Photoshop: Layers To Sprite Sheet

LayersToSpriteSheet.js

// Notes:
// 1. Save this file in Program Files\Adobe\Photoshop\Presets\Scripts\
// 2. Run the script by going to menu File > Scripts > LayersToSpriteSheet

// Based on http://alessandroituarte.com/blag/2012/07/03/470

if (documents.length > 0) {

    // Adjust this to the number of columns you want
    // leave -1 if you want it to calculate an optimal column value.
    var cols = -1;

    for (var i = activeDocument.artLayers.length - 1; i > -1; i--) {
        if (activeDocument.artLayers[i].isBackgroundLayer) {
            activeDocument.artLayers[i].remove();
        }
    }
    var numLayers = activeDocument.artLayers.length;

    if (cols < 0) {
        var sqrt = Math.floor(Math.sqrt(numLayers));
        if (Math.sqrt(numLayers) % sqrt == 0) {
            cols = sqrt;
        } else {
            for (var i = sqrt + 1; i <= numLayers; i++) {
                if (numLayers % i == 0) {
                    cols = i;
                    break;
                }
            }
        }

        if (cols < 0) {
            cols = numLayers;
        }
    }

    var rows = Math.ceil(numLayers / cols);

    var spriteX = activeDocument.width;
    var spriteY = activeDocument.height;

    // resize the canvas
    app.preferences.rulerUnits = Units.PIXELS;
    var newX = spriteX * cols;
    var newY = spriteY * rows;

    activeDocument.resizeCanvas(newX, newY, AnchorPosition.TOPLEFT);

    // move the layers to their their grid position
    var rowi = 0;
    var coli = 0;

    for (var i = (numLayers - 1); i >= 0; i--) {
        activeDocument.artLayers[i].visible = 1;

        var movX = spriteX * coli;
        var movY = spriteY * rowi;
        activeDocument.artLayers[i].translate(movX, movY);

        coli++;
        if (coli > (cols - 1)) {
            rowi++;
            coli = 0;
        }
    }
}