WICTextureLoader

A Direct3D 11 2D texture loader that uses Windows Imaging Component (WIC) to load a bitmap (BMP, JPEG, PNG, TIFF, GIF, HD Photo, or other WIC supported file container), resize if needed based on the current feature level (or by explicit parameter), format convert to a standard DXGI format if required, and then create a 2D texture. Furthermore, if a Direct3D 11 device context is provided and the current device supports it for the given pixel format, it will auto-generate mipmaps.

This loader does not support array textures, 1D textures, 3D volume textures, cubemaps, or cubemap arrays. For these scenarios, use the .DDS file format and DDSTextureLoader instead.

DDSTextureLoader is recommended for fully "precooked" textures for maximum performance and image quality, but this loader can be useful for creating simple 2D texture from standard image files at runtime.

On Windows 8.1 and Windows 10, you can load simple 2D textures in BC1, BC2, or BC3 pixel format DDS files using WIC as there is a basic DDS built-in codec present. All other pixel formats and resource types will fail, and you'll get WINCODEC_ERR_COMPONENTNOTFOUND on older versions of Windows trying to use WICTextureLoader to load DDS files. Use DDSTextureLoader instead.

A standalone version is included in the DirectXTex package for Direct3D 9, Direct3D 11, and Direct3D 12. Be sure to add both the h and cpp file to your project.

Related tutorial: Sprites and textures

Header

#include <WICTextureLoader.h>

Initialization

The library assumes that the client code will have already called CoInitialize, CoInitializeEx, or Windows::Foundation::Initialize as needed by the application before calling any Windows Imaging Component functionality.

For a Universal Windows Platform (UWP) app using /ZW, the Windows Runtime and COM is initialized by the C/C++ Run-Time. For C++/WinRT applications, this is done by calling winrt::init_apartment();.

For a classic Windows desktop application you have to do this explicitly:

#if (_WIN32_WINNT >= 0x0A00 /*_WIN32_WINNT_WIN10*/)
    Microsoft::WRL::Wrappers::RoInitializeWrapper initialize(RO_INIT_MULTITHREADED);
    if (FAILED(initialize))
        // error
#else
    HRESULT hr = CoInitializeEx(nullptr, COINIT_MULTITHREADED);
    if (FAILED(hr))
        // error
#endif

Functions

CreateWICTextureFromMemory

Loads a WIC-supported bitmap file from a memory buffer. It creates a Direct3D 11 resource from it, and optionally a Direct3D 11 shader resource view. Providing the ID311DeviceContext supports auto-generation of mipmaps.

HRESULT CreateWICTextureFromMemory( ID3D11Device* d3dDevice,
   const uint8_t* wicData, size_t wicDataSize,
   ID3D11Resource** texture, ID3D11ShaderResourceView** textureView,
   size_t maxsize = 0 );

HRESULT CreateWICTextureFromMemory( ID3D11Device* d3dDevice,
   ID3D11DeviceContext* d3dContext,
   const uint8_t* wicData, size_t wicDataSize,
   ID3D11Resource** texture, ID3D11ShaderResourceView** textureView,
   size_t maxsize = 0 );

CreateWICTextureFromFile

Loads a WIC-supported bitmap file from disk, creates a Direct3D 11 resource from it, and optionally a Direct3D 11 shader resource view. Providing the ID311DeviceContext supports auto-generation of mipmaps.

HRESULT CreateWICTextureFromFile( ID3D11Device* d3dDevice,
   const wchar_t* szFileName,
   ID3D11Resource** texture, ID3D11ShaderResourceView** textureView,
   size_t maxsize = 0 );

HRESULT CreateWICTextureFromFile( ID3D11Device* d3dDevice,
   ID3D11DeviceContext* d3dContext,
   const wchar_t* szFileName,
   ID3D11Resource** texture, ID3D11ShaderResourceView** textureView,
   size_t maxsize = 0 );

CreateWICTextureFromMemoryEx, CreateWICTextureFromFileEx

These versions provide explicit control over the created resource's usage, binding flags, CPU access flags, and miscellaneous flags for advanced / expert scenarios.

The standard routines default to D3D11_USAGE_DEFAULT, D3D11_BIND_SHADER_RESOURCE, 0, and 0 respectively.

For auto-gen mipmaps, the default binding flags are D3D11_BIND_SHADER_RESOURCE | D3D11_BIND_RENDER_TARGET and miscellaneous flags is set to D3D11_RESOURCE_MISC_GENERATE_MIPS.

There is also a loadFlags parameter. The flags are WIC_LOADER_DEFAULT, WIC_LOADER_FORCE_SRGB, WIC_LOADER_IGNORE_SRGB, WIC_LOADER_FIT_POW2, WIC_LOADER_MAKE_SQUARE, and/or WIC_LOADER_FORCE_RGBA32.

HRESULT CreateWICTextureFromMemoryEx( ID3D11Device* d3dDevice,
   const uint8_t* wicData, size_t wicDataSize,
   size_t maxsize, D3D11_USAGE usage, unsigned int bindFlags,
   unsigned int cpuAccessFlags, unsigned int miscFlags,
   WIC_LOADER_FLAGS loadFlags,
   ID3D11Resource** texture, ID3D11ShaderResourceView** textureView );

HRESULT CreateWICTextureFromMemoryEx( ID3D11Device* d3dDevice,
   ID3D11DeviceContext* d3dContext,
   const uint8_t* wicData, size_t wicDataSize,
   size_t maxsize, D3D11_USAGE usage, unsigned int bindFlags,
   unsigned int cpuAccessFlags, unsigned int miscFlags,
   WIC_LOADER_FLAGS loadFlags,
   ID3D11Resource** texture, ID3D11ShaderResourceView** textureView );

HRESULT CreateWICTextureFromFileEx( ID3D11Device* d3dDevice,
   const wchar_t* szFileName,
   size_t maxsize, D3D11_USAGE usage, unsigned int bindFlags,
   unsigned int cpuAccessFlags, unsigned int miscFlags,
   WIC_LOADER_FLAGS loadFlags,
   ID3D11Resource** texture, ID3D11ShaderResourceView** textureView );

HRESULT CreateWICTextureFromFileEx( ID3D11Device* d3dDevice,
   ID3D11DeviceContext* d3dContext,
   const wchar_t* szFileName,
   size_t maxsize, D3D11_USAGE usage, unsigned int bindFlags,
   unsigned int cpuAccessFlags, unsigned int miscFlags,
   WIC_LOADER_FLAGS loadFlags,
   ID3D11Resource** texture, ID3D11ShaderResourceView** textureView );

The WIC_LOADER_FORCE_SRGB and WIC_LOADER_IGNORE_SRGB flags are detailed below under sRGB.

The WIC_LOADER_FIT_POW2 and/or WIC_LOADER_MAKE_SQUARE flags can be used to force the image to be resized to a power-of-2 size and/or be made a square texture that has width == height. These flags are most useful for the Direct3D 9 legacy version of WICTextureLoader, but are supported in all versions.

The WIC_LOADER_FORCE_RGBA32 flag is explained under Pixel format conversions.

The loadFlags was previously a bool forceSRGB.

Parameters

Either texture or textureView can be nullptr, but not both. In most use cases for rendering, you only need the shader resource view (SRV) textureView interface.

For all these functions above, the maxsize parameter provides an upper limit on the size of the resulting texture. If given a 0, the functions assume a maximum size determined from the device's current feature level. If the bitmap file contains a larger image, it will be resized using WIC at load-time to provide scaling.

If a d3dContext is given to these functions, they will attempt to use the auto-generation of mipmaps features in the Direct3D 11 API if supported for the pixel format. Note the quality of auto-gen mipmaps is up to the driver, so can vary widely. Also if a context is passed, the function is not thread safe. If d3dContext is nullptr, then it functions the same as the version which does not take a context.

For the Ex versions, the usage is a D3D11_USAGE, typically D3D11_USAGE_DEFAULT. The bindFlags parameter is one or more D3D11_BIND_FLAG values, typically D3D11_BIND_SHADER_RESOURCE for textures. The cpuAccessFlags parameter is D3D11_CPU_ACCESS_FLAG typically 0 for default usage textures. The miscFlags parameter is a D3D11_RESOURCE_MISC_FLAG value, usually 0.

Example

This example creates a shader resource view on the Direct3D device which can be used for rendering. It also makes use of the immediate device context to auto-gen mipmaps if supported.

using namespace DirectX;
using namespace Microsoft::WRL;

ComPtr<ID3D11ShaderResourceView> srv;
HRESULT hr = CreateWICTextureFromFile( d3dDevice.Get(), immContext.Get(),
     L"LOGO.BMP", nullptr, srv.GetAddressOf() );
DX::ThrowIfFailed(hr);

For rendering you don't need the underlying resource and just want an SRV you can use to draw, which is why the above use pass a nullptr for the ID3D11Resource** parameter. You can request just the resource or get both objects back.

sRGB

• While there is no explicit 'sRGB' pixel format defined for WIC, the load functions will check for known metadata tags and may return DXGI_FORMAT_*_SRGB formats if there are equivalents of the same size and channel configuration available. Setting loadFlags to WIC_LOADER_IGNORE_SRGB will ignore this metadata.

  • For PNG, this is indicated by /sRGB/RenderingIntent set to 1.
  • For JPG this is /app1/ifd/exif/{ushort=40961} set to 1.
  • For TIFF this is /ifd/exif/{ushort=40961} set to 1.

• Setting loadFlags to WIC_LOADER_FORCE_SRGB will force conversion of the DXGI_FORMAT to one of DXGI_FORMAT_*_SRGB formats if it exist. This is useful for loading sRGB content for linearly-correct rendering that lacks the metadata tags to indicate sRGB colorspace. Note that no pixel data conversion takes place.

• gAMA chunks in PNGs are ignored. If the sRGB chunk is found, it is assumed to be gamma 2.2.

Pixel format conversions

WIC has built-in support for doing pixel format conversions.

If the loadFlags include WIC_LOADER_FORCE_RGBA32, then the result is always a DXGI_FORMAT_R8G8B8A8_UNORM texture by converting to GUID_WICPixelFormat32bppRGBA. If WIC_LOADER_FORCE_SRGB is also set, the result with be set to DXGI_FORMAT_R8G8B8A8_UNORM_SRGB.

The conversion tables are designed so that they prefer to convert to RGB if a conversion is required as a general preferance for DXGI 1.0 supporting formats supported by WDDM 1.0 drivers. The majority of Direct3D 11 devices actually support BGR DXGI 1.1 formats so we use them when they are the best match. For example, GUID_WICPixelFormat32bppBGRA loads directly as DXGI_FORMAT_B8G8R8A8_UNORM, but GUID_WICPixelFormat32bppPBGRA converts to DXGI_FORMAT_R8G8B8A8_UNORM.

GUID_WICPixelFormatBlackWhite is always converted to a greyscale DXGI_FORMAT_R8_UNORM since DXGI_FORMAT_R1_UNORM is not supported by Direct3D.

GUID_WICPixelFormat32bppRGBE is an 8:8:8:8 format, which does not match DXGI_FORMAT_R9G9B9E5_SHAREDEXP. This WIC pixel format is therefore converted to GUID_WICPixelFormat128bppRGBAFloat and returns as DXGI_FORMAT_R32G32B32A32_FLOAT.

Remarks

WICTextureLoader cannot load .TGA/.HDR files unless the system has a 3rd party WIC codec installed. You must use the DirectXTex library for TGA/HDR file format support without relying on an add-on WIC codec.

WIC2

WIC2 is available on Windows 10, Windows 8.x, and on Windows 7 Service Pack 1 with KB 2670838 installed.

• If WIC2 is supported, then it will load the new WIC pixel format GUID_WICPixelFormat96bppRGBFloat directly as DXGI_FORMAT_R32G32B32_FLOAT. Otherwise the module converts this to DXGI_FORMAT_R32G32B32A32_FLOAT.

• If WIC2 is supported, then it will include conversions cases for the new WIC pixel formats GUID_WICPixelFormat32bppRGB, GUID_WICPixelFormat64bppRGB, and GUID_WICPixelFormat64bppPRGBAHalf.

• If WIC2 is supported, then it will convert the WIC pixel format GUID_WICPixelFormat96bppRGBFixedPoint to DXGI_FORMAT_R32G32B32_FLOAT. There is special-case handling so that if auto-gen mips fails for this format (this is optional support for Feature Level 10.0 or later devices), it will use DXGI_FORMAT_R32G32B32A32_FLOAT instead (which has required support for Feature Level 10.0 or later devices).

See Windows Imaging Component and Windows 8

Windows Store apps

The texture loader function is typically used to load texture files from the application's install folder as they were included with the AppX package for Windows Store apps and Universal Windows Platform (UWP) apps. If you wish to create a texture from a file that is specified by the user from a WinRT file picker, you will need to copy the file locally to a temporary location before you can use WICTextureLoader on it. This is because you either won't have file access rights to the user's file location, or the StorageFile is actually not a local file system path (i.e. it's a URL).

C++/CX

#include <ppltasks.h>

using namespace concurrency;

using Windows::Storage;
using Windows::Storage::Pickers;

auto openPicker = ref new FileOpenPicker();
openPicker->ViewMode = PickerViewMode::Thumbnail; 
openPicker->SuggestedStartLocation = PickerLocationId::PicturesLibrary; 
openPicker->FileTypeFilter->Append(".jpg"); 
openPicker->FileTypeFilter->Append(".png"); 

create_task(openPicker->PickSingleFileAsync()).then([this](StorageFile^ file)
{
    if (file)
    {
        auto tempFolder = ApplicationData::Current->TemporaryFolder;
        create_task(file->CopyAsync( tempFolder, file->Name, NameCollisionOption::GenerateUniqueName )).then([this](StorageFile^ tempFile)
        {
            if (tempFile)
            {
                HRESULT hr = CreateWICTextureFromFile( ..., tempFile->Path->Data(), ... );
                DeleteFile(tempFile->Path->Data());
                DX::ThrowIfFailed(hr);
            }
        });
    });

C++/WinRT

#include "winrt/Windows.Storage.h"
#include "winrt/Windows.Storage.Pickers.h"

using namespace winrt::Windows::Storage;
using namespace winrt::Windows::Storage::Pickers;

FileOpenPicker openPicker;
openPicker.ViewMode(PickerViewMode::Thumbnail);
openPicker.SuggestedStartLocation(PickerLocationId::PicturesLibrary);
openPicker.FileTypeFilter().Append(L".jpg");
openPicker.FileTypeFilter().Append(L".png");

auto file = co_await openPicker.PickSingleFileAsync();
if (file)
{
    auto tempFolder = ApplicationData::Current().TemporaryFolder();
    auto tempFile = co_await file.CopyAsync(tempFolder, file.Name(), NameCollisionOption::GenerateUniqueName);
    if (tempFile)
    {
        HRESULT hr = CreateWICTextureFromFile(..., tempFile.Path().c_str(), ...);
        DeleteFile(tempFile.Path().c_str());
        DX::ThrowIfFailed(hr);
    }
}

File access and permissions (Windows Runtime apps)

Debugging texture loading

If the HRESULT is a success, but you are still having problems using the texture, the next step in debugging is to examine details about the loaded texture. You can do this easily with the following code:

ComPtr<ID3D11Resource> res;
ComPtr<ID3D11ShaderResourceView> srv;
HRESULT hr = CreateWICTextureFromFile( d3dDevice.Get(), immContext.Get(),
     L"LOGO.BMP", res.GetAddressOf(), srv.GetAddressOf() );
DX::ThrowIfFailed(hr);

ComPtr<ID3D11Texture2D> tex;
hr = res.As(&tex);
DX::ThrowIfFailed(hr);

D3D11_TEXTURE2D_DESC desc;
tex->GetDesc(&desc);

desc.Width is the texture width in pixels (of the top most mip level)
desc.Height is the texture height in pixels (of the top most mip level)
desc.MipLevels is the number of mip levels (or 1 if there are no mips)
desc.ArraySize is the number of textures in the array (or 1 if this not an array)
desc.Format is the DXGI format of the texture resource

Further reading

Linear-Space Lighting (i.e. Gamma)

Chapter 24. The Importance of Being Linear, GPU Gems 3

Gamma-correct rendering