0.12.0a5 add OKLab and oklch

CHANGELOG.md

@@ -1,11 +1,11 @@
 # Changelog
 
-## 0.12.0
+## 0.12.0 "The Color Update"
 
 * All `AuthSrc()` derivatives, deprecated and never used, have been removed.
 * New module `mat` adds a shallow reimplementation of `Matrix()` in order to implement matrix multiplication
 * Removed obsolete `configparse` implementation that has been around since 0.3 and shelved since 0.4.
-* `color`: added support for conversion from RGB to sRGB, XYZ
+* `color`: added support for conversion from RGB to sRGB, XYZ, OKLab and OKLCH.
 
 ## 0.11.2
 

src/suou/__init__.py

@@ -35,20 +35,19 @@ from .strtools import PrefixIdentifier
 from .validators import matches, not_less_than, not_greater_than, yesno
 from .redact import redact_url_password
 from .http import WantsContentType
-from .color import chalk, WebColor
+from .color import OKLabColor, chalk, WebColor, RGBColor, SRGBColor, XYZColor, OKLabColor
 from .mat import Matrix
 
-__version__ = "0.12.0a4"
+__version__ = "0.12.0a5"
 
 __all__ = (
     'ConfigOptions', 'ConfigParserConfigSource', 'ConfigSource', 'ConfigValue',
     'DictConfigSource', 'EnvConfigSource', 'I18n', 'Incomplete', 'JsonI18n',
-    'Matrix',
-    'MissingConfigError', 'MissingConfigWarning', 'PrefixIdentifier',
-    'RGBColor', 'SRGBColor',
+    'Matrix', 'MissingConfigError', 'MissingConfigWarning', 'OKLabColor', 
+    'PrefixIdentifier', 'RGBColor', 'SRGBColor',
     'Siq', 'SiqCache', 'SiqGen', 'SiqType', 'Snowflake', 'SnowflakeGen',
     'StringCase', 'TimedDict', 'TomlI18n', 'UserSigner', 'Wanted', 'WantsContentType',
-    'WebColor',
+    'WebColor', 'XYZColor',
     'addattr', 'additem', 'age_and_days', 'alru_cache', 'b2048decode', 'b2048encode',
     'b32ldecode', 'b32lencode', 'b64encode', 'b64decode', 'cb32encode',
     'cb32decode', 'chalk', 'count_ones', 'dei_args', 'deprecated',

src/suou/color.py

@@ -21,6 +21,7 @@ from __future__ import annotations
 
 from collections import namedtuple
 from functools import lru_cache
+import math
 
 from suou.mat import Matrix
 
@@ -100,6 +101,9 @@ class RGBColor(namedtuple('_WebColor', 'red green blue')):
     Representation of a color in the RGB TrueColor space.
 
     Useful for theming.
+
+    *Changed in 0.12.0*: name is now RGBColor, with WebColor being an alias.
+    Added conversions to and from OKLCH, OKLab, sRGB, and XYZ.
     """
     def lighten(self, *, factor = .75):
         """
@@ -149,7 +153,8 @@ class RGBColor(namedtuple('_WebColor', 'red green blue')):
             (-1 if i < 0 else 1) * (((abs(i) + 0.55)) / 1.055) ** 2.4) for i in self
         ))
 
-    
+    def to_oklab(self):
+        return self.to_xyz().to_oklab()
 
     __add__ = blend_with
 
@@ -165,6 +170,11 @@ class RGBColor(namedtuple('_WebColor', 'red green blue')):
     def to_xyz(self):
         return XYZColor(*(self.RGB_TO_XYZ @ Matrix.as_column(self)).get_column())
 
+    def to_oklch(self):
+        return self.to_xyz().to_oklch()
+
+    def to_oklab(self):
+        return self.to_xyz().to_oklab()
 
 WebColor = RGBColor
 
@@ -192,12 +202,15 @@ class SRGBColor(namedtuple('_SRGBColor', 'red green blue')):
     def to_xyz(self):
         return self.to_rgb().to_xyz()
 
-    
+    def to_oklab(self):
+        return self.to_rgb().to_oklab()
     
 
 class XYZColor(namedtuple('_XYZColor', 'x y z')):
     """
     Represent a color in the XYZ color space.
+
+    *New in 0.12.0*
     """
 
     XYZ_TO_RGB = Matrix([
@@ -206,10 +219,89 @@ class XYZColor(namedtuple('_XYZColor', 'x y z')):
         [ 0.05563007969699366, -0.20397695888897652,  1.0569715142428786]
     ])
 
+    XYZ_TO_LMS = Matrix([
+        [0.8190224379967030, 0.3619062600528904, -0.1288737815209879],
+        [0.0329836539323885, 0.9292868615863434,  0.0361446663506424],
+        [0.0481771893596242, 0.2642395317527308,  0.6335478284694309]
+    ])
+
+    LMSG_TO_OKLAB = Matrix([
+        [0.2104542683093140,  0.7936177747023054, -0.0040720430116193],
+        [1.9779985324311684, -2.4285922420485799,  0.4505937096174110],
+        [0.0259040424655478,  0.7827717124575296, -0.8086757549230774]
+    ])
+
     def to_rgb(self):
         return RGBColor(*(self.XYZ_TO_RGB @ Matrix.as_column(self)).get_column())
     
+    def to_oklab(self):
+        lms = (self.XYZ_TO_LMS @ Matrix.as_column(self)).get_column()
+        lmsg = [math.cbrt(i) for i in lms]
+        oklab = (self.LMSG_TO_OKLAB @ Matrix.as_column(self)).get_column()
+        return OKLabColor(*oklab)
+
+    def to_oklch(self):
+        return self.to_oklab().to_oklch()
 
 
+class OKLabColor(namedtuple('_OKLabColor', 'l a b')):
+    """
+    Represent a color in the OKLab color space.
 
-__all__ = ('chalk', 'WebColor', "RGBColor", 'SRGBColor')
+    *New in 0.12.0*
+    """
+
+    OKLAB_TO_LMSG = Matrix([
+        [1.,  0.3963377773761749,  0.2158037573099136],
+        [1., -0.1055613458156586, -0.0638541728258133],
+        [1., -0.0894841775298119, -1.2914855480194092]
+    ])
+
+    LMS_TO_XYZ = Matrix([
+        [ 1.2268798758459243, -0.5578149944602171,  0.2813910456659647],
+        [-0.0405757452148008,  1.1122868032803170, -0.0717110580655164],
+        [-0.0763729366746601, -0.4214933324022432,  1.5869240198367816]
+    ])
+
+    def to_xyz(self):
+        lmsg = (self.OKLAB_TO_LMSG @ Matrix.as_column(self)).get_column()
+        lms = [i ** 3 for i in lmsg]
+        xyz = (self.LMS_TO_XYZ @ Matrix.as_column(lms)).get_column()
+        return XYZColor(*xyz)
+
+    def to_oklch(self):
+        return OKLCHColor(
+            self.l,
+            math.sqrt(self.a ** 2 + self.b ** 2),
+            0 if abs(self.a) < .0002 and abs(self.b) < .0002 else (((math.atan2(self.b, self.a) * 180) / math.pi % 360) + 360) % 360
+        )
+
+    def to_rgb(self):
+        return self.to_xyz().to_rgb()
+
+class OKLCHColor(namedtuple('_OKLCHColor', 'l c h')):
+    """
+    Represent a color in the OKLCH color space.
+
+    *Warning*: conversion to RGB is not bound checked yet!
+
+    *New in 0.12.0*
+    """
+
+    def __str__(self):
+        l, c, h = round(self.l, 4), round(self.c, 4), round(self.h, 4)
+
+        return f'oklch({l}, {c}, {h})'
+
+
+    def to_oklab(self):
+        return OKLabColor(
+            self.l,
+            self.c * math.cos(self.h * math.pi / 180),
+            self.h * math.cos(self.h * math.pi / 180)
+        )
+
+    def to_rgb(self):
+        return self.to_oklab().to_rgb()
+
+__all__ = ('chalk', 'WebColor', "RGBColor", 'SRGBColor', 'XYZColor', 'OKLabColor')

src/suou/mat.py

@@ -24,7 +24,9 @@ _T = TypeVar('_T')
 
 class Matrix(Collection[_T]):
     """
-    Shallow reimplementation of numpy's matrices in pure Python.
+    Minimalist reimplementation of matrices in pure Python.
+    
+    This to avoid adding numpy as a dependency.
 
     *New in 0.12.0*
     """