ASTC texture generating

genastc.py

#!/usr/bin/env python

import argparse
import math
import os
import re
import sys

from PIL import Image


def main():
    arguments = argparse.ArgumentParser()
    arguments.add_argument('--file', '-f', nargs='+', required=True, help='texture file')
    arguments.add_argument('--block', '-b', default=4, type=int, help='astc block size')
    arguments.add_argument('--quality', '-q', choices=('fastest', 'fast', 'medium', 'thorough', 'exhaustive'), default='medium', help='texture quality tier')
    arguments.add_argument('--minimum', '-m', default=64, type=int, help='minimum texture size')
    options = arguments.parse_args(sys.argv[1:])
    mininum = 2**round(math.log2(options.minimum))
    for filename in options.file:
        im = Image.open(filename)
        size = im.size[0]
        if im.size[1] < size: size = im.size[1]
        dx = (im.size[0] - size)//2
        dy = (im.size[1] - size)//2
        im = im.crop((dx,dy,dx+size,dy+size))
        pot = 2**math.floor(math.log2(size))
        dir = re.sub(r'\.[^.]+$', '', filename)
        os.makedirs(dir, exist_ok=True)
        while pot >= mininum:
            mip = im.resize(size=(pot, pot), resample=Image.Resampling.BICUBIC)
            tga = os.path.join(dir, '{}.tga'.format(pot))
            mip.save(tga)
            tex = os.path.join(dir, '{}.astc'.format(pot))
            command = 'astcenc -cs {0} {1} {2}x{2} -{3}'.format(tga, tex, options.block, options.quality)
            print('+', command)
            assert os.system(command) == 0
            pot >>= 1

if __name__ == '__main__': main()