chromium/src
0
Fork 0
Code Activity

[Render text] Added variation selector to doc + fixed incorrect unicode

Browse Source 
Added a bit on variation selector codepoints and fixed an incorrect codepoint in the airplane example

Change-Id: I849ad13b4408c8e3f2a0ff60aebe697ae8e30d39
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4220143
Reviewed-by: Elaine Chien <elainechien@chromium.org>
Commit-Queue: David Yeung <dayeung@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1101802}
This commit is contained in:
David Yeung
2023-02-06 21:54:16 +00:00
committed by Chromium LUCI CQ
parent 7d6c5f41e5
commit f0d81e3b76
1 changed files with 19 additions and 1 deletions

20
docs/ui/text_rendering/unicode_overview.md

@ -98,6 +98,24 @@ ZWJ (`U+200D`) is a zero width joiner and is a codepoint that joins two
codepoints together. Left-To-Right Embedding (`U+202A`) is a codepoint that
forces text to be interpreted as left-to-right.
Variation selectors are another set of codepoints that only affects their
surrounding character. These codepoints will affect the presentation of the
preceding character. For example an emoji + U+FE0E will set the emoji to a text
display while emoji + U+FE0F will set the emoji to the colored display. If you
do not specify a variation, the shaping engine will just pick the default glyph
in the font.
```
U+2708 maps to an airplane: ✈️
Adding a variation selector (U+FE0E or U+FE0F) will affect the way the emoji is
displayed
U+2708 U+FE0E = ✈︎
U+2708 U+FE0F = ✈️
```
## **Graphemes**
A grapheme is a sequence of one or multiple codepoints. For example, “e” and “é”
@ -119,7 +137,7 @@ multiple codepoints.
👨‍✈️ is actually a combination of
👨 Man (U+1F468) +
Zero Width Joiner (U+200D) +
✈️ Airplane (U+FE0F)
✈️ Airplane (U+2708)
```
**Note: Graphemes are not breakable!**
Because of codepoints such as diatric or joiners that can append multiple