On Screen Protractor

Question

A handy program for measuring the pixel dimensions of something on-screen is screen ruler:

sudo apt install screenruler ; screenruler

I like how you can place it anywhere on your screen and it stays on top of all other applications as you use it.

I'm hoping to find something similar to this that's a protractor instead of a ruler.

I searched for "protractor" in the repository of Debian 11 and got no results:

sudo apt-cache search "protractor"

Such a tool would be great for measuring angles on-screen. However, ultimately, I will likely need something that can actually draw a line based on a specified angle.

Hopefully I won't have to learn something as sophisticated as AutoCad in order to accomplish this. What's the simplest way to measure and draw angles in Linux?

Answer 1

I've written a tool for this exact purpose a few years ago, and even uploaded it to github. But apparently I set the repository to private, probably by accident. That's fixed now.

• Anyway, here you go: https://github.com/fritzw/pyqtprotractor
• Another more powerful tool I found is this one, written in Rust: https://github.com/epilys/rlr
• And an old tool written in C++ with Qt: https://github.com/kellpossible/qProtractor

Example usage: Measuring the angle of the OSI logo.

Answer 2

Another option would be this great Chrome plugin (I'm not the author): Protractor https://chrome.google.com/webstore/detail/protractor/kpjldaeddnfokhmgdlmpdlecmobaonnj/related

Not that hard to take a screen shot and open it in Chrome to measure angles

Or measure right on a web page, if that suffices.