Function start

src/layout.js:1125–1330

()

  /* Start drawing on a canvas */
  var start = function start() {
    // For dimensions, clearCanvas etc.,
    // we only care about the first element.
    var canvas = elements[0];

    if (canvas.getContext) {
      ngx = Math.ceil(canvas.width / g);
      ngy = Math.ceil(canvas.height / g);
    } else {
      var rect = canvas.getBoundingClientRect();
      ngx = Math.ceil(rect.width / g);
      ngy = Math.ceil(rect.height / g);
    }

    // Sending a wordcloudstart event which cause the previous loop to stop.
    // Do nothing if the event is canceled.
    if (!sendEvent('wordcloudstart', true)) {
      return;
    }

    // Determine the center of the word cloud
    center = settings.origin
      ? [settings.origin[0] / g, settings.origin[1] / g]
      : [ngx / 2, ngy / 2];

    // Maxium radius to look for space
    maxRadius = Math.floor(Math.sqrt(ngx * ngx + ngy * ngy));

    /* Clear the canvas only if the clearCanvas is set,
         if not, update the grid to the current canvas state */
    grid = [];

    var gx, gy, i;
    if (!canvas.getContext || settings.clearCanvas) {
      elements.forEach(function (el) {
        if (el.getContext) {
          var ctx = el.getContext('2d');
          ctx.fillStyle = settings.backgroundColor;
          ctx.clearRect(0, 0, ngx * (g + 1), ngy * (g + 1));
          ctx.fillRect(0, 0, ngx * (g + 1), ngy * (g + 1));
        } else {
          el.textContent = '';
          el.style.backgroundColor = settings.backgroundColor;
          el.style.position = 'relative';
        }
      });

      /* fill the grid with empty state */
      gx = ngx;
      while (gx--) {
        grid[gx] = [];
        gy = ngy;
        while (gy--) {
          grid[gx][gy] = true;
        }
      }
    } else {
      /* Determine bgPixel by creating