Merge pull request #49 from nvshinde/nvshinde-cat-shooter

Author: armanbilge

src/main/scala/gsoc/contributors/all.scala

@@ -33,6 +33,7 @@ val allContributors = NonEmptyList.of(
   ap44444,
   saifk16,
   `alokkumardalei-wq`,
+  `nvshinde`,
   boss6825,
   yummy_yums,
   `thonkpad`,

src/main/scala/gsoc/contributors/nvshinde.scala

@@ -0,0 +1,133 @@
+package gsoc
+package contributors
+
+import cats.effect.*
+import cats.effect.std.Random
+import fs2.concurrent.*
+import fs2.dom.HtmlElement
+import calico.html.io.{*, given}
+import calico.syntax.*
+
+import org.scalajs.dom
+import scala.concurrent.duration.DurationInt
+
+val nvshinde: Contributor = Contributor("nvshinde"):
+  import CatShooter.*
+  for
+    rng <- Random.scalaUtilRandom[IO].toResource
+    mousePos <- randCol(rng).toResource
+    ref <- SignallingRef[IO].of(init(mousePos)).toResource
+    node <- div(
+      tabIndex := 0,
+      styleAttr := "outline:none;",
+      p(
+        "I am",
+        span(
+          styleAttr := "color:mediumseablue;font-weight:bold",
+          "@nvshinde"
+        ),
+        " on Github. I agree to follow the Typelevel CoC and GSoC AI policy."
+      ),
+      p(
+        styleAttr := "font-size:13px;color:#888;margin:4px 0;",
+        "Play the Mice invaders game below. Use arrow keys to move left and right and space to shoot!"
+      ),
+      onKeyDown --> (_.foreach { e =>
+        e.key match
+          case "ArrowLeft" => e.preventDefault *> ref.update(moveLeft)
+          case "ArrowRight" => e.preventDefault *> ref.update(moveRight)
+          case " " => e.preventDefault *> shootLaser(ref, rng)
+          case _ => IO.unit
+      }),
+      ref.map(renderSpace),
+      ref.map { s =>
+        p(
+          styleAttr := "margin-top:8px;font-size:14px;",
+          s"Score: ${s.score}"
+        )
+      }
+    )
+  yield node
+
+private object CatShooter {
+  val Size = 20
+  val CellPx = 20
+
+  final case class State(
+      cat: Int,
+      mouse: Int,
+      laserRow: Option[Int],
+      score: Int
+  )
+
+  def randCol(rng: Random[IO]): IO[Int] =
+    rng.betweenInt(0, Size)
+
+  def init(mouse: Int): State = State(
+    cat = Size / 2,
+    mouse = mouse,
+    laserRow = None,
+    score = 0
+  )
+
+  def moveLeft(s: State): State =
+    if s.cat > 0 then s.copy(cat = s.cat - 1) else s
+
+  def moveRight(s: State): State =
+    if s.cat < Size - 1 then s.copy(cat = s.cat + 1) else s
+
+  def shootLaser(
+      ref: SignallingRef[IO, State],
+      rng: Random[IO]
+  ): IO[Unit] =
+    fs2
+      .Stream
+      .range(1, Size)
+      .evalMap { row => ref.update(_.copy(laserRow = Some(row))) }
+      .metered(20.millis)
+      .compile
+      .drain >>
+      ref
+        .modify { s =>
+          if s.cat == s.mouse then
+            val updatedScore = s.copy(score = s.score + 1, laserRow = None)
+            (updatedScore, true)
+          else (s.copy(laserRow = None), false)
+        }
+        .flatMap {
+          case true =>
+            randCol(rng).flatMap(newCol => ref.update(_.copy(mouse = newCol)))
+          case false => IO.unit
+        }
+
+  def renderSpace(s: State): Resource[IO, HtmlElement[IO]] =
+    div(
+      styleAttr := s"display:grid;grid-template-columns:repeat($Size, ${CellPx}px); background:#111;width:${Size * CellPx}px;height:${Size * CellPx}px"
+    ).flatMap { gridEl =>
+      Resource
+        .eval(IO {
+          val raw = gridEl.asInstanceOf[dom.HTMLElement]
+
+          raw.innerHTML = ""
+          for
+            y <- 0 until Size
+            x <- 0 until Size
+          do
+            val cell = dom.document.createElement("div")
+            cell.setAttribute(
+              "style",
+              s"width:${CellPx}px;height:${CellPx}px;display:flex;align-items:center;justify-content:center;color:white;font-weight:bold;font-size:20px"
+            )
+
+            val content =
+              if y == 0 && x == s.cat then "C"
+              else if y == Size - 1 && x == s.mouse then "M"
+              else if s.laserRow.contains(y) && x == s.cat then "*"
+              else ""
+
+            cell.textContent = content
+            raw.appendChild(cell)
+        })
+        .map(_ => gridEl)
+    }
+}