Data commit

Task/Elementary-cellular-automaton/Java/elementary-cellular-automaton.java

@@ -0,0 +1,83 @@
+import java.awt.*;
+import java.awt.event.ActionEvent;
+import javax.swing.*;
+import javax.swing.Timer;
+
+public class WolframCA extends JPanel {
+    final int[] ruleSet = {30, 45, 50, 57, 62, 70, 73, 75, 86, 89, 90, 99,
+        101, 105, 109, 110, 124, 129, 133, 135, 137, 139, 141, 164,170, 232};
+    byte[][] cells;
+    int rule = 0;
+
+    public WolframCA() {
+        Dimension dim = new Dimension(900, 450);
+        setPreferredSize(dim);
+        setBackground(Color.white);
+        setFont(new Font("SansSerif", Font.BOLD, 28));
+
+        cells = new byte[dim.height][dim.width];
+        cells[0][dim.width / 2] = 1;
+
+        new Timer(5000, (ActionEvent e) -> {
+            rule++;
+            if (rule == ruleSet.length)
+                rule = 0;
+            repaint();
+        }).start();
+    }
+
+    private byte rules(int lhs, int mid, int rhs) {
+        int idx = (lhs << 2 | mid << 1 | rhs);
+        return (byte) (ruleSet[rule] >> idx & 1);
+    }
+
+    void drawCa(Graphics2D g) {
+        g.setColor(Color.black);
+        for (int r = 0; r < cells.length - 1; r++) {
+            for (int c = 1; c < cells[r].length - 1; c++) {
+                byte lhs = cells[r][c - 1];
+                byte mid = cells[r][c];
+                byte rhs = cells[r][c + 1];
+                cells[r + 1][c] = rules(lhs, mid, rhs); // next generation
+                if (cells[r][c] == 1) {
+                    g.fillRect(c, r, 1, 1);
+                }
+            }
+        }
+    }
+
+    void drawLegend(Graphics2D g) {
+        String s = String.valueOf(ruleSet[rule]);
+        int sw = g.getFontMetrics().stringWidth(s);
+
+        g.setColor(Color.white);
+        g.fillRect(16, 5, 55, 30);
+
+        g.setColor(Color.darkGray);
+        g.drawString(s, 16 + (55 - sw) / 2, 30);
+    }
+
+    @Override
+    public void paintComponent(Graphics gg) {
+        super.paintComponent(gg);
+        Graphics2D g = (Graphics2D) gg;
+        g.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
+                RenderingHints.VALUE_ANTIALIAS_ON);
+
+        drawCa(g);
+        drawLegend(g);
+    }
+
+    public static void main(String[] args) {
+        SwingUtilities.invokeLater(() -> {
+            JFrame f = new JFrame();
+            f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+            f.setTitle("Wolfram CA");
+            f.setResizable(false);
+            f.add(new WolframCA(), BorderLayout.CENTER);
+            f.pack();
+            f.setLocationRelativeTo(null);
+            f.setVisible(true);
+        });
+    }
+}