veekun_pokedex/pokedex/extract/lib/clim.py
Eevee (Lexy Munroe) 684aef2506 Clean up ORAS Pokémon sprite ripping
Box sprites are now ripped paletted, complete with an sBIT chunk.  Box
sprites are also saved with the right form names.  A lot of
name-mangling and error-checking code was pulled out of the binary
parsing stuff and shared between both types of sprites.
2016-10-15 18:16:41 -07:00

178 lines
4.9 KiB
Python
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import math
import struct
import construct as c
clim_header_struct = c.Struct(
'clim_header',
c.Magic(b'CLIM'),
c.Const(c.ULInt16('endianness'), 0xfeff),
c.Const(c.ULInt16('header_length'), 0x14),
c.ULInt32('version'),
c.ULInt32('file_size'),
c.ULInt32('blocks_ct'),
)
imag_header_struct = c.Struct(
'imag_header',
c.Magic(b'imag'),
c.Const(c.ULInt32('section_length'), 0x10),
c.ULInt16('width'),
c.ULInt16('height'),
c.Enum(
c.ULInt32('format'),
L8=0,
A8=1,
LA4=2,
LA8=3,
HILO8=4,
RGB565=5,
RGB8=6,
RGBA5551=7,
RGBA4=8,
RGBA8=9,
ETC1=10,
ETC1A4=11,
L4=12,
A4=13,
#ETC1=19,
)
)
COLOR_DECODERS = {}
def _register_color_decoder(name, *, bpp, depth):
def register(f):
COLOR_DECODERS[name] = f, bpp, depth
return f
return register
@_register_color_decoder('RGBA4', bpp=2, depth=4)
def decode_rgba4(data):
# The idea is that every uint16 is a packed rrrrggggbbbbaaaa, but when
# written out little-endian this becomes bbbbaaaarrrrgggg and there's just
# no pretty way to deal with this
for i in range(0, len(data), 2):
ba = data[i]
rg = data[i + 1]
r = (((rg & 0xf0) >> 4) * 255 + 7) // 15
g = (((rg & 0x0f) >> 0) * 255 + 7) // 15
b = (((ba & 0xf0) >> 4) * 255 + 7) // 15
a = (((ba & 0x0f) >> 0) * 255 + 7) // 15
yield r, g, b, a
@_register_color_decoder('RGBA5551', bpp=2, depth=5)
def decode_rgba5551(data, *, start=0, count=None):
# I am extremely irritated that construct cannot parse this mess for me
# rrrrrgggggbbbbba
if count is None:
end = len(data)
else:
end = start + count * 2
for i in range(start, end, 2):
datum = data[i] + data[i + 1] * 256
r = (((datum >> 11) & 0x1f) * 255 + 15) // 31
g = (((datum >> 6) & 0x1f) * 255 + 15) // 31
b = (((datum >> 1) & 0x1f) * 255 + 15) // 31
a = (datum & 0x1) * 255
yield r, g, b, a
del _register_color_decoder
def uncuddle_paletted_pixels(palette, data):
if len(palette) <= 16:
# Short palettes allow cramming two pixels into each byte
return (
idx
for byte in data
for idx in (byte >> 4, byte & 0x0f)
)
else:
return data
def untile_pixels(raw_pixels, width, height):
"""Unscramble pixels into plain old rows.
The pixels are arranged in 8×8 tiles, and each tile is a third-
iteration Z-order curve.
Taken from: https://github.com/Zhorken/pokemon-x-y-icons/
"""
# Images are stored padded to powers of two
stored_width = 2 ** math.ceil(math.log(width) / math.log(2))
stored_height = 2 ** math.ceil(math.log(height) / math.log(2))
num_pixels = stored_width * stored_height
tile_width = stored_width // 8
pixels = [
[None for x in range(width)]
for y in range(height)
]
for n, pixel in enumerate(raw_pixels):
if n >= num_pixels:
break
# Find the coordinates of the top-left corner of the current tile.
# n.b. The image is eight tiles wide, and each tile is 8×8 pixels.
tile_num = n // 64
tile_y = tile_num // tile_width * 8
tile_x = tile_num % tile_width * 8
# Determine the pixel's coordinates within the tile
# http://en.wikipedia.org/wiki/Z-order_curve#Coordinate_values
within_tile = n % 64
sub_x = (
(within_tile & 0b000001) |
(within_tile & 0b000100) >> 1 |
(within_tile & 0b010000) >> 2
)
sub_y = (
(within_tile & 0b000010) >> 1 |
(within_tile & 0b001000) >> 2 |
(within_tile & 0b100000) >> 3
)
# Add up the pixel's coordinates within the whole image
x = tile_x + sub_x
y = tile_y + sub_y
if x < width and y < height:
pixels[y][x] = pixel
return pixels
def decode_clim(data):
imag_header = imag_header_struct.parse(data[-20:])
if imag_header.format not in COLOR_DECODERS:
raise ValueError(
"don't know how to decode {} pixels".format(imag_header.format))
color_decoder, color_bpp, color_depth = COLOR_DECODERS[imag_header.format]
mode, = struct.unpack_from('<H', data, 0)
if mode == 2:
# Paletted
palette_length, = struct.unpack_from('<H', data, 2)
palette = list(color_decoder(data, start=4, count=palette_length))
data_start = 4 + palette_length * color_bpp
scrambled_pixels = uncuddle_paletted_pixels(palette, data[data_start:])
else:
palette = None
scrambled_pixels = color_decoder(data)
pixels = untile_pixels(
scrambled_pixels,
imag_header.width,
imag_header.height,
)
return imag_header.width, imag_header.height, color_depth, palette, pixels