Metal renderer: wrong antialiasing with CJK text
- iTerm2 version: 3.2.20180422-nightly
- OS version: 10.13.4 (17E202)
- com.googlecode.iterm2.plist
- debuglog.txt.gz
Detailed steps to reproduce the problem
- Enter some CJK text.
What happened
With the Metal 2 renderer (which I just started experimenting with today), antialiasing could go wrong as CJK text may appear thicker than they should be. What makes this more interesting is that if I just wait a few seconds, the problem may just disappear, and reappear at a later time. See the following screenshots, which were only taken a few seconds apart, with no human input in between. The difference in stroke thickness should be fairly obvious.
By the way, my non-ASCII font is simply anti-aliased 10pt Monaco, which doesn't contain CJK glyphs, so a system font is chosen for me (probably Heiti SC).
I used "Capture Metal Frame" twice, once for each of the screenshots above.
Here's the plain text used in the example:
汉语,书写可称汉文、中文、华文(马来西亚和新加坡)、唐文、国文(台湾),语言又称华语(马来西亚和新加坡)、唐话、中国话、普通话(中国大陆)、国语(台湾)等,是包括了闽东话、客家话、闽南语、粤语、普通话、山东话、上海话等等地方语言的语族,汉语当中的普通话(Mandarin)是联合国官方语言之一[注 1],属汉藏语系的分析语,具有声调。汉语的文字系统——汉字是一种意音文字,表意的同时也具一定的表音功能。汉语包含书面语以及口语两部分,古代书面汉语称为文言文,现代书面汉语一般指使用现代标准汉语语法、词汇的中文通行文体(又称白话文)。目前全球有六分之一人口使用汉语作为母语。汉语内部的语言主要分为官话、吴语、闽语、粤语、湘语、客家语和赣语等七种;根据语言学的定义,他们都是独立的语言。