JSFiddle - React, Tailwind, and code Playground

HTML

<canvas id="draw" width="300" height="300" style="position:absolute; top:0px; left:0p; margin:0; padding:0; width:300px; height:300px; border:2px solid blue;"></canvas>

JavaScript

var state = {
    width: 300,
    height: 300,
    pointRadius: 2,
    cornerThreshold: 125,
    circleThreshold: 145,
    rectangleThreshold: 45,
    diamondThreshold: 135,
    canvas: document.getElementById("draw"),
    ctx: document.getElementById("draw").getContext("2d"),
    drawing: false,
    points: [],
    getCorners: function(angles, pts) {
        var list = pts || this.points;
        var corners = [];
        for(var i=0; i<angles.length; i++) {
            if(angles[i] <= this.cornerThreshold) {
                corners.push(list[(i + 1) % list.length]);
            }
        }
        return corners;
    },
    draw: function(color, pts) {
        var list = pts||this.points;
        this.ctx.fillStyle = color;
        for(var i=0; i<list.length; i++) {
            this.ctx.beginPath();
            this.ctx.arc(list[i].x, list[i].y, this.pointRadius, 0, Math.PI * 2, false);
            this.ctx.fill();
        }
    },
    classify: function() {
        // get bounding box
        var left = this.width, right = 0, 
            top = this.height, bottom = 0;
        for(var i=0; i<this.points.length; i++) {
            var pt = this.points[i];
            if(left > pt.x) left = pt.x;
            if(right < pt.x) right = pt.x;
            if(top > pt.y) top = pt.y;
            if(bottom < pt.y) bottom = pt.y;
        }
        var center = {x: (left+right)/2, y: (top+bottom)/2};
        this.draw("#00f", [
            {x: left, y: top},
            {x: right, y: top},
            {x: left, y: bottom},
            {x: right, y: bottom},
            ]);
        // find average point in each sector (9 sectors)
        var sects = [
            {x:0,y:0,c:0},{x:0,y:0,c:0},{x:0,y:0,c:0},
            {x:0,y:0,c:0},{x:0,y:0,c:0},{x:0,y:0,c:0},
            {x:0,y:0,c:0},{x:0,y:0,c:0},{x:0,y:0,c:0}
            ];
        var x3 = (right + (1/(right-left)) - left) / 3;
        var y3 = (bottom + (1/(bottom-top)) - top) / 3;
        for(var i=0;...