/**
* Output a graph as SVG.
* @param stack_abstract_graph $g the graph to display.
* @param string $id an id to add to the SVG node in the HTML.
*/
public static function render(stack_abstract_graph $g, $id)
{
$renderer = new self($g);
list($minx, $maxx) = $g->x_range();
$width = ceil((2 + $maxx - $minx) * self::SCALE / 2);
$height = ceil((0.3 + $g->max_depth()) * self::SCALE);
$output = '';
$output .= html_writer::start_tag('svg', array('id' => $id, 'class' => 'stack_abstract_graph', 'width' => $width . 'px', 'height' => $height . 'px', 'version' => '1.1', 'xmlns' => 'http://www.w3.org/2000/svg'));
$output .= $renderer->to_svg();
$output .= html_writer::end_tag('svg');
return $output;
}
