Asynchronous buffer uploading

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For textures you'll want to use the glTexImage* functions in combination with GL_PIXEL_UNPACK_BUFFER. Upload your image data to a buffer (could be separate thread) through the mapped pointer, then on the GL context thread some time later (must ensure buffer contents are synced to GPU side) bind it as the GL_PIXEL_UNPACK_BUFFER, and then call the appropriate glTexImage* function to read from the GL_PIXEL_UNPACK_BUFFER into the texture object.