donut_filled_with_squares.js

// fill a donut with squares

const canvasSketch = require('canvas-sketch');
const penplot = require('./utils/penplot');
const utils = require('./utils/random');
const poly = require('./utils/poly');

let svgFile = new penplot.SvgFile();

// grid settings
let margin = 0.6;
let elementWidth = 2;
let elementHeight = 2;
let columns = 4;
let rows = 4;

const settings = {
  dimensions: 'A3',
  orientation: 'portrait',
  pixelsPerInch: 300,
  scaleToView: true,
  units: 'cm',
};

const sketch = (context) => {

  let drawingWidth = (columns * (elementWidth + margin)) - margin;
  let drawingHeight = (rows * (elementHeight + margin)) - margin;
  let marginLeft = (context.width - drawingWidth) / 2;
  let marginTop = (context.height - drawingHeight) / 2;


  
  
  return ({ context, width, height, units }) => {
    svgFile = new penplot.SvgFile();
    poly.init(context);

    context.fillStyle = 'white';
    context.fillRect(0, 0, width, height);
    context.strokeStyle = 'black';
    context.lineWidth = 0.02;

    const drawElement = (origin) => {
        //console.log(origin);
        let s = poly.createSquarePolygon(origin.x, origin.y, 0.3, 0.3);
        let corner = utils.getRandomInt(3);
        let i = utils.getRandomInt(1);
        let pos = utils.getRandomInt(1);
        let d = 0.03;
        let offset = pos ? d : -d;
        s[corner][i] = s[corner][i] + offset;

        poly.drawPolygonOnCanvas(context, s);
        svgFile.addLine(s, true);
      }

    // grid repeat starts here
    let posX = marginLeft;
    let posY = marginTop;

    let circle = { center: poly.point(width/2, height/2), radius: width/2 - 2 };
    let innercircle = { center: poly.point(width/2, height/2), radius: (width/2 - 2 ) / 3 }
    //poly.drawCircle(context)(circle.center.x, circle.center.y, circle.radius);

    //console.log(circle);

    for (let index = 0; index < 20000; index++) {
        let x = utils.getRandom(circle.radius*2) - circle.radius;
        let y = utils.getRandom(circle.radius* 2) - circle.radius;
        
        let point = poly.point(circle.center.x + x, circle.center.y + y);
        //console.log(point);
        if (poly.pointIsInCircle(point, circle.center, circle.radius)) {
            if (!poly.pointIsInCircle(point, innercircle.center, innercircle.radius))
            { drawElement(point); }
        }
        
    }
    

    return [
      // Export PNG as first layer
      context.canvas,
      // Export SVG for pen plotter as second layer
      {
        data: svgFile.toSvg({
          width,
          height,
          units
        }),
        extension: '.svg',
      }
    ];
  };
};

canvasSketch(sketch, settings);