pokemon/tools/png_to_nbpp.py

61 lines
1.8 KiB
Python

import os
import sys
from PIL import Image
from palette import intensity_to_index
def convert(image, bpp):
assert bpp in {8, 4, 2, 1}, bpp
px_per_byte = 8 // bpp
px_per_row = 8
bits_per_byte = 8
bytes_per_row = (px_per_row // (bits_per_byte // bpp))
assert image.mode in {'L', '1'}, image.mode
width, height = image.size
buf = bytearray(width * height // px_per_byte)
for cell_y in range(height//8):
for cell_x in range(width//8):
for y in range(8):
for x in range(8):
px = image.getpixel((cell_x * 8 + x, cell_y * 8 + y))
if image.mode == 'L':
index = intensity_to_index(px)
elif image.mode == '1':
index = int(px != 0)
buf_ix = x//px_per_byte + (bytes_per_row * (cell_x * 8 + (cell_y * width) + y))
buf[buf_ix] |= (index << bpp * ((px_per_byte - 1) - (x % px_per_byte)))
return buf
def debug(buf, bpp):
assert bpp in {8, 4, 2, 1}, bpp
px_per_byte = 8 // bpp
px_per_row = 8
bits_per_byte = 8
bytes_per_row = (px_per_row // (bits_per_byte // bpp))
bit_mask = (2 ** bpp) - 1
for row in range(len(buf) // bytes_per_row):
for x in range(bytes_per_row):
px = buf[row * bytes_per_row + x]
for shift in reversed(range(0, px_per_row, bpp)):
print((px >> shift) & bit_mask, end='')
print()
if (row % 8 == 7):
print()
bpp = int(sys.argv[1])
out_path = sys.argv[2]
assert len(sys.argv) >= 4, sys.argv
with open(out_path, 'wb') as f:
for in_path in sys.argv[3:]:
im = Image.open(in_path)
buf = convert(im, bpp)
if 'NBPP_DEBUG' in os.environ:
debug(buf, bpp)
f.write(buf)