JSFiddle - React, Tailwind, and code Playground
HTML
<canvas id="canvas1" width="500" height="500"></canvas>
JavaScript
// LIBRARY from:
// https://github.com/simonsarris/Canvas-tutorials/blob/master/transform.js
// code below
function Transform() {
this.reset();
}
Transform.prototype.reset = function() {
this.m = [1,0,0,1,0,0];
};
Transform.prototype.multiply = function(matrix) {
var m11 = this.m[0] * matrix.m[0] + this.m[2] * matrix.m[1];
var m12 = this.m[1] * matrix.m[0] + this.m[3] * matrix.m[1];
var m21 = this.m[0] * matrix.m[2] + this.m[2] * matrix.m[3];
var m22 = this.m[1] * matrix.m[2] + this.m[3] * matrix.m[3];
var dx = this.m[0] * matrix.m[4] + this.m[2] * matrix.m[5] + this.m[4];
var dy = this.m[1] * matrix.m[4] + this.m[3] * matrix.m[5] + this.m[5];
this.m[0] = m11;
this.m[1] = m12;
this.m[2] = m21;
this.m[3] = m22;
this.m[4] = dx;
this.m[5] = dy;
};
Transform.prototype.invert = function() {
var d = 1 / (this.m[0] * this.m[3] - this.m[1] * this.m[2]);
var m0 = this.m[3] * d;
var m1 = -this.m[1] * d;
var m2 = -this.m[2] * d;
var m3 = this.m[0] * d;
var m4 = d * (this.m[2] * this.m[5] - this.m[3] * this.m[4]);
var m5 = d * (this.m[1] * this.m[4] - this.m[0] * this.m[5]);
this.m[0] = m0;
this.m[1] = m1;
this.m[2] = m2;
this.m[3] = m3;
this.m[4] = m4;
this.m[5] = m5;
};
Transform.prototype.rotate = function(rad) {
var c = Math.cos(rad);
var s = Math.sin(rad);
var m11 = this.m[0] * c + this.m[2] * s;
var m12 = this.m[1] * c + this.m[3] * s;
var m21 = this.m[0] * -s + this.m[2] * c;
var m22 = this.m[1] * -s + this.m[3] * c;
this.m[0] = m11;
this.m[1] = m12;
this.m[2] = m21;
this.m[3] = m22;
};
Transform.prototype.translate = function(x, y) {
this.m[4] += this.m[0] * x + this.m[2] * y;
this.m[5] += this.m[1] * x + this.m[3] * y;
};
Transform.prototype.scale = function(sx, sy) {
this.m[0] *= sx;
this.m[1] *= sx;
this.m[2] *= sy;
this.m[3] *= sy;
};
Transform.prototype.transformPoint = function(px, py) {
var x = px;
var y = py;
px = x * this.m[0] + y * this.m[2] + this.m[4];
...