Created
September 16, 2010 17:01
-
-
Save magical/582756 to your computer and use it in GitHub Desktop.
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
#!/usr/bin/env python3 | |
from struct import pack, unpack | |
import sys | |
def main(args): | |
if not args: | |
print("Usage: python3 ndsicon.py file.nds | pnmtopng > icon.png") | |
print("Extract the game icon from a ROM dump.") | |
return 1 | |
else: | |
f = open(args[0], "rb") | |
icon = extract_icon(f) | |
write_ppm(icon) | |
return 0 | |
return 0 | |
def extract_icon(f): | |
f.seek(0x68) | |
icon_offset = unpack("<L", f.read(4))[0] | |
f.seek(icon_offset) | |
#print(hex(icon_offset)) | |
assert f.read(2) == b"\x01\x00" | |
f.read(0x1e) | |
bitmap = f.read(0x200) | |
palette = f.read(0x20) | |
bitmap = untile(bitmap, 8, 8, 4, 4) | |
palette = unpalette(palette) | |
# first palette entry is transparent | |
palette[0] = (0,0,0,0) | |
return (bitmap, palette) | |
def write_ppm(icon): | |
bitmap, palette = icon | |
def write(bs): | |
sys.stdout.buffer.write(bs) | |
#Write the image | |
print("P6") | |
print("32 32") | |
print("31") | |
sys.stdout.flush() | |
for pentry in bitmap: | |
rgb = palette[pentry] | |
write(pack("BBB", *(rgb[:3]))) | |
#write the transparency bitmap | |
print("P4") | |
print("32 32") | |
sys.stdout.flush() | |
for pentry in bitmap: | |
rgb = palette[pentry] | |
write(pack("B", bool(rgb[3]))) | |
#Tile Width, TileHeight, image Width (in tiles), image Height (in tiles) | |
def untile(bitmap, tw, th, w, h): | |
pixels = [0] * tw*w * th*h | |
for ti, tile in enumerate(chunk(unpack_pixels(bitmap), tw*th)): | |
start = ((ti // w) * th * tw*w) + ((ti % w) * tw) | |
for x, row in enumerate(chunk(tile, tw)): | |
x = start + x * tw*w | |
pixels[x:x+tw] = row | |
return pixels | |
def unpalette(palette): | |
return [rgb16_to_rgba(unpack("<H", p)[0]) for p in chunk(palette, 2)] | |
def chunk(seq, length): | |
try: | |
len(seq) | |
except TypeError: | |
seq = list(seq) | |
for i in range(0, len(seq), length): | |
yield seq[i:i+length] | |
def unpack_pixels(bs): | |
for b in bs: | |
yield b & 0xf | |
yield (b >> 4) & 0xf | |
def rgb16_to_rgba(color): | |
return ((color & 0x1f), | |
(color >> 5) & 0x1f, | |
(color >> 10) & 0x1f, | |
255) | |
if __name__ == '__main__': | |
sys.exit(main(sys.argv[1:])) |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment