import javax.swing.*;
import java.awt.*;
import java.util.*;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import static java.lang.Math.*;

public class Geom extends JFrame {
	private class PaintPanel extends JPanel {
		double minX = -5;
		double minY = -5;
		double maxX = 5;
		double maxY = 5;
		int state = 0;
		double[][] cord = new double[3][3];

		public PaintPanel() {
			addKeyListener(new KeyListener() {
				public void keyPressed(KeyEvent arg0) {
				}

				public void keyReleased(KeyEvent arg0) {
				}

				public void keyTyped(KeyEvent key) {
					if (key.getKeyChar() == ' ') {
						state = (state + 1) % 7;
						repaint();
					}
					System.err.println(state);
				}
			});
			setFocusable(true);
		}

		public void paintComponent(Graphics g) {
			super.paintComponents(g);
			Graphics2D g2 = (Graphics2D) g;
			g2.setColor(Color.black);
			g2.fill(new Rectangle(getSize()));
			paintAxis(g2);
			g2.setColor(Color.yellow);
			if (state == 0) {
				cord = createNewFigure();
			} else {
				for (int i = 0; i < cord.length; ++i) {
					cord[i] = rotate(cord[i], Math.PI / 2, Math.PI / 2);
				}
			}
			drawPolygon(cord, g2);
		}

		private double[][] createNewFigure() {
			return new double[][] { {-1, -1, 1},
									{-1, 2, 1},
									{-3, 3, 1},
									{-3, -1, 1}};
		}

		private double[] scale(double[] a, double kx, double ky) {
			double[][] m = new double[][] {	{kx, 0, 0},
											{0, ky, 0},
											{0, 0, 1} };
			return multiply(a, m)[0];
		}

		private void drawPolygon(double[][] cord, Graphics2D g2) {
			for (int i = 0; i < cord.length; ++i) {
				drawLine(cord[i][0], cord[i][1], cord[(i + 1) % cord.length][0], cord[(i + 1) % cord.length][1], g2);
			}
		}

		private double[][] createNewTriangle() {
			double[][] cord = new double[3][];
			Random rm = new Random();
			double x = (rm.nextDouble() + 0.5) * maxX / 3;
			double y = (rm.nextDouble() + 0.5) * maxY / 3;
			cord[0] = new double[] {0, 0, 1};
			cord[1] = new double[] {0, y, 1};
			cord[2] = new double[] {x, 0, 1};
			double dx = (rm.nextDouble() + 0.0) * maxX / 3 + maxX / 5;
			double dy = (rm.nextDouble() + 0.0) * maxY / 3 + maxY / 5;
			for (int i = 0; i < 3; ++i) {
				cord[i] = move(cord[i], dx, dy);
			}
			double angle = Math.PI * rm.nextDouble();
			for (int i = 0; i < 3; ++i) {
				cord[i] = rotate(cord[i], angle);
			}
			return cord;
		}

		private double[] rotate(double[] a, double angle) {
			double[][] m = new double[][] { {cos(angle), sin(angle), 0},
											{-sin(angle), cos(angle), 0},
											{0, 0, 1}};
			return multiply(a, m)[0];
		}

		private double[] move(double[] a, double dx, double dy) {
			double[][] m = new double[][] { {1, 0, 0},
											{0, 1, 0},
											{dx, dy, 1}};
			return multiply(a, m)[0];
		}

		private double[][] multiply(double[] cord, double[][] b) {
			double[][] a = new double[][] {cord};
			double[][] res = new double[a.length][b[0].length];
			for (int i = 0; i < res.length; ++i) {
				for (int j = 0; j < res[i].length; ++j) {
					for (int k = 0; k < a[i].length; ++k) {
						res[i][j] += a[i][k] * b[k][j];
					}
				}
			}
			return res;
		}

		private void paintAxis(Graphics2D g2) {
			g2.setColor(Color.green);
			drawLine(minX, 0, maxX, 0, g2);
			drawLine(0, minY, 0, maxY, g2);
		}

		private void drawLine(double x, double y, double x2, double y2, Graphics2D g2) {
			int ix = screenX(x);
			int iy = screenY(y);
			int ix2 = screenX(x2);
			int iy2 = screenY(y2);
			g2.drawLine(ix, iy, ix2, iy2);
		}

		private int screenY(double y) {
			Dimension dim = getSize();
			return (int) (dim.height * (1 - (y - minX) / (maxX - minX)));
		}

		private int screenX(double x) {
			Dimension dim = getSize();
			return (int) (dim.width * (x - minX) / (maxX - minX));
		}
	}

	public Geom() {
		Dimension dim = Toolkit.getDefaultToolkit().getScreenSize();
		setBounds(dim.width / 4, dim.height / 4, dim.width / 2, dim.height / 2);
		add(new PaintPanel());
		setDefaultCloseOperation(EXIT_ON_CLOSE);
		setVisible(true);
	}

	public static void main(String[] args) {
		new Geom();
	}

}