SortViz

import java.io.FileOutputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

/**
 * @author sci4me
 */
public final class SortViz
{
    public static final int WIDTH = 300;
    public static final int HEIGHT = 400;

    public static void main(final String[] args) throws Throwable
    {
        new SortViz().start();
    }

    private SortViz()
    {
    }

    private GifMaker gif;
    private int[] dataset;

    private int highlightedIndex;

    private void start() throws Throwable
    {
        this.gif = new GifMaker(new FileOutputStream("sort.gif"), 50, WIDTH, HEIGHT);
        this.dataset = new int[14];

        final List<Integer> data = new ArrayList<>();
        for (int i = 0; i < this.dataset.length; i++)
            data.add(i + 1);
        Collections.shuffle(data);
        for (int i = 0; i < this.dataset.length; i++)
            this.dataset[i] = data.get(i);

        this.highlightedIndex = -1;

        this.drawFrame();
        this.drawFrame();

        int pos = 1;
        while (pos < this.dataset.length)
        {
            if (this.dataset[pos] >= this.dataset[pos - 1])
            {
                pos++;
            }
            else
            {
                final int temp = this.dataset[pos];
                this.dataset[pos] = this.dataset[pos - 1];
                this.dataset[pos - 1] = temp;

                if (pos > 1)
                {
                    pos--;
                }
            }

            this.highlightedIndex = pos;

            this.drawFrame();
            this.drawFrame();
        }

        for(int i = 0; i < 100; i++)
            this.drawFrame();

        this.gif.write();
    }

    private void drawFrame() throws IOException
    {
        for (int x = 0; x < WIDTH; x++)
        {
            for (int y = 0; y < HEIGHT; y++)
            {
                this.gif.setPixel(x, y, 0xFFFFFFFF);
            }
        }

        for (int i = 0; i < this.dataset.length; i++)
        {
            final int height = (int) (((double) this.dataset[i] / this.dataset.length) * HEIGHT - 20);

            final int xStart = 10 + i * 20;
            for (int x = xStart; x < xStart + 10; x++)
            {
                final int yStart = 10;
                for (int y = yStart; y < yStart + height; y++)
                {
                    this.gif.setPixel(x, HEIGHT - y, i == this.highlightedIndex ? 0xFFFF0000 : 0xFFAA0000);
                }
            }
        }

        this.gif.nextFrame();
    }
}