Earlier quoted context omitted.
> Emojis and other symbols introduced new notions like colors that were not present before. I'm no longer certain that it is feasible to handcraft a font thwt contains all the symbols for codepoints affected by color modifiers. Color modifiers are just ZWJ sequences. Those existed before. The color modifiers themselves are not the most complicated things that get attached to ZWJ sequences among languages that Unicode…
So you agree that font rendering had to be extended to support color modifiers as specified in Unicode? That is the kind of completely creep that I am pointing out. A bunch of control codes are historically part of character encodings, and their encoding is very consistent within codepages of the same family (ASCII/ANSI and EBCDIC). You don't have to have any awareness about the active codepage/language to handle the…
Re: Why the trans flag emoji is the 5-codepoint sequence it is
#111Font rendering has always had to adapt to colors. There were (non-standard) multi-color fonts in the 8-bit era, too. It's not just emoji that are using OpenType color tables and OpenType color tables are not the only way that colors in emoji have been handled, just one of the most standardized/algorithmic methods. Part of why they were standardized is how much they resemble other tables needed for complex ligatures in other languages that aren't emoji. Emoji didn't invent complex ligatures with multi-table lookup to render. Emoji benefit from simple extensions of the exact same mechanic. It's a new table, yes, but it is not a complex table, it's one of the simplest tables in OpenType.