How does one get or create a selection or range from a dom coordinate point in javascript? -

Hopefully this is possible by using the method performed by the internal code of the browser, a point x, y in the dome coordinate Given. (Which can be relative to any node) is an element in which I want to effectively

  charInndex = characterUnderPoint (textNode, nodex, nodey);  

I think there is some kind of facilty to do this

  range = xx.creatrange (node, x, y)  

or

  selection = xx.create selection (node, x, y)  

or

  Range.Set anconstoecution (node, x, y)  

etc.

I can not get anything until now, which effectively executes, when you click to set the caret post. All methods seem to be only a character offset.

Mainly I want this because to increase a range through all the characters, to check whether the point is very slow in it (a binary search can be done, but) The layout in the code should be done faster inside the engine.

There is no easy way to do this. The range will not help you, it's all about nodes and offsets.