Fade In From Playhead

// Cavalry Script: Keyfast - Fade In from Playhead
// For each selected layer, animates opacity from 0 to 100 over 30 frames

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 frameOffset = 30; // Number of frames for the animation
    var secondFrame = currentFrame + frameOffset;
    
    console.info("Animating opacity on " + selectedLayers.length + " selected layer(s)...");
    
    for (var i = 0; i < selectedLayers.length; i++) {
        var layerId = selectedLayers[i];
        var layerName = api.getNiceName(layerId);
        
        try {
            if (api.hasAttribute(layerId, "opacity")) {
                // Keyframe 1: opacity 0 at current frame
                var opacity1 = 0;
                // Keyframe 2: opacity 100 at current+30
                var opacity2 = 100;
                
                // Set keyframe at current frame (opacity 0)
                api.keyframe(layerId, currentFrame, {"opacity": opacity1});
                // Set keyframe at current+30 (opacity 100)
                api.keyframe(layerId, secondFrame, {"opacity": opacity2});
                
                console.log("✓ " + layerName + ": Keyframed opacity from " + opacity1 + " to " + opacity2 + " (frames " + currentFrame + " → " + secondFrame + ")");
            } else {
                console.warn("✗ " + layerName + ": No opacity attribute");
            }
        } catch (error) {
            console.error("✗ Error processing " + layerName + ": " + error);
        }
    }