exclude powerline chars from min contrast for webgl and dom

[meganrogge]

related https://github.com/xtermjs/xterm.js/pull/3740/files

fixes #3741

[jerch]

@meganrogge Just a minor headsup - the webgl code considers a smaller codepoint range to be powerline glyphs: https://github.com/meganrogge/xterm.js/blob/341ca24dda672475f683eaf8f0ff6318e3143513/addons/xterm-addon-webgl/src/atlas/WebglCharAtlas.ts#L379

Is this intended? (If not, maybe the check should be coded in one central place to avoid incongruence?)

[meganrogge]

Yes I was wondering about that, but not sure. I might wait until @Tyriar is back to make further changes. Sound good?

[meganrogge]

Actually, should probably just be consistent. Will do

[jerch]

Yes I was wondering about that, but not sure. I might wait until @Tyriar is back to make further changes. Sound good?

Actually, should probably just be consistent. Will do

Well I dont mind, whatever suits your plans. My first reflex would be consistency over code repetitions, but I dont know if the webgl code has the smaller range for a good but non-obvious reason. Maybe go the consistency route in the first place, and introduce a special case in webgl code later, if @Tyriar had a specific reason for the smaller range?