epub-chinese-cleaner

Converts Chinese epub files from vertical (直排) + RTL page flow to horizontal (橫排) + LTR page flow.

What it does

1. Detects whether the epub needs conversion (checks CSS writing-mode and OPF page-progression-direction)
2. Converts writing mode from vertical-rl to horizontal-tb (including vendor prefixes)
3. Normalizes punctuation from vertical Unicode forms to horizontal equivalents
4. Fixes page direction by removing page-progression-direction="rtl" from OPF spine
5. Preserves original — outputs a new file with _horizontal suffix

Usage

Run the conversion script:

python3 scripts/convert_horizontal.py <input.epub> [-o output.epub]

If no -o is specified, output is <input>_horizontal.epub.

The script automatically:

• Tries Calibre CLI (TradSimpChinese plugin) if available at standard paths
• Falls back to direct epub manipulation if Calibre is not installed
• Skips conversion if the epub is already horizontal

Example

python3 scripts/convert_horizontal.py 三體.epub

Output: 三體_horizontal.epub

Self-test

python3 scripts/convert_horizontal.py --self-test

Creates a test epub with vertical layout, converts it, and verifies the output.

Punctuation mapping

See references/punctuation-map.md for the full vertical → horizontal punctuation mapping.