可以使用 Windows 图像处理组件 API 从文件初始化 纹理 。 若要加载纹理,必须创建纹理和纹理视图。 本主题演示如何使用 Windows 图像处理组件 (WIC) 分别创建纹理和视图。

本主题适用于创建为简单 2D 纹理的图像。 对于更复杂的资源,请使用 DDS 。 有关功能齐全的 DDS 文件读取器、编写器和纹理处理管道,请参阅 DirectXTex DirectXTK

在本主题末尾,你将找到完整的示例代码。 本主题介绍创建纹理和视图的示例代码部分。

分别初始化纹理和视图。

  • 调用 CoCreateInstance 以 ( IWICImagingFactory ) 创建映像工厂接口。

  • 调用 IWICImagingFactory::CreateDecoderFromFilename 方法以从图像文件名创建 IWICBitmapDecoder 对象。

  • 调用 IWICBitmapDecoder::GetFrame 方法以检索图像帧的 IWICBitmapFrameDecode 接口。

  • 调用 IWICBitmapSource::GetPixelFormat 方法 ( IWICBitmapFrameDecode 接口继承自 IWICBitmapSource ) 以获取图像的像素格式。

  • 根据下表将像素格式转换为 DXGI_FORMAT 类型:

    WIC 像素格式 等效 DXGI_FORMAT

    * 单通道 DXGI 格式都是红色通道,因此需要 HLSL 着色器重排(如 .rrr)将这些格式呈现为灰度。

  • 调用 IWICBitmapSource::CopyPixels 方法将图像像素复制到缓冲区中。 使用 DXGI_FORMAT 类型和缓冲区初始化 2D 纹理资源和着色器资源视图对象。

  • 调用 ID3D11Device::CreateTexture2D 方法以初始化 2D 纹理资源。 在此调用中,传递 ID3D11Texture2D 接口指针的地址。

        // Create texture
        D3D11_TEXTURE2D_DESC desc;
        desc.Width = width;
        desc.Height = height;
        desc.MipLevels = 1;
        desc.ArraySize = 1;
        desc.Format = format;
        desc.SampleDesc.Count = 1;
        desc.SampleDesc.Quality = 0;
        desc.Usage = D3D11_USAGE_DEFAULT;
        desc.BindFlags = D3D11_BIND_SHADER_RESOURCE;
        desc.CPUAccessFlags = 0;
        desc.MiscFlags = 0;
        D3D11_SUBRESOURCE_DATA initData;
        initData.pSysMem = temp.get();
        initData.SysMemPitch = static_cast<UINT>( rowPitch );
        initData.SysMemSlicePitch = static_cast<UINT>( imageSize );
        ID3D11Texture2D* tex = nullptr;
        hr = d3dDevice->CreateTexture2D( &desc, &initData, &tex );
    
  • 调用 ID3D11Device::CreateShaderResourceView 方法以初始化 shader-resource-view 对象。 传递 NULL 着色器资源视图说明 (以获取具有默认参数的视图) 或非 NULL 着色器资源视图说明 (以获取具有非默认参数的视图) 。 如有必要,通过调用 ID3D11Resource::GetType 来确定纹理类型,并通过调用 ID3D11ShaderResourceView::GetDesc 确定纹理格式。

        if ( SUCCEEDED(hr) && tex != 0 )
            if (textureView != 0)
                D3D11_SHADER_RESOURCE_VIEW_DESC SRVDesc;
                memset( &SRVDesc, 0, sizeof( SRVDesc ) );
                SRVDesc.Format = format;
                SRVDesc.ViewDimension = D3D11_SRV_DIMENSION_TEXTURE2D;
                SRVDesc.Texture2D.MipLevels = 1;
                hr = d3dDevice->CreateShaderResourceView( tex, &SRVDesc, textureView );
                if ( FAILED(hr) )
                    tex->Release();
                    return hr;
    

    前面的示例代码假定 d3dDevice 变量是先前已初始化的 ID3D11Device 对象。

    下面是可以包含在应用中的标头。 标头声明 CreateWICTextureFromFileCreateWICTextureFromMemory 函数,你可以在应用中调用这些函数以从文件和内存创建纹理。

    //--------------------------------------------------------------------------------------
    // File: WICTextureLoader.h
    // Function for loading a WIC image and creating a Direct3D 11 runtime texture for it
    // (auto-generating mipmaps if possible)
    // Note: Assumes application has already called CoInitializeEx
    // Warning: CreateWICTexture* functions are not thread-safe if given a d3dContext instance for
    //          auto-gen mipmap support.
    // Note these functions are useful for images created as simple 2D textures. For
    // more complex resources, DDSTextureLoader is an excellent light-weight runtime loader.
    // For a full-featured DDS file reader, 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.
    // https://go.microsoft.com/fwlink/?LinkId=248926
    // https://go.microsoft.com/fwlink/?LinkId=248929
    //--------------------------------------------------------------------------------------
    #ifdef _MSC_VER
    #pragma once
    #endif
    #include <d3d11.h>
    #pragma warning(push)
    #pragma warning(disable : 4005)
    #include <stdint.h>
    #pragma warning(pop)
    HRESULT CreateWICTextureFromMemory( _In_ ID3D11Device* d3dDevice,
                                        _In_opt_ ID3D11DeviceContext* d3dContext,
                                        _In_bytecount_(wicDataSize) const uint8_t* wicData,
                                        _In_ size_t wicDataSize,
                                        _Out_opt_ ID3D11Resource** texture,
                                        _Out_opt_ ID3D11ShaderResourceView** textureView,
                                        _In_ size_t maxsize = 0
    HRESULT CreateWICTextureFromFile( _In_ ID3D11Device* d3dDevice,
                                      _In_opt_ ID3D11DeviceContext* d3dContext,
                                      _In_z_ const wchar_t* szFileName,
                                      _Out_opt_ ID3D11Resource** texture,
                                      _Out_opt_ ID3D11ShaderResourceView** textureView,
                                      _In_ size_t maxsize = 0
    

    下面是可在应用中使用的完整源。 源实现 CreateWICTextureFromFileCreateWICTextureFromMemory 函数。

    //--------------------------------------------------------------------------------------
    // File: WICTextureLoader.cpp
    // Function for loading a WIC image and creating a Direct3D 11 runtime texture for it
    // (auto-generating mipmaps if possible)
    // Note: Assumes application has already called CoInitializeEx
    // Warning: CreateWICTexture* functions are not thread-safe if given a d3dContext instance for
    //          auto-gen mipmap support.
    // Note these functions are useful for images created as simple 2D textures. For
    // more complex resources, DDSTextureLoader is an excellent light-weight runtime loader.
    // For a full-featured DDS file reader, 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.
    // https://go.microsoft.com/fwlink/?LinkId=248926
    // https://go.microsoft.com/fwlink/?LinkId=248929
    //--------------------------------------------------------------------------------------
    // We could load multi-frame images (TIFF/GIF) into a texture array.
    // For now, we just load the first frame (note: DirectXTex supports multi-frame images)
    #include <dxgiformat.h>
    #include <assert.h>
    #pragma warning(push)
    #pragma warning(disable : 4005)
    #include <wincodec.h>
    #pragma warning(pop)
    #include <memory>
    #include "WICTextureLoader.h"
    #if (_WIN32_WINNT >= 0x0602 /*_WIN32_WINNT_WIN8*/) && !defined(DXGI_1_2_FORMATS)
    #define DXGI_1_2_FORMATS
    #endif
    //---------------------------------------------------------------------------------
    template<class T> class ScopedObject
    public:
        explicit ScopedObject( T *p = 0 ) : _pointer(p) {}
        ~ScopedObject()
            if ( _pointer )
                _pointer->Release();
                _pointer = nullptr;
        bool IsNull() const { return (!_pointer); }
        T& operator*() { return *_pointer; }
        T* operator->() { return _pointer; }
        T** operator&() { return &_pointer; }
        void Reset(T *p = 0) { if ( _pointer ) { _pointer->Release(); } _pointer = p; }
        T* Get() const { return _pointer; }
    private:
        ScopedObject(const ScopedObject&);
        ScopedObject& operator=(const ScopedObject&);
        T* _pointer;
    //-------------------------------------------------------------------------------------
    // WIC Pixel Format Translation Data
    //-------------------------------------------------------------------------------------
    struct WICTranslate
        GUID                wic;
        DXGI_FORMAT         format;
    static WICTranslate g_WICFormats[] = 
        { GUID_WICPixelFormat128bppRGBAFloat,       DXGI_FORMAT_R32G32B32A32_FLOAT },
        { GUID_WICPixelFormat64bppRGBAHalf,         DXGI_FORMAT_R16G16B16A16_FLOAT },
        { GUID_WICPixelFormat64bppRGBA,             DXGI_FORMAT_R16G16B16A16_UNORM },
        { GUID_WICPixelFormat32bppRGBA,             DXGI_FORMAT_R8G8B8A8_UNORM },
        { GUID_WICPixelFormat32bppBGRA,             DXGI_FORMAT_B8G8R8A8_UNORM }, // DXGI 1.1
        { GUID_WICPixelFormat32bppBGR,              DXGI_FORMAT_B8G8R8X8_UNORM }, // DXGI 1.1
        { GUID_WICPixelFormat32bppRGBA1010102XR,    DXGI_FORMAT_R10G10B10_XR_BIAS_A2_UNORM }, // DXGI 1.1
        { GUID_WICPixelFormat32bppRGBA1010102,      DXGI_FORMAT_R10G10B10A2_UNORM },
        { GUID_WICPixelFormat32bppRGBE,             DXGI_FORMAT_R9G9B9E5_SHAREDEXP },
    #ifdef DXGI_1_2_FORMATS
        { GUID_WICPixelFormat16bppBGRA5551,         DXGI_FORMAT_B5G5R5A1_UNORM },
        { GUID_WICPixelFormat16bppBGR565,           DXGI_FORMAT_B5G6R5_UNORM },
    #endif // DXGI_1_2_FORMATS
        { GUID_WICPixelFormat32bppGrayFloat,        DXGI_FORMAT_R32_FLOAT },
        { GUID_WICPixelFormat16bppGrayHalf,         DXGI_FORMAT_R16_FLOAT },
        { GUID_WICPixelFormat16bppGray,             DXGI_FORMAT_R16_UNORM },
        { GUID_WICPixelFormat8bppGray,              DXGI_FORMAT_R8_UNORM },
        { GUID_WICPixelFormat8bppAlpha,             DXGI_FORMAT_A8_UNORM },
    #if (_WIN32_WINNT >= 0x0602 /*_WIN32_WINNT_WIN8*/)
        { GUID_WICPixelFormat96bppRGBFloat,         DXGI_FORMAT_R32G32B32_FLOAT },
    #endif
    //-------------------------------------------------------------------------------------
    // WIC Pixel Format nearest conversion table
    //-------------------------------------------------------------------------------------
    struct WICConvert
        GUID        source;
        GUID        target;
    static WICConvert g_WICConvert[] = 
        // Note target GUID in this conversion table must be one of those directly supported formats (above).
        { GUID_WICPixelFormatBlackWhite,            GUID_WICPixelFormat8bppGray }, // DXGI_FORMAT_R8_UNORM
        { GUID_WICPixelFormat1bppIndexed,           GUID_WICPixelFormat32bppRGBA }, // DXGI_FORMAT_R8G8B8A8_UNORM 
        { GUID_WICPixelFormat2bppIndexed,           GUID_WICPixelFormat32bppRGBA }, // DXGI_FORMAT_R8G8B8A8_UNORM 
        { GUID_WICPixelFormat4bppIndexed,           GUID_WICPixelFormat32bppRGBA }, // DXGI_FORMAT_R8G8B8A8_UNORM 
        { GUID_WICPixelFormat8bppIndexed,           GUID_WICPixelFormat32bppRGBA }, // DXGI_FORMAT_R8G8B8A8_UNORM 
        { GUID_WICPixelFormat2bppGray,              GUID_WICPixelFormat8bppGray }, // DXGI_FORMAT_R8_UNORM 
        { GUID_WICPixelFormat4bppGray,              GUID_WICPixelFormat8bppGray }, // DXGI_FORMAT_R8_UNORM 
        { GUID_WICPixelFormat16bppGrayFixedPoint,   GUID_WICPixelFormat16bppGrayHalf }, // DXGI_FORMAT_R16_FLOAT 
        { GUID_WICPixelFormat32bppGrayFixedPoint,   GUID_WICPixelFormat32bppGrayFloat }, // DXGI_FORMAT_R32_FLOAT 
    #ifdef DXGI_1_2_FORMATS
        { GUID_WICPixelFormat16bppBGR555,           GUID_WICPixelFormat16bppBGRA5551 }, // DXGI_FORMAT_B5G5R5A1_UNORM
    #else
        { GUID_WICPixelFormat16bppBGR555,           GUID_WICPixelFormat32bppRGBA }, // DXGI_FORMAT_R8G8B8A8_UNORM
        { GUID_WICPixelFormat16bppBGRA5551,         GUID_WICPixelFormat32bppRGBA }, // DXGI_FORMAT_R8G8B8A8_UNORM
        { GUID_WICPixelFormat16bppBGR565,           GUID_WICPixelFormat32bppRGBA }, // DXGI_FORMAT_R8G8B8A8_UNORM
    #endif // DXGI_1_2_FORMATS
        { GUID_WICPixelFormat32bppBGR101010,        GUID_WICPixelFormat32bppRGBA1010102 }, // DXGI_FORMAT_R10G10B10A2_UNORM
        { GUID_WICPixelFormat24bppBGR,              GUID_WICPixelFormat32bppRGBA }, // DXGI_FORMAT_R8G8B8A8_UNORM 
        { GUID_WICPixelFormat24bppRGB,              GUID_WICPixelFormat32bppRGBA }, // DXGI_FORMAT_R8G8B8A8_UNORM 
        { GUID_WICPixelFormat32bppPBGRA,            GUID_WICPixelFormat32bppRGBA }, // DXGI_FORMAT_R8G8B8A8_UNORM 
        { GUID_WICPixelFormat32bppPRGBA,            GUID_WICPixelFormat32bppRGBA }, // DXGI_FORMAT_R8G8B8A8_UNORM 
        { GUID_WICPixelFormat48bppRGB,              GUID_WICPixelFormat64bppRGBA }, // DXGI_FORMAT_R16G16B16A16_UNORM
        { GUID_WICPixelFormat48bppBGR,              GUID_WICPixelFormat64bppRGBA }, // DXGI_FORMAT_R16G16B16A16_UNORM
        { GUID_WICPixelFormat64bppBGRA,             GUID_WICPixelFormat64bppRGBA }, // DXGI_FORMAT_R16G16B16A16_UNORM
        { GUID_WICPixelFormat64bppPRGBA,            GUID_WICPixelFormat64bppRGBA }, // DXGI_FORMAT_R16G16B16A16_UNORM
        { GUID_WICPixelFormat64bppPBGRA,            GUID_WICPixelFormat64bppRGBA }, // DXGI_FORMAT_R16G16B16A16_UNORM
        { GUID_WICPixelFormat48bppRGBFixedPoint,    GUID_WICPixelFormat64bppRGBAHalf }, // DXGI_FORMAT_R16G16B16A16_FLOAT 
        { GUID_WICPixelFormat48bppBGRFixedPoint,    GUID_WICPixelFormat64bppRGBAHalf }, // DXGI_FORMAT_R16G16B16A16_FLOAT 
        { GUID_WICPixelFormat64bppRGBAFixedPoint,   GUID_WICPixelFormat64bppRGBAHalf }, // DXGI_FORMAT_R16G16B16A16_FLOAT 
        { GUID_WICPixelFormat64bppBGRAFixedPoint,   GUID_WICPixelFormat64bppRGBAHalf }, // DXGI_FORMAT_R16G16B16A16_FLOAT 
        { GUID_WICPixelFormat64bppRGBFixedPoint,    GUID_WICPixelFormat64bppRGBAHalf }, // DXGI_FORMAT_R16G16B16A16_FLOAT 
        { GUID_WICPixelFormat64bppRGBHalf,          GUID_WICPixelFormat64bppRGBAHalf }, // DXGI_FORMAT_R16G16B16A16_FLOAT 
        { GUID_WICPixelFormat48bppRGBHalf,          GUID_WICPixelFormat64bppRGBAHalf }, // DXGI_FORMAT_R16G16B16A16_FLOAT 
        { GUID_WICPixelFormat96bppRGBFixedPoint,    GUID_WICPixelFormat128bppRGBAFloat }, // DXGI_FORMAT_R32G32B32A32_FLOAT 
        { GUID_WICPixelFormat128bppPRGBAFloat,      GUID_WICPixelFormat128bppRGBAFloat }, // DXGI_FORMAT_R32G32B32A32_FLOAT 
        { GUID_WICPixelFormat128bppRGBFloat,        GUID_WICPixelFormat128bppRGBAFloat }, // DXGI_FORMAT_R32G32B32A32_FLOAT 
        { GUID_WICPixelFormat128bppRGBAFixedPoint,  GUID_WICPixelFormat128bppRGBAFloat }, // DXGI_FORMAT_R32G32B32A32_FLOAT 
        { GUID_WICPixelFormat128bppRGBFixedPoint,   GUID_WICPixelFormat128bppRGBAFloat }, // DXGI_FORMAT_R32G32B32A32_FLOAT 
        { GUID_WICPixelFormat32bppCMYK,             GUID_WICPixelFormat32bppRGBA }, // DXGI_FORMAT_R8G8B8A8_UNORM 
        { GUID_WICPixelFormat64bppCMYK,             GUID_WICPixelFormat64bppRGBA }, // DXGI_FORMAT_R16G16B16A16_UNORM
        { GUID_WICPixelFormat40bppCMYKAlpha,        GUID_WICPixelFormat64bppRGBA }, // DXGI_FORMAT_R16G16B16A16_UNORM
        { GUID_WICPixelFormat80bppCMYKAlpha,        GUID_WICPixelFormat64bppRGBA }, // DXGI_FORMAT_R16G16B16A16_UNORM
    #if (_WIN32_WINNT >= 0x0602 /*_WIN32_WINNT_WIN8*/)
        { GUID_WICPixelFormat32bppRGB,              GUID_WICPixelFormat32bppRGBA }, // DXGI_FORMAT_R8G8B8A8_UNORM
        { GUID_WICPixelFormat64bppRGB,              GUID_WICPixelFormat64bppRGBA }, // DXGI_FORMAT_R16G16B16A16_UNORM
        { GUID_WICPixelFormat64bppPRGBAHalf,        GUID_WICPixelFormat64bppRGBAHalf }, // DXGI_FORMAT_R16G16B16A16_FLOAT 
    #endif
        // We don't support n-channel formats
    //--------------------------------------------------------------------------------------
    static IWICImagingFactory* _GetWIC()
        static IWICImagingFactory* s_Factory = nullptr;
        if ( s_Factory )
            return s_Factory;
        HRESULT hr = CoCreateInstance(
            CLSID_WICImagingFactory,
            nullptr,
            CLSCTX_INPROC_SERVER,
            __uuidof(IWICImagingFactory),
            (LPVOID*)&s_Factory
        if ( FAILED(hr) )
            s_Factory = nullptr;
            return nullptr;
        return s_Factory;
    //---------------------------------------------------------------------------------
    static DXGI_FORMAT _WICToDXGI( const GUID& guid )
        for( size_t i=0; i < _countof(g_WICFormats); ++i )
            if ( memcmp( &g_WICFormats[i].wic, &guid, sizeof(GUID) ) == 0 )
                return g_WICFormats[i].format;
        return DXGI_FORMAT_UNKNOWN;
    //---------------------------------------------------------------------------------
    static size_t _WICBitsPerPixel( REFGUID targetGuid )
        IWICImagingFactory* pWIC = _GetWIC();
        if ( !pWIC )
            return 0;
        ScopedObject<IWICComponentInfo> cinfo;
        if ( FAILED( pWIC->CreateComponentInfo( targetGuid, &cinfo ) ) )
            return 0;
        WICComponentType type;
        if ( FAILED( cinfo->GetComponentType( &type ) ) )
            return 0;
        if ( type != WICPixelFormat )
            return 0;
        ScopedObject<IWICPixelFormatInfo> pfinfo;
        if ( FAILED( cinfo->QueryInterface( __uuidof(IWICPixelFormatInfo), reinterpret_cast<void**>( &pfinfo )  ) ) )
            return 0;
        UINT bpp;
        if ( FAILED( pfinfo->GetBitsPerPixel( &bpp ) ) )
            return 0;
        return bpp;
    //---------------------------------------------------------------------------------
    static HRESULT CreateTextureFromWIC( _In_ ID3D11Device* d3dDevice,
                                         _In_opt_ ID3D11DeviceContext* d3dContext,
                                         _In_ IWICBitmapFrameDecode *frame,
                                         _Out_opt_ ID3D11Resource** texture,
                                         _Out_opt_ ID3D11ShaderResourceView** textureView,
                                         _In_ size_t maxsize )
        UINT width, height;
        HRESULT hr = frame->GetSize( &width, &height );
        if ( FAILED(hr) )
            return hr;
        assert( width > 0 && height > 0 );
        if ( !maxsize )
            // This is a bit conservative because the hardware could support larger textures than
            // the Feature Level defined minimums, but doing it this way is much easier and more
            // performant for WIC than the 'fail and retry' model used by DDSTextureLoader
            switch( d3dDevice->GetFeatureLevel() )
                case D3D_FEATURE_LEVEL_9_1:
                case D3D_FEATURE_LEVEL_9_2:
                    maxsize = 2048 /*D3D_FL9_1_REQ_TEXTURE2D_U_OR_V_DIMENSION*/;
                    break;
                case D3D_FEATURE_LEVEL_9_3:
                    maxsize = 4096 /*D3D_FL9_3_REQ_TEXTURE2D_U_OR_V_DIMENSION*/;
                    break;
                case D3D_FEATURE_LEVEL_10_0:
                case D3D_FEATURE_LEVEL_10_1:
                    maxsize = 8192 /*D3D10_REQ_TEXTURE2D_U_OR_V_DIMENSION*/;
                    break;
                default:
                    maxsize = D3D11_REQ_TEXTURE2D_U_OR_V_DIMENSION;
                    break;
        assert( maxsize > 0 );
        UINT twidth, theight;
        if ( width > maxsize || height > maxsize )
            float ar = static_cast<float>(height) / static_cast<float>(width);
            if ( width > height )
                twidth = static_cast<UINT>( maxsize );
                theight = static_cast<UINT>( static_cast<float>(maxsize) * ar );
                theight = static_cast<UINT>( maxsize );
                twidth = static_cast<UINT>( static_cast<float>(maxsize) / ar );
            assert( twidth <= maxsize && theight <= maxsize );
            twidth = width;
            theight = height;
        // Determine format
        WICPixelFormatGUID pixelFormat;
        hr = frame->GetPixelFormat( &pixelFormat );
        if ( FAILED(hr) )
            return hr;
        WICPixelFormatGUID convertGUID;
        memcpy( &convertGUID, &pixelFormat, sizeof(WICPixelFormatGUID) );
        size_t bpp = 0;
        DXGI_FORMAT format = _WICToDXGI( pixelFormat );
        if ( format == DXGI_FORMAT_UNKNOWN )
            for( size_t i=0; i < _countof(g_WICConvert); ++i )
                if ( memcmp( &g_WICConvert[i].source, &pixelFormat, sizeof(WICPixelFormatGUID) ) == 0 )
                    memcpy( &convertGUID, &g_WICConvert[i].target, sizeof(WICPixelFormatGUID) );
                    format = _WICToDXGI( g_WICConvert[i].target );
                    assert( format != DXGI_FORMAT_UNKNOWN );
                    bpp = _WICBitsPerPixel( convertGUID );
                    break;
            if ( format == DXGI_FORMAT_UNKNOWN )
                return HRESULT_FROM_WIN32( ERROR_NOT_SUPPORTED );
            bpp = _WICBitsPerPixel( pixelFormat );
        if ( !bpp )
            return E_FAIL;
        // Verify our target format is supported by the current device
        // (handles WDDM 1.0 or WDDM 1.1 device driver cases as well as DirectX 11.0 Runtime without 16bpp format support)
        UINT support = 0;
        hr = d3dDevice->CheckFormatSupport( format, &support );
        if ( FAILED(hr) || !(support & D3D11_FORMAT_SUPPORT_TEXTURE2D) )
            // Fallback to RGBA 32-bit format which is supported by all devices
            memcpy( &convertGUID, &GUID_WICPixelFormat32bppRGBA, sizeof(WICPixelFormatGUID) );
            format = DXGI_FORMAT_R8G8B8A8_UNORM;
            bpp = 32;
        // Allocate temporary memory for image
        size_t rowPitch = ( twidth * bpp + 7 ) / 8;
        size_t imageSize = rowPitch * theight;
        std::unique_ptr<uint8_t[]> temp( new uint8_t[ imageSize ] );
        // Load image data
        if ( memcmp( &convertGUID, &pixelFormat, sizeof(GUID) ) == 0
             && twidth == width
             && theight == height )
            // No format conversion or resize needed
            hr = frame->CopyPixels( 0, static_cast<UINT>( rowPitch ), static_cast<UINT>( imageSize ), temp.get() );  
            if ( FAILED(hr) )
                return hr;
        else if ( twidth != width || theight != height )
            // Resize
            IWICImagingFactory* pWIC = _GetWIC();
            if ( !pWIC )
                return E_NOINTERFACE;
            ScopedObject<IWICBitmapScaler> scaler;
            hr = pWIC->CreateBitmapScaler( &scaler );
            if ( FAILED(hr) )
                return hr;
            hr = scaler->Initialize( frame, twidth, theight, WICBitmapInterpolationModeFant );
            if ( FAILED(hr) )
                return hr;
            WICPixelFormatGUID pfScaler;
            hr = scaler->GetPixelFormat( &pfScaler );
            if ( FAILED(hr) )
                return hr;
            if ( memcmp( &convertGUID, &pfScaler, sizeof(GUID) ) == 0 )
                // No format conversion needed
                hr = scaler->CopyPixels( 0, static_cast<UINT>( rowPitch ), static_cast<UINT>( imageSize ), temp.get() );  
                if ( FAILED(hr) )
                    return hr;
                ScopedObject<IWICFormatConverter> FC;
                hr = pWIC->CreateFormatConverter( &FC );
                if ( FAILED(hr) )
                    return hr;
                hr = FC->Initialize( scaler.Get(), convertGUID, WICBitmapDitherTypeErrorDiffusion, 0, 0, WICBitmapPaletteTypeCustom );
                if ( FAILED(hr) )
                    return hr;
                hr = FC->CopyPixels( 0, static_cast<UINT>( rowPitch ), static_cast<UINT>( imageSize ), temp.get() );  
                if ( FAILED(hr) )
                    return hr;
            // Format conversion but no resize
            IWICImagingFactory* pWIC = _GetWIC();
            if ( !pWIC )
                return E_NOINTERFACE;
            ScopedObject<IWICFormatConverter> FC;
            hr = pWIC->CreateFormatConverter( &FC );
            if ( FAILED(hr) )
                return hr;
            hr = FC->Initialize( frame, convertGUID, WICBitmapDitherTypeErrorDiffusion, 0, 0, WICBitmapPaletteTypeCustom );
            if ( FAILED(hr) )
                return hr;
            hr = FC->CopyPixels( 0, static_cast<UINT>( rowPitch ), static_cast<UINT>( imageSize ), temp.get() );  
            if ( FAILED(hr) )
                return hr;
        // See if format is supported for auto-gen mipmaps (varies by feature level)
        bool autogen = false;
        if ( d3dContext != 0 && textureView != 0 ) // Must have context and shader-view to auto generate mipmaps
            UINT fmtSupport = 0;
            hr = d3dDevice->CheckFormatSupport( format, &fmtSupport );
            if ( SUCCEEDED(hr) && ( fmtSupport & D3D11_FORMAT_SUPPORT_MIP_AUTOGEN ) )
                autogen = true;
        // Create texture
        D3D11_TEXTURE2D_DESC desc;
        desc.Width = twidth;
        desc.Height = theight;
        desc.MipLevels = (autogen) ? 0 : 1;
        desc.ArraySize = 1;
        desc.Format = format;
        desc.SampleDesc.Count = 1;
        desc.SampleDesc.Quality = 0;
        desc.Usage = D3D11_USAGE_DEFAULT;
        desc.BindFlags = (autogen) ? (D3D11_BIND_SHADER_RESOURCE | D3D11_BIND_RENDER_TARGET) : (D3D11_BIND_SHADER_RESOURCE);
        desc.CPUAccessFlags = 0;
        desc.MiscFlags = (autogen) ? D3D11_RESOURCE_MISC_GENERATE_MIPS : 0;
        D3D11_SUBRESOURCE_DATA initData;
        initData.pSysMem = temp.get();
        initData.SysMemPitch = static_cast<UINT>( rowPitch );
        initData.SysMemSlicePitch = static_cast<UINT>( imageSize );
        ID3D11Texture2D* tex = nullptr;
        hr = d3dDevice->CreateTexture2D( &desc, (autogen) ? nullptr : &initData, &tex );
        if ( SUCCEEDED(hr) && tex != 0 )
            if (textureView != 0)
                D3D11_SHADER_RESOURCE_VIEW_DESC SRVDesc;
                memset( &SRVDesc, 0, sizeof( SRVDesc ) );
                SRVDesc.Format = format;
                SRVDesc.ViewDimension = D3D11_SRV_DIMENSION_TEXTURE2D;
                SRVDesc.Texture2D.MipLevels = (autogen) ? -1 : 1;
                hr = d3dDevice->CreateShaderResourceView( tex, &SRVDesc, textureView );
                if ( FAILED(hr) )
                    tex->Release();
                    return hr;
                if ( autogen )
                    assert( d3dContext != 0 );
                    d3dContext->UpdateSubresource( tex, 0, nullptr, temp.get(), static_cast<UINT>(rowPitch), static_cast<UINT>(imageSize) );
                    d3dContext->GenerateMips( *textureView );
            if (texture != 0)
                *texture = tex;
    #if defined(_DEBUG) || defined(PROFILE)
                tex->SetPrivateData( WKPDID_D3DDebugObjectName,
                                     sizeof("WICTextureLoader")-1,
                                     "WICTextureLoader"
    #endif
                tex->Release();
        return hr;
    //--------------------------------------------------------------------------------------
    HRESULT CreateWICTextureFromMemory( _In_ ID3D11Device* d3dDevice,
                                        _In_opt_ ID3D11DeviceContext* d3dContext,
                                        _In_bytecount_(wicDataSize) const uint8_t* wicData,
                                        _In_ size_t wicDataSize,
                                        _Out_opt_ ID3D11Resource** texture,
                                        _Out_opt_ ID3D11ShaderResourceView** textureView,
                                        _In_ size_t maxsize
        if (!d3dDevice || !wicData || (!texture && !textureView))
            return E_INVALIDARG;
        if ( !wicDataSize )
            return E_FAIL;
    #ifdef _M_AMD64
        if ( wicDataSize > 0xFFFFFFFF )
            return HRESULT_FROM_WIN32( ERROR_FILE_TOO_LARGE );
    #endif
        IWICImagingFactory* pWIC = _GetWIC();
        if ( !pWIC )
            return E_NOINTERFACE;
        // Create input stream for memory
        ScopedObject<IWICStream> stream;
        HRESULT hr = pWIC->CreateStream( &stream );
        if ( FAILED(hr) )
            return hr;
        hr = stream->InitializeFromMemory( const_cast<uint8_t*>( wicData ), static_cast<DWORD>( wicDataSize ) );
        if ( FAILED(hr) )
            return hr;
        // Initialize WIC
        ScopedObject<IWICBitmapDecoder> decoder;
        hr = pWIC->CreateDecoderFromStream( stream.Get(), 0, WICDecodeMetadataCacheOnDemand, &decoder );
        if ( FAILED(hr) )
            return hr;
        ScopedObject<IWICBitmapFrameDecode> frame;
        hr = decoder->GetFrame( 0, &frame );
        if ( FAILED(hr) )
            return hr;
        hr = CreateTextureFromWIC( d3dDevice, d3dContext, frame.Get(), texture, textureView, maxsize );
        if ( FAILED(hr)) 
            return hr;
    #if defined(_DEBUG) || defined(PROFILE)
        if (texture != 0 && *texture != 0)
            (*texture)->SetPrivateData( WKPDID_D3DDebugObjectName,
                                        sizeof("WICTextureLoader")-1,
                                        "WICTextureLoader"
        if (textureView != 0 && *textureView != 0)
            (*textureView)->SetPrivateData( WKPDID_D3DDebugObjectName,
                                            sizeof("WICTextureLoader")-1,
                                            "WICTextureLoader"
    #endif
        return hr;
    //--------------------------------------------------------------------------------------
    HRESULT CreateWICTextureFromFile( _In_ ID3D11Device* d3dDevice,
                                      _In_opt_ ID3D11DeviceContext* d3dContext,
                                      _In_z_ const wchar_t* fileName,
                                      _Out_opt_ ID3D11Resource** texture,
                                      _Out_opt_ ID3D11ShaderResourceView** textureView,
                                      _In_ size_t maxsize )
        if (!d3dDevice || !fileName || (!texture && !textureView))
            return E_INVALIDARG;
        IWICImagingFactory* pWIC = _GetWIC();
        if ( !pWIC )
            return E_NOINTERFACE;
        // Initialize WIC
        ScopedObject<IWICBitmapDecoder> decoder;
        HRESULT hr = pWIC->CreateDecoderFromFilename( fileName, 0, GENERIC_READ, WICDecodeMetadataCacheOnDemand, &decoder );
        if ( FAILED(hr) )
            return hr;
        ScopedObject<IWICBitmapFrameDecode> frame;
        hr = decoder->GetFrame( 0, &frame );
        if ( FAILED(hr) )
            return hr;
        hr = CreateTextureFromWIC( d3dDevice, d3dContext, frame.Get(), texture, textureView, maxsize );
        if ( FAILED(hr)) 
            return hr;
    #if defined(_DEBUG) || defined(PROFILE)
        if (texture != 0 || textureView != 0)
            CHAR strFileA[MAX_PATH];
            WideCharToMultiByte( CP_ACP,
                                 WC_NO_BEST_FIT_CHARS,
                                 fileName,
                                 strFileA,
                                 MAX_PATH,
                                 nullptr,
                                 FALSE
            const CHAR* pstrName = strrchr( strFileA, '\\' );
            if (!pstrName)
                pstrName = strFileA;
                pstrName++;
            if (texture != 0 && *texture != 0)
                (*texture)->SetPrivateData( WKPDID_D3DDebugObjectName,
                                            static_cast<UINT>( strnlen_s(pstrName, MAX_PATH) ),
                                            pstrName
            if (textureView != 0 && *textureView != 0 )
                (*textureView)->SetPrivateData( WKPDID_D3DDebugObjectName,
                                                static_cast<UINT>( strnlen_s(pstrName, MAX_PATH) ),
                                                pstrName
    #endif
        return hr;
    

    如何使用 Direct3D 11

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