Apple Inc.

Digital Equipment Corporation

John I McConnell

Peter K Edberg

Andrew Michael Daniels

Yung-Fong Frank Tang

Mordehai Huberman

A character code conversion system that provides round trip fidelity, while ensuring that the resulting character codes are interchangeable with other platforms. The code conversion system is able to map a single source character or a sequence of characters to either a single target character or a sequence of target characters. With round trip fidelity, source text can be converted to target text and then back again to the original source text. The interchangability is ensured by maximizing the use of standard target characters, and by minimizing the use of private characters. The code conversion is particularly useful for converting to/from Unicode characters from/to other character sets.

Unicode converter

A code conversion system that takes direction into consideration when converting characters from a source character encoding to a target character encoding is disclosed. The code conversion system is able to map a single source character or a sequence of characters to either a single target character or a sequence of target characters. By determining or resolving the direction of the characters being converted, the code conversion system can then utilize the determined or resolved direction of the characters to ensure that the correct mapping to the target character encoding is obtained.

Bidirectional code converter

A code conversion system that takes context into consideration when converting characters from a source character encoding to a target character encoding. The code conversion system is able to map a single source character or a sequence of characters to either a single target character or a sequence of target characters. By determining the context of the characters, the code conversion system can then utilize the determined context of the characters to ensure that the correct mapping to the target encoding is obtained.

Context-based code convertor

A truncation technique for a character code conversion system is disclosed. The truncation technique ensures that a source string received for conversion is accurately converted into a different, target character encoding even when the source string exceeds the length of an input buffer which holds the source string for conversion. The truncation processing technique operates to truncate a portion of the source string held in the input buffer so that the truncated portion is able to be converted to the target character encoding without being affected by subsequent characters in the source string.

Code converter with truncation processing

A method and apparatus for generating glyphs for text elements input to a computer having a memory with at least one look-up table storing glyphs corresponding to such text elements. Each text element is made up of at least one code point, and often of several code points. The system searches the table for a glyph representing an input text element, and if it is not found methodically generates subsets of the text element and searches the table for glyphs representing each of the subsets. Default characters are generated for code points not represented in the table. The system uses a classification for each code point, such as the Unicode classifications, and handles unknown code points in a manner dependent upon their classification. Where a text element includes two characters with an intermediate joining character, and the text element as a whole is not represented in the table, the two characters are output for rendering separately. Where a text element includes combining characters and the combined text element as whole is not represented in the table, the system generates the characters separately and then combines them for rendering as a single glyph. Unknown combining characters are replaced by a code point for a blank combining character, for allowing any surrounding combining characters to be rendered in a combined fashion.

Growing community of inventors

Menlo Park, CA, United States of America

John I McConnell