Data commit

Task/Draw-a-rotating-cube/Java/draw-a-rotating-cube.java

@@ -0,0 +1,92 @@
+import java.awt.*;
+import java.awt.event.ActionEvent;
+import static java.lang.Math.*;
+import javax.swing.*;
+
+public class RotatingCube 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}};
+
+    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}};
+
+    public RotatingCube() {
+        setPreferredSize(new Dimension(640, 640));
+        setBackground(Color.white);
+
+        scale(100);
+        rotateCube(PI / 4, atan(sqrt(2)));
+
+        new Timer(17, (ActionEvent e) -> {
+            rotateCube(PI / 180, 0);
+            repaint();
+        }).start();
+    }
+
+    final void scale(double s) {
+        for (double[] node : nodes) {
+            node[0] *= s;
+            node[1] *= s;
+            node[2] *= s;
+        }
+    }
+
+    final 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
+    public void paintComponent(Graphics gg) {
+        super.paintComponent(gg);
+        Graphics2D g = (Graphics2D) gg;
+        g.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
+                RenderingHints.VALUE_ANTIALIAS_ON);
+
+        drawCube(g);
+    }
+
+    public static void main(String[] args) {
+        SwingUtilities.invokeLater(() -> {
+            JFrame f = new JFrame();
+            f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+            f.setTitle("Rotating Cube");
+            f.setResizable(false);
+            f.add(new RotatingCube(), BorderLayout.CENTER);
+            f.pack();
+            f.setLocationRelativeTo(null);
+            f.setVisible(true);
+        });
+    }
+}