Pokitto-Raycasting/convert_png.py

# Convert png image to 256 palette image for Pokitto.
#
# author: Miloslav Ciz
# license: CC0

import sys
from PIL import Image

def rgbToIndex(r, g, b):
  return (r & 0b00000111) | ((g & 0b00000111) << 3) | ((b & 0b00000011) << 6) 

image = Image.open(sys.argv[1])
pixels = image.load()

sys.stdout.write("const unsigned char image[] =\n{  ")
sys.stdout.write(str(image.size[0]) + ", " + str(image.size[1]) + " // width, height")

count = 0

for x in range(image.size[0]):
  for y in range(image.size[1]):
    if count % 14 == 0:
      sys.stdout.write("\n  ");

    p = pixels[x,y]

    sys.stdout.write(",0x{:02x}".format(rgbToIndex(p[0] / 32, p[1] / 32, p[2] / 85)))

    count += 1

print("\n};")