nxu/uxnmeta

149 lines
4.6 KiB
Python
Executable File

#!/usr/bin/env python
#
# extract metadata from uxn rom files.
#
# see https://wiki.xxiivv.com/site/manifest.html
#
# (also converts the icon to a monochrome BMP file.)
from sys import argv, exit
# convert two bytes into an address, subtracting for zero page
def toaddr(x, y):
return x * 256 + y - 256
# parse null-terminated string
def parsestr(data, start):
end = start + data[start:].find(b'\0')
return end + 1, data[start:end].decode('ascii')
# emit 24-bit integer (big endian)
def emit24(n):
return bytes([(n >> 16) & 0xff, (n >> 8) & 0xff, n & 0xff])
# convert 64x64 icn to bmp
# since we are always dealing with a 1-bit 64x64
# image we can just hardcode the BMP header data
def tobmp(icn, light, dark):
bmp = b"BM" # 0: bitmap file
bmp += b"\x20\x10\x00\x00" # 2: file size: 4128 (32 + 4096)
bmp += b"\x00\x00" # 6: reserved: 0
bmp += b"\x00\x00" # 8: reserved: 0
bmp += b"\x20\x00\x00\x00" # 10: pixel data offset: 32
bmp += b"\x0c\x00\x00\x00" # 14: header size: 12
bmp += b"\x40\x00" # 18: width in pixels: 64
bmp += b"\x40\x00" # 20: height in pixels: 64
bmp += b"\x01\x00" # 22: color planes: 1
bmp += b"\x01\x00" # 24: bits per pixel: 1
bmp += emit24(light) # 26: color 0
bmp += emit24(dark) # 29: color 1
# 32: start of pixel data
# ICN is composed of a grid of 8x8 tiles. for BMP we need
# to create 64 rows of 64 pixels each.
rows = []
for offset in range(0, 512, 64):
for y in range(0, 8):
rows.append([])
for x in range(0, 64, 8):
rows[-1].append(icn[offset + y + x])
for row in reversed(rows):
bmp += bytes(row)
return bmp
# read the icon from the given binary data and address
def parseicon(path, data, pos0, light, dark):
if len(data[pos0:]) < 512:
print('needed 512 bytes, only had %d' % len(data[pos0:]))
icn = data[pos0:pos0+512]
bmp = tobmp(icn, light, dark)
return bmp
# try to parse LIT2 x y .System/[rgb] DEO2
# returns (shift, tint)
# shift 16=red, 8=green, 0=blue
def parsecolor(data, pos0):
a,b,c,d,e,f = data[pos0:pos0+6]
if a == 0xa0 and d == 0x80 and f == 0x37:
tint = b * 256 + c
# we only care about 'b' i.e. the first two colors
if e == 0x08: return (16, tint)
if e == 0x0a: return (8, tint)
if e == 0x0c: return (0, tint)
return None
# parse the metadata from the given binary data and address
def parsemeta(path, data, pos0):
a,b,c,d = data[pos0:pos0+4]
endaddr = toaddr(a, b)
iconaddr = toaddr(c, d)
pos1, name = parsestr(data, pos0 + 4)
pos2, version = parsestr(data, pos1)
pos3, desc = parsestr(data, pos2)
pos4, author = parsestr(data, pos3)
if pos4 != endaddr:
print('%s: data ended by %04x but expected %04x' % (path, pos4, endaddr))
meta = {'name': name, 'version': version, 'desc': desc, 'author': author, 'icon': iconaddr}
return meta
# parse metadata from the given uxn rom
def parse(path, data):
if len(data) < 6:
print("%s: file too small (%d bytes)" % (path, len(data)))
exit(1)
a,x,y,d,e,f = data[:6]
if a != 0xa0 or d != 0x80 or e != 0xf0 or f != 0x37:
print('%s: no metadata detected' % path)
exit(1)
return parsemeta(path, data, toaddr(x, y))
# go for it!
def main():
if len(argv[1:]) != 1:
print('usage: %s ROMFILE' % argv[0])
exit(1)
path = argv[1]
f = open(path, 'rb')
data = f.read()
f.close()
meta = parse(path, data)
i = 6
colors = [0, 0, 0, 0]
while True:
res = parsecolor(data, i)
i += 6
if res is None:
break
shift, tint = res
colors[0] |= ((((tint >> 12) & 0xf) * 0x11) << shift)
colors[1] |= ((((tint >> 8) & 0xf) * 0x11) << shift)
colors[2] |= ((((tint >> 4) & 0xf) * 0x11) << shift)
colors[3] |= ((((tint >> 0) & 0xf) * 0x11) << shift)
if colors == [0, 0, 0, 0]:
dark, light = 0x000000, 0xffffff
else:
dark, light = colors[0], colors[1]
iconpath = path + '.bmp'
bmp = parseicon(path, data, meta['icon'], light, dark)
with open(iconpath, 'wb') as f:
f.write(bmp)
print('%s:' % path)
print(' Name: %s' % meta['name'])
print(' Version: %s' % meta['version'])
print(' Description: %s' % meta['desc'])
print(' Author: %s' % meta['author'])
print('')
print(' Icon: %s' % iconpath)
print('')
if __name__ == "__main__":
main()