Akkha Script Font

Overview

The working documentation for building the Akkha-Rik script font in Glyphs 3: vertical metrics, zone architecture, anchors and joiners, stacking behaviour, OpenType shaping and the reasoning behind a Unicode proposal. It supports the Akkha-Rik learning apps with a font that shapes the script correctly.

The problem

A script with a small community and no Unicode block has no reliable font, and a script whose consonants stack vertically breaks fonts that were designed for left-to-right Latin text: marks collide, lines clip and conjuncts protrude.

The approach

Decide the geometry first and write it down. Vertical metrics are fixed with a safety margin so stacked conjuncts are not clipped on Windows, macOS or the web, the script is divided into top, base and bottom zones, and marks attach on four sides of the consonant. Conjuncts are built as consonant, halant, joiner, with joiners for ya, ha and va. Typing order stays logical and phonetic while the shaping places marks visually.

Outcome

• Six generated spacing-test files with 104,246 combinations in total, from a base and one mark up to a base, subjoined consonant, mark, follower and follower-mark
• Vertical metrics, script zoning and the conjunct strategy are final; the tallest glyph sits safely inside the current metrics
• Private Use Area mappings are assigned for base letters and marks for development and testing
• The font licence and a Latin book edition are kept alongside

What it does

• A test matrix, not spot checks

  Start with base plus mark to catch protrusion, then kerning with followers, then the double-chain gaps. Each file targets one class of failure.

• Designed for a Unicode proposal

  The rationale for each decision is written so it can serve as evidence in a proposal, not only as notes to self.