I am just watching this tutorial https://www.youtube.com/watch?v=HwUnMy_pR6A and the guy (who seems to be pretty competent) is using a single array to store and access the pixels of his to-be-rendered image.

I was wondering if this really is the best way to do this. The alternative of Multi-Array does have one pointer more, but Arrays do have an O(1) for accessing each index and calculating the index in a single array seems to take one addition and one multiplication operation per pixel.

And if Multi-Arrays really are bad, can't you use something with Hashing to avoid those addition and multiplication operations?

EDIT: here is his code...

public class Screen {
private int width, height;
public int[] pixels;

public Screen(int width, int height) {
    this.width = width;
    this.height = height;

    // creating array the size of one index/int for every pixel
    // single array has better performance than multi-array
    pixels = new int[width * height];
}

public void render() {
    for (int y = 0; y < height; y++) {
        for (int x = 0; x < width; x++) {
            pixels[x + y * width] = 0xff00ff;
        }
    }
}
}