index.html

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    <meta charset="utf-8" />
    <title>Shin Megami Tensei 4 Alignment Editor</title>
    <style>
        p,h1,div {
            margin: auto;
            width: 50%;
            padding: 10px;
            text-align: center;
        }
        ol,ul {
            display: table;
            margin: 0 auto;
            text-align: left;
        }
    </style>
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<body>

<h1>Shin Megami Tensei 4 Alignment Editor</h1>
<p><small>by <a href="https://reddit.com/u/ThatManOfCulture">u/ThatManOfCulture</a></small></p>

<div>
    <label for="savefile">Select a savefile:</label>
    <input type="file" id="savefile" name="savefile" onchange="readSavefile()">
</div>

<div>
    <label for="points">Alignment points (+100 to -100):</label>
    <input type="number" id="points" name="points" min="-100" max="100">
</div>

<div>
    <input id="btnExport" type="button" value="Export" onclick="exportSavefile()" />
</div>

<div>
    <h4>To unlock neutral ending:</h4>

    <ol>
        <li>Use a savefile prior to the King Kenji boss fight in Infernal Tokyo.</li>
        <li>Set a value such that the sum with below answers will result in a value between +8 and -8.</li>
    </ol>

    <p>"Push the button?"</p>
    <ul>
        <li>[+5] Press the button</li>
        <li>[+0] Don't press the button</li>
    </ul>

    <p>"Do you intend to preserve the current status quo? Are you going to destroy the order of things?"</p>
    <ul>
        <li>[+10] I'll preserve the status quo.</li>
        <li>[-10] I'll destroy the order of things.</li>
    </ul>

    </p>
</div>

<script>
function readSavefile()
{
    var savefile = document.getElementById("savefile").files[0]
    if (savefile)
    {
        var reader = new FileReader();
        reader.readAsArrayBuffer(savefile);
        reader.onload = function (evt)
        {
            var arrayBuffer = evt.target.result;
            var bytes = new Int16Array(arrayBuffer)
            document.getElementById("points").value = bytes[0xc2];
        }
        reader.onerror = function (evt)
        {
            document.getElementById("fileContents").innerHTML = "error reading savefile";
        }
    }
}

function exportSavefile()
{
    var savefile = document.getElementById("savefile").files[0]
    if (savefile)
    {
        var reader = new FileReader();
        reader.readAsArrayBuffer(savefile);
        reader.onload = function (evt)
        {
            var arrayBuffer = evt.target.result;
            var bytes = new Uint16Array(arrayBuffer)
            var newPoints = document.getElementById("points").value
            bytes[0xc2] = newPoints

            var newBytes = new Uint16Array(bytes);
            var blob = new Blob([newBytes]);
            var link = document.createElement('a');
            link.href = window.URL.createObjectURL(blob);
            link.download = savefile.name;
            link.click();
        }
        reader.onerror = function (evt)
        {
            document.getElementById("fileContents").innerHTML = "error reading savefile";
        }
    }
}
</script>

</body>
</html>