# 70002254 polygons combination

 Article 70002254 Type HowTo Product WebJS Version 9 Date Added 8/18/2022 12:00:00 AM Fixed 10.1002.0.2 (8/18/2022 12:00:00 AM) Submitted by Brendan Fry

## Summary

How to merge polygons or make other combinations

## Solution

example of polygon clip between regions.

```
//create 2 rectangle polylines
var pl1 = vdcanvas.AddPolyline([[0, 0, 0], [2, 0, 0], [2, 2, 0], [0, 2, 0], [0, 0, 0]], false, {});
var pl2 = vdcanvas.AddPolyline([[1, 1, 0], [3, 1, 0], [3, 3, 0], [1, 3, 0], [1, 1, 0]], false, {});
//get the sample points of each polyline
var pts1 = vdcanvas.GetEntitySamplePoints(pl1);
var pts2 = vdcanvas.GetEntitySamplePoints(pl2);

//Calculate an array of regions that represent the clipping result of passed ptsarray regions according to the passed opers
var regions = gpc.clip_oper([pts1, pts2], [gpc.OPER_UNION, gpc.OPER_UNION]);//the union of both polygons
//var regions = gpc.clip_oper([pts1, pts2], [gpc.OPER_INT, gpc.OPER_INT]);//the  intersection
//var regions = gpc.clip_oper([pts1, pts2], [gpc.OPER_DIFF, gpc.OPER_DIFF]);//the difference of the first minus the second

//create a hatch to display the result