How to draw a grid out of grid squares seamlessly in JavaFX

Question

I'm been writing maze algorithms, and want to draw the mazes generated using JavaFX.

To begin with, I'm attempting to draw a simple grid - but made up of smaller shapes so that I'll later be able to change the shape of the grid into that of a maze.

I'm using little upper left corner shapes (like ┏) and a GridPane, but this is leading to small discontinuities between the cells. (screenshot and code below). How can I wedge these shapes together seamlessly? Am I barking up the wrong tree with the Gridpane idea?

attempted grid drawing so far

My code, below, is actually written in Scala; I'm using ScalaFX, but finding help for ScalaFX online is a nightmare so I've been going solely off JavaFX docs - they are pretty much the same thing as far as I've gathered.

val lineLength: Int = 30

def makeClosedCell(length: Int = lineLength): Shape = {
    val wallN = Line(0,0,length,0)
    val wallW = Line(0,0,0,length)
    val closedCell: Shape = Shape.union(wallN, wallW)
    return closedCell
}

def makeOpenW(length: Int = lineLength): Shape = Line(0,0,length,0)

def makeOpenN(length: Int = lineLength): Shape = Line(0,0,0,length)

def initialiseGrid(r: GridPane, sizex: Int, sizey: Int): Unit = {
    for (i <- 0 until sizex) {
        val colConst = new ColumnConstraints()
        colConst.setPercentWidth(100.0 / sizex)
        r.getColumnConstraints().add(colConst)
    }
    for (i <- 0 until sizey) {
        val rowConst = new RowConstraints()
        rowConst.setPercentHeight(100.0 / sizey)
        r.getRowConstraints().add(rowConst)     
    }
    for(j <- sizey-1 to 0 by -1){
        for(i <- 0 until sizex){
            r.add(makeClosedCell(),i,j)
        }
        r.add(makeOpenN(),sizex,j)
    }
    for(i <- 0 until sizex){
        r.add(makeOpenW(),i,sizey)
    }
}

Answer 1

Just found a solution. I've found this can be solved by fixing the exact column and row widths and heights to the same value as the line lengths, like so:

val rowConst = new RowConstraints()
// remove: rowConst.setPercentHeight(100.0 / sizey)
rowConst.setMinHeight(length)
rowConst.setMaxHeight(length)
r.getRowConstraints().add(rowConst) 

With length passed into the initialisation function, of course.