Create a JavaScript Lasso-tool upon a canvas inside the OpenLayers framework

We are looking for a JavaScript implementation of a Lasso-tool. It has to be accompanied by a rectangular box and a circle or ellipse. The user has to be able to create each of these by using his mouse. So the lasso-tool would be a tracking of his mouse-cursor within the defined canvas. While the user creates these shapes they have to be drawn on the fly and the coordinates of the polygon have to be returned by the function, using the lat/lon format you will have to poll from open layers. So the function you will have to implement get as input: color of the line, the width of the line, the color of the filling and the transperancy of the filling. Here you ought to use set-methods. The parameters passed, have to be considered when drawing the shapes to the canvas. The canvas size will be passed as a parameter. It will fit into our already existing OpenLayers framework. So you need to have great skills in HTML5, Javascript and Openlayers (a Javascript Framework) You have to be a resident of the European Union.