gunter 1.0.4

Program to turn any image of glyphs into a .hex-like format, and that into a .bdf

Gunter

Gunter is a collection of tools for processing GTR files. It provides utilities for converting images to GTR format, indexing GTR files, merging GTR files, and converting GTR files to BDF fonts.

---

Installation

You can install gunter using pip:

pip install gunter

Alternatively, you can install it from the source:

1. Clone the repository:

   git clone https://git.icosahedr.online/sapero/gunter.git
   cd gunter
   

2. Install the package:

   pip install .
   

---

Usage

gunter provides several commands for processing GTR files. Each command can be accessed via the gunter command-line tool.

General Syntax

gunter <command> [options]

Available Commands

1. sheet

Convert an image containing cells with drawn characters into a .gtr file.

Usage:

gunter sheet -i <input.png> -x <cell_width> -y <cell_height> -o <output.gtr>

Options:

• -i, --input: Path to the input image file.
• -x, --width: Width of a cell in the image.
• -y, --height: Height of a cell in the image.
• -o, --output: Path to the output .gtr file.

Example:

gunter sheet -i characters.png -x 8 -y 16 -o font.gtr

Note: Empty cells are skipped, except if that empty cell is the first cell (if you want to have a dedicated SPACE character) of the image.

---

2. draw

Convert between a character drawn in a text file into a gtr string and back.

Usage:

gunter draw <mode> -i <input>

Modes:

• txt: Convert a text file into a gtr string.
• gtr: Print the text a .gtr

Options:

• -i, --input: Path to the input file OR input string.

Example:

gunter draw gtr -i 5/00888888F820202000
gunter draw txt -i character.txt

Note: The text file must consist out of hyphens and hashtags.

---

3. index

Reindex a .gtr file using a character list.

Usage:

gunter index -g <input.gtr> -c <characters.txt> -o <output.gtr>

Options:

• -g, --gtr: Path to the input .gtr file.
• -c, --char: Path to the file containing the characters.
• -o, --out: Path to the output .gtr file.

Example:

gunter index -g font.gtr -c characters.txt -o reindex.gtr

Note: The character list file must be in UTF-8.

---

4. merge

Merge two .gtr files into one.

Usage:

gunter merge -1 <gtr1.gtr> -2 <gtr2.gtr> -o <output.gtr>

Options:

• -1, --gtr1: Path to the first .gtr file.
• -2, --gtr2: Path to the second .gtr file.
• -o, --out: Path to the output .gtr file.

Example:

gunter merge -1 set1.gtr -2 set2.gtr -o merged.gtr

Note: Both GTR files may not contain characters on the same codepoint

---

5. to_bdf

Convert a .gtr file into a .bdf font using a JSON properties file.

Usage:

gunter to_bdf -i <input.gtr> -j <properties.json> -o <output.bdf>

Options:

• -i, --input: Path to the input .gtr file.
• -j, --json: Path to the JSON properties file.
• -o, --output: Path to the output .bdf file.

Example:

gunter to_bdf -i merged.gtr -j props.json -o font.bdf

---

Example Workflow Script

This is in a project with many images of different widths (and those images/character lists labelled with said width)

files=("1" "2" "3" "4" "5" "6")
height=9

echo -n > font.gtr
for file in "${files[@]}"; do
	gunter sheet -i res/${file}.png -x ${file} -y ${height} -o /tmp/${file}.gtr
	gunter index -g /tmp/${file}.gtr -o /tmp/${file}.gtr -c res/${file}.txt
	gunter merge -1 font.gtr -2 /tmp/${file}.gtr -o font.gtr
done

gunter to_bdf -i font.gtr -j res/props.json -o font.bdf

---

Properties.JSON

The following JSON structure represents the default font properties used in Gunter:

{
    "version": "1.0.0",
    "foundry": "author",
    "family_name": "default",
    "weight_name": "medium",
    "slant": "R",
    "pixel_size": 16,
    "resolution_x": 72,
    "resolution_y": 72,
    "average_width": 80,
    "charset_registry": "ISO10646",
    "charset_encoding": "1",
    "x_height": 8,
    "font_ascent": 14,
    "font_descent": 2,
    "default_char": 32,
    "right_margin": 0
}

Property Descriptions:

• version: Version of the font metadata.
• foundry: Author or creator of the font.
• family_name: Name of the font family.
• weight_name: Weight classification of the font (e.g., light, medium, bold).
• slant: Slant style (e.g., "R" for regular, "I" for italic).
• pixel_size: Size of the font in pixels.
• resolution_x / resolution_y: Font resolution in DPI.
• average_width: Average character width.
• charset_registry / charset_encoding: Character encoding standard.
• x_height: Height of lowercase letters like 'x'.
• font_ascent: The ascent height of the font.
• font_descent: The descent depth of the font.
• default_char: Default character used for missing glyphs.
• right_margin: Right-side spacing after each character.

---

License

This project is licensed under the MIT License. See the LICENSE file for details.