By Prince McLean

Published: 11:00 AM EST

Apple Computer is looking to secure exclusive rights to techniques required to produce resolution independent user interfaces, one of the supported features of its forthcoming Mac OS X Leopard operating system.

The Cupertino, Calif.-based Mac maker described several approaches to the technique in a July 21, 2006 filing with the United States Patent and Trademark Office titled "Resolution Independent User Interface Design", which was first published on Thursday.

Essentially, the technology breaks the software assumption that all display output is to be rendered at 72 dots per inch (DPI), allowing an operating system like Mac OS X to draw or represent user interface elements using a scale factor.

"The invention provides a method to represent a graphical user interface object's material map in a procedural and, therefore, resolution independent manner," Apple wrote in the filing. "The method includes receiving values for each of a plurality of attributes associated with a material map object, associating a value for each of the plurality of attributes, and storing the plurality of attributes and their associated values in a file."

The company said 'recipe' files for resolution independent user interfaces may be "flat" or hierarchically-ordered, where a collection of attribute-value pairs form a complete description of the graphical user interface object's material map, hence allowing a rendering module to create a visual representation of the material map at any number of resolutions.

In one interesting aspect of the otherwise predominately procedural filing, Apple notes that "because material maps in accordance with the invention are represented procedurally, they may be encrypted to prevent unauthorized inspection or use."

Another benefit of the technology, the company said, is that each user interface attribute may be associated with a plurality of values, thereby permitting the designer to optimize an object's design for each of a specified number of resolutions.



In a case where the displayed resolution of the graphical object falls between two of the resolutions specified by the designer, a rendering engine may interpolate between the two values -- a technique that generally provides a significantly improved display -- Apple added.

Earlier this year, Apple informed developers through documentation for Leopard that the introduction of resolution independence means that they may have some work to do in order to make their applications look as good as possible.

"For modern Cocoa and Carbon applications, most of the work will center around raster-based resources," the company said. "For older applications that use QuickDraw, more work will be required to replace QuickDraw-based calls with Quartz ones."

Apple's intention to support resolution independence with Mac OS X was first detailed in an August 2004 AppleInsider report.