Files
snikket-web-portal/snikket_web/colour.py
2021-01-16 16:05:54 +01:00

37 lines
801 B
Python

import functools
import hashlib
import typing
import hsluv
# This is essentially an implementation of XEP-0392.
RGBf = typing.Tuple[float, float, float]
def clip_rgb(r: float, g: float, b: float) -> RGBf:
return (
min(max(r, 0), 1),
min(max(g, 0), 1),
min(max(b, 0), 1),
)
@functools.lru_cache(128)
def text_to_colour(text: str) -> RGBf:
MASK = 0xffff
h = hashlib.sha1()
h.update(text.encode("utf-8"))
hue = (int.from_bytes(h.digest()[:2], "little") & MASK) / MASK
r, g, b = hsluv.hsluv_to_rgb((hue * 360, 75, 60))
# print(text, cb, cr, r, g, b)
r, g, b = clip_rgb(r, g, b)
return r, g, b
def text_to_css(text: str) -> str:
return "#{:02x}{:02x}{:02x}".format(
*(round(v * 255) for v in text_to_colour(text))
)