intersectSegment2Segment does not report touching segments

[saraedum]

Looking at the implementation, I understand that Segment.intersect(Segment) should return a single point if two segments are collinear and touch. (The documentation does not really mention this I think.)

However, the implementation eventually calls intersectSegment2Segment which compares the bounding boxes without adding an epsilon: https://github.com/alexbol99/flatten-js/blob/master/src/algorithms/intersection.js#L141

I think this leads to points that are touching up to an epsilon not always to be reported as such.

I could try to create a reproducer for this. But I am not sure if this is the desired behavior.

[alexbol99]

Hi, @saraedum , sorry for delay with response Do you mean that two segments touch in one point but touching is not exact? You'd better add data example Thanks, Alex

[saraedum]

I believe that there should be an intersection point reported here since the two segments touch (modulo tolerance):

const {Point, Segment} = require("@flatten-js/core");

const a = new Segment(new Point(-1, 0), new Point(0, 0));
const b = new Segment(new Point(1e-30, 0), new Point(1, 0));

a.intersect(b)

However, a.intersect(b) is empty.