font2bytes

Python program to create new fonts for e-Paper / e-Ink displays. Generate C font files for e-Paper from TTF files.

Acknowledgments

Forked from TheHeXstyle's font2byte.

Rational

I am super happy of my e-ink display from Waveshare, but their library only offers basic fonts types, and only 5 fonts sizes (font8, font12, font16, font20 and font24). This is unfortunately very limiting :(

This python script is inspired by the waveshare blogpost this. But they do not provide any code to use...

On the other hand the font2bytes from Dominik Kapusta is available but requires C++ compilers.

This is a version in Python. It converts a .ttf font file into a C file compatible with Waveshare/STMicroelectronics fonts.h (sFONT type struct). It only recreates ASCII caracters, but you can use any font and specify any size.

Requirements

• Python 3
• Pillow library (NOTE: Pillow and PIL cannot co-exist in the same environment. Before installing Pillow, please uninstall PIL.)
• numpy library

The simplest way is probably to run it with uv thanks to the pyproject.toml file:

uv run font2bytes.py

Use

1. Get any font you want to use (.tff). Some are available in the ./fonts folder.

2. Run font2bytes, example for 40 pixel Roboto Bold font:

uv run font2bytes.py --ttf-input-file ./fonts/Roboto-Bold.ttf --height 40 --output-dir output/

3. C font file is created under --output-dir directory. Name is derived from TTF filename, in the example: output/FontRobotoBold40.c

4. Copy this C file within you project source folder (Arduino, STM32, ...)

5. Modify fonts.h to add a new extern, example: extern sFONT FontRobotoBold40;

6. Use the new font and enjoy!

Paint_DrawString_EN(5, 0, "Made with font2bytes!", &FontRobotoBold40, BLACK, WHITE);

Examples

Within the ./output folder there are already a couple of .c files already generated that can be used without running font2bytes program.

font2bytes Usage

usage: font2bytes [-h] [-t TTF_INPUT_FILE] [-o OUTPUT_FILE | -d OUTPUT_DIR] [-n FONT_NAME]
                  [--height HEIGHT] [--width WIDTH] [--threshold THRESHOLD]
                  [--font-offset FONT_OFFSET] [-b BMP_DIR]

Generate C font files for e-Paper (WaveShare like) from .ttf files

options:
  -h, --help            show this help message and exit
  -t TTF_INPUT_FILE, --ttf-input-file TTF_INPUT_FILE
                        A .ttf font file (default: ./fonts/Roboto-Regular.ttf)
  -o OUTPUT_FILE, --output-file OUTPUT_FILE
                        C output filename (default: None)
  -d OUTPUT_DIR, --output-dir OUTPUT_DIR
                        C output directory. Use --font-name as file name or guess it.
                        (default: ./output/)
  -n FONT_NAME, --font-name FONT_NAME
                        Name of the sFONT object in the C file. If unspecified derive it
                        form input file name. (default: None)
  --height HEIGHT       Height of the generated font in pixel (default: 36)
  --width WIDTH         Width of the generated font in pixel. Defaults to 3/5 of --height.
                        (default: None)
  --threshold THRESHOLD
                        Image intensity threshold for binary conversion. It changes the
                        contrast of the final font. (default: 120)
  --font-offset FONT_OFFSET
                        Font offset, recommended to be at least 4. (default: 4)
  -b BMP_DIR, --bmp-dir BMP_DIR
                        Folder to save BMP intermediate image, if unspecified BMP image are
                        not saved. Useful for debugging. (default: None)

Authors

• TheHeXstyle
• jfgd

License

GPL v3.0, see LICENSE for details.