            for (auto &enemy: enemy_spawner.values) {
+                if (enemy.alive && CheckCollisionCircles(center, tear_radius, enemy.center, enemy.radius)) {
                     active = false;
                     enemy.alive = false;
                     score++;
@@ -213,8 +228,8 @@ int main() {
     InitWindow(800, 600, "Isaac++");
     SetTargetFPS(60);
 
-    EnemySpawner spawner{2};
-    spawner.start();
+
+    enemy_spawner.start();
 
     player.width = 50;
     player.height = 50;
@@ -283,7 +298,7 @@ int main() {
 
         {
             std::lock_guard enemy_guard{enemy_mutex};
-            for (auto &[center, radius, speed, alive]: enemies) {
+            for (auto &[center, radius, speed, alive]: enemy_spawner.values) {
                 if (alive) {
                     center = Vector2MoveTowards(center, player.center(), speed);
                     DrawCircleV(center, radius, RED);