Initial data commit

Task/Pythagoras-tree/Java/pythagoras-tree.java

@@ -0,0 +1,75 @@
+import java.awt.*;
+import java.awt.geom.Path2D;
+import javax.swing.*;
+
+public class PythagorasTree extends JPanel {
+    final int depthLimit = 7;
+    float hue = 0.15f;
+
+    public PythagorasTree() {
+        setPreferredSize(new Dimension(640, 640));
+        setBackground(Color.white);
+    }
+
+    private void drawTree(Graphics2D g, float x1, float y1, float x2, float y2,
+            int depth) {
+
+        if (depth == depthLimit)
+            return;
+
+        float dx = x2 - x1;
+        float dy = y1 - y2;
+
+        float x3 = x2 - dy;
+        float y3 = y2 - dx;
+        float x4 = x1 - dy;
+        float y4 = y1 - dx;
+        float x5 = x4 + 0.5F * (dx - dy);
+        float y5 = y4 - 0.5F * (dx + dy);
+
+        Path2D square = new Path2D.Float();
+        square.moveTo(x1, y1);
+        square.lineTo(x2, y2);
+        square.lineTo(x3, y3);
+        square.lineTo(x4, y4);
+        square.closePath();
+
+        g.setColor(Color.getHSBColor(hue + depth * 0.02f, 1, 1));
+        g.fill(square);
+        g.setColor(Color.lightGray);
+        g.draw(square);
+
+        Path2D triangle = new Path2D.Float();
+        triangle.moveTo(x3, y3);
+        triangle.lineTo(x4, y4);
+        triangle.lineTo(x5, y5);
+        triangle.closePath();
+
+        g.setColor(Color.getHSBColor(hue + depth * 0.035f, 1, 1));
+        g.fill(triangle);
+        g.setColor(Color.lightGray);
+        g.draw(triangle);
+
+        drawTree(g, x4, y4, x5, y5, depth + 1);
+        drawTree(g, x5, y5, x3, y3, depth + 1);
+    }
+
+    @Override
+    public void paintComponent(Graphics g) {
+        super.paintComponent(g);
+        drawTree((Graphics2D) g, 275, 500, 375, 500, 0);
+    }
+
+    public static void main(String[] args) {
+        SwingUtilities.invokeLater(() -> {
+            JFrame f = new JFrame();
+            f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+            f.setTitle("Pythagoras Tree");
+            f.setResizable(false);
+            f.add(new PythagorasTree(), BorderLayout.CENTER);
+            f.pack();
+            f.setLocationRelativeTo(null);
+            f.setVisible(true);
+        });
+    }
+}