export function drawGrid (x, y, w, h, wv, hv, color) {
  color = color || '#999';
  let path = ['M', x, y, 'L', x + w, y, x + w, y + h, x, y + h, x, y];
  const rowHeight = h / hv;
  const columnWidth = w / wv;
  for (var i = 0; i < hv + 1; i++) {
    var offset = y + i * rowHeight;
    path = this.path(['M', x, offset, 'L', x + w, y + i * rowHeight]);
    if (offset == 0 || offset == h) {
      path.attr({ stroke: '#000' });
    } else if (offset == h / 2) {
      path.attr({ stroke: '#c00' });
    } else {
      path.attr({ stroke: '#999' });
    }
  }
  for (var i = 0; i < wv + 1; i++) {
    var offset = x + i * columnWidth;
    path = this.path(['M', offset, y, 'L', x + i * columnWidth, y + h]);
    if (offset == 0 || offset == w) {
      path.attr({ stroke: '#000' });
    } else if (offset == w / 2) {
      path.attr({ stroke: '#c00' });
    } else {
      path.attr({ stroke: '#999' });
    }
  }
  return this.path;
};