import struct, sys

# from http://stackoverflow.com/questions/35988/c-like-structures-in-python
class Bunch:
    def __init__(self, **kwds):
        self.__dict__.update(kwds)

# RBF loading code from rbfEditor, rebUtils.py
# http://freecode.com/projects/rbfeditor
_FNT_HDR_MAGIC 	= '\xE0\x0E\xF0\x0D\x03\x00\x00\x00'
_FNT_HDR_SIZE	= 0x74
_FNT_MAX_NAME 	= 64

def rbf_load(file):
    '''
        Load rebFont instance from file.
        <file> - python file object
    '''
    self = Bunch()

    file.seek(0)
    magic = file.read(len(_FNT_HDR_MAGIC))
    if magic == _FNT_HDR_MAGIC :
        fmt = "="+str(_FNT_MAX_NAME)+'s'
        self.name		= struct.unpack(fmt,file.read(_FNT_MAX_NAME))[0]
        fmt = '=l'
        fmt_size = 4
        self._charSize 	= struct.unpack(fmt,file.read(fmt_size))[0]
        self.points 	= struct.unpack(fmt,file.read(fmt_size))[0]
        self.height		= struct.unpack(fmt,file.read(fmt_size))[0]
        self.maxWidth 	= struct.unpack(fmt,file.read(fmt_size))[0]
        self.charFirst 	= struct.unpack(fmt,file.read(fmt_size))[0]
        self._charLast	= struct.unpack(fmt,file.read(fmt_size))[0]
        self._unknown4 	= struct.unpack(fmt,file.read(fmt_size))[0]
        self._wmapAddr 	= struct.unpack(fmt,file.read(fmt_size))[0]
        self._cmapAddr 	= struct.unpack(fmt,file.read(fmt_size))[0]
        self.descent	= struct.unpack(fmt,file.read(fmt_size))[0]
        self.intline 	= struct.unpack(fmt,file.read(fmt_size))[0]
        self.wTable		= []
        self.cTable		= []

        self.width = 8 * self._charSize / self.height
        self.charCount = self._charLast - self.charFirst + 1

        charlist = xrange(0, self.charCount)
        file.seek(self._wmapAddr)
        for char in charlist:
            self.wTable.append(struct.unpack('=B',file.read(1))[0])
        file.seek(self._cmapAddr)
        for char in charlist:
            self.cTable.append(file.read(self._charSize))
    
    return self

font = None

def rbf_init_font(file):
    global font
    font = rbf_load(open(file,"rb"))

def extent_func(string):
    w = 0
    for c in string:
        w += font.wTable[ord(c) - font.charFirst]
    return (w,0)