DirectWrite is a text layout and glyph rendering

API An application programming interface (API) is a way for two or more computer programs to communicate with each other. It is a type of software Interface (computing), interface, offering a service to other pieces of software. A document or standa ...

Microsoft Microsoft Corporation is an American multinational technology corporation producing computer software, consumer electronics, personal computers, and related services headquartered at the Microsoft Redmond campus located in Redmond, Washing ...

. It was designed to replace

GDI GDI may refer to: Science and technology * Gasoline direct injection, a type of fuel injection * Graphics Device Interface, a component of Microsoft Windows * Guanosine nucleotide dissociation inhibitor, a protein Organisations * Gabriel Dumont I ...

/GDI+ and

Uniscribe Uniscribe is the Microsoft Windows set of services for rendering Unicode-encoded text, supporting complex text layout. It is implemented in the dynamic link library . Uniscribe has been released with Windows 2000 and Internet Explorer 5.0. In addi ...

for screen-oriented rendering and was first shipped with

Windows 7 Windows 7 is a major release of the Windows NT operating system developed by Microsoft. It was released to manufacturing on July 22, 2009, and became generally available on October 22, 2009. It is the successor to Windows Vista, released nearly ...

and

Windows Server 2008 R2 Windows Server 2008 R2 is the fifth version of the Windows Server operating system produced by Microsoft and released as part of the Windows NT family of operating systems. It was released to manufacturing on July 22, 2009, and became General av ...

, as well as

Windows Vista Windows Vista is a major release of the Windows NT operating system developed by Microsoft. It was the direct successor to Windows XP, which was released five years before, at the time being the longest time span between successive releases of ...

and

Windows Server 2008 Windows Server 2008 is the fourth release of the Windows Server operating system produced by Microsoft as part of the Windows NT family of the operating systems. It was released to manufacturing on February 4, 2008, and generally to retail on Fe ...

(with Platform Update installed). DirectWrite is

hardware-accelerated Hardware acceleration is the use of computer hardware designed to perform specific functions more efficiently when compared to software running on a general-purpose central processing unit (CPU). Any transformation of data that can be calculat ...

(using the

GPU A graphics processing unit (GPU) is a specialized electronic circuit designed to manipulate and alter memory to accelerate the creation of images in a frame buffer intended for output to a display device. GPUs are used in embedded systems, mobil ...

) when running on top of

Direct2D Direct2D is a 2D computer graphics, 2D vector graphics, vector graphics application programming interface (API) designed by Microsoft and implemented in Windows 10, Windows 8, Windows 7 and Windows Server 2008 R2, and also Windows Vista and Windows ...

, but can also use the CPU to render on any target, including a

bitmap In computing, a bitmap is a mapping from some domain (for example, a range of integers) to bits. It is also called a bit array A bit array (also known as bitmask, bit map, bit set, bit string, or bit vector) is an array data structure that c ...

Features

* Comprehensive support for

Unicode Unicode, formally The Unicode Standard,The formal version reference is is an information technology Technical standard, standard for the consistent character encoding, encoding, representation, and handling of Character (computing), text expre ...

, with over 20 scripts providing layout and rendering of every language supported in Windows. DirectWrite supports measuring, drawing, and

hit-testing In computer graphics programming, hit-testing (hit detection, picking, or pick correlation ) is the process of determining whether a user-controlled cursor (such as a mouse cursor or touch-point on a touch-screen interface) intersects a given graphi ...

of multi-format text. Supported Unicode features include

BIDI A bidirectional text contains two text directionalities, right-to-left (RTL) and left-to-right (LTR). It generally involves text containing different types of alphabets, but may also refer to boustrophedon, which is changing text direction in eac ...

, line breaking, surrogates, UVS, language-guided script itemization, number substitution, and glyph shaping. * Sub-pixel

ClearType ClearType is Microsoft's implementation of subpixel rendering technology in rendering text in a font system. ClearType attempts to improve the appearance of text on certain types of computer display screens by sacrificing color fidelity for additi ...

text rendering with bi-directional

antialiasing Anti-aliasing may refer to any of a number of techniques to combat the problems of aliasing in a sampled signal such as a digital image or digital audio recording. Specific topics in anti-aliasing include: * Anti-aliasing filter, a filter used be ...

which can interoperate with GDI/GDI+,

Direct3D Direct3D is a graphics application programming interface (API) for Microsoft Windows. Part of DirectX, Direct3D is used to render three-dimensional graphics in applications where performance is important, such as games. Direct3D uses hardware a ...

and any application-specific technology. When using with Direct2D, text rendering can be hardware-accelerated or can use WARP software rasterizer when hardware acceleration is not available. * Supports advanced typographic features of

OpenType OpenType is a format for scalable computer fonts. It was built on its predecessor TrueType, retaining TrueType's basic structure and adding many intricate data structures for prescribing typographic behavior. OpenType is a registered trademark o ...

, such as stylistic alternates and swashes, which were never supported in GDI and

WinForms Windows Forms (WinForms) is a free and open-source graphical user interface, graphical (GUI) Library (computing), class library included as a part of Microsoft .NET Core, .NET, .NET Framework or Mono Framework, providing a platform to write client ...

. These features were demoed at DirectWrite's launch (at PDC2008) using the Gabriola font, itself also introduced with Windows 7. * Provides a low-level glyph rendering API for those who employ proprietary text layout and Unicode-to-glyph processing. In

Windows 8.1 Windows 8.1 is a release of the Windows NT operating system developed by Microsoft. It was released to manufacturing on August 27, 2013, and broadly released for retail sale on October 17, 2013, about a year after the retail release of its pre ...

, DirectWrite gained support for color fonts.

DWriteCore

DWriteCore is the

Windows App SDK Windows App SDK (formerly known as Project Reunion) is a software development kit (SDK) from Microsoft that targets the development of native desktop applications on Windows 11 and Windows 10 back to version 1809. Windows App SDK does not replac ...

(Project Reunion) implementation of DirectWrite that runs on versions of Windows down to Windows 10, version 1809 (10.0; Build 17763), and opens the door for cross-platform usage.

Uses

The XPS viewer in Windows 7 uses DirectWrite, but it renders the output on a GDI+ surface.

Internet Explorer 9 Internet Explorer 9 or IE9 (officially Windows Internet Explorer 9) is a web browser for Windows. It was released by Microsoft on March 14, 2011, as the ninth version of Internet Explorer and the successor to Internet Explorer 8, and can replace p ...

and later versions use DirectWrite layered over Direct2D for improved visual quality and performance. Firefox 4 also added DirectWrite support, but rendering in the DirectWrite specific style was made non-default for some fonts in Firefox 7 due to user complaints about the rendering quality.

Microsoft Office 2013 Microsoft Office 2013 (codenamed Office 15) is a version of Microsoft Office, a productivity suite for Microsoft Windows. It is the successor to Microsoft Office 2010 and the predecessor to Microsoft Office 2016. Unlike with Office 2010, no OS ...

supports either Direct2D/DirectWrite or GDI/Uniscribe for display rendering and typography.

Google Chrome Google Chrome is a cross-platform web browser developed by Google. It was first released in 2008 for Microsoft Windows, built with free software components from Apple WebKit and Mozilla Firefox. Versions were later released for Linux, macOS ...

in Windows supports DirectWrite starting from version 37.

Telegram Telegraphy is the long-distance transmission of messages where the sender uses symbolic codes, known to the recipient, rather than a physical exchange of an object bearing the message. Thus flag semaphore is a method of telegraphy, whereas p ...

's desktop client uses DirectWrite to render color emojis on Windows.

Steam Steam is a substance containing water in the gas phase, and sometimes also an aerosol of liquid water droplets, or air. This may occur due to evaporation or due to boiling, where heat is applied until water reaches the enthalpy of vaporization ...

has the option to enable DirectWrite for improved font smoothing and kerning on its desktop client

References

{{Microsoft APIs Text rendering libraries

Features

DWriteCore

Uses

See also

References