https://github.com/damianc/math-distantpoint

Getting a point by distance from other point.
https://github.com/damianc/math-distantpoint

Last synced: about 1 month ago
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Getting a point by distance from other point.

• Host: GitHub
• URL: https://github.com/damianc/math-distantpoint
• Owner: damianc
• Created: 2023-10-17T00:40:13.000Z (about 1 year ago)
• Default Branch: master
• Last Pushed: 2023-10-17T00:52:49.000Z (about 1 year ago)
• Last Synced: 2023-10-17T10:50:56.679Z (about 1 year ago)
• Language: JavaScript
• Size: 1.95 KB
• Stars: 0
• Watchers: 1
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

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README

        
# math-distantPoint

The `Math.distantPoint()` method is meant to get a point by distance from other point along a line segment.

```

distantPoint(

  [x1,y1],

  [x2,y2],

  dist,

  relative = false

)

```

It may be interpreted as follows:

- get a line $f$ that passes through both $(x_1,y_1)$ and $(x_2,y_2)$ points

- go given distance along the line $f$ from $(x_1,y_1)$ towards $(x_2,y_2)$

- if the `relative` parameter is `true`, then it is a percent of a full distance between the points

- return `[x,y]`, i.e., coordinates of the point found

## Examples

```

const p = {x:2, y:4};

const q = {x:8, y:3};

const distance = 2;

const [rx,ry] = Math.distantPoint(

	[p.x,p.y], [q.x,q.y], distance

);

const prDist = Math.hypot(

	rx-p.x, ry-p.y

);

console.log(

	distance === Math.round(prDist)

);

// true

const h = [

	(p.x+q.x)/2,

	(p.y+q.y)/2

];

const half = Math.distantPoint(

	[p.x,p.y], [q.x,q.y], 50, true

);

console.log(h, half);

// [5, 3.5]

// [5, 3.5]

```