Ponymote spritesheet packer

pmpacker.py

#!/usr/bin/env python
# -*- coding: utf8 -*-
################################################################################
##
## Copyright (C) 2012 Typhos
##
## This Source Code Form is subject to the terms of the Mozilla Public
## License, v. 2.0. If a copy of the MPL was not distributed with this
## file, You can obtain one at http://mozilla.org/MPL/2.0/.
##
################################################################################

import argparse
import os
import sys

import PIL.Image

def main():
    parser = argparse.ArgumentParser(description="Spritesheet packer")
    parser.add_argument("directory", help="Image directory")
    parser.add_argument("image", help="Output image file")
    parser.add_argument("css", help="Output CSS")
    parser.add_argument("width", help="Width out spritesheet", type=int)
    args = parser.parse_args()

    filenames = os.listdir(args.directory)
    emotes = {}
    images = {}
    for name in filenames:
        images[os.path.splitext(name)[0]] = PIL.Image.open(os.path.join(args.directory, name))
    assert all(image.size[0] <= args.width for image in images.values())

    spritesheet = PIL.Image.new("RGBA", (args.width, 1), (0, 0, 0, 0))

    placements = []
    left = 0
    top = 0

    for (name, image) in sorted(images.items(), key=lambda ni: (ni[1].size[1], ni[1].size[0]), reverse=True):
        right = left + image.size[0]
        bottom = top + image.size[1]
        if right >= spritesheet.size[0]:
            # Move to new line...
            left, right = 0, image.size[0]
            top = max(placements) if placements else 0
            bottom = top + image.size[1]
        if bottom >= spritesheet.size[1]:
            new_spritesheet = PIL.Image.new("RGBA", (spritesheet.size[0], bottom), (0, 0, 0, 0))
            new_spritesheet.paste(spritesheet, (0, 0))
            spritesheet = new_spritesheet
        spritesheet.paste(image, (left, top))
        emotes[name] = (image.size[0], image.size[1], left, top)
        left = right
        placements.append(bottom)

    spritesheet.save(args.image)

    css = open(args.css, "w")
    selectors = {}
    for name in emotes:
        selectors[name] = "a[href|='/%s']" % (name)
    css.write("""\
%s {
    display: block;
    float: left;
    background-image: url(%%%%image%%%%)
}
""" % (", ".join(sorted(selectors.values()))))
    for (name, pos) in sorted(emotes.items()):
        css.write("""\
%s {
    width: %spx;
    height: %spx;
    background-position: -%spx -%spx
}
""" % (selectors[name], pos[0], pos[1], pos[2], pos[3]))

if __name__ == "__main__":
    main()