Pos Down Fade

// Cavalry Script: Keyfast - Pos down fade
// For each selected layer, animates from 30px higher Y (numerically +30) down to current Y.
// Timing: position.y over 46 frames; opacity fades 0 → 100 over 30 frames (both start at current frame).
// Uses Bezier handles matching the provided reference.

var selectedLayers = api.getSelection();

if (selectedLayers.length === 0) {
    console.warn("No layers are selected. Please select some layers first.");
} else {
    var currentFrame = api.getFrame();
    var opacityOffset = 30; // frames for opacity fade
    var posOffset = 46;     // frames for position move
    var opacityEndFrame = currentFrame + opacityOffset;
    var posEndFrame = currentFrame + posOffset;

    // Bezier easing for position.y (from provided keyCopy reference)
    var posEaseStart = {
        interpolation: 0,
        leftBez: { x: -7.666666666666629, y: 0.0 },
        rightBez: { x: 11.95999999999998, y: -30.0 },
        locked: true,
        weightLocked: true
    };
    var posEaseEnd = {
        interpolation: 0,
        leftBez: { x: -23.920000000000016, y: 0.0 },
        rightBez: { x: 7.666666666666686, y: 0.0 },
        locked: true,
        weightLocked: true
    };

    console.info("Animating Pos down + Fade on " + selectedLayers.length + " selected layer(s)...");

    for (var i = 0; i < selectedLayers.length; i++) {
        var layerId = selectedLayers[i];
        var layerName = api.getNiceName(layerId);