Creating circles

We now can easily construct a single strut by using std::geo2d::Circle() and repeat the lesson we had before, but our Lego brick needs three of them.

The shape of each strut remains the same - they’re simply offset horizontally by 8mm to left and right. From the concept we know already, a first solution could be to write the strut three times and translate them using std::ops::translate().

use std::geo2d::*;
use std::ops::*;

Circle(d = 6.51mm) - Circle(d =  4.8mm);
(Circle(d = 6.51mm) - Circle(d =  4.8mm)).translate(x = 8mm);
(Circle(d = 6.51mm) - Circle(d =  4.8mm)).translate(x = -8mm);

The code above produces the expected result. However, the code is quite repetitive. We could improve it slightly by storing the expression Circle(d = 6.51mm) - Circle(d = 4.8mm) in a value, say strut. But even then, we’d still need to write out each translate(...) call manually.

And more importantly: What if we wanted the number of struts to be flexible or generated dynamically?

To solve this in a clean and scalable way, µcad supports multiplicity, allowing us to generate repeated geometry with minimal, reusable code.

Let’s explore that next.

TODO

• Do we need to explain that we now uses ( .. ).translate() instead of curly brackets?