Advanced text expression needed for motion design

I came up with a solution which seems to work, but still need some optimization.

I have a "Source" textlayer which gives the textinput.
I have a dummy textlayer with the same text in 100px
and dummy textlayer with the same text in 300px.
The textlayer "Final" ist giving the final text output.

This is the code so far:

var sourceText = thisComp.layer("Source").text.sourceText; var maxLines = 3; var maxWidth = 1000; // Max. Breite in Pixel var minFontSize = 100; var maxFontSize = 300; var leadingFactor = 0.9; // Zeilenabstandsfaktor // Funktion zur Berechnung der durchschnittlichen Buchstabenbreite function calculateAverageCharWidth(fontSize) { var tempLayer = fontSize > 200 ? thisComp.layer("Source 300") : thisComp.layer("Source 100"); var text = tempLayer.text.sourceText; var textWidth = tempLayer.sourceRectAtTime(time, false).width; return textWidth / text.length; // Durchschnittliche Breite eines Buchstabens } // Berechne die durchschnittliche Buchstabenbreite bei 100px und 300px var avgCharWidth100 = calculateAverageCharWidth(100); var avgCharWidth300 = calculateAverageCharWidth(300); // Schätzung der durchschnittlichen Buchstabenbreite in Abhängigkeit der Schriftgröße function estimateTextWidth(text, fontSize) { var avgCharWidth = avgCharWidth100 + ((avgCharWidth300 - avgCharWidth100) * ((fontSize - 100) / (300 - 100))); return text.length * avgCharWidth; // Geschätzte Textbreite } // Schriftgrößenanpassung basierend auf der Breite var fontSize = maxFontSize; var fits = false; var lines = []; while (fontSize >= minFontSize && !fits) { // Text in Zeilen aufteilen var words = sourceText.split(" "); var currentLine = ""; var firstLine = ""; // Ästhetik-Logik: Schätzen, wo der beste Umbruch für die erste Zeile ist for (var i = 0; i < words.length; i++) { var testLine = firstLine + words[i] + " "; if (estimateTextWidth(testLine, fontSize) > maxWidth * 0.8) { break; // Abbruch, wenn die Zeile länger als 80% der Maximalbreite ist } firstLine = testLine; // Der mögliche erste Umbruchpunkt } lines.push(firstLine.trim()); // Der restliche Text wird in maximal 2 weitere Zeilen umgebrochen var remainingText = sourceText.replace(firstLine, "").trim(); var remainingWords = remainingText.split(" "); currentLine = ""; for (var i = 0; i < remainingWords.length; i++) { var testLine = currentLine + remainingWords[i] + " "; if (estimateTextWidth(testLine, fontSize) <= maxWidth || lines.length >= maxLines - 1) { currentLine = testLine; } else { lines.push(currentLine.trim()); currentLine = remainingWords[i] + " "; } } if (currentLine !== "") { lines.push(currentLine.trim()); } // Falls die Anzahl der Zeilen die Maximalanzahl überschreitet, schneide den Text ab if (lines.length > maxLines) { lines = lines.slice(0, maxLines); } // Prüfen, ob der Text innerhalb der maximalen Breite passt if (lines.every(line => estimateTextWidth(line, fontSize) <= maxWidth)) { fits = true; // Wenn alle Zeilen passen, ist die Schriftgröße optimal } else { fontSize--; // Schriftgröße verringern und erneut testen lines = []; // Zurücksetzen der Zeilen für den nächsten Versuch } } // Textstil erstellen und die berechnete Schriftgröße und den Zeilenabstand setzen var style = text.sourceText.createStyle() .setFontSize(fontSize) .setLeading(fontSize * leadingFactor) .setText(lines.join("\n")); // Finalen Textstil zurückgeben style;

Sorry for the lost line break because of copy / paste.

And this is the result:

You would probably involve some string.replace() somewhere with a suitable regex inside the parenthesis to filter the characters, determine the word count and word boundaries or whatever. Similar could be done with an expression text animator set to per word mode. Apparently this could go as far as running everything in a complex loop and determining the sourceRectAtTime() on some dummy layers to figure out the actual dimensions of the rendered text. There is per se no elegant way of doing it, though, since you're basically trying to re-create the auto-scale paragraph text found in classic page layout programs, but don't have access to all the necessary parameters for the calculations due to AE's fixed evaluation and rendering order. That's why you have to construct nested loops and do it recursively, i.e. figure out the displayed text lengths first with a generous margin on the dummy layers, then in a second loop scale them down to fit within your criteria on the output layer where you re-assemble the individual lines.

Mylenium