With this library you can render minecraft banners on a 2d canvas by providing the different patterns in a array. The BannerPatternType and dyecolor enum is identical to the one in bukkit. You might need to convert them if you want to display vanilla banners.
To use this renderer you need to create a atlas image. Simply run the kotlin project in the atlas-generator folder to generate one. The images will be automatically downloaded and extracted from the official minecraft client.