> For the complete documentation index, see [llms.txt](https://docs.flatredball.com/flatredball/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.flatredball.com/flatredball/api/flatredball/camera/setbordersatz.md).

# SetBordersAtZ

### Introduction

As explained in [this tutorial](https://github.com/flatredball/FlatRedBallDocs/tree/main/frb/docs/index.php) the Camera's X and Y position are the center of the screen (unless the Camera is rotated). Therefore, to keep the Camera from viewing outside of a specific area, the visible width and height must be calculated. In other words, if the Camera should not be able to see anything to the left of X = 0, then the width of the Camera needs to be calculated, and the actual minimum X becomes

```
0 + cameraWidthAtSomeZ/2.0f;
```

The SetBordersAtZ simplifies this process by doing the calculation of cameraWidthAtSomeZ automatically, and even updating mins and maxes if the Camera moves along the Z axis. The SetBordersAtZ sets the following Camera properties:

* MinimumX
* MinimumY
* MaximumX
* MaximumY

The SetBordersAtZ calculates what the minimum and maximum values need to be set at to keep the first four argument values as the visible borders at the Z value passed (fifth argument).

### Code Example

The following code prevents the user from viewing behind +/- 40 on the X and Y axes. Note that bounds will be exceeded if the field of view or aspect ratio is too large for the argument values. The [Keyboard](https://github.com/flatredball/FlatRedBallDocs/tree/main/frb/docs/index.php) moves the Camera so the bounds can be tested. Add the following using statements:

```
using FlatRedBall.Input;
```

Add the following to Initialize after initializing FlatRedBall:

```
float minimumX = -40;
float minimumY = -40;
float maximumX = 40;
float maximumY = 40;
float zToSetAt = 0;

SpriteManager.Camera.SetBordersAtZ(minimumX, minimumY, maximumX, maximumY, zToSetAt);

// Add a Sprite so the bounds can be visibly tested
Sprite sprite = SpriteManager.AddSprite("redball.bmp");
sprite.ScaleX = 40;
sprite.ScaleY = 40;
```

Add the following to Update:

```
// Use the arrow keys to move the Camera
InputManager.Keyboard.ControlPositionedObject(SpriteManager.Camera);
```

![CameraBounds.png](https://951240982-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-M_fye9Ufg3vzJxwX5Hk%2Fuploads%2Fgit-blob-57938ed02e1d8ba0890739bc4fe727c5796d6aaa%2Fmigrated_media-CameraBounds.png?alt=media)


---

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