GraphicsMemory

DirectXTK

This class is used for the Xbox One platform to manage video memory allocations.

Related tutorial: Adding the DirectX Tool Kit

Header

#include <GraphicsMemory.h>

Initialization

The graphics memory helper is a singleton. It needs explicit initialization because it requires the device and the backbuffer count provided when you set up your swapchain.

std::unique_ptr<GraphicsMemory> graphicsMemory;
graphicsMemory = std::make_unique<GraphicsMemory>(device, backBufferCount);

For exception safety, it is recommended you make use of the C++ RAII pattern and use a std::unique_ptr.

Present

The graphics memory helper manages memory allocation for 'in-flight' data shared between the CPU and GPU. After each frame is rendered, the application needs to call Commit to let the manager know that a frame's worth of video memory has been sent to the GPU. This allows the manager to check to see if a previous frame's data is complete and can be released.

swapChain->Present(...);

graphicsMemory->Commit();

Since GraphicsMemory is a singleton, you can make use of the static method Get if desired: GraphicsMemory::Get().Commit()

Threading model

Allocation of memory resources is fully asynchronous, but should be sync'd once-per-frame to ensure the proper Commit semantics.

Platform Notes

Use of this class is only required for the Xbox One with DirectX 11--it's required for all platforms with DirectX Tool Kit for DX12. If you fail to create the singleton, an exception is thrown when using classes that make use of dynamic memory allocation for constant buffers, dynamic index buffers, and dynamic vertex buffers notably all Effects, PrimitiveBatch, and SpriteBatch.

For other Direct3D 11 platforms including Windows desktop and Universal Windows Platform apps, the use of this class is entirely optional. If created, the class performs a 'no-op' and does nothing. The Allocate class will always return nullptr.