Last updated on August 26th, 2026 at 11:47 am
The main lesson is simple: mixed Japanese, Chinese, Korean, and English text needs more than ordinary word wrapping. A reliable image renderer must choose a font with the right glyphs, preserve Latin words, allow CJK text to break between characters, and invalidate old cached images after the logic changes.
Why normal wrapping fails
English text usually has spaces, so a renderer can wrap at word boundaries. CJK text often has few or no spaces. A space-only wrapper may let a long line overflow.
Splitting every character fixes that overflow, but creates a new problem: an English word inside the same title can be cut in half.
What I learned
The solution is script-aware wrapping. Treat consecutive Latin letters and numbers as one token. Treat CJK characters as safe break points. Then measure each candidate line using the actual font and font size.
Character counts are not enough because glyph widths vary. The renderer must use the font engine’s bounding-box measurement before deciding whether a token fits.
A practical rendering process
- Inspect the text. Detect whether it contains Japanese, Chinese, or Korean characters.
- Select a compatible font. Use a font that includes the required glyphs. A fallback font is useful when the normal Latin font lacks them.
- Build safe tokens. Keep Latin words intact while allowing CJK characters to wrap individually.
- Measure and fit. Add tokens one at a time, measure the rendered width, and start a new line when the limit is exceeded.
- Regenerate cached images. Change the renderer’s cache version or key so old output is not mistaken for a failed fix.
Example
For a title containing Korean text and the English word ExampleGame, the wrapper may break between Korean characters or phrases. It should keep ExampleGame on one line whenever the image width allows it.
If that single English word is wider than the image, reduce the font size or apply a deliberate overflow rule. Do not silently split it character by character unless that behavior is explicitly wanted.
Common mistakes and fixes
- Cause: the chosen font has no CJK glyphs. Fix: select a font based on the text’s Unicode scripts.
- Cause: wrapping happens only at spaces. Fix: add character-level break points for CJK text.
- Cause: all characters are treated as separate tokens. Fix: group consecutive Latin characters into whole words.
- Cause: the code is fixed but the image looks unchanged. Fix: invalidate the generated-image cache.
Conclusion
Mixed-script image text works best when font selection, tokenization, width measurement, and caching are treated as one rendering pipeline. The next action is to add a test title that combines CJK text with one long English word and verify both its line breaks and regenerated output.