Function place

index.js:110–157

(board, tag, bounds)

  }

  function place(board, tag, bounds) {
    var perimeter = [{x: 0, y: 0}, {x: size[0], y: size[1]}],
        startX = tag.x,
        startY = tag.y,
        maxDelta = Math.sqrt(size[0] * size[0] + size[1] * size[1]),
        s = spiral(size),
        dt = random() < .5 ? 1 : -1,
        t = -dt,
        dxdy,
        dx,
        dy;

    while (dxdy = s(t += dt)) {
      dx = ~~dxdy[0];
      dy = ~~dxdy[1];

      if (Math.min(Math.abs(dx), Math.abs(dy)) >= maxDelta) break;

      tag.x = startX + dx;
      tag.y = startY + dy;

      if (tag.x + tag.x0 < 0 || tag.y + tag.y0 < 0 ||
          tag.x + tag.x1 > size[0] || tag.y + tag.y1 > size[1]) continue;
      // TODO only check for collisions within current bounds.
      if (!bounds || collideRects(tag, bounds)) {
        if (!cloudCollide(tag, board, size[0])) {
          var sprite = tag.sprite,
              w = tag.width >> 5,
              sw = size[0] >> 5,
              lx = tag.x - (w << 4),
              sx = lx & 0x7f,
              msx = 32 - sx,
              h = tag.y1 - tag.y0,
              x = (tag.y + tag.y0) * sw + (lx >> 5),
              last;
          for (var j = 0; j < h; j++) {
            last = 0;
            for (var i = 0; i <= w; i++) {
              board[x + i] |= (last << msx) | (i < w ? (last = sprite[j * w + i]) >>> sx : 0);
            }
            x += sw;
          }
          return true;
        }
      }
    }
    return false;
  }

  cloud.timeInterval = function(_) {
    return arguments.length ? (timeInterval = _ == null ? Infinity : _, cloud) : timeInterval;