private void drawFontTextLine(String text,
      DocumentData documentData,
      Canvas canvas,
      float tracking,
      int characterIndexAtStartOfLine,
      int parentAlpha) {
    for (int i = 0; i < text.length(); ) {
      String charString = codePointToString(text, i);
      drawCharacterFromFont(charString, documentData, canvas, characterIndexAtStartOfLine + i, parentAlpha);
      float charWidth = fillPaint.measureText(charString);
      float tx = charWidth + tracking;
      canvas.translate(tx, 0);
      i += charString.length();
    }
  }
@param characterIndexAtStartOfLine The index within the overall document of the character at the start of the line
@param parentAlpha
lottie/src/main/java/com/airbnb/lottie/model/layer/TextLayer.java