// User Interface for Sierpinski Lab
// Author: Chris Wilcox
// Date:   11/3/2016
// Class:  CS163
// Email:  wilcox@cs.colostate.edu

// Copied from:
// http://stackoverflow.com/questions/16311976/drawing-sierpinski-triangle-fractal-java

import java.awt.Color;
import java.awt.Dimension;
import java.awt.GradientPaint;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.util.ArrayList;

import javax.swing.JFrame;
import javax.swing.JPanel;

public class UserInterface extends JPanel {

    private static final long serialVersionUID = 1L;

    // Array list of triangles from student code
    ArrayList<Triangle> triangles;

    // Constructor builds frame for rendering
    public UserInterface() {

        JFrame frame = new JFrame();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setSize(new Dimension(400, 400));
        frame.setLocationRelativeTo(null);
        frame.add(this);
        frame.setVisible(true);
    }

    // Send triangles to be drawn
    public void draw(ArrayList<Triangle> triangles) {
        this.triangles = triangles;
        this.repaint();
    }

    // Render triangles using graphics context
    public void paintComponent(Graphics g) {

        // Enable antialiasing
        Graphics2D g2 = (Graphics2D) g;
        g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, 
                            RenderingHints.VALUE_ANTIALIAS_ON);
        

        // Iterate triangles
        for (int i = 0; i < triangles.size(); i++) {

            Triangle t = triangles.get(i);
            int[] xPoints = {(int)t.x0, (int)t.x1, (int)t.x2};
            int[] yPoints = {(int)t.y0, (int)t.y1, (int)t.y2};
            
            // Reverse coordinates
            int panelHeight = this.getSize().height;
            yPoints[0] = panelHeight - yPoints[0] - 1;
            yPoints[1] = panelHeight - yPoints[1] - 1;
            yPoints[2] = panelHeight - yPoints[2] - 1;
            
            // Inside triangles are filled, outside are wireframe
            if (i % 4 == 0) {
                
                // Draw inside triangle
                g2.setPaint(new GradientPaint(xPoints[0], yPoints[0], Color.lightGray, 
                                              xPoints[1], yPoints[1], Color.blue, false));
                g.fillPolygon(xPoints, yPoints, 3);
            }
            else {

                // Draw outside triangles
                g.setColor(Color.blue);
                g.drawPolygon(xPoints, yPoints, 3);
            }
        }
    }
}