Redesign asynchronous buffer uploads

[libs/gl.git] / source / core / buffer.h

diff --git a/source/core/buffer.h b/source/core/buffer.h
index 8aba95b10f08176be725bbafb0aa4b5771e6e8c8..66eb8d41fc44e76c91eddc4865b2a2f1dcb43c9d 100644 (file)
--- a/source/core/buffer.h
+++ b/source/core/buffer.h
@@ -39,6 +39,36 @@ class Buffer: public BufferBackend
 {
        friend BufferBackend;
 
+public:
+       /**
+       An RAII handle for asynchronously writing data into a buffer.
+       */
+       class AsyncTransfer: public NonCopyable
+       {
+               friend BufferBackend;
+               friend class Buffer;
+
+       private:
+               Buffer &buffer;
+               std::size_t offset = 0;
+               std::size_t size = 0;
+               void *dest_addr = 0;
+
+               AsyncTransfer(Buffer &, std::size_t, std::size_t);
+       public:
+               AsyncTransfer(AsyncTransfer &&);
+               ~AsyncTransfer();
+
+       private:
+               void allocate();
+               void finalize();
+
+       public:
+               /** Returns an address for writing the data.  It should not be used
+               beyond the lifetime of the object. */
+               void *get_address() { return dest_addr; }
+       };
+
 private:
        std::size_t size = 0;
        BufferUsage usage = STATIC;
@@ -57,6 +87,15 @@ public:
        The range must be fully inside the buffer. */
        void sub_data(std::size_t, std::size_t, const void *);
 
+       /** Creates an asynchronous transfer for writing data to a range of bytes in
+       the buffer.  While the transfer is pending, the state of the buffer region
+       is indeterminate. */
+       AsyncTransfer sub_data_async(std::size_t, std::size_t);
+
+private:
+       void check_sub_data(std::size_t, std::size_t, const char *);
+
+public:
        std::size_t get_size() const { return size; }
        using BufferBackend::get_multiplicity;
        std::size_t get_total_size() const { return size*get_multiplicity(); }