screenshot seeded animated christmas

MainApp.java

import java.awt.*;
    PImage orig;
    int scaledown = 2;
    public void settings()
    {
        orig = screenshot();
//        orig = loadImage("C:\\Projects\\Sand\\ohno.jpg");
        if(orig.width == 1920 && orig.height == 1080){
            fullScreen();
            scaledown = 1;
        }else{
            size(orig.width/ scaledown, orig.height/ scaledown);
        }
    }

    public void setup(){
        imageMode(CENTER);
        image(orig, width/2, height/2,orig.width/scaledown, orig.height/scaledown);

    }

    public void draw()
    {
        loadPixels();
        modifyPixels();
        updatePixels();
//        saveFrame();
        checkInput();
    }

    private void modifyPixels(){
        for(int x = 0; x < width; x++) {
            for (int y = 0; y < height; y++) {
                if(coinFlip()){
                    shiftUpwards(x, y);
                }
                else{
                    shiftLeft(x,y);
                }
            }
        }
    }

    private void shiftUpwards(int x, int y){
        if(getPixel(x, y) > getPixel(x+1, y)){
            swapPixels(x, y, x, y+1);
        }
    }

    private void shiftLeft(int x, int y){
        if(getPixel(x, y) > getPixel(x, y+1)){
            swapPixels(x, y, x+1, y);
        }
    }

    private boolean coinFlip(){
        return (random(1)>0.5f);
    }

    private int getPixel(int x, int y){
        int index = x + y * width;
        if(index < pixels.length && index > 0){
            return pixels[index];
        }
        return 0;
    }

    private void setPixel(int x, int y, int clr){
        int index = x + y * width;
        if(index < pixels.length && index > 0){
            pixels[x + y * width] = clr;
        }
    }



    private void swapPixels(int x0, int y0, int x1, int y1){
        int a = getPixel(x0, y0);
        int b = getPixel(x1, y1);
        setPixel(x0, y0, b);
        setPixel(x1, y1, a);
    }

    private PImage screenshot() {
        PImage screenshot = null;
        try {
            screenshot = new PImage(new Robot().createScreenCapture(
                    new Rectangle(0, 0, displayWidth, displayHeight)));
        } catch (AWTException e) {
            e.printStackTrace();
        }
        return screenshot;
    }

    public void checkInput(){
        frame.requestFocus();
        if(keyPressed){
            exit();
        }
    }