17 Februari, 2009

Windows 7 Fonts

As an integral part of taking the graphics capabilities of Windows 7 to the next level, Microsoft has also catalyzed the evolution of text, both in relation to typography and text rendering, in the next iteration of the Windows client. According to Microsoft, over 80% of the time spent in front of a computer is related to either reading or writing text. This is why the Redmond company has poured resources into improving the quality of text in Windows 7, quality which is synonymous with typography. “As a platform, the role of Windows is to deliver great presentation of text and offering software developers great tools for creating the best presentation possible in the context of the software they develop,” revealed Worachai Chaoweeraprasit, a development lead on the Graphics feature team.

First off, Windows 7 is designed to kick ClearType up a notch. Taking advantage of the LCD pixel architecture and leveraging the human visual system, ClearType manages to spread the energy associated with a single pixel to the neighboring sub-pixels in, making text appear sharper. In Windows 7, ClearType comes with increased clarity, allowing end users to opt from a wider variety of granular choices via the ClearType Text Tuner.

“One of the graphics improvements we made in Windows 7, therefore, is to move from the physical pixel model of the past, and instead creating a new design around what we call the “device independent pixel” unit (or “DIP”), a “virtual pixel” that is one-ninety-sixth an inch in floating-point data type,” Chaoweeraprasit added. “In this model, a glyph (or any other geometric primitive for that matter) can size to fractional pixels, and be positioned anywhere in between the two pixels. The new ClearType improvement allows sizing and placement of glyph to the screen’s sub-pixel nearest to its ideal condition, creating a more natural looking word shape and making text on screen look a lot closer to print quality.”

Users will be happy to know that in Windows 7 they will be able to enjoy an estimated 40% more fonts than in Windows Vista, which in its turn also delivered 40% more fronts over XP. Microsoft currently plans to ship no less than 235 fronts with Windows 7, having offered just 191 in Vista and 133 in XP. “The default common controls’ font dialog and the font chunk in Windows 7 Ribbon are also updated to be more intelligently selective of what fonts to be present to the user of the current user’s profile. Depending on a number of settings including the current UI language, the user locale, and the current set of keyboard input locales, the font list hides fonts of languages not typically used by the user of different culture and locale,” Chaoweeraprasit said.

At the same time, the evolution of the Windows 7’s new font system now allows the operating system to group fonts. In Vista’s successor, collections will dictate how fonts are organized, based on the stylistic root of fonts. Chaoweeraprasit explained that “the notion of “font collection” allows partitioning of fonts sharing the same usage into a separate namespace. The system collection is similar to what exists today and is created and managed by the system whereas custom collection can be created and managed, as many as needed, entirely by the application program.”

In Windows 7, users will notice that Microsoft has added a new font, namely “Gabriola,” developed by John Hudson. The addition is just an accessory to the new level of OpenType support introduced in the next version of Windows. An offshoot of the TrueType Open technology Microsoft, OpenType controls the interaction and transformation of glyphs in stages.

“Windows 7 new text system not only uses available OpenType features internally but also allows access to any feature made available in the font in the high level programming interface, making it easier for application developer to discover and exercise the font feature in mainstream scenario,” Chaoweeraprasit said. “Gabriola makes heavy use of contextual letterforms and offers an unprecedented number of stylistic sets for different usages of the font in different occasions.”

According to Microsoft, Windows 7’s new text system has been assembled into what the company referred to as the DirectWrite self-sufficient system. This because, even in the early stages of development the company labored to resolve the shortcomings of non-homogeneous text processing.

“The [DirectWrite] API is provided in four layers – the interfaces for font data, rendering support, language processing, and typesetting, each built upon the others with the lower layer makes no requirement to the upper one, and none depends on a specific graphics model. To illustrate the latter point, the figure below shows a sample application that uses the new typesetting interface and language processor while the final rendering happens as an extruded filled 3D geometry from the 2D graphics environment also new to Windows 7 called Direct2D,” Chaoweeraprasit said.