package algs91; // section 9.8
import stdlib.*;
import algs12.Point2D;
import algs13.Bag;
/* ***********************************************************************
 *  Compilation:  javac InteractiveConvexHull.java
 *  Execution:    java InteractiveConvexHull
 *  Dependencies: GrahamScan.java Point2D.java StdDraw.java Bag.java
 *
 *************************************************************************/

public class XInteractiveConvexHull {

	public static void main(String[] args) {
		StdDraw.setCanvasSize(800, 800);
		StdDraw.setXscale(0, 10000);
		StdDraw.setYscale(0, 10000);
		StdDraw.show(0);
		Bag<Point2D> bag = new Bag<>();

		while (true) {
			if (StdDraw.mousePressed()) {
				// mouse pressed so add point to list of points
				int x = (int) (Math.round(StdDraw.mouseX()));
				int y = (int) (Math.round(StdDraw.mouseY()));
				bag.add(new Point2D(x, y));

				// extract array of points
				int N = bag.size();
				Point2D[] points = new Point2D[N];
				int n = 0;
				for (Point2D p : bag) {
					points[n++] = p;
				}

				// compute convex hull
				GrahamScan graham = new GrahamScan(points);


				StdDraw.clear();

				// draw the points in black
				StdDraw.setPenRadius(.01);
				StdDraw.setPenColor(StdDraw.BLACK);
				for (int i = 0; i < N; i++)
					points[i].draw();

				// draw the hull points in red
				StdDraw.setPenColor(StdDraw.RED);
				for (Point2D p : graham.hull())
					p.draw();

				// draw the hull line segments in blue
				StdDraw.setPenRadius();
				StdDraw.setPenColor(StdDraw.BLUE);
				Point2D prev = null;
				for (Point2D p : graham.hull()) {
					if (prev != null) prev.drawTo(p);
					prev = p;
				}
				// hack to connect first and last points
				for (Point2D p : graham.hull()) {
					prev.drawTo(p);
					break;
				}
			}
			StdDraw.show(20);
		}

	}

}