Argument out of range exception

Questions & Answers
1

What I’m trying to do is look at a list of sprites and make a list out of each pixel in the array. This is most likely a bit confusing, so let me show you my code.

public List<Sprite> img = new List<Sprite>();

	public List<List<Color>> color = new List<List<Color>>();

	void Start(){
		//for every image
		for (int a = 0; a < img.Count; a++) {
			//for every pixel that image is wide
			for (int i = 0; i < img[a].texture.width; i++) {
				//for every pixel that image is high
				for (int j = 0; j < img[a].texture.height; j++) {
					//new color for every pixel of image a
					Color pixel = img[a].texture.GetPixel (i, j);
					//add all the pixel colors to the list in the color list at index a
					//error here
					color[a].Add (pixel);
				}
			}
		}
		Debug.Log (color.Count);
		Debug.Log (color[0].Count);
		Debug.Log (color[1].Count);
	}

I’m getting an argument out of range exception on line 16, and I’m not sure why. If anyone else does, it would be very much appreciated.

And if it makes anyone feel better, I also wrote this other description of what I want it to do. (sorry its sideways, I don’t know how to fix it.)

88527-img-4028.jpg
88527-img-4028.jpg480×640 102 KB

2

Simple problem - you’re calling color[a].Add (pixel), but there’s no element [a] in color yet! So what you need to do is add a List < Color > for every image. Your script should actually look like this:

 public List<Sprite> img = new List<Sprite>();
 
     public List<List<Color>> color = new List<List<Color>>();
 
     void Start(){
         //for every image
         for (int a = 0; a < img.Count; a++) {
             color.Add(new List<Color>()) //THIS IS THE LINE I ADDED
             //for every pixel that image is wide
             for (int i = 0; i < img[a].texture.width; i++) {
                 //for every pixel that image is high
                 for (int j = 0; j < img[a].texture.height; j++) {
                     //new color for every pixel of image a
                     Color pixel = img[a].texture.GetPixel (i, j);
                     //add all the pixel colors to the list in the color list at index a
                     //error here
                     color[a].Add (pixel);
                 }
             }
         }
         Debug.Log (color.Count);
         Debug.Log (color[0].Count);
         Debug.Log (color[1].Count);
     }