GPU渲染时代——2D图形图像中的应用（二）

代码和例子的下载路径：http://pan.baidu.com/s/1ntFPXhv

联系方式：[email protected]

这篇博文来介绍DX的初始化，并封装成MDxKernel模块。

MDxKernel模块非常简单，类似于一个工厂模式，其中MDxKernel和DX是对外导出的接口和类。

该模块中最重要的是MDxKernelImp类的实现

1）创建和设备无关的的资源：

创建DirectWrite，WIC，Direct2D相对应的工厂对象。

// These are the resources required independent of the device.
void MDxKernelImp::CreateDeviceIndependentResources()
{
    D2D1_FACTORY_OPTIONS options;
    ZeroMemory(&options, sizeof(D2D1_FACTORY_OPTIONS));

#if defined(_DEBUG)
    // If the project is in a debug build, enable Direct2D debugging via SDK Layers.
    options.debugLevel = D2D1_DEBUG_LEVEL_INFORMATION;
#endif

    DX::ThrowIfFailed(
        D2D1CreateFactory(
            D2D1_FACTORY_TYPE_SINGLE_THREADED,
			//D2D1_FACTORY_TYPE_MULTI_THREADED,
            __uuidof(ID2D1Factory1),
            &options,
            &m_d2dFactory
            )
        );

    DX::ThrowIfFailed(
        DWriteCreateFactory(
            DWRITE_FACTORY_TYPE_SHARED,
            __uuidof(IDWriteFactory1),
            &m_dwriteFactory
            )
        );

/*
    DX::ThrowIfFailed(
        CoCreateInstance(
            CLSID_WICImagingFactory,
            nullptr,
            CLSCTX_INPROC_SERVER,
            IID_PPV_ARGS(&m_wicFactory)
            )
        );
*/

	DX::ThrowIfFailed(
		CoCreateInstance(
			CLSID_WICImagingFactory,
			NULL,CLSCTX_INPROC_SERVER,
			IID_IWICImagingFactory,
			(void **)&m_wicFactory
			)
		);
		
}

2）创建设备相关的资源

创建Direct3D和DXGI的设备

// These are the resources that depend on the device.
void MDxKernelImp::CreateDeviceResources()
{
    // This flag adds support for surfaces with a different color channel ordering
    // than the API default. It is required for compatibility with Direct2D.
    UINT creationFlags = D3D11_CREATE_DEVICE_BGRA_SUPPORT;
    ComPtr dxgiDevice;

#if defined(_DEBUG)
    if (DX::SdkLayersAvailable())
    {
        // If the project is in a debug build, enable debugging via SDK Layers with this flag.
        creationFlags |= D3D11_CREATE_DEVICE_DEBUG;
    }
#endif

    // This array defines the set of DirectX hardware feature levels this app will support.
    // Note the ordering should be preserved.
    // Don't forget to declare your application's minimum required feature level in its
    // description.  All applications are assumed to support 9.1 unless otherwise stated.
    D3D_FEATURE_LEVEL featureLevels[] =
    {
        D3D_FEATURE_LEVEL_11_1,
        D3D_FEATURE_LEVEL_11_0,
        D3D_FEATURE_LEVEL_10_1,
        D3D_FEATURE_LEVEL_10_0,
        D3D_FEATURE_LEVEL_9_3,
        D3D_FEATURE_LEVEL_9_2,
        D3D_FEATURE_LEVEL_9_1
    };

    // Create the Direct3D 11 API device object and a corresponding context.
    ComPtr device;
    ComPtr context;
    DX::ThrowIfFailed(
        D3D11CreateDevice(
            nullptr,                    // Specify nullptr to use the default adapter.
            D3D_DRIVER_TYPE_HARDWARE,
            0,
            creationFlags,              // Set debug and Direct2D compatibility flags.
            featureLevels,              // List of feature levels this app can support.
            ARRAYSIZE(featureLevels),
            D3D11_SDK_VERSION,          // Always set this to D3D11_SDK_VERSION for Windows Store apps.
            &device,                    // Returns the Direct3D device created.
            &m_featureLevel,            // Returns feature level of device created.
            &context                    // Returns the device immediate context.
            )
        );

    // Get the Direct3D 11.1 API device and context interfaces.
    DX::ThrowIfFailed(
        device.As(&m_d3dDevice)
        );

    DX::ThrowIfFailed(
        context.As(&m_d3dContext)
        );

    // Get the underlying DXGI device of the Direct3D device.
    DX::ThrowIfFailed(
        m_d3dDevice.As(&dxgiDevice)
        );

    // Create the Direct2D device object and a corresponding context.
    DX::ThrowIfFailed(
        m_d2dFactory->CreateDevice(dxgiDevice.Get(), &m_d2dDevice)
        );

    DX::ThrowIfFailed(
        m_d2dDevice->CreateDeviceContext(
            D2D1_DEVICE_CONTEXT_OPTIONS_NONE,
            &m_d2dContext
            )
        );
}

3）设置输出设备

创建交换链，

通过DXGI，将交换链和窗口句柄进行绑定。

// Allocate all memory resources that change on a window SizeChanged event.
void MDxKernelImp::CreateWindowSizeDependentResources()
{
    // Store the window bounds so the next time we get a SizeChanged event we can
    // avoid rebuilding everything if the size is identical.
    //m_windowBounds = m_window->Bounds;
	HRESULT hr=S_OK;

    if (m_swapChain != nullptr)
    {
        // If the swap chain already exists, resize it.
        HRESULT hr = m_swapChain->ResizeBuffers(2, 0, 0, DXGI_FORMAT_B8G8R8A8_UNORM, 0);

        if (hr == DXGI_ERROR_DEVICE_REMOVED)
        {
            // If the device was removed for any reason, a new device and swapchain will need to be created.
            HandleDeviceLost();

            // Everything is set up now. Do not continue execution of this method.
            return;
        }
        else
        {
            DX::ThrowIfFailed(hr);
        }
    }
    else
    {
        // Otherwise, create a new one using the same adapter as the existing Direct3D device.
        DXGI_SWAP_CHAIN_DESC1 swapChainDesc = {0};
        swapChainDesc.Width = 0;                                     // Use automatic sizing.
        swapChainDesc.Height = 0;
        swapChainDesc.Format = DXGI_FORMAT_B8G8R8A8_UNORM;           // This is the most common swap chain format.
        swapChainDesc.Stereo = false;
        swapChainDesc.SampleDesc.Count = 1;                          // Don't use multi-sampling.
        swapChainDesc.SampleDesc.Quality = 0;
        swapChainDesc.BufferUsage = DXGI_USAGE_RENDER_TARGET_OUTPUT;
        swapChainDesc.BufferCount = 2;                               // Use double-buffering to minimize latency.
        //swapChainDesc.Scaling = DXGI_SCALING_NONE;
		swapChainDesc.Scaling = DXGI_SCALING_STRETCH;
        //swapChainDesc.SwapEffect = DXGI_SWAP_EFFECT_FLIP_SEQUENTIAL; // All Windows Store apps must use this SwapEffect.
		//swapChainDesc.SwapEffect = DXGI_SWAP_EFFECT_DISCARD;
		swapChainDesc.SwapEffect = DXGI_SWAP_EFFECT_SEQUENTIAL;
        swapChainDesc.Flags = 0;

        ComPtr dxgiDevice;
        DX::ThrowIfFailed(
            m_d3dDevice.As(&dxgiDevice)
            );

        ComPtr dxgiAdapter;
        DX::ThrowIfFailed(
            dxgiDevice->GetAdapter(&dxgiAdapter)
            );

        ComPtr dxgiFactory;
        DX::ThrowIfFailed(
            dxgiAdapter->GetParent(IID_PPV_ARGS(&dxgiFactory))
            );

//         CoreWindow^ window = m_window.Get();
//         DX::ThrowIfFailed(
//             dxgiFactory->CreateSwapChainForCoreWindow(
//                 m_d3dDevice.Get(),
//                 reinterpret_cast(window),
//                 &swapChainDesc,
//                 nullptr,
//                 &m_swapChain
//                 )
//             );


		/*DX::ThrowIfFailed(*/
		hr = dxgiFactory->CreateSwapChainForHwnd(
			m_d3dDevice.Get(),
			m_hWnd,
			&swapChainDesc,
			nullptr,
			nullptr,
			&m_swapChain
			);
		//);

        // Ensure that DXGI does not queue more than one frame at a time. This both reduces latency and
        // ensures that the application will only render after each VSync, minimizing power consumption.
        DX::ThrowIfFailed(
            dxgiDevice->SetMaximumFrameLatency(1)
            );
    }

    // Create a Direct3D render target view of the swap chain back buffer.
    ComPtr backBuffer;
    DX::ThrowIfFailed(
        m_swapChain->GetBuffer(0, IID_PPV_ARGS(&backBuffer))
        );

    DX::ThrowIfFailed(
        m_d3dDevice->CreateRenderTargetView(
            backBuffer.Get(),
            nullptr,
            &m_d3dRenderTargetView
            )
        );

    // Cache the rendertarget dimensions in our helper class for convenient use.
    D3D11_TEXTURE2D_DESC backBufferDesc = {0};
    backBuffer->GetDesc(&backBufferDesc);
    m_renderTargetSize.cx  = backBufferDesc.Width;
    m_renderTargetSize.cy = backBufferDesc.Height;

    // Create a depth stencil view for use with 3D rendering if needed.
    CD3D11_TEXTURE2D_DESC depthStencilDesc(
        DXGI_FORMAT_D24_UNORM_S8_UINT,
        backBufferDesc.Width,
        backBufferDesc.Height,
        1,
        1,
        D3D11_BIND_DEPTH_STENCIL
        );

    ComPtr depthStencil;
    DX::ThrowIfFailed(
        m_d3dDevice->CreateTexture2D(
            &depthStencilDesc,
            nullptr,
            &depthStencil
            )
        );

    auto viewDesc = CD3D11_DEPTH_STENCIL_VIEW_DESC(D3D11_DSV_DIMENSION_TEXTURE2D);
    DX::ThrowIfFailed(
        m_d3dDevice->CreateDepthStencilView(
            depthStencil.Get(),
            &viewDesc,
            &m_d3dDepthStencilView
            )
        );

    // Set the 3D rendering viewport to target the entire window.
    CD3D11_VIEWPORT viewport(
        0.0f,
        0.0f,
        static_cast(backBufferDesc.Width),
        static_cast(backBufferDesc.Height)
        );

    m_d3dContext->RSSetViewports(1, &viewport);

    // Create a Direct2D target bitmap associated with the
    // swap chain back buffer and set it as the current target.
    D2D1_BITMAP_PROPERTIES1 bitmapProperties =
        BitmapProperties1(
            D2D1_BITMAP_OPTIONS_TARGET | D2D1_BITMAP_OPTIONS_CANNOT_DRAW,
            PixelFormat(DXGI_FORMAT_B8G8R8A8_UNORM, D2D1_ALPHA_MODE_PREMULTIPLIED),
            m_dpi,
            m_dpi
            );

    ComPtr dxgiBackBuffer;
    DX::ThrowIfFailed(
        m_swapChain->GetBuffer(0, IID_PPV_ARGS(&dxgiBackBuffer))
        );

    DX::ThrowIfFailed(
        m_d2dContext->CreateBitmapFromDxgiSurface(
            dxgiBackBuffer.Get(),
            &bitmapProperties,
            &m_d2dTargetBitmap
            )
        );

    m_d2dContext->SetTarget(m_d2dTargetBitmap.Get());

    // Grayscale text anti-aliasing is recommended for all Windows Store apps.
    m_d2dContext->SetTextAntialiasMode(D2D1_TEXT_ANTIALIAS_MODE_GRAYSCALE);
}

4)根据垂直同步，控制交换链输出到窗口

// Method to deliver the final image to the display.
void MDxKernelImp::Present(CRect *dtRect)
{
    // The application may optionally specify "dirty" or "scroll" rects to improve efficiency
    // in certain scenarios.  In this sample, however, we do not utilize those features.
    DXGI_PRESENT_PARAMETERS parameters = {0};
	if(dtRect)
	{
		parameters.DirtyRectsCount = 1;
		parameters.pDirtyRects = dtRect;
	}
	else
	{
		parameters.DirtyRectsCount = 0;
		parameters.pDirtyRects = nullptr;
	}
	
    parameters.pScrollRect = nullptr;
    parameters.pScrollOffset = nullptr;

    // The first argument instructs DXGI to block until VSync, putting the application
    // to sleep until the next VSync. This ensures we don't waste any cycles rendering
    // frames that will never be displayed to the screen.
    //HRESULT hr = m_swapChain->Present1(1, 0, ¶meters);

	
	HRESULT hr = m_swapChain->Present1(1, 0, ¶meters);
	
    // Discard the contents of the render target.
    // This is a valid operation only when the existing contents will be entirely
    // overwritten. If dirty or scroll rects are used, this call should be removed.
 //   m_d3dContext->DiscardView(m_d3dRenderTargetView.Get());

    // Discard the contents of the depth stencil.
 //   m_d3dContext->DiscardView(m_d3dDepthStencilView.Get());

    // If the device was removed either by a disconnect or a driver upgrade, we
    // must recreate all device resources.
    if (hr == DXGI_ERROR_DEVICE_REMOVED)
    {
        HandleDeviceLost();
    }
//     else
//     {
//         DX::ThrowIfFailed(hr);
//     }

    if (m_windowSizeChangeInProgress)
    {
        // A window size change has been initiated and the app has just completed presenting
        // the first frame with the new size. Notify the resize manager so we can short
        // circuit any resize animation and prevent unnecessary delays.
        //CoreWindowResizeManager::GetForCurrentView()->NotifyLayoutCompleted();
        m_windowSizeChangeInProgress = false;
    }
}

5）设备丢失的处理

这个就不贴代码了。

以上列出了MDxKernel模块的五个重点，完整的封装请查看代码。

其中多处地方参考微软官网和MSDN，在此表示感谢。

代码和例子的下载路径：http://pan.baidu.com/s/1ntFPXhv

联系方式：[email protected]