Data commit

Task/Superellipse/Scala/superellipse.scala

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+import java.awt._
+import java.awt.geom.Path2D
+import java.util
+
+import javax.swing._
+import javax.swing.event.{ChangeEvent, ChangeListener}
+
+object SuperEllipse extends App {
+
+    SwingUtilities.invokeLater(() => {
+      new JFrame("Super Ellipse") {
+
+        class SuperEllipse extends JPanel with ChangeListener {
+          setPreferredSize(new Dimension(650, 650))
+          setBackground(Color.white)
+          setFont(new Font("Serif", Font.PLAIN, 18))
+          private var exp = 2.5
+
+          override def paintComponent(gg: Graphics): Unit = {
+            val g = gg.asInstanceOf[Graphics2D]
+
+           def drawGrid(g: Graphics2D): Unit = {
+              g.setStroke(new BasicStroke(2))
+              g.setColor(new Color(0xEEEEEE))
+              val w = getWidth
+              val h = getHeight
+              val spacing = 25
+
+              for (i <- 0 until (w / spacing)) {
+                g.drawLine(0, i * spacing, w, i * spacing)
+                g.drawLine(i * spacing, 0, i * spacing, w)
+              }
+              g.drawLine(0, h - 1, w, h - 1)
+              g.setColor(new Color(0xAAAAAA))
+              g.drawLine(0, w / 2, w, w / 2)
+              g.drawLine(w / 2, 0, w / 2, w)
+            }
+
+            def drawLegend(g: Graphics2D): Unit = {
+              g.setColor(Color.black)
+              g.setFont(getFont)
+              g.drawString("n = " + String.valueOf(exp), getWidth - 150, 45)
+              g.drawString("a = b = 200", getWidth - 150, 75)
+            }
+
+            def drawEllipse(g: Graphics2D): Unit = {
+              val a = 200
+              // calculate first quadrant
+              val points = Array.tabulate(a + 1)(n =>
+                math.pow(math.pow(a, exp) - math.pow(n, exp), 1 / exp))
+              val p = new Path2D.Double
+
+              p.moveTo(a, 0)
+              for (n <- a to 0 by -1) p.lineTo(n, -points(n))
+              // mirror to others
+              for (x <- points.indices) p.lineTo(x, points(x))
+              for (y <- a to 0 by -1) p.lineTo(-y, points(y))
+              for (z <- points.indices) p.lineTo(-z, -points(z))
+              g.translate(getWidth / 2, getHeight / 2)
+              g.setStroke(new BasicStroke(2))
+              g.setColor(new Color(0x25B0C4DE, true))
+              g.fill(p)
+              g.setColor(new Color(0xB0C4DE)) // LightSteelBlue
+              g.draw(p)
+            }
+
+            super.paintComponent(gg)
+            g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON)
+            g.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_ON)
+            drawGrid(g)
+            drawLegend(g)
+            drawEllipse(g)
+          }
+
+          override def stateChanged(e: ChangeEvent): Unit = {
+            val source = e.getSource.asInstanceOf[JSlider]
+            exp = source.getValue / 2.0
+            repaint()
+          }
+        }
+
+        setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE)
+        setResizable(false)
+        val panel = new SuperEllipse
+        add(panel, BorderLayout.CENTER)
+        val exponent = new JSlider(SwingConstants.HORIZONTAL, 1, 9, 5)
+        exponent.addChangeListener(panel)
+        exponent.setBackground(Color.white)
+        exponent.setBorder(BorderFactory.createEmptyBorder(20, 20, 20, 20))
+        exponent.setMajorTickSpacing(1)
+        exponent.setPaintLabels(true)
+        val labelTable = new util.Hashtable[Integer, JLabel]
+        for (i <- 1 until 10) labelTable.put(i, new JLabel(String.valueOf(i * 0.5)))
+
+        exponent.setLabelTable(labelTable)
+        add(exponent, BorderLayout.SOUTH)
+        pack()
+        setLocationRelativeTo(null)
+        setVisible(true)
+      }
+
+    })
+
+}