interpolation_and_convert_png_to_ppm.py

interpolation_and_convert_png_to_ppm.py

SRC_BASE = f'{BASE}/misc'
SRC_BITMAP_8x8 = f'{SRC_BASE}/bmp_hex_136x8.png'
SRC_BITMAP_16x16 = f'{SRC_BASE}/bmp_hex_256x256_16x16.png'
PPM_BASE = f'{BASE}/textures'
PPM_TEXTURE_8x8 = f'{PPM_BASE}/custom_%c.ppm'
PPM_TEXTURE_16x16 = f'{PPM_BASE}/ascii_%02X.ppm'

cols = [
  (0xff, 0x00, 0xff),
  (0xff, 0x00, 0x00),
  (0xee, 0xbb, 0x22),
  (0xff, 0xff, 0x00),
  (0x88, 0xee, 0x22),
  (0x00, 0xff, 0x00),
  (0x00, 0xff, 0xff),
  (0x00, 0x00, 0xff)]

def interpol(s, e, a):
  o = np.array(s)
  d = np.array(e) - o
  return (d * (a / 255.0) + o).astype(np.uint8)

def test_img(fn):
  Image.open(fn).convert('RGB').show()

def create_p6_texture_8x8(k, a=None):
  with open(PPM_TEXTURE_8x8 % k, 'wb') as ppm:
    ppm.write(b'P6\n8 8\n255\n')
    if k == 'R': # custom_R (horizontal)
      for c in cols: ppm.write(bytes(c) * 8)
    elif k == 'L': # custom_L (vertical)
      for r in range(8):
        for c in cols: ppm.write(bytes(c))
    elif '0' <= k <= '9' or 'A' <= k <= 'F' or k == 'P': # custom_* (hex dot)
      if '0' <= k <= '9': o = ord(k) - ord('0')
      if 'A' <= k <= 'F': o = ord(k) - ord('A') + 10
      if k == 'P': o = 16
      for r in range(8):
        for c in range(8):
          ppm.write(bytes(cols[7] if a[r][o * 8 + (c + 4) % 8] else cols[2]))
    else: # dummy
      for c in cols: ppm.write(bytes(c) * 8)

def write_p6_texture_8x8():
  create_p6_texture_8x8('R')
  create_p6_texture_8x8('L')

  im = Image.open(SRC_BITMAP_8x8).convert('L')
  a = np.asarray(im, dtype=np.uint8) # rows:8 cols:136
  for i in range(16): create_p6_texture_8x8('%X' % i, a)
  create_p6_texture_8x8('P', a)

  test_img(PPM_TEXTURE_8x8 % '4')

def create_p6_texture_16x16(k, a, b):
  with open(PPM_TEXTURE_16x16 % k, 'wb') as ppm:
    ppm.write(b'P6\n16 16\n255\n')
    f = 0 <= k <= 0x1f or k == 0x7f
    o = k % 16
    p = k // 16
    for r in range(16):
      for c in range(16):
        d = (b if f else a)[p * 16 + r][o * 16 + c]
        m = (255 - d) if f else d[3]
        ppm.write(bytes(interpol(cols[7], cols[2], m) if m else cols[7]))

def write_p6_texture_16x16():
  im = Image.open(SRC_BITMAP_16x16)
  a = np.asarray(im, dtype=np.uint8) # rows:16 cols:16 'RGBA'
  b = np.asarray(im.convert('L'), dtype=np.uint8) # rows:16 cols:16 'L'
  for i in range(128): create_p6_texture_16x16(i, a, b)
  test_c = [
    0x00, 0x12, 0x14, 0x1f, # @ R T _ (reversed)
    0x20, 0x24, 0x30, 0x34, # (SPC) $ 0 4
    0x40, 0x52, 0x54, 0x5f, # @ R T _
    0x60, 0x6f, 0x72, 0x74, # ` o r t
    0x7b, 0x7c, 0x7d, 0x7e, # { | } ~
    0x7f] # (DEL) (reversed)
  for c in test_c: test_img(PPM_TEXTURE_16x16 % c)

if __name__ == '__main__':
  write_p6_texture_8x8()
  write_p6_texture_16x16()