//--------------------------------------------------------------------------------------
// File: ScreenGrab.cpp
//
// Function for capturing a 2D texture and saving it to a file (aka a 'screenshot'
// when used on a Direct3D Render Target).
//
// Note these functions are useful as a light-weight runtime screen grabber. For
// full-featured texture capture, DDS writer, and texture processing pipeline,
// see the 'Texconv' sample and the 'DirectXTex' library.
//
// THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF
// ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO
// THE IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A
// PARTICULAR PURPOSE.
//
// Copyright (c) Microsoft Corporation. All rights reserved.
//
// http://go.microsoft.com/fwlink/?LinkId=248926
// http://go.microsoft.com/fwlink/?LinkId=248929
//--------------------------------------------------------------------------------------

// Does not capture 1D textures or 3D textures (volume maps)

// Does not capture mipmap chains, only the top-most texture level is saved

// For 2D array textures and cubemaps, it captures only the first image in the array

#include "pch.h"

#include "ScreenGrab.h"
#include "DirectXHelpers.h"

#include "dds.h"
#include "PlatformHelpers.h"
#include "LoaderHelpers.h"

using Microsoft::WRL::ComPtr;
using namespace DirectX;
using namespace DirectX::LoaderHelpers;

namespace
{
    //--------------------------------------------------------------------------------------
    HRESULT CaptureTexture(_In_ ID3D11DeviceContext* pContext,
        _In_ ID3D11Resource* pSource,
        D3D11_TEXTURE2D_DESC& desc,
        ComPtr<ID3D11Texture2D>& pStaging)
    {
        if (!pContext || !pSource)
            return E_INVALIDARG;

        D3D11_RESOURCE_DIMENSION resType = D3D11_RESOURCE_DIMENSION_UNKNOWN;
        pSource->GetType(&resType);

        if (resType != D3D11_RESOURCE_DIMENSION_TEXTURE2D)
            return HRESULT_FROM_WIN32(ERROR_NOT_SUPPORTED);

        ComPtr<ID3D11Texture2D> pTexture;
        HRESULT hr = pSource->QueryInterface(IID_GRAPHICS_PPV_ARGS(pTexture.GetAddressOf()));
        if (FAILED(hr))
            return hr;

        assert(pTexture);

        pTexture->GetDesc(&desc);

        ComPtr<ID3D11Device> d3dDevice;
        pContext->GetDevice(d3dDevice.GetAddressOf());

        if (desc.SampleDesc.Count > 1)
        {
            // MSAA content must be resolved before being copied to a staging texture
            desc.SampleDesc.Count = 1;
            desc.SampleDesc.Quality = 0;

            ComPtr<ID3D11Texture2D> pTemp;
            hr = d3dDevice->CreateTexture2D(&desc, 0, pTemp.GetAddressOf());
            if (FAILED(hr))
                return hr;

            assert(pTemp);

            DXGI_FORMAT fmt = EnsureNotTypeless(desc.Format);

            UINT support = 0;
            hr = d3dDevice->CheckFormatSupport(fmt, &support);
            if (FAILED(hr))
                return hr;

            if (!(support & D3D11_FORMAT_SUPPORT_MULTISAMPLE_RESOLVE))
                return E_FAIL;

            for (UINT item = 0; item < desc.ArraySize; ++item)
            {
                for (UINT level = 0; level < desc.MipLevels; ++level)
                {
                    UINT index = D3D11CalcSubresource(level, item, desc.MipLevels);
                    pContext->ResolveSubresource(pTemp.Get(), index, pSource, index, fmt);
                }
            }

            desc.BindFlags = 0;
            desc.MiscFlags &= D3D11_RESOURCE_MISC_TEXTURECUBE;
            desc.CPUAccessFlags = D3D11_CPU_ACCESS_READ;
            desc.Usage = D3D11_USAGE_STAGING;

            hr = d3dDevice->CreateTexture2D(&desc, 0, pStaging.ReleaseAndGetAddressOf());
            if (FAILED(hr))
                return hr;

            assert(pStaging);

            pContext->CopyResource(pStaging.Get(), pTemp.Get());
        }
        else if ((desc.Usage == D3D11_USAGE_STAGING) && (desc.CPUAccessFlags & D3D11_CPU_ACCESS_READ))
        {
            // Handle case where the source is already a staging texture we can use directly
            pStaging = pTexture;
        }
        else
        {
            // Otherwise, create a staging texture from the non-MSAA source
            desc.BindFlags = 0;
            desc.MiscFlags &= D3D11_RESOURCE_MISC_TEXTURECUBE;
            desc.CPUAccessFlags = D3D11_CPU_ACCESS_READ;
            desc.Usage = D3D11_USAGE_STAGING;

            hr = d3dDevice->CreateTexture2D(&desc, 0, pStaging.ReleaseAndGetAddressOf());
            if (FAILED(hr))
                return hr;

            assert(pStaging);

            pContext->CopyResource(pStaging.Get(), pSource);
        }

#if defined(_XBOX_ONE) && defined(_TITLE)

        if (d3dDevice->GetCreationFlags() & D3D11_CREATE_DEVICE_IMMEDIATE_CONTEXT_FAST_SEMANTICS)
        {
            ComPtr<ID3D11DeviceX> d3dDeviceX;
            hr = d3dDevice.As(&d3dDeviceX);
            if (FAILED(hr))
                return hr;

            ComPtr<ID3D11DeviceContextX> d3dContextX;
            hr = pContext->QueryInterface(IID_GRAPHICS_PPV_ARGS(d3dContextX.GetAddressOf()));
            if (FAILED(hr))
                return hr;

            UINT64 copyFence = d3dContextX->InsertFence(0);

            while (d3dDeviceX->IsFencePending(copyFence))
            {
                SwitchToThread();
            }
        }

#endif

        return S_OK;
    }
} // anonymous namespace


//--------------------------------------------------------------------------------------
_Use_decl_annotations_
HRESULT DirectX::SaveDDSTextureToFile( ID3D11DeviceContext* pContext,
                                       ID3D11Resource* pSource,
                                       const wchar_t* fileName )
{
    if ( !fileName )
        return E_INVALIDARG;

    D3D11_TEXTURE2D_DESC desc = {};
    ComPtr<ID3D11Texture2D> pStaging;
    HRESULT hr = CaptureTexture( pContext, pSource, desc, pStaging );
    if ( FAILED(hr) )
        return hr;

    // Create file
#if (_WIN32_WINNT >= _WIN32_WINNT_WIN8)
    ScopedHandle hFile( safe_handle( CreateFile2( fileName, GENERIC_WRITE | DELETE, 0, CREATE_ALWAYS, nullptr ) ) );
#else
    ScopedHandle hFile( safe_handle( CreateFileW( fileName, GENERIC_WRITE | DELETE, 0, nullptr, CREATE_ALWAYS, 0, nullptr ) ) );
#endif
    if ( !hFile )
        return HRESULT_FROM_WIN32( GetLastError() );

    auto_delete_file delonfail(hFile.get());

    // Setup header
    const size_t MAX_HEADER_SIZE = sizeof(uint32_t) + sizeof(DDS_HEADER) + sizeof(DDS_HEADER_DXT10);
    uint8_t fileHeader[ MAX_HEADER_SIZE ];

    *reinterpret_cast<uint32_t*>(&fileHeader[0]) = DDS_MAGIC;

    auto header = reinterpret_cast<DDS_HEADER*>( &fileHeader[0] + sizeof(uint32_t) );
    size_t headerSize = sizeof(uint32_t) + sizeof(DDS_HEADER);
    memset( header, 0, sizeof(DDS_HEADER) );
    header->size = sizeof( DDS_HEADER );
    header->flags = DDS_HEADER_FLAGS_TEXTURE | DDS_HEADER_FLAGS_MIPMAP;
    header->height = desc.Height;
    header->width = desc.Width;
    header->mipMapCount = 1;
    header->caps = DDS_SURFACE_FLAGS_TEXTURE;

    // Try to use a legacy .DDS pixel format for better tools support, otherwise fallback to 'DX10' header extension
    DDS_HEADER_DXT10* extHeader = nullptr;
    switch( desc.Format )
    {
    case DXGI_FORMAT_R8G8B8A8_UNORM:        memcpy_s( &header->ddspf, sizeof(header->ddspf), &DDSPF_A8B8G8R8, sizeof(DDS_PIXELFORMAT) );    break;
    case DXGI_FORMAT_R16G16_UNORM:          memcpy_s( &header->ddspf, sizeof(header->ddspf), &DDSPF_G16R16, sizeof(DDS_PIXELFORMAT) );      break;
    case DXGI_FORMAT_R8G8_UNORM:            memcpy_s( &header->ddspf, sizeof(header->ddspf), &DDSPF_A8L8, sizeof(DDS_PIXELFORMAT) );        break;
    case DXGI_FORMAT_R16_UNORM:             memcpy_s( &header->ddspf, sizeof(header->ddspf), &DDSPF_L16, sizeof(DDS_PIXELFORMAT) );         break;
    case DXGI_FORMAT_R8_UNORM:              memcpy_s( &header->ddspf, sizeof(header->ddspf), &DDSPF_L8, sizeof(DDS_PIXELFORMAT) );          break;
    case DXGI_FORMAT_A8_UNORM:              memcpy_s( &header->ddspf, sizeof(header->ddspf), &DDSPF_A8, sizeof(DDS_PIXELFORMAT) );          break;
    case DXGI_FORMAT_R8G8_B8G8_UNORM:       memcpy_s( &header->ddspf, sizeof(header->ddspf), &DDSPF_R8G8_B8G8, sizeof(DDS_PIXELFORMAT) );   break;
    case DXGI_FORMAT_G8R8_G8B8_UNORM:       memcpy_s( &header->ddspf, sizeof(header->ddspf), &DDSPF_G8R8_G8B8, sizeof(DDS_PIXELFORMAT) );   break;
    case DXGI_FORMAT_BC1_UNORM:             memcpy_s( &header->ddspf, sizeof(header->ddspf), &DDSPF_DXT1, sizeof(DDS_PIXELFORMAT) );        break;
    case DXGI_FORMAT_BC2_UNORM:             memcpy_s( &header->ddspf, sizeof(header->ddspf), &DDSPF_DXT3, sizeof(DDS_PIXELFORMAT) );        break;
    case DXGI_FORMAT_BC3_UNORM:             memcpy_s( &header->ddspf, sizeof(header->ddspf), &DDSPF_DXT5, sizeof(DDS_PIXELFORMAT) );        break;
    case DXGI_FORMAT_BC4_UNORM:             memcpy_s( &header->ddspf, sizeof(header->ddspf), &DDSPF_BC4_UNORM, sizeof(DDS_PIXELFORMAT) );   break;
    case DXGI_FORMAT_BC4_SNORM:             memcpy_s( &header->ddspf, sizeof(header->ddspf), &DDSPF_BC4_SNORM, sizeof(DDS_PIXELFORMAT) );   break;
    case DXGI_FORMAT_BC5_UNORM:             memcpy_s( &header->ddspf, sizeof(header->ddspf), &DDSPF_BC5_UNORM, sizeof(DDS_PIXELFORMAT) );   break;
    case DXGI_FORMAT_BC5_SNORM:             memcpy_s( &header->ddspf, sizeof(header->ddspf), &DDSPF_BC5_SNORM, sizeof(DDS_PIXELFORMAT) );   break;
    case DXGI_FORMAT_B5G6R5_UNORM:          memcpy_s( &header->ddspf, sizeof(header->ddspf), &DDSPF_R5G6B5, sizeof(DDS_PIXELFORMAT) );      break;
    case DXGI_FORMAT_B5G5R5A1_UNORM:        memcpy_s( &header->ddspf, sizeof(header->ddspf), &DDSPF_A1R5G5B5, sizeof(DDS_PIXELFORMAT) );    break;
    case DXGI_FORMAT_R8G8_SNORM:            memcpy_s( &header->ddspf, sizeof(header->ddspf), &DDSPF_V8U8, sizeof(DDS_PIXELFORMAT) );        break;
    case DXGI_FORMAT_R8G8B8A8_SNORM:        memcpy_s( &header->ddspf, sizeof(header->ddspf), &DDSPF_Q8W8V8U8, sizeof(DDS_PIXELFORMAT) );    break;
    case DXGI_FORMAT_R16G16_SNORM:          memcpy_s( &header->ddspf, sizeof(header->ddspf), &DDSPF_V16U16, sizeof(DDS_PIXELFORMAT) );      break;
    case DXGI_FORMAT_B8G8R8A8_UNORM:        memcpy_s( &header->ddspf, sizeof(header->ddspf), &DDSPF_A8R8G8B8, sizeof(DDS_PIXELFORMAT) );    break; // DXGI 1.1
    case DXGI_FORMAT_B8G8R8X8_UNORM:        memcpy_s( &header->ddspf, sizeof(header->ddspf), &DDSPF_X8R8G8B8, sizeof(DDS_PIXELFORMAT) );    break; // DXGI 1.1
    case DXGI_FORMAT_YUY2:                  memcpy_s( &header->ddspf, sizeof(header->ddspf), &DDSPF_YUY2, sizeof(DDS_PIXELFORMAT) );        break; // DXGI 1.2
    case DXGI_FORMAT_B4G4R4A4_UNORM:        memcpy_s( &header->ddspf, sizeof(header->ddspf), &DDSPF_A4R4G4B4, sizeof(DDS_PIXELFORMAT) );    break; // DXGI 1.2

    // Legacy D3DX formats using D3DFMT enum value as FourCC
    case DXGI_FORMAT_R32G32B32A32_FLOAT:    header->ddspf.size = sizeof(DDS_PIXELFORMAT); header->ddspf.flags = DDS_FOURCC; header->ddspf.fourCC = 116; break; // D3DFMT_A32B32G32R32F
    case DXGI_FORMAT_R16G16B16A16_FLOAT:    header->ddspf.size = sizeof(DDS_PIXELFORMAT); header->ddspf.flags = DDS_FOURCC; header->ddspf.fourCC = 113; break; // D3DFMT_A16B16G16R16F
    case DXGI_FORMAT_R16G16B16A16_UNORM:    header->ddspf.size = sizeof(DDS_PIXELFORMAT); header->ddspf.flags = DDS_FOURCC; header->ddspf.fourCC = 36;  break; // D3DFMT_A16B16G16R16
    case DXGI_FORMAT_R16G16B16A16_SNORM:    header->ddspf.size = sizeof(DDS_PIXELFORMAT); header->ddspf.flags = DDS_FOURCC; header->ddspf.fourCC = 110; break; // D3DFMT_Q16W16V16U16
    case DXGI_FORMAT_R32G32_FLOAT:          header->ddspf.size = sizeof(DDS_PIXELFORMAT); header->ddspf.flags = DDS_FOURCC; header->ddspf.fourCC = 115; break; // D3DFMT_G32R32F
    case DXGI_FORMAT_R16G16_FLOAT:          header->ddspf.size = sizeof(DDS_PIXELFORMAT); header->ddspf.flags = DDS_FOURCC; header->ddspf.fourCC = 112; break; // D3DFMT_G16R16F
    case DXGI_FORMAT_R32_FLOAT:             header->ddspf.size = sizeof(DDS_PIXELFORMAT); header->ddspf.flags = DDS_FOURCC; header->ddspf.fourCC = 114; break; // D3DFMT_R32F
    case DXGI_FORMAT_R16_FLOAT:             header->ddspf.size = sizeof(DDS_PIXELFORMAT); header->ddspf.flags = DDS_FOURCC; header->ddspf.fourCC = 111; break; // D3DFMT_R16F

    case DXGI_FORMAT_AI44:
    case DXGI_FORMAT_IA44:
    case DXGI_FORMAT_P8:
    case DXGI_FORMAT_A8P8:
        return HRESULT_FROM_WIN32( ERROR_NOT_SUPPORTED );

    default:
        memcpy_s( &header->ddspf, sizeof(header->ddspf), &DDSPF_DX10, sizeof(DDS_PIXELFORMAT) );

        headerSize += sizeof(DDS_HEADER_DXT10);
        extHeader = reinterpret_cast<DDS_HEADER_DXT10*>( reinterpret_cast<uint8_t*>(&fileHeader[0]) + sizeof(uint32_t) + sizeof(DDS_HEADER) );
        memset( extHeader, 0, sizeof(DDS_HEADER_DXT10) );
        extHeader->dxgiFormat = desc.Format;
        extHeader->resourceDimension = D3D11_RESOURCE_DIMENSION_TEXTURE2D;
        extHeader->arraySize = 1;
        break;
    }

    size_t rowPitch, slicePitch, rowCount;
    GetSurfaceInfo( desc.Width, desc.Height, desc.Format, &slicePitch, &rowPitch, &rowCount );

    if ( IsCompressed( desc.Format ) )
    {
        header->flags |= DDS_HEADER_FLAGS_LINEARSIZE;
        header->pitchOrLinearSize = static_cast<uint32_t>( slicePitch );
    }
    else
    {
        header->flags |= DDS_HEADER_FLAGS_PITCH;
        header->pitchOrLinearSize = static_cast<uint32_t>( rowPitch );
    }

    // Setup pixels
    std::unique_ptr<uint8_t[]> pixels( new (std::nothrow) uint8_t[ slicePitch ] );
    if (!pixels)
        return E_OUTOFMEMORY;

    D3D11_MAPPED_SUBRESOURCE mapped;
    hr = pContext->Map( pStaging.Get(), 0, D3D11_MAP_READ, 0, &mapped );
    if ( FAILED(hr) )
        return hr;

    auto sptr = reinterpret_cast<const uint8_t*>( mapped.pData );
    if ( !sptr )
    {
        pContext->Unmap( pStaging.Get(), 0 );
        return E_POINTER;
    }

    uint8_t* dptr = pixels.get();

    size_t msize = std::min<size_t>( rowPitch, mapped.RowPitch );
    for( size_t h = 0; h < rowCount; ++h )
    {
        memcpy_s( dptr, rowPitch, sptr, msize );
        sptr += mapped.RowPitch;
        dptr += rowPitch;
    }

    pContext->Unmap( pStaging.Get(), 0 );

    // Write header & pixels
    DWORD bytesWritten;
    if ( !WriteFile( hFile.get(), fileHeader, static_cast<DWORD>( headerSize ), &bytesWritten, nullptr ) )
        return HRESULT_FROM_WIN32( GetLastError() );

    if ( bytesWritten != headerSize )
        return E_FAIL;

    if ( !WriteFile( hFile.get(), pixels.get(), static_cast<DWORD>( slicePitch ), &bytesWritten, nullptr ) )
        return HRESULT_FROM_WIN32( GetLastError() );

    if ( bytesWritten != slicePitch )
        return E_FAIL;

    delonfail.clear();

    return S_OK;
}

//--------------------------------------------------------------------------------------
namespace DirectX
{
extern bool _IsWIC2();
extern IWICImagingFactory* _GetWIC();
}

_Use_decl_annotations_
HRESULT DirectX::SaveWICTextureToFile( ID3D11DeviceContext* pContext,
                                       ID3D11Resource* pSource,
                                       REFGUID guidContainerFormat, 
                                       const wchar_t* fileName,
                                       const GUID* targetFormat,
                                       std::function<void(IPropertyBag2*)> setCustomProps )
{
    if ( !fileName )
        return E_INVALIDARG;

    D3D11_TEXTURE2D_DESC desc = {};
    ComPtr<ID3D11Texture2D> pStaging;
    HRESULT hr = CaptureTexture( pContext, pSource, desc, pStaging );
    if ( FAILED(hr) )
        return hr;

    // Determine source format's WIC equivalent
    WICPixelFormatGUID pfGuid;
    bool sRGB = false;
    switch ( desc.Format )
    {
    case DXGI_FORMAT_R32G32B32A32_FLOAT:            pfGuid = GUID_WICPixelFormat128bppRGBAFloat; break;
    case DXGI_FORMAT_R16G16B16A16_FLOAT:            pfGuid = GUID_WICPixelFormat64bppRGBAHalf; break;
    case DXGI_FORMAT_R16G16B16A16_UNORM:            pfGuid = GUID_WICPixelFormat64bppRGBA; break;
    case DXGI_FORMAT_R10G10B10_XR_BIAS_A2_UNORM:    pfGuid = GUID_WICPixelFormat32bppRGBA1010102XR; break; // DXGI 1.1
    case DXGI_FORMAT_R10G10B10A2_UNORM:             pfGuid = GUID_WICPixelFormat32bppRGBA1010102; break;
    case DXGI_FORMAT_B5G5R5A1_UNORM:                pfGuid = GUID_WICPixelFormat16bppBGRA5551; break;
    case DXGI_FORMAT_B5G6R5_UNORM:                  pfGuid = GUID_WICPixelFormat16bppBGR565; break;
    case DXGI_FORMAT_R32_FLOAT:                     pfGuid = GUID_WICPixelFormat32bppGrayFloat; break;
    case DXGI_FORMAT_R16_FLOAT:                     pfGuid = GUID_WICPixelFormat16bppGrayHalf; break;
    case DXGI_FORMAT_R16_UNORM:                     pfGuid = GUID_WICPixelFormat16bppGray; break;
    case DXGI_FORMAT_R8_UNORM:                      pfGuid = GUID_WICPixelFormat8bppGray; break;
    case DXGI_FORMAT_A8_UNORM:                      pfGuid = GUID_WICPixelFormat8bppAlpha; break;

    case DXGI_FORMAT_R8G8B8A8_UNORM:
        pfGuid = GUID_WICPixelFormat32bppRGBA;
        break;

    case DXGI_FORMAT_R8G8B8A8_UNORM_SRGB:
        pfGuid = GUID_WICPixelFormat32bppRGBA;
        sRGB = true;
        break;

    case DXGI_FORMAT_B8G8R8A8_UNORM: // DXGI 1.1
        pfGuid = GUID_WICPixelFormat32bppBGRA;
        break;

    case DXGI_FORMAT_B8G8R8A8_UNORM_SRGB: // DXGI 1.1
        pfGuid = GUID_WICPixelFormat32bppBGRA;
        sRGB = true;
        break;

    case DXGI_FORMAT_B8G8R8X8_UNORM: // DXGI 1.1
        pfGuid = GUID_WICPixelFormat32bppBGR;
        break; 

    case DXGI_FORMAT_B8G8R8X8_UNORM_SRGB: // DXGI 1.1
        pfGuid = GUID_WICPixelFormat32bppBGR;
        sRGB = true;
        break; 

    default:
        return HRESULT_FROM_WIN32( ERROR_NOT_SUPPORTED );
    }

    auto pWIC = _GetWIC();
    if ( !pWIC )
        return E_NOINTERFACE;

    ComPtr<IWICStream> stream;
    hr = pWIC->CreateStream( stream.GetAddressOf() );
    if ( FAILED(hr) )
        return hr;

    hr = stream->InitializeFromFilename( fileName, GENERIC_WRITE );
    if ( FAILED(hr) )
        return hr;

    auto_delete_file_wic delonfail(stream, fileName);

    ComPtr<IWICBitmapEncoder> encoder;
    hr = pWIC->CreateEncoder( guidContainerFormat, 0, encoder.GetAddressOf() );
    if ( FAILED(hr) )
        return hr;

    hr = encoder->Initialize( stream.Get(), WICBitmapEncoderNoCache );
    if ( FAILED(hr) )
        return hr;

    ComPtr<IWICBitmapFrameEncode> frame;
    ComPtr<IPropertyBag2> props;
    hr = encoder->CreateNewFrame( frame.GetAddressOf(), props.GetAddressOf() );
    if ( FAILED(hr) )
        return hr;

    if ( targetFormat && memcmp( &guidContainerFormat, &GUID_ContainerFormatBmp, sizeof(WICPixelFormatGUID) ) == 0 && _IsWIC2() )
    {
        // Opt-in to the WIC2 support for writing 32-bit Windows BMP files with an alpha channel
        PROPBAG2 option = {};
        option.pstrName = const_cast<wchar_t*>(L"EnableV5Header32bppBGRA");

        VARIANT varValue;    
        varValue.vt = VT_BOOL;
        varValue.boolVal = VARIANT_TRUE;      
        (void)props->Write( 1, &option, &varValue ); 
    }

    if ( setCustomProps )
    {
        setCustomProps( props.Get() );
    }

    hr = frame->Initialize( props.Get() );
    if ( FAILED(hr) )
        return hr;

    hr = frame->SetSize( desc.Width , desc.Height );
    if ( FAILED(hr) )
        return hr;

    hr = frame->SetResolution( 72, 72 );
    if ( FAILED(hr) )
        return hr;

    // Pick a target format
    WICPixelFormatGUID targetGuid;
    if ( targetFormat )
    {
        targetGuid = *targetFormat;
    }
    else
    {
        // Screenshots don’t typically include the alpha channel of the render target
        switch ( desc.Format )
        {
#if (_WIN32_WINNT >= _WIN32_WINNT_WIN8) || defined(_WIN7_PLATFORM_UPDATE)
        case DXGI_FORMAT_R32G32B32A32_FLOAT:            
        case DXGI_FORMAT_R16G16B16A16_FLOAT:
            if ( _IsWIC2() )
            {
                targetGuid = GUID_WICPixelFormat96bppRGBFloat;
            }
            else
            {
                targetGuid = GUID_WICPixelFormat24bppBGR;
            }
            break;
#endif

        case DXGI_FORMAT_R16G16B16A16_UNORM: targetGuid = GUID_WICPixelFormat48bppBGR; break;
        case DXGI_FORMAT_B5G5R5A1_UNORM:     targetGuid = GUID_WICPixelFormat16bppBGR555; break;
        case DXGI_FORMAT_B5G6R5_UNORM:       targetGuid = GUID_WICPixelFormat16bppBGR565; break;

        case DXGI_FORMAT_R32_FLOAT:
        case DXGI_FORMAT_R16_FLOAT:
        case DXGI_FORMAT_R16_UNORM:
        case DXGI_FORMAT_R8_UNORM:
        case DXGI_FORMAT_A8_UNORM:
            targetGuid = GUID_WICPixelFormat8bppGray;
            break;

        default:
            targetGuid = GUID_WICPixelFormat24bppBGR;
            break;
        }
    }

    hr = frame->SetPixelFormat( &targetGuid );
    if ( FAILED(hr) )
        return hr;

    if ( targetFormat && memcmp( targetFormat, &targetGuid, sizeof(WICPixelFormatGUID) ) != 0 )
    {
        // Requested output pixel format is not supported by the WIC codec
        return E_FAIL;
    }

    // Encode WIC metadata
    ComPtr<IWICMetadataQueryWriter> metawriter;
    if ( SUCCEEDED( frame->GetMetadataQueryWriter( metawriter.GetAddressOf() ) ) )
    {
        PROPVARIANT value;
        PropVariantInit( &value );

        value.vt = VT_LPSTR;
        value.pszVal = const_cast<char*>("DirectXTK");

        if ( memcmp( &guidContainerFormat, &GUID_ContainerFormatPng, sizeof(GUID) ) == 0 )
        {
            // Set Software name
            (void)metawriter->SetMetadataByName( L"/tEXt/{str=Software}", &value );

            // Set sRGB chunk
            if (sRGB)
            {
                value.vt = VT_UI1;
                value.bVal = 0;
                (void)metawriter->SetMetadataByName(L"/sRGB/RenderingIntent", &value);
            }
            else
            {
                // add gAMA chunk with gamma 1.0
                value.vt = VT_UI4;
                value.uintVal = 100000; // gama value * 100,000 -- i.e. gamma 1.0
                (void)metawriter->SetMetadataByName(L"/gAMA/ImageGamma", &value);

                // remove sRGB chunk which is added by default.
                (void)metawriter->RemoveMetadataByName(L"/sRGB/RenderingIntent");
            }
        }
#if defined(_XBOX_ONE) && defined(_TITLE)
        else if ( memcmp( &guidContainerFormat, &GUID_ContainerFormatJpeg, sizeof(GUID) ) == 0 )
        {
            // Set Software name
            (void)metawriter->SetMetadataByName( L"/app1/ifd/{ushort=305}", &value );

            if ( sRGB )
            {
                // Set EXIF Colorspace of sRGB
                value.vt = VT_UI2;
                value.uiVal = 1;
                (void)metawriter->SetMetadataByName( L"/app1/ifd/exif/{ushort=40961}", &value );
            }
        }
        else if ( memcmp( &guidContainerFormat, &GUID_ContainerFormatTiff, sizeof(GUID) ) == 0 )
        {
            // Set Software name
            (void)metawriter->SetMetadataByName( L"/ifd/{ushort=305}", &value );

            if ( sRGB )
            {
                // Set EXIF Colorspace of sRGB
                value.vt = VT_UI2;
                value.uiVal = 1;
                (void)metawriter->SetMetadataByName( L"/ifd/exif/{ushort=40961}", &value );
            }
        }
#else
        else
        {
            // Set Software name
            (void)metawriter->SetMetadataByName( L"System.ApplicationName", &value );

            if ( sRGB )
            {
                // Set EXIF Colorspace of sRGB
                value.vt = VT_UI2;
                value.uiVal = 1;
                (void)metawriter->SetMetadataByName( L"System.Image.ColorSpace", &value );
            }
        }
#endif
    }

    D3D11_MAPPED_SUBRESOURCE mapped;
    hr = pContext->Map( pStaging.Get(), 0, D3D11_MAP_READ, 0, &mapped );
    if ( FAILED(hr) )
        return hr;

    if ( memcmp( &targetGuid, &pfGuid, sizeof(WICPixelFormatGUID) ) != 0 )
    {
        // Conversion required to write
        ComPtr<IWICBitmap> source;
        hr = pWIC->CreateBitmapFromMemory( desc.Width, desc.Height, pfGuid,
                                           mapped.RowPitch, mapped.RowPitch * desc.Height,
                                           reinterpret_cast<BYTE*>( mapped.pData ), source.GetAddressOf() );
        if ( FAILED(hr) )
        {
            pContext->Unmap( pStaging.Get(), 0 );
            return hr;
        }

        ComPtr<IWICFormatConverter> FC;
        hr = pWIC->CreateFormatConverter( FC.GetAddressOf() );
        if ( FAILED(hr) )
        {
            pContext->Unmap( pStaging.Get(), 0 );
            return hr;
        }

        BOOL canConvert = FALSE;
        hr = FC->CanConvert( pfGuid, targetGuid, &canConvert );
        if ( FAILED(hr) || !canConvert )
        {
            return E_UNEXPECTED;
        }

        hr = FC->Initialize( source.Get(), targetGuid, WICBitmapDitherTypeNone, nullptr, 0, WICBitmapPaletteTypeMedianCut );
        if ( FAILED(hr) )
        {
            pContext->Unmap( pStaging.Get(), 0 );
            return hr;
        }

        WICRect rect = { 0, 0, static_cast<INT>( desc.Width ), static_cast<INT>( desc.Height ) };
        hr = frame->WriteSource( FC.Get(), &rect );
        if ( FAILED(hr) )
        {
            pContext->Unmap( pStaging.Get(), 0 );
            return hr;
        }
    }
    else
    {
        // No conversion required
        hr = frame->WritePixels( desc.Height, mapped.RowPitch, mapped.RowPitch * desc.Height, reinterpret_cast<BYTE*>( mapped.pData ) );
        if ( FAILED(hr) )
            return hr;
    }

    pContext->Unmap( pStaging.Get(), 0 );

    hr = frame->Commit();
    if ( FAILED(hr) )
        return hr;

    hr = encoder->Commit();
    if ( FAILED(hr) )
        return hr;

    delonfail.clear();

    return S_OK;
}