Update to support CSS HDR color syntax updates (#464)

facelessuser · web-flow · commit 6d821a81e935 · 2025-03-27T13:52:17.000-06:00
* Update to support CSS HDR color syntax updates

Jzazbz, JzCzhz, and ICtCp will all now use named color functions by
default and serialize in the `color()` form with the custom names
`--jzazbz`, `--jzczhz`, `--ictcp`. The non-hyphenated `color()` form is
still supported but usage should be discontinued as it will be
removed in the future at some point.

* Ensure reference range of HDR colors match CSS
diff --git a/coloraide/color.py b/coloraide/color.py
@@ -46,9 +46,9 @@
 from .spaces.rec2100_pq import Rec2100PQ
 from .spaces.rec2100_hlg import Rec2100HLG
 from .spaces.rec2100_linear import Rec2100Linear
-from .spaces.jzazbz import Jzazbz
-from .spaces.jzczhz import JzCzhz
-from .spaces.ictcp import ICtCp
+from .spaces.jzazbz.css import Jzazbz
+from .spaces.jzczhz.css import JzCzhz
+from .spaces.ictcp.css import ICtCp
 from .distance import DeltaE
 from .distance.delta_e_76 import DE76
 from .distance.delta_e_94 import DE94
diff --git a/coloraide/css/parse.py b/coloraide/css/parse.py
@@ -30,7 +30,7 @@
 RE_FUNC_END = re.compile(r'\s*(\))')
 RE_COMMA = re.compile(r'\s*(,)\s*')
 RE_SLASH = re.compile(r'\s*(/)\s*')
-RE_CSS_FUNC = re.compile(r'\b(color|rgba?|hsla?|hwb|(?:ok)?lab|(?:ok)?lch)\b')
+RE_CSS_FUNC = re.compile(r'\b(color|rgba?|hsla?|hwb|(?:ok)?lab|(?:ok)?lch|jzazbz|jzczhz|ictcp)\b')
 
 
 def norm_float(string: str) -> float:
@@ -426,13 +426,13 @@ def tokenize_css(css: str, start: int = 0) -> dict[str, Any]:
             if not validate_cylindrical_srgb(tokens):
                 return {}
 
-        elif func_name in ('lab', 'oklab'):
+        elif func_name in ('lab', 'oklab', 'jzazbz', 'ictcp'):
             tokens['id'] = '--' + func_name
 
             if not validate_lab(tokens):
                 return {}
 
-        elif func_name in ('oklch', 'lch'):
+        elif func_name in ('oklch', 'lch', 'jzczhz'):
             tokens['id'] = '--' + func_name
 
             if not validate_lch(tokens):
diff --git a/coloraide/spaces/ictcp/__init__.py b/coloraide/spaces/ictcp/__init__.py
@@ -4,12 +4,12 @@
 https://professional.dolby.com/siteassets/pdfs/ictcp_dolbywhitepaper_v071.pdf
 """
 from __future__ import annotations
-from .lab import Lab
-from ..cat import WHITES
-from ..channels import Channel, FLG_MIRROR_PERCENT
-from .. import util
-from .. import algebra as alg
-from ..types import Vector
+from ..lab import Lab
+from ...cat import WHITES
+from ...channels import Channel, FLG_MIRROR_PERCENT
+from ... import util
+from ... import algebra as alg
+from ...types import Vector
 
 # All PQ Values are equivalent to defaults as stated in link below:
 # https://en.wikipedia.org/wiki/High-dynamic-range_video#Perceptual_quantizer
@@ -93,8 +93,8 @@ class ICtCp(Lab):
     SERIALIZE = ("ictcp", "--ictcp",)
     CHANNELS = (
         Channel("i", 0.0, 1.0),
-        Channel("ct", -1.0, 1.0, flags=FLG_MIRROR_PERCENT),
-        Channel("cp", -1.0, 1.0, flags=FLG_MIRROR_PERCENT)
+        Channel("ct", -0.5, 0.5, flags=FLG_MIRROR_PERCENT),
+        Channel("cp", -0.5, 0.5, flags=FLG_MIRROR_PERCENT)
     )
     CHANNEL_ALIASES = {
         "intensity": "i",
diff --git a/coloraide/spaces/ictcp/css.py b/coloraide/spaces/ictcp/css.py
@@ -0,0 +1,49 @@
+"""ICtCp class."""
+from __future__ import annotations
+from .. import ictcp as base
+from ...css import parse
+from ...css import serialize
+from ...types import Vector
+from typing import Any, TYPE_CHECKING, Sequence
+
+if TYPE_CHECKING:  # pragma: no cover
+    from ...color import Color
+
+
+class ICtCp(base.ICtCp):
+    """ICtCp class."""
+
+    def to_string(
+        self,
+        parent: Color,
+        *,
+        alpha: bool | None = None,
+        precision: int | Sequence[int] | None = None,
+        fit: bool | str | dict[str, Any] = True,
+        none: bool = False,
+        color: bool = False,
+        percent: bool | Sequence[bool] = False,
+        **kwargs: Any
+    ) -> str:
+        """Convert to CSS."""
+
+        return serialize.serialize_css(
+            parent,
+            func='ictcp',
+            alpha=alpha,
+            precision=precision,
+            fit=fit,
+            none=none,
+            color=color,
+            percent=percent
+        )
+
+    def match(
+        self,
+        string: str,
+        start: int = 0,
+        fullmatch: bool = True
+    ) -> tuple[tuple[Vector, float], int] | None:
+        """Match a CSS color string."""
+
+        return parse.parse_css(self, string, start, fullmatch)
diff --git a/coloraide/spaces/jzazbz/__init__.py b/coloraide/spaces/jzazbz/__init__.py
@@ -10,12 +10,12 @@
 If at some time that these assumptions are incorrect, we will be happy to alter the model.
 """
 from __future__ import annotations
-from ..cat import WHITES
-from ..channels import Channel, FLG_MIRROR_PERCENT
-from .. import util
-from .. import algebra as alg
-from ..types import Vector, Matrix  # noqa: F401
-from .lab import Lab
+from ...cat import WHITES
+from ...channels import Channel, FLG_MIRROR_PERCENT
+from ... import util
+from ... import algebra as alg
+from ...types import Vector, Matrix  # noqa: F401
+from ..lab import Lab
 
 B = 1.15
 G = 0.66
@@ -129,8 +129,8 @@ class Jzazbz(Lab):
     SERIALIZE = ("jzazbz", "--jzazbz",)
     CHANNELS = (
         Channel("jz", 0.0, 1.0),
-        Channel("az", -1.0, 1.0, flags=FLG_MIRROR_PERCENT),
-        Channel("bz", -1.0, 1.0, flags=FLG_MIRROR_PERCENT)
+        Channel("az", -0.21, 0.21, flags=FLG_MIRROR_PERCENT),
+        Channel("bz", -0.21, 0.21, flags=FLG_MIRROR_PERCENT)
     )
     CHANNEL_ALIASES = {
         "lightness": 'jz',
diff --git a/coloraide/spaces/jzazbz/css.py b/coloraide/spaces/jzazbz/css.py
@@ -0,0 +1,49 @@
+"""Jzazbz class."""
+from __future__ import annotations
+from .. import jzazbz as base
+from ...css import parse
+from ...css import serialize
+from ...types import Vector
+from typing import Any, TYPE_CHECKING, Sequence
+
+if TYPE_CHECKING:  # pragma: no cover
+    from ...color import Color
+
+
+class Jzazbz(base.Jzazbz):
+    """Jzazbz class."""
+
+    def to_string(
+        self,
+        parent: Color,
+        *,
+        alpha: bool | None = None,
+        precision: int | Sequence[int] | None = None,
+        fit: bool | str | dict[str, Any] = True,
+        none: bool = False,
+        color: bool = False,
+        percent: bool | Sequence[bool] = False,
+        **kwargs: Any
+    ) -> str:
+        """Convert to CSS."""
+
+        return serialize.serialize_css(
+            parent,
+            func='jzazbz',
+            alpha=alpha,
+            precision=precision,
+            fit=fit,
+            none=none,
+            color=color,
+            percent=percent
+        )
+
+    def match(
+        self,
+        string: str,
+        start: int = 0,
+        fullmatch: bool = True
+    ) -> tuple[tuple[Vector, float], int] | None:
+        """Match a CSS color string."""
+
+        return parse.parse_css(self, string, start, fullmatch)
diff --git a/coloraide/spaces/jzczhz/__init__.py b/coloraide/spaces/jzczhz/__init__.py
@@ -4,9 +4,9 @@
 https://www.osapublishing.org/oe/fulltext.cfm?uri=oe-25-13-15131&id=368272
 """
 from __future__ import annotations
-from ..cat import WHITES
-from .lch import LCh
-from ..channels import Channel, FLG_ANGLE
+from ...cat import WHITES
+from ..lch import LCh
+from ...channels import Channel, FLG_ANGLE
 
 
 class JzCzhz(LCh):
@@ -31,7 +31,7 @@ class JzCzhz(LCh):
     }
     CHANNELS = (
         Channel("jz", 0.0, 1.0),
-        Channel("cz", 0.0, 1.0),
+        Channel("cz", 0.0, 0.26),
         Channel("hz", 0.0, 360.0, flags=FLG_ANGLE)
     )
 
diff --git a/coloraide/spaces/jzczhz/css.py b/coloraide/spaces/jzczhz/css.py
@@ -0,0 +1,49 @@
+"""JzCzhz class."""
+from __future__ import annotations
+from .. import jzczhz as base
+from ...css import parse
+from ...css import serialize
+from ...types import Vector
+from typing import Any, TYPE_CHECKING, Sequence
+
+if TYPE_CHECKING:  # pragma: no cover
+    from ...color import Color
+
+
+class JzCzhz(base.JzCzhz):
+    """JzCzhz class."""
+
+    def to_string(
+        self,
+        parent: Color,
+        *,
+        alpha: bool | None = None,
+        precision: int | Sequence[int] | None = None,
+        fit: bool | str | dict[str, Any] = True,
+        none: bool = False,
+        color: bool = False,
+        percent: bool | Sequence[bool] = False,
+        **kwargs: Any
+    ) -> str:
+        """Convert to CSS."""
+
+        return serialize.serialize_css(
+            parent,
+            func='jzczhz',
+            alpha=alpha,
+            precision=precision,
+            fit=fit,
+            none=none,
+            color=color,
+            percent=percent
+        )
+
+    def match(
+        self,
+        string: str,
+        start: int = 0,
+        fullmatch: bool = True
+    ) -> tuple[tuple[Vector, float], int] | None:
+        """Match a CSS color string."""
+
+        return parse.parse_css(self, string, start, fullmatch)
diff --git a/docs/src/markdown/about/changelog.md b/docs/src/markdown/about/changelog.md
@@ -1,5 +1,14 @@
 # Changelog
 
+## 4.5.0
+
+-   **NEW**: Support change in CSS HDR spec that now specifies Jzazbz, JzCzhz, and ICtCp serialization as using the
+    respective named color functions: `jzazbz()`, `jzczhz()`, and `ictcp()`. The `color()` will prefer the custom
+    hyphenated forms using `--jzazbz`, `--jzczhz`, and `--ictcp` respectively. The non-hyphenated names are still
+    supported in the `color()` form for backwards compatibility, but usage is discouraged as at some future time
+    support for non-hyphenated names will be dropped as CSS has moved away from this as a supported convention.
+-   **FIX**: Reference ranges for Jzazbz, JzCzhz, and ICtCp, now match the latest CSS HDR spec.
+
 ## 4.4.1
 
 -   **FIX**: Fix XYB transform.
diff --git a/docs/src/markdown/advanced.md b/docs/src/markdown/advanced.md
@@ -106,7 +106,7 @@ clamped to the SDR range. If we convert an HDR color from Jzazbz to HSLuv, round
 simply does not support the HDR range.
 
 ```py play
-jz = Color('color(jzazbz 0.25 0 0)')
+jz = Color('jzazbz(0.25 0 0)')
 jz
 hsluv = jz.convert('hsluv')
 hsluv
diff --git a/docs/src/markdown/color.md b/docs/src/markdown/color.md
@@ -283,7 +283,7 @@ RE_COLOR_START = re.compile(
     r"""(?ix)
     (?:
         # CSS functions
-        \b(?<![-#&$])(?:color\((?!\s*-)|(?:hsla?|(?:ok)?(?:lch|lab)|hwb|rgba?)\()|
+        \b(?<![-#&$])(?:color\((?!\s*-)|(?:hsla?|(?:ok)?(?:lch|lab)|jzczhz|jzazbz|ictcp|hwb|rgba?)\()|
         # Color words
         \b(?<![-#&$])[\w]{3,}(?![(-])\b|
         # Hex codes
diff --git a/docs/src/markdown/colors/ictcp.md b/docs/src/markdown/colors/ictcp.md
@@ -19,8 +19,7 @@ Name       | Range^\*^
 `ct`       | [-0.5, 0.5]
 `cp`       | [-0.5, 0.5]
 
-^\*^ Space is not bound to the above, defined range but represents a practical range for HDR color spaces. CSS uses a
-range of `i` = [0, 1], `ct` = [-1, 1] and `cp` = [1, 1] for percentage input and output.
+^\*^ Space is not bound to the above, defined range but represents a practical range for HDR color spaces.
 ////
 
 ![ICtCp](../images/ictcp-3d.png)
@@ -46,10 +45,12 @@ Channels | Aliases
 
 ## Input/Output
 
-Parsed input and string output formats support all valid CSS forms:
+Parsed input and string output formats support all valid CSS forms in addition to allowing the `#!css-color color()`
+function format as well using the custom name `#!css-color --ictcp`.
 
 ```css-color
-color(ictcp i ct cp / a)  // Color function
+ictcp(i ct cp / a)          // ICtCp function
+color(--ictcp i ct cp / a)  // Color function
 ```
 
 When manually creating a color via raw data or specifying a color space as a parameter in a function, the color
@@ -59,19 +60,21 @@ space name is always used:
 Color("ictcp", [0, 0, 0], 1)
 ```
 
-The string representation of the color object and the default string output use the
-`#!css-color color(ictcp i ct cp / a)` form.
+The string representation of the color object will always default to the `#!css-color color(--ictcp i ct cp / a)`
+form, but the default string output will be the `#!css-color ictcp(i ct cp / a)` form.
 
 ```py play
-Color("ictcp", [0.42785, -0.11574, 0.2788])
-Color("ictcp", [0.50497, -0.20797, 0.11077]).to_string()
+Color("ictcp", [0.42788, -0.1157, 0.27873])
+Color("ictcp", [0.50498, -0.20797, 0.11073]).to_string()
+Color("ictcp", [0.56983, -0.25169, 0.03788]).to_string(percent=True)
+Color("ictcp", [0.39138, -0.24061, -0.04423]).to_string(color=True)
 ```
 
 ## Registering
 
 ```py
 from coloraide import Color as Base
-from coloraide.spaces.ictcp import ICtCp
+from coloraide.spaces.ictcp.css import ICtCp
 
 class Color(Base): ...
 
diff --git a/docs/src/markdown/colors/jzazbz.md b/docs/src/markdown/colors/jzazbz.md
diff --git a/docs/src/markdown/colors/jzczhz.md b/docs/src/markdown/colors/jzczhz.md
diff --git a/docs/src/markdown/gamut.md b/docs/src/markdown/gamut.md
diff --git a/tests/test_ictcp.py b/tests/test_ictcp.py
diff --git a/tests/test_jzazbz.py b/tests/test_jzazbz.py
diff --git a/tests/test_jzczhz.py b/tests/test_jzczhz.py
