https://github.com/kevingodell/polygon-points

Determine if an x y coordinate exists in a polygon. This is being used in a motion detection project where specific regions of an image are being filtered and measured. It works fast when iterating pixels because it caches the bounding box value and uses it to quickly eliminate non-targeted pixels from unnecessary difference calculations.
https://github.com/kevingodell/polygon-points

detection motion nodejs pixels points polygon

Last synced: 5 months ago
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Determine if an x y coordinate exists in a polygon. This is being used in a motion detection project where specific regions of an image are being filtered and measured. It works fast when iterating pixels because it caches the bounding box value and uses it to quickly eliminate non-targeted pixels from unnecessary difference calculations.

• Host: GitHub
• URL: https://github.com/kevingodell/polygon-points
• Owner: kevinGodell
• License: mit
• Created: 2017-10-12T01:28:04.000Z (almost 9 years ago)
• Default Branch: master
• Last Pushed: 2023-04-19T07:08:35.000Z (about 3 years ago)
• Last Synced: 2025-09-03T04:24:33.984Z (11 months ago)
• Topics: detection, motion, nodejs, pixels, points, polygon
• Language: JavaScript
• Homepage: https://www.npmjs.com/package/polygon-points
• Size: 419 KB
• Stars: 1
• Watchers: 1
• Forks: 0
• Open Issues: 2
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

          
# polygon-points

###### [![Build Status](https://travis-ci.org/kevinGodell/polygon-points.svg?branch=master)](https://travis-ci.org/kevinGodell/polygon-points) [![Build status](https://ci.appveyor.com/api/projects/status/al11is88xms9kqq9/branch/master?svg=true)](https://ci.appveyor.com/project/kevinGodell/polygon-points/branch/master) [![GitHub issues](https://img.shields.io/github/issues/kevinGodell/polygon-points.svg)](https://github.com/kevinGodell/polygon-points/issues) [![GitHub license](https://img.shields.io/badge/license-MIT-blue.svg)](https://raw.githubusercontent.com/kevinGodell/polygon-points/master/LICENSE) [![Greenkeeper badge](https://badges.greenkeeper.io/kevinGodell/polygon-points.svg)](https://greenkeeper.io/)

Determine if an x y coordinate exists in a polygon. This is being used in a motion detection project where specific regions of an image are being filtered and measured. It works fast when iterating pixels because it caches the bounding box value and uses it to quickly eliminate non-targeted pixels from unnecessary difference calculations. It is designed to be used with positive integer values starting with an x y value of 0 0 at the top left.

### installation:

``` 

npm install polygon-points --save

```

### usage:

```javascript

const PP = require('polygon-points');

const polygonPoints = new PP([{x: 0, y: 0}, {x: 0, y: 100}, {x: 100, y: 100}, {x: 100, y: 0}]);

//public methods

//check if a point exists in the polygon

polygonPoints.containsPoint(1, 1);//returns true

//get bounding box of polygon

polygonPoints.boundingBox;//returns an array of 4 x y coordinates

//get total number of points that exist in polygon

polygonPoints.pointsLength;//returns 10000

//set vertexes after creating polygonPoints object

polygonPoints.vertexes = [{x: 0, y: 0}, {x: 0, y: 100}, {x: 100, y: 100}, {x: 100, y: 0}];

//get minX, maxX, minY, and maxY unsigned integers of bounding box

polygonPoints.minX, polygonPoints.maxX, polygonPoints.minY, polygonPoints.maxY;

```