Hold shader data bindings through to rendering worker

lib/graphicsdev/Common.hpp

@@ -0,0 +1,54 @@
+#ifndef BOO_GRAPHICSDEV_COMMON_HPP
+#define BOO_GRAPHICSDEV_COMMON_HPP
+
+/* Private header for managing shader data
+ * binding lifetimes through rendering cycle */
+
+#include "boo/graphicsdev/IGraphicsDataFactory.hpp"
+
+namespace boo
+{
+
+template <class DataImpl>
+class IGraphicsDataPriv : public IGraphicsData
+{
+    std::atomic_int m_refCount = {1};
+public:
+    void increment() { m_refCount++; }
+    void decrement()
+    {
+        if (m_refCount.fetch_sub(1) == 1)
+            delete static_cast<DataImpl*>(this);
+    }
+};
+
+template <class DataImpl>
+class IShaderDataBindingPriv : public IShaderDataBinding
+{
+    IGraphicsDataPriv<DataImpl>* m_parent;
+
+public:
+    IShaderDataBindingPriv(IGraphicsDataPriv<DataImpl>* p) : m_parent(p) {}
+    class Token
+    {
+        IGraphicsDataPriv<DataImpl>* m_data = nullptr;
+    public:
+        Token() = default;
+        Token(const IShaderDataBindingPriv* p)
+        : m_data(p->m_parent)
+        { m_data->increment(); }
+        Token& operator=(const Token&) = delete;
+        Token(const Token&) = delete;
+        Token& operator=(Token&& other)
+        { m_data = other.m_data; other.m_data = nullptr; return *this; }
+        Token(Token&& other)
+        { m_data = other.m_data; other.m_data = nullptr; }
+        ~Token() { if (m_data) m_data->decrement(); }
+    };
+
+    Token lock() const { return Token(this); }
+};
+
+}
+
+#endif // BOO_GRAPHICSDEV_COMMON_HPP