robust-segment-intersect/README.md

Exact arithmetic test for line segment intersection

robust-segment-intersect
========================
Exact arithmetic predicate to determine if two closed linesegments intersect.

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# Example

```javascript

var crosses = require("robust-segment-intersect")

var a0 = [-1, 0]
var a1 = [ 1, 0]
var b0 = [ 0,-1]
var b1 = [ 0, 1]

//Check if line segment a0, a1  crosses segment b0, b1
console.log(crosses(a0, a1, b0, b1))
```

# Install

```
npm install robust-segment-intersect
```

# API

#### `require("robust-segment-intersect")(a0, a1, b0, b1)`
Tests if the closed line segment `[a0,a1]` intersects the closed line segment `[b0,b1]`.

* `a0, a1` are the end points of the first line segment encoded as length 2 arrays
* `b0, b1` are the end points of the second line segment encoded again as length 2 arrays

**Returns** `true` if the linesegments intersect, false otherwise

# Credits
(c) 2014 Mikola Lysenko. MIT License