Functions use node-style callback convention. Callback function is always the last given parameter.

Shapes have different SVG canvas sizes:

Shape	Canvas size
Circle	100x100
SemiCircle	100x50
Line	100x{opts.strokeWidth}

All shapes are fitted exactly to their canvases.

Important: make sure that your container has same aspect ratio as the SVG canvas. For example: if you are using SemiCircle, set e.g.

#container {
    width: 300px;
    height: 150px;
}