Resolution independence

Resolution independence in Mac OS X v10.4 in iWeb. Note the Apple logo is pixelated; it is rendered as a bitmap.

Resolution independence is a computing concept whereby elements on a computer screen are rendered at sizes independent from the pixel grid, resulting in a UI that is displayed at a consistent size, regardless of the size of the screen.

Concept

As early as 1978, the typesetting system TeX due to Donald Knuth introduced resolution independence into the world of computers. The intended view can be rendered beyond the atomic resolution without any artifacts, and the automatic typesetting decisions are guaranteed to be identical on any computer up to an error less than the diameter of an atom. This pioneering system has a corresponding font system, the Metafont, which provides suitable fonts of the same high standards of resolution independence.

The terminology Device independent file format is the file format of Donald Knuth's pioneering TeX system. The content of such a file can be interpreted at any resolution without any artifacts, even at very high resolutions not currently in use.

Implementation

Mac OS X

Apple has included some support for resolution independence in earlier versions of Mac OS X, which could be demonstrated with the developer tools Quartz Debug, which included a feature which allows the user to scale the interface. However, the feature was incomplete, as some icons will not show (such as in System Preferences), UI elements were displayed at odd positions and certain bitmap GUI elements are not scaled smoothly.^[1] Since Mac OS X v10.7, Apple has removed the rudimentary support for resolution independence, and prepared the operating system for HiDPI modes, which simply double the resolution in every direction.

The Mac OS X 10.5.2 System Preferences dialog, non-scaled (left) and scaled (right)

Microsoft Windows

Microsoft Windows has supported DPI aware programs since Windows Vista^[2] and allows user specified DPI settings for the windowing interface^[3]

The Windows Presentation Foundation from Microsoft, and consequently, WPF applications, are also designed to be resolution-independent.

Other

Although not related to true resolution independence, some other operating systems use GUIs that are able to adapt to changed font sizes. Microsoft Windows 95 onwards used the Marlett TrueType font in order to scale some window controls (close, maximize, minimize, resize handles) to arbitrary sizes. AmigaOS from version 2.04 (1991) was able to adapt its window controls to any font size.^{[not in citation given]}

Video games are often resolution independent; an early example is Another World (video game) for DOS, which used polygons to draw its 2D content and was later remade using the same polygons at a much higher resolution. 3D games are resolution independent since the perspective is calculated every frame and so it can vary its resolution.

See also

• Display PostScript
• Fresco (computing)
• Metrics: Himetric and Twips
• Page zooming

References

External links

Declaration of resolution-independence by John Siracusa