Golf me a polygonal loader

Question

Codidact post, CGCC Sandbox, Codidact Sandbox

Given three positive integers as input, animate an ascii-art polygonal loading symbol on the screen.

Intro

You will be given three inputs, \$n\$, \$l\$, and \$d\$...

\$n\$ (one of \$3\$, \$4\$, \$6\$, or \$8\$), is the number of sides of a polygon:

                           * * *
                          *     *
                * * *    *       *
               *     *   *       *
  *    * * *  *       *  *       *
 * *   *   *   *     *    *     *
* * *  * * *    * * *      * * *

\$l\$ is the side length to use. (The above all use \$l = 3\$, the minimum possible value).

You may use any printable ASCII character other than space instead of *.

\$d\$ is the load length and is less than the perimeter.

The task is to create a loading animation as follows:

1. Make the first frame of the animation by starting at any one of the topmost corners and drawing the perimeter until its length is \$d\$.
2. Make the next frame by shifting this partial perimeter by 1 clockwise.
3. Repeat step 2 ad-infinitum.

For example, \$n=3,l=3,d=4\$ would result in the following steps:

  *                          *       *        *
   *  ->    *  ->  *    ->  *   ->  * *  ->  * *  -> . . .
  * *    * * *    * * *    * *     *            *

Example

Here is a solution made by Hakerh400: Try It Online!

Further details(important):

• You are guaranteed that \$n∊(3,4,6,8)\$
• You are guaranteed that \$l≥3.\$ You are guaranteed that \$d<(l-1)×n.\$
• There must be a delay of at least 0.1 s between each step. You can have a delay of up to 10 seconds.
• Your language is allowed to output a list of steps infinitely if and only if it cannot clear the screen or do something similar.
• If so, there must be at least 2 newlines between each step.
• This is not graphical-output.

Scoring

This is code-golf. Shortest answer in each language wins.

Answer 1

JavaScript (ES8), 265 bytes

(n,l,d)=>setInterval(_=>(g=i=>i<q?g(i+1,(m[y-=634%~(D+=i%l?0:+("02112122230"[(n*12^i/l)%43%29]||1))-2>>1]=m[y]||[...''.padEnd(l*4)])[x-=D<4?D-1:5-D]=(i+j)%q<d?0:" "):C.log(m.reverse().map(r=>r.join``).join`
`))(y=D=!++j,(C=console).clear(x=l*3,m=[])),j=100,q=n*--l)

Try it online!

Snippet

f=

(n,l,d)=>setInterval(_=>(g=i=>i<q?g(i+1,(m[y-=634%~(D+=i%l?0:+("02112122230"[(n*12^i/l)%43%29]||1))-2>>1]=m[y]||[...''.padEnd(l*4)])[x-=D<4?D-1:5-D]=(i+j)%q<d?0:" "):C.log(m.reverse().map(r=>r.join``).join`
`))(y=D=!++j,(C=console).clear(x=l*3,m=[])),j=100,q=n*--l)

console.log = s => o.innerHTML = s; f(3, 5, 9)

<pre id="o"></pre>

Answer 2

JavaScript (V8), 353 318 bytes

f=(n,l,d,o=0)=>{w=[...{3:'330231',4:'42240220',6:'423313021131',8:'4233231302112131'}[n]]
a=Array(3*l).fill().map(_=>Array(4*l).fill` `)
x=n==4?0:l,y=0
for(i=0;i<d+o;++i){a[y][x]=i>=o?'*':' '
j=~~(i/(l-1))%n*2
x+=w[j]-2
y+=w[j+1]-2}(c=console).clear()
c.log(a.join`
`.replace(/,/g,''))
setTimeout(_=>f(n,l,d,o+1),100)}

Try it online!

On the tio.run it displays all output instantly, but in the browser console it animates as it should.

f=(n,l,d,o=0)=>{w=[...{3:'330231',4:'42240220',6:'423313021131',8:'4233231302112131'}[n]]
a=Array(3*l).fill().map(_=>Array(4*l).fill` `)
x=n==4?0:l,y=0
for(i=0;i<d+o;++i){a[y][x]=i>=o?'*':' '
j=~~(i/(l-1))%n*2
x+=w[j]-2
y+=w[j+1]-2}(c=console).clear()
c.log(a.join`
`.replace(/,/g,''))
setTimeout(_=>f(n,l,d,o+1),100)}
f(3,3,4)
    

Answer 3

Charcoal, 69 65 bytes

ＮθＮηＮζ≔⁰εＲＷφ¹«≦⊖εＦ§⪪”)″‴Byε=μχ？⟦⌕r”8θＦ⊖η«≦⊕ε✳Ｉκ⁺§ *‹﹪ε×⊖ηθζ× №04κ

Try it online! Link is to verbose version of code with 100× speed-up (φ replaced with χ) so that you can get results in a reasonable amount of time; each frame is separated by ␛ [2J␛ [0;0H. Explanation:

ＮθＮηＮζ

Input n, l and d as numbers.

≔⁰ε

Keep track of how many frames have passed and which step we are on the current frame.

ＲＷφ¹«

Every second, run the rest of the code and refresh the screen.

≦⊖ε

Decrement the frame/step counter, so that each frame starts a step later than the previous.

Ｆ§⪪”)″‴Byε=μχ？⟦⌕r”8θ

Look up the direction vectors for the appropriate shape in a compressed string and loop over them.

Ｆ⊖η«

Loop over the length of each side.

≦⊕ε

Increment the frame/step counter.

✳Ｉκ⁺§ *‹﹪ε×⊖ηθζ× №04κ

Print a * if the frame/step counter is within the input length, plus a further space for a horizontal movement.