Sprite Sheet Maker for http://opengameart.org/content/tuscan

def getFileNumber(fileName)
    parts = fileName.split('_')
    return parts[parts.length-1].split('.')[0];
end

source      = ARGV[0]
destination = ARGV[1]

direction = 0
command = "convert \\("
images = Dir.entries("./#{source}").sort
images.each do |imageFile|
    next if imageFile == '.' or imageFile == '..'

    fileNumber = getFileNumber(imageFile)
    if (fileNumber[0].to_i > direction)
        direction += 1
        command.concat(" +append \\) \\(")
    end
    command.concat(" #{source}/#{imageFile} ")
end

command.concat(" +append \\) -background none -append #{destination}")
system(command)