code: public static SpriteFont loadSpriteFont(Media media, Media data, int letterWidth, int letterHeight)
      {
          return new SpriteFontImpl(getMediaDpi(media), data, letterWidth, letterHeight);
      }
docs: Load a font based on an image.
  <p>
  Once created, sprite must call {@link SpriteFont#load()} before any other operations.
  </p>
  
  @param media The font sprite media (must not be <code>null</code>).
  @param data The font data media (must not be <code>null</code>).
  @param letterWidth The font image letter width (must be strictly positive).
  @param letterHeight The font image letter height (must be strictly positive).
  @return The created font sprite.
  @throws LionEngineException If an error occurred when creating the font.