KAS Text

A rich-text processing library suitable for KAS and other GUI tools.

What it does (or plans to) do:

• Provides a representation for rich-text
• Manages loading and selection of fonts (partial)
• Transforms input text to a sequence of positioned glyphs
• Performs line-wrapping and alignment
• Supports bi-directional text
• Supports font shaping via HarfBuzz (optional: shaping feature; requires HarfBuzz library)
• Simple integrated "shaper" supporting kerning
• Provides helpers for text editing / navigation
• Fast line-wrapping when only width changes
• Scale well to large documents

What it does not do:

• Draw glyphs — this is left to other libraries such as glyph-brush
• Directly handle text editing — this is mostly about handling input, however this library does provide helper methods for navigating prepared text

What it arguably should do, but is beyond the current scope:

• Support font fallbacks for missing glyphs
• Emojis, vertical text, sub-ligature navigation, correctly positioning multiple diacritics, and many more details

For more, see the initial design document and issue #1.

Contributing

Contributions are welcome. For the less straightforward contributions it is advisable to discuss in an issue before creating a pull-request.

Testing is currently done in a very ad-hoc manner via KAS examples. This is facilitated by tying KAS commits to kas-text commit hashes during development and allows testing editing as well as display. A comprehensive test framework must consider a huge number of cases and the test framework alone would consitute considerably more work than building this library, so for now user-testing and bug reports will have to suffice.

Copyright and Licence

The COPYRIGHT file includes a list of contributors who claim copyright on this project. This list may be incomplete; new contributors may optionally add themselves to this list.

The KAS library is published under the terms of the Apache License, Version 2.0. You may obtain a copy of this licence from the LICENSE file or on the following webpage: https://www.apache.org/licenses/LICENSE-2.0