Espacement entre les lettres en fonction de la largeur de la composition

Je l'ai optimisé un peu et je suis tombé à 20 secondes pour 10 lignes 

Il suffit de sélectionner un calque de texte et exécuter le script:

Text_Tracking_to_Comp_Width_Adjuster.jsx

var project = app.project;
var activeComp = project.activeItem;

if (activeComp && activeComp.selectedLayers.length > 0) {
    var selectedTextLayer = activeComp.selectedLayers[0];
    
    if (selectedTextLayer.property("Source Text")) {
        app.beginUndoGroup("Adjust Text Tracking");
        var duplicatedLayer = selectedTextLayer.duplicate();
        duplicatedLayer.enabled = false;
        var originalTextDocument = selectedTextLayer.property("Source Text").value;
        var originalText = duplicatedLayer.property("Source Text").value;
        var lines = originalTextDocument.toString().split('\r');
        var startRange = 0;
        var defaultTrackingValue = originalTextDocument.tracking;
        var maxTrackingValue = 1000;

        for (var i = 0; i < lines.length; i++) {
            originalText.text = lines[i];
            duplicatedLayer.property("Source Text").setValue(originalText);

            var trackingValue = originalText.tracking;
            var currentIteration = 1;
            var bigStep = 10;
            var smallStep = 1;
            var maxIterations = maxTrackingValue / bigStep + bigStep * smallStep;

            while (duplicatedLayer.sourceRectAtTime(0, false).width < activeComp.width && currentIteration < maxIterations) {
                trackingValue += bigStep;

                if (trackingValue > maxTrackingValue) {
                    trackingValue = maxTrackingValue;
                    break;
                }

                originalText.tracking = trackingValue;
                duplicatedLayer.property("Source Text").setValue(originalText);

                if (duplicatedLayer.sourceRectAtTime(0, false).width > activeComp.width) {
                    trackingValue -= bigStep; 
                    originalText.tracking = trackingValue;
                    duplicatedLayer.property("Source Text").setValue(originalText);

                    while (duplicatedLayer.sourceRectAtTime(0, false).width < activeComp.width && currentIteration < maxIterations) {
                        trackingValue += smallStep;

                        if (trackingValue > maxTrackingValue) {
                            trackingValue = maxTrackingValue;
                            break;
                        }

                        originalText.tracking = trackingValue;
                        duplicatedLayer.property("Source Text").setValue(originalText);

                        if (duplicatedLayer.sourceRectAtTime(0, false).width > activeComp.width) {
                            originalText.tracking = trackingValue - smallStep;
                            duplicatedLayer.property("Source Text").setValue(originalText);
                            break;
                        }
                        currentIteration++;
                    }
                    break;
                }
                currentIteration++;
            }

            originalTextDocument.characterRange(startRange, startRange + originalText.toString().length).tracking = originalText.tracking;
            selectedTextLayer.property("Source Text").setValue(originalTextDocument);
            originalText.tracking = defaultTrackingValue;
            duplicatedLayer.property("Source Text").setValue(originalText);
            startRange += originalText.toString().length + 1;
        }
        duplicatedLayer.remove();
        app.endUndoGroup();
    }
}