feamerge 0.1.4

Python script to merge Adobe feature files into a single variable feature file

feamerge

Merge Adobe feature files into a single variable feature file

feamerge is a tool designed to solve the challenge of compiling designspace files with varying OpenType features. It automates the preprocessing of UFO feature files—expanding kerning and positioning groups—before merging them into a valid variable font feature file.

🔄 New Workflow

Previously, this process required running three separate scripts manually. With version 0.1.1, these have been unified into a single command:

1. Break Kerning Groups: Expands @group definitions into individual glyph-to-glyph pairs.

2. Break Positioning Groups: Expands group references in mark, abvm, and blwm statements into single-glyph anchor rules.

3. Intelligent Merge: Combines the expanded features from all masters in the designspace into variable font syntax (e.g., pos A A (wght=400:10 wght=900:20)).

🚀 Installation

The package now supports standard Python installation, which automatically sets up the feamerge command in your environment.

# Create and activate a virtual environment
python3 -m venv venv
source venv/bin/activate  # On Windows use `venv\Scripts\activate`

# Install the package and dependencies
pip install .

💻 Usage

Command Line (Recommended)

You no longer need to call individual Python files. Simply use the feamerge command:

feamerge path/to/YourFont.ufo MyFont.designspace variable_features.fea

Programmatic Usage

If you still wish to use the combiner logic directly in a script:

from feamerge.combine_features import VariableFeatureCombiner

combiner = VariableFeatureCombiner("path/to/font.designspace")
combiner.save_combined_features("output/variable_features.fea")

📜 Changelog

v0.1.3

Bug Fixes & Pipeline Enhancements:

• Added ufoLib2 to packaging dependencies.
• Corrected package license configuration file reference.
• Fixed CLI to preprocess all masters and properly chain sequential expansion steps.
• Implemented fallback to retrieve anchor coordinates from UFO glyph data for empty feature anchor definitions.
• Renamed and restructured combiner module to combine_features.

v0.1.2

Package Restructuring: Moved all scripts into the feamerge/ package directory for proper bundling.

Unified CLI: Added a single feamerge entry point to run the entire preprocessing and merging sequence automatically.

Improved Metadata: Consolidated project configuration into pyproject.toml.

Version Bump: Updated version to 0.1.1.

v0.1.0

Initial release with separate scripts for kerning expansion and feature merging.

Key Features

• Designspace Integration: Handles both absolute and relative paths for UFO source references.

• Variable Font Syntax: Generates coordinate:value pairs for positioning rules.

• Intelligent Merging: Deduplicates glyph classes and maintains OpenType features across masters.