Turn on the stem darkening may improve the cjk characters display quality.
In the following issue, I noticed some cjk characters' glyph are different in GTK and Qt. In GTK program, some characters' bottom pixel are obviously lower than others.
Now I find the stem darkening function of freetype causes the difference. When turn it on , freetype makes the problem alleviated, as in Qt application. But it also brings side effects: the strokes get darker.
With this feature, freetype modified the font's glyph and color to make it darker. I don't know should we turn on the feature on GTK, because we have no gamma correction, stem darkening will make the strokes too darker. Or we can add a series of switches, anyone need them can turn it on.
Steps to reproduce
- use gtk program, set the "Noto Sans Mono CJK SC 12" as the program font.
- copy these characters "配置创建类型帮助键盘" and paste them into the text box.
The "置", "创", "类", "键" are lower than others.
Turn this feature on manually, characters' shape is better than before. (but too black)