Llama using Javascript (Typescript)

llama_p5.ts

import * as M from 'mathjs';
let points = [];
let pts = [];
let complexPts = [];
let coeffs = [];
let time = 0;

export class Llama {
    public load() {
        pts = await this.sampleSvgPoints(text, this.samples);
        complexPts = pts.map(pt => ptToComplex(pt));
        coeffs = dft(complexPts);
    }

    private parameterize(cn: M.Complex[]) {
        return async (t: number): Promise<M.Complex> => await this.sigma(k =>
            M.multiply(M.complex(cn[k - 1].re, cn[k - 1].im), M.exp(M.multiply(M.i, (k - 1) * t))), [1, this.samples]) as M.Complex;
    }

    private async sigma(exp: (k: number) => M.MathType, interval: [number, number]): Promise<M.MathType> {
        let sum: M.MathType = 0;
        for (let i = interval[0]; i <= interval[1]; i++)
            sum = M.add(sum, exp(i));
        return sum;
    }

    public setup() {
        createCanvas(800,600);
    }
    public draw(p) {
        const pFn = this.parameterize(coeffs);
        p.background(25);
        p.translate(300, 200);
        const pt = await pFn(time);
        points.unshift(p.createVector(pt.re, pt.im));
        p.stroke(230);
        p.noFill();
        p.beginShape();
        for (let i =0 ; i < points.length; i++)
            p.vertex(points[i].x, points[i].y);
        p.endShape();
        
        if (time > M.pi * 2)
            points.pop();

        time += ((2 * M.pi) / pts.length);
    }
}

Full code for this is available as https://github.com/adekau/fourier