Scala trial: clean up Laminar interface

Also, drop unused Breeze code in favor of Slash.

lang-trials/scala/src/main/scala/LatticeCircleApp.scala

@@ -8,7 +8,6 @@
 //
 
 import com.raquo.laminar.api.L.{*, given}
-/*import breeze.linalg._*/
 import narr.*
 import org.scalajs.dom
 import org.scalajs.dom.document
@@ -20,57 +19,7 @@ class Circle(var centerX: Double, var centerY: Double, var radius: Double)
 object LatticeCircleApp:
   val canvas = canvasTag(widthAttr := 600, heightAttr := 600)
   val ctx = canvas.ref.getContext("2d").asInstanceOf[dom.CanvasRenderingContext2D]
-  val dataBusList = List.tabulate(6)(_ => new EventBus[Double])
+  val data = List("-1", "0", "0", "-1", "1", "0").map(Var(_))
-  val dataStream = dataBusList(0).events
-    .combineWith(dataBusList(1).events)
-    .combineWith(dataBusList(2).events)
-    .combineWith(dataBusList(3).events)
-    .combineWith(dataBusList(4).events)
-    .combineWith(dataBusList(5).events)
-    .map(dataTuple => NArray(dataTuple(0), dataTuple(1), dataTuple(2), dataTuple(3), dataTuple(4), dataTuple(5)))
-    .filter(data => data.forall(!_.isNaN()))
-  /*
-  val dataList = List(-1.0, 0.0, 0.0, -1.0, 1.0, 0.0).map(Var(_))
-  val dataStream = dataList(0).signal
-    .combineWith(dataList(1).signal)
-    .combineWith(dataList(2).signal)
-    .combineWith(dataList(3).signal)
-    .combineWith(dataList(4).signal)
-    .combineWith(dataList(5).signal)
-    .map(dataTuple => NArray(dataTuple(0), dataTuple(1), dataTuple(2), dataTuple(3), dataTuple(4), dataTuple(5)))
-  */
-  val pointStream = dataStream.map(data => Matrix[3, 2](data))
-  /* Breeze version */
-  /*
-  val pointStream = dataStream.map(data => new DenseMatrix(2, 3, Array(data(0), data(1), data(2), data(3), data(4), data(5))))
-  */
-  
-  /* Breeze version */
-  /*
-  def circThru(points: DenseMatrix[Double]): Circle =
-    // build the matrix that maps the circle's coefficient vector to the
-    // negative of the linear part of the circle's equation, evaluated at the
-    // given points
-    val negLinPart = DenseMatrix.horzcat(
-      2.0*points.t,
-      DenseMatrix.ones[Double](3, 1)
-    )
-    
-    // find the quadrdatic part of the circle's equation, evaluated at the given
-    // points
-    val quadPart = points(::, *).map(v => v dot v)
-    
-    // find the circle's coefficient vector, and from there its center and
-    // radius
-    val coeffs = negLinPart \ quadPart
-    val centerX = coeffs(0, 0)
-    val centerY = coeffs(1, 0)
-    Circle(
-      centerX,
-      centerY,
-      math.sqrt(coeffs(2, 0) + centerX*centerX + centerY*centerY)
-    )
-  */
   
   def circThru(points: Matrix[3, 2]): Option[Circle] =
     // build the matrix that maps the circle's coefficient vector to the
@@ -78,8 +27,6 @@ object LatticeCircleApp:
     // given points
     val negLinPart = Matrix.ones[3, 3]
     negLinPart.setMatrix(0, 0, points * 2.0)
-    println("built neg lin part")
-    println(negLinPart)
     
     // find the quadrdatic part of the circle's equation, evaluated at the given
     // points
@@ -88,8 +35,6 @@ object LatticeCircleApp:
         k => points(k, 0)*points(k, 0) + points(k, 1)*points(k, 1)
       )
     )
-    println("build quad part")
-    println(quadPart)
     
     // find the circle's coefficient vector, and from there its center and
     // radius
@@ -105,7 +50,7 @@ object LatticeCircleApp:
     catch
       _ => return None
   
-  def draw(points: Matrix[3, 2]): Unit =
+  def draw(): Unit =
     // center and normalize the coordinate system
     val width = canvas.ref.width
     val height = canvas.ref.height
@@ -144,6 +89,15 @@ object LatticeCircleApp:
       ctx.stroke()
     
     // find and draw the circle through the given points
+    val dataNow = NArray.tabulate(6)(n =>
+      try
+        data(n).signal.now().toDouble
+      catch
+        _ => Double.NaN
+    )
+    if dataNow.forall(t => t == t.floor) then
+      // all of the coordinates are integer and non-NaN
+      val points = Matrix[3, 2](dataNow)
       circThru(points) match
         case Some(circ) =>
           ctx.beginPath()
@@ -159,95 +113,48 @@ object LatticeCircleApp:
     
     // draw the data points
     for n <- 0 to 2 do
+      val indX = 2*n
+      val indY = indX + 1
+      if
+        dataNow(indX) == dataNow(indX).floor &&
+        dataNow(indY) == dataNow(indY).floor
+      then
         ctx.beginPath()
         ctx.fillStyle = pointFillStyles(n)
         ctx.strokeStyle = pointStrokeStyles(n)
         ctx.arc(
-        res * points(n, 0),
+          res * dataNow(indX),
-        res * points(n, 1),
+          res * dataNow(indY),
           3.0,
           0.0, 2.0*math.Pi
         )
         ctx.fill()
         ctx.stroke()
   
+  def coordInput(n: Int): Input =
+    input(
+      typ := "number",
+      cls := s"point-${(1.0 + 0.5*n).floor.toInt}",
+      controlled(
+        value <-- data(n).signal,
+        onInput.mapToValue --> data(n).writer
+      ),
+      data(n).signal --> { _ => draw() }
+    )
+  
   def main(args: Array[String]): Unit =
     lazy val app = div(
       canvas,
       div(
-        pointStream --> draw,
         idAttr := "data-panel",
         div("x"),
         div("y"),
-        input(typ := "number", cls := "point-1", inContext(thisNode => onInput.mapTo(thisNode.ref.valueAsNumber) --> dataBusList(0))),
+        coordInput(0),
-        input(typ := "number", cls := "point-1", inContext(thisNode => onInput.mapTo(thisNode.ref.valueAsNumber) --> dataBusList(1))),
+        coordInput(1),
-        input(typ := "number", cls := "point-2", inContext(thisNode => onInput.mapTo(thisNode.ref.valueAsNumber) --> dataBusList(2))),
+        coordInput(2),
-        input(typ := "number", cls := "point-2", inContext(thisNode => onInput.mapTo(thisNode.ref.valueAsNumber) --> dataBusList(3))),
+        coordInput(3),
-        input(typ := "number", cls := "point-3", inContext(thisNode => onInput.mapTo(thisNode.ref.valueAsNumber) --> dataBusList(4))),
+        coordInput(4),
-        input(typ := "number", cls := "point-3", inContext(thisNode => onInput.mapTo(thisNode.ref.valueAsNumber) --> dataBusList(5)))
+        coordInput(5)
-        /* attempt to use controlled inputs */
-        /*
-        input(
-          typ := "number",
-          cls := "point-1",
-          controlled(
-            value <-- dataList(0).signal,
-            inContext(
-              thisNode => onInput.mapTo(thisNode.ref.valueAsNumber) --> dataList(0).writer
-            )
-          )
-        ),
-        input(
-          typ := "number",
-          cls := "point-1",
-          controlled(
-            value <-- dataList(1).signal,
-            inContext(
-              thisNode => onInput.mapTo(thisNode.ref.valueAsNumber) --> dataList(1).writer
-            )
-          )
-        ),
-        input(
-          typ := "number",
-          cls := "point-2",
-          controlled(
-            value <-- dataList(2).signal,
-            inContext(
-              thisNode => onInput.mapTo(thisNode.ref.valueAsNumber) --> dataList(2).writer
-            )
-          )
-        ),
-        input(
-          typ := "number",
-          cls := "point-2",
-          controlled(
-            value <-- dataList(3).signal,
-            inContext(
-              thisNode => onInput.mapTo(thisNode.ref.valueAsNumber) --> dataList(3).writer
-            )
-          )
-        ),
-        input(
-          typ := "number",
-          cls := "point-3",
-          controlled(
-            value <-- dataList(4).signal,
-            inContext(
-              thisNode => onInput.mapTo(thisNode.ref.valueAsNumber) --> dataList(4).writer
-            )
-          )
-        ),
-        input(
-          typ := "number",
-          cls := "point-3",
-          controlled(
-            value <-- dataList(5).signal,
-            inContext(
-              thisNode => onInput.mapTo(thisNode.ref.valueAsNumber) --> dataList(5).writer
-            )
-          )
-        )
-        */
       )
     )
     renderOnDomContentLoaded(document.body, app)