sandboxels/mods/pixelResizeTool.js

pixelResizeButton = document.createElement("button");
pixelResizeButton.onclick = function(pixel) {
    let canvas_width = document.getElementById("game").width;
    let canvas_height = document.getElementById("game").height;
    let pixelSizeNeeded = prompt("How big should pixels be?");
    if (!pixelSizeNeeded || isNaN(pixelSizeNeeded)) { alert('number is invalid!'); return; }
    resizeCanvas(canvas_height,canvas_width, parseFloat(pixelSizeNeeded), true);
};
pixelResizeButton.textContent = "Resize";
window.addEventListener("load",function(){
   document.getElementById("toolControls").appendChild(pixelResizeButton); 
});