From 8151edeebfd7ddda822cceebfb9b35a09de78274 Mon Sep 17 00:00:00 2001
From: zongor <admin@alfrescocavern.com>
Date: Thu, 24 Jul 2025 00:16:52 -0400
Subject: [PATCH] update ring buffer

---
 src/ring_buffer.h  | 84 ++++++++++++++++++++++++++++------------------
 src/simulation.cpp | 38 ++++++++++-----------
 src/simulation.h   |  2 +-
 3 files changed, 71 insertions(+), 53 deletions(-)

diff --git a/src/ring_buffer.h b/src/ring_buffer.h
index dfa0064..c48c0bb 100644
--- a/src/ring_buffer.h
+++ b/src/ring_buffer.h
@@ -1,51 +1,71 @@
 #ifndef RING_BUFFER_H
 #define RING_BUFFER_H
 
-#include <array>
-#include <atomic>
-#include <cstddef>
+#include <mutex>
+#include <optional>
+#include <vector>
 
-template <typename T, size_t Capacity>
-class RingBuffer {
-    static_assert((Capacity & (Capacity - 1)) == 0, "Capacity must be power of 2");
+template <typename T> class RingBuffer {
+  std::vector<T> buffer;
+  size_t capacity;
+  size_t head;
+  size_t tail;
+  bool full;
 
-private:
-    std::array<T, Capacity> buffer;
-    std::atomic<size_t> head = 0; // write index
-    std::atomic<size_t> tail = 0; // read index
+  mutable std::mutex mtx;
+  bool empty_unlocked() const { return (!full && (head == tail)); }
 
 public:
-    bool push(const T& item) {
-        size_t current_head = head.load(std::memory_order_relaxed);
-        size_t next_head = (current_head + 1) & (Capacity - 1);
+  explicit RingBuffer(size_t capacity)
+      : buffer(capacity), capacity(capacity), head(0), tail(0), full(false) {}
 
-        if (next_head == tail.load(std::memory_order_acquire)) {
-            return false; // buffer full
-        }
-
-        buffer[current_head] = item;
-        head.store(next_head, std::memory_order_release);
-        return true;
+  bool push(const T &item) {
+    std::lock_guard<std::mutex> lock(mtx);
+    if (full) {
+      return false;
     }
 
-    bool pop(T& item) {
-        size_t current_tail = tail.load(std::memory_order_relaxed);
-        if (current_tail == head.load(std::memory_order_acquire)) {
-            return false; // buffer empty
-        }
+    buffer[tail] = item;
+    tail = (tail + 1) % capacity;
+    full = (tail == head);
+    return true;
+  }
 
-        item = buffer[current_tail];
-        tail.store((current_tail + 1) & (Capacity - 1), std::memory_order_release);
-        return true;
+  std::optional<T> pop() {
+    std::lock_guard<std::mutex> lock(mtx);
+
+    if (empty_unlocked()) {
+      return std::nullopt;
     }
 
-    bool empty() const {
-        return head.load() == tail.load();
+    T item = buffer[head];
+    full = false;
+    head = (head + 1) % capacity;
+  }
+
+  bool empty() const {
+    std::lock_guard<std::mutex> lock(mtx);
+    return empty_unlocked();
+  }
+
+  bool full_() const {
+    std::lock_guard<std::mutex> lock(mtx);
+    return full;
+  }
+
+  size_t size() const {
+    std::lock_guard<std::mutex> lock(mtx);
+
+    if (full) {
+      return capacity;
     }
 
-    bool full() const {
-        return ((head.load() + 1) & (Capacity - 1)) == tail.load();
+    if (tail >= head) {
+      return tail - head;
     }
+
+    return capacity + tail - head;
+  }
 };
 
 #endif
diff --git a/src/simulation.cpp b/src/simulation.cpp
index 29d4bd9..97d861a 100644
--- a/src/simulation.cpp
+++ b/src/simulation.cpp
@@ -4,33 +4,31 @@
 #include <thread>
 
 std::atomic<bool> running(true);
-RingBuffer<Vec3, 64> snapshot_buffer;
+RingBuffer<Vec3> snapshot_buffer(128);
 
 void simulation_loop(std::shared_ptr<SimulationState> state) {
-    Vec3 velocity(0.01, 0.02, 0.03);
+  Vec3 velocity(0.01, 0.02, 0.03);
 
-    while (running) {
-        // Update position
-        for (auto &p : state->positions) {
-            p += velocity;
-        }
-
-        // Push latest position to buffer
-        if (!snapshot_buffer.push(state->positions[0])) {
-            std::cerr << "Snapshot buffer full, dropping frame\n";
-        }
+  while (running) {
+    for (auto &p : state->positions) {
+      p += velocity;
     }
+
+    while (snapshot_buffer.push(state->positions[0])) {
+      std::this_thread::yield();
+    }
+  }
 }
 
 void render_loop() {
-    Vec3 latest;
+  while (running) {
 
-    while (running) {
-        while (snapshot_buffer.pop(latest)) {
-            std::cout << "[Render] ";
-            latest.print();
-        }
-        // Optional: add very short pause to avoid spinning too fast
-        std::this_thread::yield(); // cooperative multitasking
+    Vec3 latest;
+    while (latest = snapshot_buffer.pop()) {
+      std::cout << "[Render] ";
+      latest.print();
     }
+    // Optional: add very short pause to avoid spinning too fast
+    std::this_thread::yield(); // cooperative multitasking
+  }
 }
diff --git a/src/simulation.h b/src/simulation.h
index 953b24c..b3444ec 100644
--- a/src/simulation.h
+++ b/src/simulation.h
@@ -13,7 +13,7 @@ struct SimulationState {
 };
 
 extern std::atomic<bool> running;
-extern RingBuffer<Vec3, 64> snapshot_buffer;
+extern RingBuffer<Vec3> snapshot_buffer;
 
 void simulation_loop(std::shared_ptr<SimulationState> state);
 void render_loop();