Another update from ingydotnet^djgoku

Task/Draw-a-cuboid/Java/draw-a-cuboid.java

@@ -1,30 +1,92 @@
 import java.awt.*;
+import java.awt.event.*;
+import static java.lang.Math.*;
 import javax.swing.*;
 
-public class Cuboid extends JFrame {
+public class Cuboid extends JPanel {
+    double[][] nodes = {{-1, -1, -1}, {-1, -1, 1}, {-1, 1, -1}, {-1, 1, 1},
+    {1, -1, -1}, {1, -1, 1}, {1, 1, -1}, {1, 1, 1}};
 
-    public static void main(String[] args) {
-        JFrame f = new Cuboid();
-        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
-        f.setVisible(true);
-    }
+    int[][] edges = {{0, 1}, {1, 3}, {3, 2}, {2, 0}, {4, 5}, {5, 7}, {7, 6},
+    {6, 4}, {0, 4}, {1, 5}, {2, 6}, {3, 7}};
+
+    int mouseX, prevMouseX, mouseY, prevMouseY;
 
     public Cuboid() {
-        Container content = getContentPane();
-        content.setLayout(new BorderLayout());
-        content.add(new CuboidPanel(), BorderLayout.CENTER);
-        setTitle("Cuboid");
-        setResizable(false);
-        pack();
-        setLocationRelativeTo(null);
-    }
-}
-
-class CuboidPanel extends JPanel {
-
-    public CuboidPanel() {
-        setPreferredSize(new Dimension(600, 500));
+        setPreferredSize(new Dimension(640, 640));
         setBackground(Color.white);
+
+        scale(80, 120, 160);
+        rotateCube(PI / 5, PI / 9);
+
+        addMouseListener(new MouseAdapter() {
+            @Override
+            public void mousePressed(MouseEvent e) {
+                mouseX = e.getX();
+                mouseY = e.getY();
+            }
+        });
+
+        addMouseMotionListener(new MouseAdapter() {
+            @Override
+            public void mouseDragged(MouseEvent e) {
+                prevMouseX = mouseX;
+                prevMouseY = mouseY;
+                mouseX = e.getX();
+                mouseY = e.getY();
+
+                double incrX = (mouseX - prevMouseX) * 0.01;
+                double incrY = (mouseY - prevMouseY) * 0.01;
+
+                rotateCube(incrX, incrY);
+                repaint();
+            }
+        });
+    }
+
+    private void scale(double sx, double sy, double sz) {
+        for (double[] node : nodes) {
+            node[0] *= sx;
+            node[1] *= sy;
+            node[2] *= sz;
+        }
+    }
+
+    private void rotateCube(double angleX, double angleY) {
+        double sinX = sin(angleX);
+        double cosX = cos(angleX);
+
+        double sinY = sin(angleY);
+        double cosY = cos(angleY);
+
+        for (double[] node : nodes) {
+            double x = node[0];
+            double y = node[1];
+            double z = node[2];
+
+            node[0] = x * cosX - z * sinX;
+            node[2] = z * cosX + x * sinX;
+
+            z = node[2];
+
+            node[1] = y * cosY - z * sinY;
+            node[2] = z * cosY + y * sinY;
+        }
+    }
+
+    void drawCube(Graphics2D g) {
+        g.translate(getWidth() / 2, getHeight() / 2);
+
+        for (int[] edge : edges) {
+            double[] xy1 = nodes[edge[0]];
+            double[] xy2 = nodes[edge[1]];
+            g.drawLine((int) round(xy1[0]), (int) round(xy1[1]),
+                    (int) round(xy2[0]), (int) round(xy2[1]));
+        }
+
+        for (double[] node : nodes) {
+            g.fillOval((int) round(node[0]) - 4, (int) round(node[1]) - 4, 8, 8);
+        }
     }
 
     @Override
@@ -34,13 +96,19 @@ class CuboidPanel extends JPanel {
         g.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                 RenderingHints.VALUE_ANTIALIAS_ON);
 
-        g.translate(165, -80);
+        drawCube(g);
+    }
 
-        g.drawRect(50, 275, 100, 100);
-        g.drawLine(50, 275, 130, 240);
-        g.drawLine(150, 275, 210, 240);
-        g.drawLine(130, 240, 210, 240);
-        g.drawLine(210, 240, 210, 340);
-        g.drawLine(150, 375, 210, 340);
+    public static void main(String[] args) {
+        SwingUtilities.invokeLater(() -> {
+            JFrame f = new JFrame();
+            f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+            f.setTitle("Cuboid");
+            f.setResizable(false);
+            f.add(new Cuboid(), BorderLayout.CENTER);
+            f.pack();
+            f.setLocationRelativeTo(null);
+            f.setVisible(true);
+        });
     }
 }