Implement virtual com port receiver

AdaptiveBrightnessFirmware/Inc/vcp_receiver.hpp

@@ -0,0 +1,53 @@
+#pragma once
+
+#include <algorithm>
+#include <cstdint>
+#include <cstring>
+
+extern "C" void vcpReceiveCallback(uint8_t*, uint32_t);
+
+namespace detail {
+
+constexpr auto VCP_RECEIVE_BUFFER_SIZE = 64;
+
+} // namespace detail
+
+class VcpReceiver {
+  public:
+    static inline bool rxByte(uint8_t& data)
+    {
+        if(m_receiveBuffer.head == m_receiveBuffer.tail)
+            return false;
+
+        const uint8_t newTail = (m_receiveBuffer.tail + 1) % detail::VCP_RECEIVE_BUFFER_SIZE;
+        data = m_receiveBuffer.data[newTail];
+        m_receiveBuffer.tail = newTail;
+
+        return true;
+    }
+
+  private:
+    friend void vcpReceiveCallback(uint8_t*, uint32_t);
+
+    template<size_t Size>
+    struct RingBuffer {
+        size_t head = 0;
+        size_t tail = 0;
+        uint8_t data[Size];
+    };
+
+    static volatile RingBuffer<detail::VCP_RECEIVE_BUFFER_SIZE> m_receiveBuffer;
+
+    static inline void rxHandler(const uint8_t& data)
+    {
+        const uint8_t newHead = (m_receiveBuffer.head + 1) % detail::VCP_RECEIVE_BUFFER_SIZE;
+
+        if(newHead != m_receiveBuffer.tail) {
+            m_receiveBuffer.head = newHead;
+            m_receiveBuffer.data[newHead] = data;
+        }
+        else {
+            // TODO: Handle overflow
+        }
+    }
+};