import java.awt.Color;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.Point;
import java.awt.image.BufferedImage;
import java.awt.image.RenderedImage;
import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import javax.imageio.ImageIO;

public final class BezierCubic {

	public static void main(String[] args) throws IOException {
		final int width = 200;
	    final int height = 200;
	    BasicBitmapStorage bitmap = new BasicBitmapStorage(width, height);	
        bitmap.fill(Color.YELLOW);

        Point point1 = new Point(0, 150);
        Point point2 = new Point(30, 50);
        Point point3 = new Point(120, 130);
        Point point4 = new Point(160, 30);
        bitmap.cubicBezier(point1, point2, point3, point4, Color.BLACK, 20);

        File bezierFile = new File("CubicBezierJava.jpg");
        ImageIO.write((RenderedImage) bitmap.getImage(), "jpg", bezierFile);
	}
	
}
	
final class BasicBitmapStorage {

	public BasicBitmapStorage(int width, int height) {
        image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
    }
	
	public void fill(Color color) {
		Graphics graphics = image.getGraphics();
	    graphics.setColor(color);
	    graphics.fillRect(0, 0, image.getWidth(), image.getHeight());
	}

    public Color getPixel(int x, int y) {
        return new Color(image.getRGB(x, y));
    }

    public void setPixel(int x, int y, Color color) {
        image.setRGB(x, y, color.getRGB());
    }

    public Image getImage() {
    	return image;
    }

    public void cubicBezier(
    		Point point1, Point point2, Point point3, Point point4, Color color, int intermediatePointCount) {
    	
     	List<Point> points = new ArrayList<Point>();

        for ( int i = 0; i <= intermediatePointCount; i++ ) {
            final double t = (double) i / intermediatePointCount;
            final double u = 1.0 - t;
            final double a = u * u * u;
            final double b = 3.0 * t * u * u;
            final double c = 3.0 * t * t * u;
            final double d = t * t * t;

            final int x = (int) ( a * point1.x + b * point2.x + c * point3.x + d * point4.x );
            final int y = (int) ( a * point1.y + b * point2.y + c * point3.y + d * point4.y );
            points.add( new Point(x, y) );
            setPixel(x, y, color);
        }

        for ( int i = 0; i < intermediatePointCount; i++ ) {
            drawLine(points.get(i).x, points.get(i).y, points.get(i + 1).x, points.get(i + 1).y, color);
        }
    }

    public void drawLine(int x0, int y0, int x1, int y1, Color color) {
    	final int dx = Math.abs(x1 - x0);
    	final int dy = Math.abs(y1 - y0);
    	final int xIncrement = x0 < x1 ? 1 : -1;
    	final int yIncrement = y0 < y1 ? 1 : -1;
    	
    	int error = ( dx > dy ? dx : -dy ) / 2;
    	
    	while ( x0 != x1 || y0 != y1 ) {
    	    setPixel(x0, y0, color);
    	    int error2 = error;
    	
    	    if ( error2 > -dx ) {
    	    	error -= dy;
    	    	x0 += xIncrement;
    	    }
    	
    	    if ( error2 < dy ) {
    	    	error += dx;
    	    	y0 += yIncrement;
    	    }
    	}
    	setPixel(x0, y0, color);
    }

    private BufferedImage image;

}