femto | A terminal based text editor written in rust in 300 LOC | Editor library

I know that you might not accept this answer because it is written in C++. That's ok; I just want to show you a possible approach for detecting the squares. I'll try to include as much detail as possible if you wish to port this code to Python.

The goal is to detect all 9 squares, as accurately as possible. These are the steps:

1. Get an edge mask where the outline of the complete cube is clear and visible.
2. Filter these edges to get a binary cube (segmentation) mask.
3. Use the cube mask to get the cube’s bounding box/rectangle.
4. Use the bounding rectangle to get the dimensions and location of each square (all the squares have constant dimensions).

First, I'll try to get an edges mask applying the steps you described. I just want to make sure I get to a similar starting point like where you currently are.

The pipeline is this: read the image > grayscale conversion > Gaussian Blur > Canny Edge detector:

In Visual Studio, precompiled header is usually named "pch.h" (for console based applications), but it is possible to use different name, or not use it at all. Which file would be precompiled header, if any, is determined by projects settings.

If the precompiled header file is "pch.h" and the compile option is /Yu, Visual Studio will not compile anything before the #include "pch.h" in the source file; it assumes all code in the source up to and including that line is already compiled.

So, you could write in the following form:

what would be the most paradigmatic way to work with a 'unit' ratio?

The most pragmatic way to work with a unit ratio is to not use it.

It's a bit like asking what is the best way to multiply by 1. You don't.

For example, when duration_cast-ing to whole seconds.

You would write std::chrono::duration_cast.

std::ratio<1,1> has no name because you never need a name for it. For example std::duration has already a default period of std::ratio<1,1>.

If you still want to give it a name you can do so:

The problem is that the ::before element used to be on the background robot div which has height and width applied so the positioning, width and height of the ::before element had values to style against.

Since you moved everything to the span, there is nothing telling that element how to size.

Here's an updated pen with the span moved to the background div:

https://codepen.io/chrislafrombois/pen/XWdpQVd

Here's the code that changed: