#!/usr/bin/env python

# You need to install Pillow for this script to work
# pip install Pillow

import argparse
from PIL import Image

# Currently this utility script is very specific to my needs for generating
# a header file from a 200x200 pixel bmp. It could easily be expanded to work
# for different sizes

def generateHeaderFromBitmap(bitmap_path, header_path, name=None):
  headerRows = []

  with Image.open(bitmap_path) as original:
    all_pixels = list(original.convert('1', None, Image.NONE).getdata())
    # Loop through every scan line
    for rows in xrange(0, 200):
      rowstart = rows*200
      rowEnd = rowstart + 200
      rowPixels = all_pixels[rowstart:rowEnd]
      rowBytes = [0xFF] * 25
      # For a 200px wide black/white row each scan line can be represented as 25 bytes
      for byte_index in range(0,25):
        byteStart = byte_index * 8
        byteEnd = byteStart + 8
        bytePixels = rowPixels[byteStart:byteEnd]
        # Translate each pixel value into the correct scan line byte
        for pixel_index, pixel_value in enumerate(bytePixels):
          if pixel_value:
            # pixel not set
            rowBytes[byte_index] |= (1 << (7 - pixel_index % 8))
          else:
            # pixel is set
            rowBytes[byte_index] &= 0xFF ^ (1 << (7 - pixel_index % 8))

      headerRow = [format(val, '#04x') for val in rowBytes]
      headerRows.append('    {},\n'.format(','.join(headerRow)))

  with open(header_path, 'w') as headerFile:

    headerFile.write('const unsigned char {}[5000] PROGMEM = {{\n'.format(name or 'bmp_data'))
    headerFile.writelines(headerRows)
    headerFile.write('};')

parser = argparse.ArgumentParser(description='Create a header file from a Bitmap image.')
parser.add_argument('bmp', nargs=1, help='the bitmap file')
parser.add_argument('header', nargs=1, help='the output header file path')
parser.add_argument('-n', metavar='obj_name', nargs=1, help='name of the header object')

args = parser.parse_args()

generateHeaderFromBitmap(args.bmp[0], args.header[0], args.n[0] if args.n else None)