Implementation of new functions setRandom2D() and setRandom3D() in p5.Vector

[inaridarkfox4231]

Among the functions that obtain random values, functions such as shuffle() and randomGaussian() are affected by randomSeed() because they use p5.js random() internally.

However, p5.Vector's random2D and random3D functions are static, so p5.js's random() cannot be used and the seed value cannot be fixed.

Therefore, I thought it would be nice to have a function that can obtain such a random unit vector with a fixed seed value, so I decided to propose an implementation.

Resolves #6141

Changes:

Implements functions that operate on vectors and set their components to a 2D or 3D unit vector. A unit vector is chosen randomly. In the 2D case, only objects with a z component of 0 are selected.

Pass a reference to random() in p5.js when the p5.Vector is created with createVector(). As a result, when applying this function to a vector prepared by createVector(), the p5.js function random() is used. For example, it will be affected by randomSeed().

example

for setRandom3D():

  randomSeed(999);
  const v1 = new p5.Vector().setRandom3D();
  const v2 = createVector().setRandom3D();
  randomSeed(999);
  const v3 = new p5.Vector().setRandom3D();
  const v4 = createVector().setRandom3D();

  console.log(v1.mag()); // 1.
  console.log(v1.x === v3.x && v1.y === v3.y && v1.z === v3.z); // almost always false.
  console.log(v2.x === v4.x && v2.y === v4.y && v2.z === v4.z); // always true.

PR Checklist

• npm run lint passes
• Inline documentation is included / updated
• Unit tests are included / updated

[inaridarkfox4231]

I thought it was a bug, but I was wrong...

That aside, I modified random2D() and random3D() because it's easier to write using the newly created functions.

[inaridarkfox4231]

Since vectors created with createVector() and vectors created with new p5.Vector() have slightly different properties, I thought it would be better to clarify that.

[inaridarkfox4231]

As for the example, I would like to replace it with a simpler one that just confirms the effect of randomSeed().
Also, replace the sentence I added at createVector() with something simpler.
As for the annotation itself, I think it makes sense.
Because the difference between these vectors is not mentioned anywhere in the reference.

[inaridarkfox4231]

It may be better to increase the parameters so that the range can be specified.

[inaridarkfox4231]

Since the issue is open, I think I'll open it as well.

[inaridarkfox4231]

The reason is as written in the issue. I would like to close this pull request.