AspectUtility.cs

/*
This code is a modified and trimmed-down version of the code from
http://wiki.unity3d.com/index.php?title=AspectRatioEnforcer
and was originally written by Eric Haines.

It is only intended for demonstration purposes, and the full code is available for free online.
...Is what this originally said. The linked website went down, so I'm reuploading this for preservation purposes.
*/
using UnityEngine;

public class AspectUtility : MonoBehaviour {
    public float _wantedAspectRatio = 1.7777778f;
    public Camera cam;

    public void Reset() {
        cam = GetComponent<Camera>();
    }

    public void SetCamera () {
        float currentAspectRatio = (float)Screen.width / Screen.height;
        if ((int)(currentAspectRatio * 100) / 100.0f == (int)(_wantedAspectRatio * 100) / 100.0f) {
            cam.rect = new Rect(0.0f, 0.0f, 1.0f, 1.0f);
            return;
        }
        // Pillarbox
        if (currentAspectRatio > _wantedAspectRatio) {
            float inset = 1.0f - _wantedAspectRatio/currentAspectRatio;
            cam.rect = new Rect(inset/2, 0.0f, 1.0f-inset, 1.0f);
        }
        // Letterbox
        else {
            float inset = 1.0f - currentAspectRatio/_wantedAspectRatio;
            cam.rect = new Rect(0.0f, inset/2, 1.0f, 1.0f-inset);
        }
    }
}