createParticleCanvas static method

CanvasElement createParticleCanvas()

Implementation

static HTML.CanvasElement createParticleCanvas() {
  int d = 64;
  HTML.CanvasElement canvas = HTML.CanvasElement(width: d, height: d);
  HTML.CanvasRenderingContext2D ctx =
      canvas.getContext('2d') as HTML.CanvasRenderingContext2D;
  int x = d ~/ 2, y = d ~/ 2;

  var gradient = ctx.createRadialGradient(x, y, 1, x, y, 22);
  gradient.addColorStop(0, 'gray');
  gradient.addColorStop(1, 'black');

  ctx.fillStyle = gradient;
  ctx.fillRect(0, 0, d, d);

  gradient = ctx.createRadialGradient(x, y, 1, x, y, 6);
  gradient.addColorStop(0, 'white');
  gradient.addColorStop(1, 'gray');

  ctx.globalAlpha = 0.9;
  ctx.fillStyle = gradient;
  ctx.arc(x, y, 4, 0, 2 * Math.pi);
  ctx.fill();
  return canvas;
}