How to interactively Draw a Circle in openlayers-3 - openlayers-3

Question

I'am intersted in a fuctionality, that was present in openlayers-2, but absent at the moment in 3rd installment - interactive circle drawing.
As you can see in example here: http://openlayers.org/en/v3.0.0/examples/draw-and-modify-features.html
There's no available option for Circle. Even though comment states, that there should be available all of #type {ol.geom.GeometryType}, circle dowsen't work. Tried it myself with this piece of code:
function addInteraction(type) {
draw = new ol.interaction.Draw({
features: featureOverlay.getFeatures(),
type: /** #type {ol.geom.GeometryType} */ 'Circle'
});
map.addInteraction(draw);
}
Is there any native\patch\hack solutions present?

Answer 1

This feature has now been added in version 3.5.0, with an example here: http://openlayers.org/en/v3.5.0/examples/draw-features.html
It works exactly like you guessed, that is
draw = new ol.interaction.Draw({
features: featureOverlay.getFeatures(),
type: 'Circle'
});
map.addInteraction(draw);

Answer 2

I had nearly the same problem. The Question is if you want to add just a circle for styling reasons or you need it as a polygon? When you try too achieve a polygon you can easyily use the Poylgon.based circular function. As you can see in the source code below you only need the sphere. For example ol.sphere.WGS84. The center point and the radius. The optional input defines the number of points. which are used to define the circle.
ol.geom.Polygon.circular = function(sphere, center, radius, opt_n) {
var n = goog.isDef(opt_n) ? opt_n : 32;
/** #type {Array.<number>} */
var flatCoordinates = [];
var i;
for (i = 0; i < n; ++i) {
goog.array.extend(
flatCoordinates, sphere.offset(center, radius, 2 * Math.PI * i / n));
}
flatCoordinates.push(flatCoordinates[0], flatCoordinates[1]);
var polygon = new ol.geom.Polygon(null);
polygon.setFlatCoordinates(
ol.geom.GeometryLayout.XY, flatCoordinates, [flatCoordinates.length]);
return polygon;
};
It is even Api Stable so you can access it from outside. IN my case i created an own control which extended the draw feature. Hope i was able to help you.