Quick ruler

Use: Drawing straight lines fast and having maximum control of the line look.

Description how would it work: So idea is you hold (for exampe) Shift while having brush tool selected and it creates Screenspace horizontal, vertical, 45deg assistant ruler at the position of your brush that you can trace. Quick ruler are closed (assistants removed) when Shift is relased and youre free to keep painting.
  
Why not just use Line tool?
-Line tool require you to change tool and you will always get pretty uniform line that stands out.

Why not just use Assistan tool?
-Its just takes to long to place assistants, switch tools, just to draw line.

Hello,
you can use "v" or "v+shift" to do that :
https://docs.krita.org/en/reference_man ... /line.html

The difference between v + shift and the proposed solution is that

(1) trying to do the v + shift trick is tricky, you need to first press v, then start drawing a line, then press shift to make sure it's aligned to one of those angles, then finish the line. Shift during making a line is what I think makes Line tool lines this look of unnaturalness despite being pressure-sensitive like all strokes.

(2) when you make a line with a line tool, it has a bigger delay than when you draw next to the assistant.

On the other hand, that would require creating at least four assistants - all 90* and 45* - but as far as I remember from trying to paint with two ellipses, two rulers and one vanishing point, the more assistants you have, the laggier Krita is, and five assistants was outside of my laptop's abilities. Granted, most of the time those assistants would be disabled (since I guess it's better to create them once and just change the visibility), but still, it can be a bit laggy while drawing with the modifier that makes them enabled.

I personally don't see much of a use for this. V + Shift seems to be enough.
But if you must, adding another Tool Invocation that can activate both Line tool + Straight fucntions at once would be good, in my opinion...

@tayloryoung
If You dont see difference in how line look between drawing line using assistants and line tool Im unable to convince You.
Issue is not about that Im to lazy to press SHIFT while using line tool to get horizontal line, Its about how this line looks and not using line tool all together.

I really like assistant tool and i wish using it would be somehow faster.

@Zer0Frost

Yes, I have no idea what's the difference in resulting looks. Could you attatch a screenshot or video comparing those?

@tayloryoung

Using Assistant allows you to have more control over lines.




Assistant quality more suits my style where Line tool feels out of place.

@Zer0Frost

Ok, I see what you mean.
Have you tried the shortcut? As a workaround, you can toggle the assistant with any shortcut. (Check Settings > Configure Krita > Keyboard Shortcuts > Krita > Painting > Toggle Assistant)

@tayloryoung

Yes and here's where inefficiency of using Assistants come:
Lets say you use "V" as shortcut, It looks like this:

Pess B for brush and paint
Hold V to Bring up Assistant tool
if ( doing this first time after opening krita == true)
{
Switch elipse to Ruler;
Now you do longer have to hold V because Assistant Tool got Selected;
};
Set up two points
Press B to select brush
if ( doing this first time after opening krita == true)
{
Click on Tool Options tab;
Turn on Snap to Assistant;
};
Draw a line you want
Hold V to Bring up Assistant tool
Remove Assistant
Release V and look how your tool got reset to Select Shapes Tool
Press B to select brush

If you need assistants for some complex scene and setup bunch of them at once this workflow is not so bad.
But if you are in dire need of straight line right now this is bad.