turf-safe-ops

Turf module for pre- and post-processing geometries in order to make basic operations safe. It allows invalid geometries to be passed to the operations and attempts to make the output valid.

Turf-safe-ops tries to make sure that the operation will not produce collections with linestrings and point as "artifacts". The implemented operations remove these artifacts and calls turf.unkinkPolygon if needed.

Only safeIntersect, safeDifference and safeUnion for polygon arguments are implemented so far.

Usage

The operations follow the original method signature:

var turfSafeOps = require('turf-safe-ops');

var result = turfSafeOps.safeIntersect(geomA, geomB);

For safeIntersect and safeDifference, there's an extra parameter that can be passed, inputBufferConfig = {min: minBufferValue, max: maxBufferValue}. This parameter will be used only if the operation between the input geometries fails. In this case, turf_safe_ops will try to apply buffers from minBufferValue to maxBufferValue, with 10x increments, to the geometries (one at a time) until the operation succeeds.

var turfSafeOps = require('turf-safe-ops');

/*
If geomA.intersect(geomB) fails, geomA will be buffered by 0.0000001.
If geomA.intersect(geomB) fails again, geomB will be buffered by 0.0000001.
If geomA.intersect(geomB) fails, geomA will be buffered by 0.0000001 * 10.
...
Until it succeeds, or _inputBufferConfig.max = 0.001_ is reached.
 */
var result = turfSafeOps.safeIntersect(geomA, geomB, {min: 0.0000001, max: 0.001});