banana curve
the path must be closed, besause then I plan users to modify theese qurves
HTML
<canvas id="c" width="550" height="600">
</canvas>
JavaScript
var canvas = this.__canvas = new fabric.Canvas('c');
fabric.Object.prototype.originX = fabric.Object.prototype.originY = 'center';
var line = new fabric.Path('M 0,0 A75,55 00, 1 160,140', { fill: '', stroke: 'black' });
canvas.add(line);