Terminal rendering shows space between lines with zoomlevel:1

[jordwalke]

cc @Tyriar

My terminal application draws background color, and this is how it looks. I believe this is a bug.

[Tyriar]

Must be a mac-specific issue, what's in your settings.json?

[jordwalke]

// Place your settings in this file to overwrite the default settings
{
    "editor.fontFamily": "Menlo, 'PragmataPro', Menlo, Monaco, 'Courier New', monospace",
    "window.zoomLevel": 1
}

I discovered that this doesn't happen at window zoomlevel 0.

[Tyriar]

Does setting "terminal.integrated.lineHeight": 1.2 fix the problem at "window.zoomLevel": 1
and others? I think Mac has a different line-height that's inherited from the editor, maybe it could just use 1.2 too if so?

On my Linux machine it works until zoom level is 4.

[jordwalke]

There's a couple settings that don't work on my setup. 1 and -1 both have the same issue. 4 works on my system. It could be some combination of my retina screen with the zoom level etc which causes some rounding error.

[Tyriar]

Yes that's likely the case

[Tyriar]

Will likely be fixed when #9958 is implemented

[jordwalke]

So what's happening in this bug? When I set lineheight=1, and I used a font like PragmataPro, the text should fit perfectly within one line correct? But with lineheight=1, (zoom level 0 or 1), you can see that text is clipped. Is this related?

{
    "editor.fontFamily": "PragmataPro, Menlo, Monaco, 'Courier New', monospace",
    "window.zoomLevel": 1,
    "editor.fontSize": 14,
    "terminal.integrated.lineHeight": 1.0
}

Then, as originally discussed setting lineheight to 1.2 causes there to be lines between the background:

{
    "editor.fontFamily": "PragmataPro, Menlo, Monaco, 'Courier New', monospace",
    "window.zoomLevel": 1,
    "editor.fontSize": 14,
    "terminal.integrated.lineHeight": 1.2
}

I think the the clipping at line height 1 is unrelated but not correct, but it has me wanting to increase the lineheight, which then surfaces the originally reported bug.

When the terminal draws "background color", shouldn't it be filing in the additional line space below it?

[Tyriar]

The way this will be fixed is by implementing "virtual selection" upstream xtermjs/xterm.js#207

It's the next terminal feature I want to work on and it will allow xterm.js to completely control the selection model, how it's rendered and how it's copied which will fix a huge amount of issues with the terminal. Here's the list of impacted issues it will touch when I last checked:

(moved the list to #9958 (comment))

[Tyriar]

Fixed in #9958, xtermjs/xterm.js#670