# coding: utf-8

"""

This is part of the MSS Python's module.

Source: https://github.com/BoboTiG/python-mss

"""

import struct

import zlib

def to_png(data, size, output):

# type: (bytes, Tuple[int, int], str) -> None

"""

Dump data to a PNG file.

:param bytes data: RGBRGB...RGB data.

:param tuple size: The (width, height) pair.

:param str output: Output file name.

"""

width, height = size

line = width * 3

png_filter = struct.pack('>B', 0)

scanlines = b''.join(

[png_filter + data[y * line:y * line + line]

for y in range(height)])

magic = struct.pack('>8B', 137, 80, 78, 71, 13, 10, 26, 10)

# Header: size, marker, data, CRC32

ihdr = [b'', b'IHDR', b'', b'']

ihdr[2] = struct.pack('>2I5B', width, height, 8, 2, 0, 0, 0)

ihdr[3] = struct.pack('>I', zlib.crc32(b''.join(ihdr[1:3])) & 0xffffffff)

ihdr[0] = struct.pack('>I', len(ihdr[2]))

# Data: size, marker, data, CRC32

idat = [b'', b'IDAT', zlib.compress(scanlines), b'']

idat[3] = struct.pack('>I', zlib.crc32(b''.join(idat[1:3])) & 0xffffffff)

idat[0] = struct.pack('>I', len(idat[2]))

# Footer: size, marker, None, CRC32

iend = [b'', b'IEND', b'', b'']

iend[3] = struct.pack('>I', zlib.crc32(iend[1]) & 0xffffffff)

iend[0] = struct.pack('>I', len(iend[2]))

with open(output, 'wb') as fileh:

fileh.write(magic)

fileh.write(b''.join(ihdr))

fileh.write(b''.join(idat))

fileh.write(b''.join(iend))