package normalfill;

import java.awt.image.BufferedImage;
import java.io.File;
import javax.imageio.ImageIO;

/**
 *
 * @author maik
 */
public class Normalfill {

    public static void main(String[] args) throws Exception {

        File f = new File("/tmp/test.png");

        BufferedImage bi = ImageIO.read(f);

        boolean finished;

        do {
            finished = true;
            for (int x = 0; x < bi.getWidth(); ++x) {
                for (int y = 0; y < bi.getHeight(); ++y) {
                    int pixel = bi.getRGB(x, y) & 0xFFFFFF;
                    if (pixel == 0) {
                        int fillcolor = getNextNeighbour(bi, x, y);
                        if (fillcolor != 0) {
                            bi.setRGB(x, y, fillcolor);
                            finished = false;
                        }
                    }
                }
            }
        } while (!finished);


        ImageIO.write(bi, "png", new File("/tmp/test2.png"));
    }

    private static int getNextNeighbour(BufferedImage bi, int x, int y) {

        for (int xoff = -1; xoff < 2; xoff++) {
            int xpos = x + xoff;
            if (xpos >= 0 && xpos < bi.getWidth()) {
                for (int yoff = -1; yoff < 2; yoff++) {
                    if (Math.abs(xoff) + Math.abs(yoff) == 1) {
                        int ypos = y + yoff;
                        if (ypos >= 0 && ypos < bi.getHeight()) {
                            int pixel = bi.getRGB(xpos, ypos);
                            if ((pixel & 0xFFFFFF) != 0) {
                                return pixel;
                            }
                        }
                    }
                }
            }
        }

        return 0;

    }
}