DirectWrite is a text-layout and glyph-rendering API

Application programming interface

An application programming interface is a source code based specification intended to be used as an interface by software components to communicate with each other...

 by Microsoft

Microsoft

Microsoft Corporation is an American public multinational corporation headquartered in Redmond, Washington, USA that develops, manufactures, licenses, and supports a wide range of products and services predominantly related to computing through its various product divisions...

. It was designed to replace GDI

Graphics Device Interface

The Graphics Device Interface is a Microsoft Windows application programming interface and core operating system component responsible for representing graphical objects and transmitting them to output devices such as monitors and printers....

/GDI+ and Uniscribe

Uniscribe

Uniscribe is the Microsoft Windows set of services for rendering Unicode-encoded text, especially complex text layout. They are implemented in the DLL USP10.DLL. USP10.dll became available to the public with Windows 2000 and Internet Explorer 5.0...

 for screen-oriented rendering and was shipped with Windows 7 and Windows Server 2008 R2

Windows Server 2008 R2

Windows Server 2008 R2 is a server operating system produced by Microsoft. It was released to manufacturing on July 22, 2009 and launched on October 22, 2009. According to the Windows Server Team blog, the retail availability was September 14, 2009. It is built on Windows NT 6.1, the same core...

, as well as Windows Vista

Windows Vista

Windows Vista is an operating system released in several variations developed by Microsoft for use on personal computers, including home and business desktops, laptops, tablet PCs, and media center PCs...

 and Windows Server 2008 (with Platform Update installed and Platform Update Supplement for Windows Vista and for Windows Server 2008(KB2117917) & KB2505189 update installed.

Microsoft has fixed many DirectWrite bugs in Windows 7 through Windows 7 Service Pack 1(SP1) and KB2505438 update.

Features

• Comprehensive support for Unicode
  Unicode
  Unicode is a computing industry standard for the consistent encoding, representation and handling of text expressed in most of the world's writing systems...
  
  , with over 20 scripts providing layout and rendering of every language supported in Windows. DirectWrite supports measuring, drawing, and hit-testing
  Hit-testing
  In computer graphics programming, hit-testing is the process of determining whether a user-controlled cursor intersects a given shape, line, or curve drawn on the screen...
  
   of multi-format text. Supported Unicode features include BIDI
  Bi-directional text
  Bi-directional text is text containing text in both text directionalities, both right-to-left and left-to-right . It generally involves text containing different types of alphabets, but may also refer to boustrophedon, which is changing text directionality in each row.Some writing systems of the...
  
  , line breaking, surrogates, UVS, language-guided script itemization, number substitution, and glyph shaping.

• Sub-pixel ClearType
  ClearType
  ClearType is a trademark for Microsoft's implementation of subpixel rendering technology. ClearType attempts to improve the appearance of text on certain types of computer display screens by sacrificing color fidelity for additional intensity variation. This trade-off is asserted to work well on...
  
   text rendering with bi-directional antialiasing which can interoperate with GDI/GDI+, Direct2D
  Direct2D
  Direct2D is a 2D and vector graphics application programming interface designed by Microsoft and implemented in Windows 7 and Windows Server 2008 R2, and also Windows Vista and Windows Server 2008 and Platform Update Supplement for Windows Vista and for Windows Server 2008 & KB2505189 update...
  
  /Direct3D
  Direct3D
  Direct3D is part of Microsoft's DirectX application programming interface . Direct3D is available for Microsoft Windows operating systems , and for other platforms through the open source software Wine. It is the base for the graphics API on the Xbox and Xbox 360 console systems...
  
   and any application-specific technology. When using with Direct2D, text rendering can be hardware-accelerated or can use WARP software rasterizer
  Windows Advanced Rasterization Platform
  The Windows Advanced Rasterization Platform is a software rasterizer device that is a component of Windows Graphics runtime in Windows 7 and Windows Server 2008 R2, as well as Windows Vista and Windows Server 2008 ....
  
   when hardware acceleration is not available. It is, however, unable to render aliased (or bi-level) text.

• Supports advanced typographic features of OpenType
  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...
  
  , such as stylistic alternates and swashes
  Swash (typography)
  A swash is a typographical flourish on a glyph, like an exaggerated serif.Capital swash characters, which extended to the left, were historically often used to begin sentences. There were also minuscule swash characters, which came either extending to the left, to begin words, or to the right to...
  
  , which were never supported in GDI and WinForms
  Windows Forms
  Windows Forms is the name given to the graphical application programming interface included as a part of Microsoft .NET Framework, providing access to native Microsoft Windows interface elements by wrapping the extant Windows API in managed code...
  
  .

• Provides a low-level glyph rendering API for those who employ proprietary text layout and Unicode-to-glyph processing.

Supported scripts

• Arabic
• Armenian
  Armenian language
  The Armenian language is an Indo-European language spoken by the Armenian people. It is the official language of the Republic of Armenia as well as in the region of Nagorno-Karabakh. The language is also widely spoken by Armenian communities in the Armenian diaspora...
  
  
• Bengali
  Bengali language
  Bengali or Bangla is an eastern Indo-Aryan language. It is native to the region of eastern South Asia known as Bengal, which comprises present day Bangladesh, the Indian state of West Bengal, and parts of the Indian states of Tripura and Assam. It is written with the Bengali script...
  
  
• Bopomofo
  Bopomofo
  Zhuyin fuhao , often abbreviated as zhuyin and colloquially called bopomofo, was introduced in the 1910s as the first official phonetic system for transcribing Chinese, especially Mandarin....
  
  
• ‡ Braille
  Braille
  The Braille system is a method that is widely used by blind people to read and write, and was the first digital form of writing.Braille was devised in 1825 by Louis Braille, a blind Frenchman. Each Braille character, or cell, is made up of six dot positions, arranged in a rectangle containing two...
  
  

• Canadian aboriginal syllabics
  Canadian Aboriginal Syllabics
  Canadian Aboriginal syllabic writing, or simply syllabics, is a family of abugidas used to write a number of Aboriginal Canadian languages of the Algonquian, Inuit, and Athabaskan language families....
  
  
• Cherokee
  Cherokee language
  Cherokee is an Iroquoian language spoken by the Cherokee people which uses a unique syllabary writing system. It is the only Southern Iroquoian language that remains spoken. Cherokee is a polysynthetic language.-North American etymology:...
  
  
• Chinese Simplified
• Chinese Traditional
• Cyrillic
• ‡ Coptic
  Coptic language
  Coptic or Coptic Egyptian is the current stage of the Egyptian language, a northern Afro-Asiatic language spoken in Egypt until at least the 17th century. Egyptian began to be written using the Greek alphabet in the 1st century...
  
  

• Devanagari
  Devanagari
  Devanagari |deva]]" and "nāgarī" ), also called Nagari , is an abugida alphabet of India and Nepal...
  
  
• Ethiopic
• Georgian
  Georgian alphabet
  The Georgian alphabet is the writing system used to write the Georgian language and other Kartvelian languages , and occasionally other languages of the Caucasus such as Ossetic and Abkhaz during the 1940s...
  
  
• ‡ Glagolitic
• Greek
  Greek language
  Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...
  
  
• Gujarati
  Gujarati script
  The Gujarati script , which like all Nāgarī writing systems is strictly speaking an abugida rather than an alphabet, is used to write the Gujarati and Kutchi languages...
  
  
• Gurmukhi

• Hebrew
• Japanese
  Japanese language
  is a language spoken by over 130 million people in Japan and in Japanese emigrant communities. It is a member of the Japonic language family, which has a number of proposed relationships with other languages, none of which has gained wide acceptance among historical linguists .Japanese is an...
  
  
• Kannada
• Khmer
  Khmer language
  Khmer , or Cambodian, is the language of the Khmer people and the official language of Cambodia. It is the second most widely spoken Austroasiatic language , with speakers in the tens of millions. Khmer has been considerably influenced by Sanskrit and Pali, especially in the royal and religious...
  
  
• Korean
  Korean language
  Korean is the official language of the country Korea, in both South and North. It is also one of the two official languages in the Yanbian Korean Autonomous Prefecture in People's Republic of China. There are about 78 million Korean speakers worldwide. In the 15th century, a national writing...
  
  
• Lao
  Lao language
  Lao or Laotian is a tonal language of the Tai–Kadai language family. It is the official language of Laos, and also spoken in the northeast of Thailand, where it is usually referred to as the Isan language. Being the primary language of the Lao people, Lao is also an important second language for...
  
  
• Latin
  Latin
  Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
  
  

• Malayalam
• Mongolian
  Mongolian language
  The Mongolian language is the official language of Mongolia and the best-known member of the Mongolic language family. The number of speakers across all its dialects may be 5.2 million, including the vast majority of the residents of Mongolia and many of the Mongolian residents of the Inner...
  
  
• Myanmar
  Myanmar
  Burma , officially the Republic of the Union of Myanmar , is a country in Southeast Asia. Burma is bordered by China on the northeast, Laos on the east, Thailand on the southeast, Bangladesh on the west, India on the northwest, the Bay of Bengal to the southwest, and the Andaman Sea on the south....
  
  
• New Tai Lue
  New Tai Lue
  New Tai Lue script, also known as Simplified Tai Lue, is an alphabet used to write the Tai Lü language. Developed in China in the 1950s, New Tai Lue is based on the traditional Tai Lue script developed ca. 1200 AD...
  
  
• ‡ Ogham
  Ogham
  Ogham is an Early Medieval alphabet used primarily to write the Old Irish language, and occasionally the Brythonic language. Ogham is sometimes called the "Celtic Tree Alphabet", based on a High Medieval Bríatharogam tradition ascribing names of trees to the individual letters.There are roughly...
  
  
• Oriya
  Oriya language
  Oriya , officially Odia from November, 2011, is an Indian language, belonging to the Indo-Aryan branch of the Indo-European language family. It is mainly spoken in the Indian states of Orissa and West Bengal...
  
  

• ’Phags-pa
• ‡ Runic
• Sinhala
• Syriac

• Tai Le
  Tai Le script
  Tai Le is the name of Tai Nüa script, the script used for the Tai Nüa language, given by Microsoft.-Unicode:Tai Le script was added to the Unicode Standard in April, 2003 with the release of version 4.0....
  
  
• Tamil
  Tamil language
  Tamil is a Dravidian language spoken predominantly by Tamil people of the Indian subcontinent. It has official status in the Indian state of Tamil Nadu and in the Indian union territory of Pondicherry. Tamil is also an official language of Sri Lanka and Singapore...
  
  
• Telugu
  Telugu script
  Telugu script, an abugida from the Brahmic family of scripts, is used to write the Telugu language, a language found in the South-Central Indian state of Andhra Pradesh as well as several other neighboring states. The Telugu script is derived from the Bhattiprolu script...
  
  
• Thaana
  Thaana
  Thaana, Taana or Tāna is the modern writing system of the Divehi language spoken in the Maldives. Taana has characteristics of both an abugida and a true alphabet , with consonants derived from indigenous and Arabic numerals, and vowels derived from the vowel diacritics of the Arabic abjad...
  
  
• Thai
  Thai language
  Thai , also known as Central Thai and Siamese, is the national and official language of Thailand and the native language of the Thai people, Thailand's dominant ethnic group. Thai is a member of the Tai group of the Tai–Kadai language family. Historical linguists have been unable to definitively...
  
  
• Tibetan
  Standard Tibetan
  Standard Tibetan is the most widely used spoken form of the Tibetan languages. It is based on the speech of Lhasa, an Ü-Tsang dialect belonging to the Central Tibetan languages. For this reason, Standard Tibetan is often called Central Tibetan...
  
  
• Yi
  Yi script
  The Yi script, also historically known as Cuan Wen or Wei Shu , is used to write the Yi languages.-Classical Yi:Classical Yi is a syllabic logographic system that was reputedly devised during the Tang dynasty by someone called Aki...
  
  

‡ No default system font provided in Windows. Braille, Ogham, and Runic are supported by Segoe UI Symbol.

External links

• MSDN: Introducing DirectWrite