使用 Scala 3 实现 2048
游戏。配色参考 main.css。
本文代码
main.scala
import java.awt.event.KeyEvent.{VK_DOWN, VK_LEFT, VK_RIGHT, VK_UP}
import java.awt.event.{KeyAdapter, KeyEvent}
import java.awt.{Color, Dimension, Font, Graphics}
import java.util.Random
import javax.swing.WindowConstants.EXIT_ON_CLOSE
import javax.swing.{JFrame, JPanel, SwingUtilities}
import scala.collection.mutable.Seq as MutSeq
@main
def main(): Unit = {
SwingUtilities.invokeLater(() =>
new JFrame {
setDefaultCloseOperation(EXIT_ON_CLOSE)
setTitle("2048")
add(Panel())
setVisible(true)
pack()
setLocationRelativeTo(null)
}
)
}
class Panel extends JPanel {
import Panel.*
setPreferredSize(Dimension(Width, Height))
setBackground(Color(0xfaf8ef))
setFocusable(true)
addKeyListener(new KeyAdapter {
override def keyPressed(e: KeyEvent): Unit = {
e.getKeyCode match {
case VK_UP =>
for (index <- 0 until GridNumber) {
var currentOpt: Option[Int] = None
var mergedIndex = 0
tiles.map(_(index)).zipWithIndex.foreach { case (itOpt, i) =>
(itOpt, currentOpt) match
case (Some(it), Some(current)) =>
tiles(i)(index) = None
if (it == current) {
tiles(mergedIndex - 1)(index) = Some(current * 2)
currentOpt = None
} else {
tiles(mergedIndex)(index) = itOpt
mergedIndex += 1
currentOpt = itOpt
}
case (Some(_), None) =>
tiles(i)(index) = None
tiles(mergedIndex)(index) = itOpt
mergedIndex += 1
currentOpt = itOpt
case _ =>
}
}
case VK_DOWN =>
for (index <- 0 until GridNumber) {
var currentOpt: Option[Int] = None
var mergedIndex = GridNumber - 1
tiles.map(_(index)).zipWithIndex.reverse.foreach {
case (itOpt, i) =>
(itOpt, currentOpt) match
case (Some(it), Some(current)) =>
tiles(i)(index) = None
if (it == current) {
tiles(mergedIndex + 1)(index) = Some(current * 2)
currentOpt = None
} else {
tiles(mergedIndex)(index) = itOpt
mergedIndex -= 1
currentOpt = itOpt
}
case (Some(_), None) =>
tiles(i)(index) = None
tiles(mergedIndex)(index) = itOpt
mergedIndex -= 1
currentOpt = itOpt
case _ =>
}
}
case VK_LEFT =>
for (index <- 0 until GridNumber) {
var currentOpt: Option[Int] = None
var mergedIndex = 0
tiles(index).zipWithIndex.foreach { case (itOpt, i) =>
(itOpt, currentOpt) match
case (Some(it), Some(current)) =>
tiles(index)(i) = None
if (it == current) {
tiles(index)(mergedIndex - 1) = Some(current * 2)
currentOpt = None
} else {
tiles(index)(mergedIndex) = itOpt
mergedIndex += 1
currentOpt = itOpt
}
case (Some(_), None) =>
tiles(index)(i) = None
tiles(index)(mergedIndex) = itOpt
mergedIndex += 1
currentOpt = itOpt
case _ =>
}
}
case VK_RIGHT =>
for (index <- 0 until GridNumber) {
var currentOpt: Option[Int] = None
var mergedIndex = GridNumber - 1
tiles(index).zipWithIndex.reverse.foreach { case (itOpt, i) =>
(itOpt, currentOpt) match
case (Some(it), Some(current)) =>
tiles(index)(i) = None
if (it == current) {
tiles(index)(mergedIndex + 1) = Some(current * 2)
currentOpt = None
} else {
tiles(index)(mergedIndex) = itOpt
mergedIndex -= 1
currentOpt = itOpt
}
case (Some(_), None) =>
tiles(index)(i) = None
tiles(index)(mergedIndex) = itOpt
mergedIndex -= 1
currentOpt = itOpt
case _ =>
}
}
case it =>
System.err.println(s"不支持 `${KeyEvent.getKeyText(it)}` 键")
return
}
// 生成一个 Tile
genTile()
// 重绘 Panel
repaint()
}
})
override def paintComponent(it: Graphics): Unit = {
super.paintComponent(it)
it.setColor(gridColor)
it.fillRoundRect(X, Y, Size, Size, Arc, Arc)
for (rowIndex <- 0 until GridNumber; index <- 0 until GridNumber)
tiles(rowIndex)(index) match
case Some(value) =>
// 使用换底公式计算以 2 为底 value 的对数，即 2 的几次方为 value
val log = (math.log(value) / log2).toInt
it.setColor(colorTable(math.min(log, colorTable.size) - 1))
it.fillRoundRect(
GridX + index * GridFullSize,
GridY + rowIndex * GridFullSize,
GridSize,
GridSize,
GridArc,
GridArc
)
// 根据 value 的值范围设置不同的字体颜色和字体大小
val (fontColor, fontSize) = if (value < 8) {
(smallFontColor, 55)
} else if (value < 128) {
(bigFontColor, 45)
} else {
(bigFontColor, 35)
}
it.setColor(fontColor)
it.setFont(Font(null, Font.BOLD, fontSize))
val tile = value.toString
val metrics = it.getFontMetrics
it.drawString(
tile,
GridX + index * GridFullSize + {
// 保持 tile 在 grid 水平居中
(GridSize - metrics.stringWidth(tile)) / 2
},
GridY + rowIndex * GridFullSize + {
// 保持 tile 在 grid 垂直居中
(GridSize - metrics.getHeight) / 2 + metrics.getAscent
}
)
case None =>
it.setColor(emptyColor)
it.fillRoundRect(
GridX + index * GridFullSize,
GridY + rowIndex * GridFullSize,
GridSize,
GridSize,
GridArc,
GridArc
)
}
}
object Panel {
final val Width = 800
final val Height = 600
final val Arc = 12
final val GridNumber = 4
final val GridArc = 6
// 单个 grid 的大小
final val GridSize = 100
final val GridFullSize = GridSize + Arc
final val Size = GridFullSize * GridNumber + Arc
final val X = (Width - Size) / 2
final val Y = (Height - Size) / 2
final val GridX = X + Arc
final val GridY = Y + Arc
val log2: Double = math.log(2)
val colorTable: Seq[Color] = {
given Conversion[Int, Color] = Color(_)
import scala.language.implicitConversions
Seq(
// 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048
0xeee4da, 0xeee1c9, 0xf3b27a, 0xf69664, 0xf77c5f, 0xf75f3b, 0xedd073,
0xedcc62, 0xedc950, 0xedc53f, 0xedc22e
)
}
val gridColor: Color = Color(0xbbada0)
val emptyColor: Color = Color(238, 228, 218, Math.round(.35f * 255f))
val smallFontColor: Color = Color(0x776e65)
val bigFontColor: Color = Color(0xf9f6f2)
val random: Random = Random()
val tiles: Seq[MutSeq[Option[Int]]] =
Seq.fill(GridNumber)(
MutSeq.fill[Option[Int]](GridNumber)(None)
)
// 生成两个 Tile
for _ <- 0 until 2 do genTile()
def genTile(): Unit = {
val noneTiles = tiles.zipWithIndex.flatMap { case (row, i) =>
row.zipWithIndex.filter(_._1.isEmpty).map(it => (i, it._2))
}
if (noneTiles.isEmpty)
println("Game over!")
return
val (xIndex, yIndex) =
if (noneTiles.size == 1)
noneTiles.head
else
noneTiles(random.nextInt(noneTiles.size - 1))
tiles(xIndex)(yIndex) = Some(2)
}
}