Efficient Direct2D multithreading

Question

I\'m writing a ebook reader app for Windows Store. I\'m using Direct2D + DXGI swap chains to render book pages on screen.

My book content sometimes is quite complex (ge

Answer 1

Ok, I've found a solution.

Basically, all I needed is to modify approach 2 to use DXGI resource sharing between two DirectX factory sets. I'll skip all the gory details (they can be found here: http://xboxforums.create.msdn.com/forums/t/66208.aspx), but basic steps are:

1. Create two sets of DirectX resources: main (which will be used to onscreen rendering), and secondary (for offscreen rendering).
2. Using ID3D11Device2 from main resource set, create D3D 2D texture by CreateTexture2D D3D11_BIND_RENDER_TARGET, D3D11_BIND_SHADER_RESOURCE, D3D11_RESOURCE_MISC_SHARED_NTHANDLE and D3D11_RESOURCE_MISC_SHARED_KEYEDMUTEX flags.
3. Get shared handle from it by casting it to IDXGIResource1 and calling CreateSharedHandle from it with XGI_SHARED_RESOURCE_READ and DXGI_SHARED_RESOURCE_WRITE.
4. Open this shared texture in secondary resource set in background thread by calling ID3D11Device2::OpenSharedResource1.
5. Acquire keyed mutex of this texture (IDXGIKeyedMutex::AcquireSync), create render target from it (ID2D1Factory2::CreateDxgiSurfaceRenderTarget), draw on it and release mutex (IDXGIKeyedMutex::ReleaseSync).
6. On the main thread, in the main resource set, acquire mutex and create shared bitmap from texture created in step 2, draw this bitmap, then release mutex.

Note that mutex locking stuff is necessary. Not doing it results in some cryptic DirectX debug error messages, and erroneous operation or even crashing.