from PIL import Image
import sys
import os

SEPARATOR_COLOR = (255,0,255, 255)
NO_COL = (0, 0, 0, 0)

def chk_vline_empty(img, x):
    for y in range(img.size[1]):
        _, _, _, a = img.getpixel((x, y))
        if a != 0:
            return False
    else:
        return True

def make_sfont(img_filename, output_name = None):
    img = Image.open(img_filename)
    ow, oh = img.size
    xlist = []
    cx = -1
    for x in range(ow):
        if chk_vline_empty(img, x):
            if cx >= 0:
                xlist.append([cx, x - cx])
                cx = -1
        else:
            if cx < 0:
                cx = x
    if cx >= 0:
        xlist.append([cx, ow - cx])

    if len(xlist) != 94:
        print "Error: character length %d != 94" % len(xlist)
        return

    nw = 1
    for _, w in xlist:
        nw += (w + 1)

    nimg = Image.new("RGBA", (nw, oh), NO_COL)
    nimg.putpixel((0, 0), SEPARATOR_COLOR)
    cx = 1
    for x, w in xlist:
        box = (x, 0, x + w, oh)
        nbox = (cx, 0, cx + w, oh)
        nimg.paste(img.crop(box), nbox)
        nimg.putpixel((cx + w, 0), SEPARATOR_COLOR)
        cx += (w + 1)

    if output_name is None:
        base, name = os.path.split(img_filename)
        name, ext = os.path.splitext(name)
        name = name + '_sfont' + ext
        name = os.path.join(base, name)
    else:
        name = output_name

    nimg.save(name)
    print 'SFont written to %s' % name

if __name__ == '__main__':
    args = len(sys.argv)
    if args == 1 or args > 3 :
        print 'Usage: make_sfont_wt.py IN.png OUT.png'
    elif args == 3:
        make_sfont(sys.argv[1], sys.argv[2])
    else:
        make_sfont(sys.argv[1])