Font Lengths Generator

fontlengths is a Go tool that generates visual representations of character widths for all fonts installed on your system. It creates a PNG image for each font, displaying lines of repeated characters sorted by their pixel length.

This tool was inspired by a tweet about font character width visualization: https://twitter.com/FreyaHolmer/status/1776007184117063807

Features

• Automatic Font Discovery: Scans your system for installed fonts using go-findfont.
• Format Support: Supports both TrueType (.ttf) and OpenType (.otf) fonts.
• Visualization:
  • Generates a line for each letter from 'A' to 'Z'.
  • Each line consists of 20 repetitions of the character (e.g., "AAAA...").
  • Lines are sorted by their total pixel length (width), allowing you to easily see which characters are widest and narrowest in a specific font.
  • Images are rendered at high resolution (16pt font size at 300 DPI).
• Batch Processing: Processes all found fonts in one go.

Installation

Prerequisites

• Go (version 1.21 or later recommended)
• System fonts (standard on most operating systems)

Build from Source

1. Clone the repository:

   git clone https://github.com/arran4/fontlengths.git
   cd fontlengths

2. Download dependencies:

   go mod download

3. Build the binary:

   go build -o fontlengths ./cmd/generate

Usage

Run the built executable:

./fontlengths

The tool will log its progress as it finds and processes fonts.

Output

Generated images are saved in the out/ directory within the project folder. The directory will be created automatically if it doesn't exist.

Each file is named after the font's full name, for example:

• out/Arial.png
• out/Ubuntu Regular.png
• out/DejaVu Sans Mono.png

Example Output:

(Note: The above image is an example. Run the tool to generate images for your own fonts.)

Configuration

Currently, the tool operates with default settings hardcoded in cmd/generate/main.go. You can modify the source code to change:

• Font Size: Change the 16 in GetTTFontFace and GetOTFontFace calls.
• DPI: Change the 300 in the same calls.
• Text Content: Modify the loop in CreateImage (currently 'A'-'Z', repeated 20 times).
• Colors: Change image.White (background) or image.Black (text) in CreateImage.

Troubleshooting

• No fonts found: Ensure your system has fonts installed in standard locations. The go-findfont library searches common font directories.
• Permission errors: If the tool crashes or fails to write files, check that you have write permissions for the out/ directory.
• Skipped fonts: Some fonts might be corrupted or in an unsupported format. The tool logs these errors and skips to the next font.

License

This project is open source. See the LICENSE file for details.

Credits

• Inspiration: Freya Holmér
• Dependencies:
  • github.com/arran4/golang-wordwrap
  • github.com/flopp/go-findfont
  • golang.org/x/image
  • github.com/golang/freetype