---
title: "Project onto Unit Vector"
description: "Demonstrates projecting a vector onto a normalized (unit) vector using the projectUnit method."
phaser: "4.1.0"
size: "800x600"
files: 1
url: https://phaser.io/oss/examples/v4.1.0/geom/point/view/project-unit
site: Phaser - https://phaser.io
---

> This page is about the open-source Phaser framework, for writing a game's code by hand. To make a game with AI, use Phaser AE (https://phaser.io/): the desk's tools work with Web MCP, and the CLI works with your own coding agent. See "For AI agents: Phaser AE" at the end of this page.

# Project onto Unit Vector

Demonstrates projecting a vector onto a normalized (unit) vector using the projectUnit method.

A Phaser 4.1.0 example in [Geom / Point](https://phaser.io/oss/examples/v4.1.0/geom/point.md). It runs at 800 × 600, and loads its assets from https://cdn.phaserfiles.com/v410. See it running, with its code, at https://phaser.io/oss/examples/v4.1.0/geom/point/view/project-unit.

To run it, load Phaser 4.1.0 (`https://cdn.jsdelivr.net/npm/phaser@4.1.0/dist/phaser.min.js`), then the file, on a page with a `<div id="game-container">`.

## Code

### project unit.js

```js
class Example extends Phaser.Scene
{
    angle = 0;
    projectedPoint;
    point2;
    point;
    graphics;

    create ()
    {
        this.graphics = this.add.graphics({ lineStyle: { width: 2, color: 0x2266aa }, fillStyle: { color: 0xaa0000 } });

        // ProjectUnit assumes normalized point
        // i.e. it has magnitude of 1
        this.point = new Phaser.Math.Vector2(1, 0);

        this.point2 = new Phaser.Math.Vector2(250, 0);

        this.projectedPoint = this.point2.projectUnit(this.point);

        this.input.on('pointermove', pointer =>
        {

            this.point2.copy(pointer);

            this.point2.x -= 400;
            this.point2.y -= 300;
        });
    }

    update ()
    {
        this.graphics.clear();

        this.angle += 0.005;

        // unit vector
        this.point.setTo(Math.cos(this.angle), Math.sin(this.angle));

        // project a point on point2 on point
        this.point2.projectUnit(this.point, this.projectedPoint);

        // set magnitude to 250, because it's unit point, we can simply multiply
        this.point.x *= 250;
        this.point.y *= 250;

        // drawn from the center (as if center was 0/0)
        this.graphics.lineBetween(400, 300, 400 + this.point.x, 300 + this.point.y);

        // draw projecting point
        this.graphics.lineStyle(2, 0x00aa00);
        this.graphics.lineBetween(400, 300, 400 + this.point2.x, 300 + this.point2.y);

        // move relative to center
        this.projectedPoint.x += 400;
        this.projectedPoint.y += 300;

        this.graphics.fillPointShape(this.projectedPoint, 15);

        this.graphics.lineStyle(1, 0xaa0000);
        this.graphics.lineBetween(this.point2.x + 400, this.point2.y + 300, this.projectedPoint.x, this.projectedPoint.y);
    }
}

const config = {
    scale: { mode: Phaser.Scale.FIT },
    width: 800,
    height: 600,
    type: Phaser.AUTO,
    parent: 'game-container',
    scene: Example
};

const game = new Phaser.Game(config);
```

## More in Point

- [Creating and Drawing Points](https://phaser.io/oss/examples/v4.1.0/geom/point/view/create.md): Demonstrates how to initialize Vector2 objects using various constructor arguments and render them as filled shapes using a Graphics object.
- [Get Bounding Rectangle from Points](https://phaser.io/oss/examples/v4.1.0/geom/point/view/get-rectangle-from-points.md): Demonstrates how to calculate a bounding box that encompasses a dynamic set of points using Phaser.Math.GetVec2Bounds.
- [Get Centroid](https://phaser.io/oss/examples/v4.1.0/geom/point/view/get-centroid.md): Demonstrates how to use Phaser.Math.GetCentroid to calculate and visualize the geometric center of a dynamic set of points.
- [Get Magnitude Squared](https://phaser.io/oss/examples/v4.1.0/geom/point/view/get-magnitude-sq.md): Demonstrates using Vector2.lengthSq to efficiently check distances between points by avoiding expensive square root calculations.
- [Invert Point](https://phaser.io/oss/examples/v4.1.0/geom/point/view/invert.md): Demonstrates using the invert method to negate the x and y components of a Vector2 point.
- [Negate a Point](https://phaser.io/oss/examples/v4.1.0/geom/point/view/negative.md): Demonstrates how to use the negate method to invert the coordinates of a Vector2, reflecting it across a central origin.
- [Point Ceil](https://phaser.io/oss/examples/v4.1.0/geom/point/view/ceil.md): Demonstrates rounding a point's coordinates up to the nearest integer using the ceil method.
- [Point Floor](https://phaser.io/oss/examples/v4.1.0/geom/point/view/floor.md): Demonstrates how to use the floor method to round a point's coordinates down to the nearest integer value.
- [Point Magnitude](https://phaser.io/oss/examples/v4.1.0/geom/point/view/get-magnitude.md): Calculates and displays the magnitude (length) of a Vector2 relative to the origin as it follows the mouse pointer.
- [Point Negation Pattern](https://phaser.io/oss/examples/v4.1.0/geom/point/view/negative-2.md): Demonstrates creating symmetrical geometric patterns by using the negate method on vectors to flip their coordinates relative to an origin.
- [Vector Cross Product](https://phaser.io/oss/examples/v4.1.0/geom/point/view/cross.md): Demonstrates how to use the cross product of two 2D vectors to calculate the angle between them and determine their relative orientation.
- [Vector Interpolation](https://phaser.io/oss/examples/v4.1.0/geom/point/view/interpolate.md): Calculates a point between two Vector2 objects using the lerp method, visualizing the movement along a line connecting a fixed point and the mouse pointer.
- [All 18 examples in Point](https://phaser.io/oss/examples/v4.1.0/geom/point.md)

---

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