# MathFunctions

### Introduction

The MathFunctions class provides helper methods for performing common game math.

### World and Screen Coordinates

#### World to Pixel

The following code returns the screen pixel coordinates of a [PositionedObject](https://github.com/flatredball/FlatRedBallDocs/blob/main/frb/docs/index.php). Remember, by by default in world coordinates:

* Positive X points to the right
* Positive Y points up

In pixel coordinates

* Positive X points to the right
* **Positive Y points down (only when dealing with screen pixels)**

Add the following using statements

```
using FlatRedBall.Math;
```

Assuming myObject is a valid [PositionedObject](https://github.com/flatredball/FlatRedBallDocs/blob/main/frb/docs/index.php)

```
int screenX = 0;
int screenY = 0;

MathFunctions.AbsoluteToWindow(
   myObject.X,
   myObject.Y,
   myObject.Z,
   ref screenX,
   ref screenY,
   Camera.Main // assuming using the default camera.
);
```

#### Pixel to World

See [FlatRedBall.Math.MathFunctions.WindowToAbsolute](https://github.com/flatredball/FlatRedBallDocs/blob/main/frb/docs/index.php)