val-variants.html

<form>
    Inner twists
    <input name="innerTwists" id="innerTwists" type="number" value="1" min="0" style="width:3em" onchange="update()">
    Outer twists
    <input name="outerTwists" id="outerTwists" type="number" value="1" min="0" style="width:3em" onchange="update()">
    Plait length
    <input name="plaitLength" id="plaitLength" type="number" value="2" min="0" style="width:3em" onchange="update()">
    <a id="link" href="#val"><button type="button">Go</button></a>
    <script>
    function update(){
        var plait = "c" + "tc".repeat(document.getElementById("plaitLength").value * 1)
        var innerTwists = document.getElementById("innerTwists").value * 1
        var outerTwists = document.getElementById("outerTwists").value * 1
        var tile = "tile=-5-,B-C&shiftColsSW=-2&shiftRowsSW=2&shiftColsSE=2&shiftRowsSE=2"
        var leftPlait = `${plait}${"l".repeat(innerTwists)}${"r".repeat(outerTwists)}`
        var rightPlait = `${plait}${"r".repeat(innerTwists)}${"l".repeat(outerTwists)}`
        var join = `ctc${"t".repeat(innerTwists)}`
        var stitches = `b1=${join}&a2=${leftPlait}&c2=${rightPlait}`
        var href = `/GroundForge/stitches?patchWidth=11&patchHeight=12&${stitches}&${tile}`
        document.getElementById("link").href = href
    }
    update()
    </script>
</form>