Sorting builtin arrays

Questions & Answers
1

I need to sort the return of RaycastAll (a builtin array) from the nearest object to the farthest, but I can't figure out how to sort builtin arrays in a nice, tidy fashion.

What would be the best way to accomplish this?

Thanks

3

This looks like this post. You could write your own comparer class or function or just store an IComparable class within your array.

Using an IComparable

Unity mono

using System.Collections.Generic;

public class RaycastResult: IComparable<RaycastResult>
{
    public float distance;
    public Collider collider;

    public RaycastResult(RaycastHit hit)
    {
        distance = hit.distance;
        collider = hit.collider;
    }

    public int CompareTo(RaycastResult other)
    {
        return distance.CompareTo(other.distance);
    }
}

//A sorted collection
SortedSet<RaycastResult> raycastResults = new SortedSet<RaycastResult>();

void SortDistances()
{
    raycastResults.Clear();
    RaycastHit[] hits = Physics.RaycastAll(transform.position, transform.forward, 100.0);

    foreach(RaycastHit hit in hits)
    {
        raycastResults.Add(new RaycastResult(hit));
    }
    //With an unsorted collection, call raycastResults.sort();
}

Unity js

import System;

class RaycastResult implements IComparable
{
    var distance : float;
    var collider : Collider;

    function RaycastResult(hit : RaycastHit)
    {
        distance = hit.distance;
        collider = hit.collider;
    }

    function CompareTo(other : System.Object) : int
    {
        if (!(other instanceof RaycastResult)) return;
        var raycastResultOther : RaycastResult = other;
        return distance.CompareTo(raycastResultOther);
    }
}

var raycastResults : Array = new Array();

function SortDistances()
{
    raycastResults = new Array();
    var hits : RaycastHit[] = Physics.RaycastAll(transform.position, transform.forward, 100.0);

    for(var hit : RaycastHit in hits)
    {
        raycastResults.push(new RaycastResult(hit));
    }
    raycastResults.sort();
}

Using Comparer

Unity mono

public class RaycastComp : Comparer<RaycastHit>
{
    public int Compare(RaycastHit x, RaycastHit y)
    {
        return x.distance.CompareTo(y.distance);
    }
}

RaycastHit[] hits = Physics.RaycastAll(transform.position, transform.forward, 100.0);
RaycastComp rc = new RaycastComp();

//...Somewhere else put Array.Sort(hits, rc);

Unity js (pretty much what Mike posted)

class RaycastComp extends IComparer
{
    function Compare(x : System.Object, y : System.Object) : int
    {
        if ( !(x instanceof RaycastHit) || !(y instanceof RaycastHit)) return;
        var raycastHitX : RaycastHit = x;
        var raycastHitY : RaycastHit = x;
        return raycastHitX .distance.CompareTo(raycastHitY.distance);
    }
}

var hits : RaycastHit[] = Physics.RaycastAll(transform.position, transform.forward, 100.0);
var rc : RaycastComp = new RaycastComp();

//...Somewhere else put System.Array.Sort(hits, rc);

Using a comparison function

Unity mono

public int CompareHits(RaycastHit x, RaycastHit y)
{
    return x.distance.CompareTo(y.distance);
}

RaycastHit[] hits = Physics.RaycastAll(transform.position, transform.forward, 100.0);

//...Somewhere else put Array.Sort(hits, CompareHits);

Unity js

function CompareHits(var x : RaycastHit, var y : RaycastHit) : int
{
    return x.distance.CompareTo(y.distance);
}

var hits : RaycastHit[] = Physics.RaycastAll(transform.position, transform.forward, 100.0);

//...Somewhere else put hits.Sort(CompareHits);
2

http://msdn.microsoft.com/en-us/library/system.array.sort.aspx

You'd have to write your own comparer class, but it's pretty trivial (and very customizable)

Edit:

import System;

function Start () {
    var raycasthits = Physics.RaycastAll(Camera.main.transform.position, Camera.main.transform.forward);

    var output = ""; //this is for debugging
    for(var rch in raycasthits) output += rch.collider.name + "   "; //this is for debugging
    Debug.Log(output); //this is for debugging

    System.Array.Sort(raycasthits, new RaycastSorter());

    output = ""; //this is for debugging
    for(var rch in raycasthits) output += rch.collider.name + "   "; //this is for debugging
    Debug.Log(output); //this is for debugging
}

class RaycastSorter implements IComparer
//class RaycastSorter extends IComparer //in unity 2.6
{
    function Compare(a : System.Object, b : System.Object) : int
    {
        if ( !(a instanceof RaycastHit) || !(b instanceof RaycastHit)) return;
        var raycastHitA : RaycastHit = a;
        var raycastHitB : RaycastHit = b;

        return sqDistA.distance.CompareTo(sqDistB.distance);
    }
}