Fix issues with continuous interpolations and derived interpolations (#…

…441)

* Fix issues with continuous interpolations and derived interpolations

Continuous interpolation would sometimes apply premultiplication to a
color twice and also would apply a hue offset to a hue during fixup
twice.

Fixes #440

* Ignore lint errors we don't care about and fix conditional parenthesis

* Reference the appropriate index

* Adjust changelog phrasing

coloraide/__meta__.py

@@ -193,5 +193,5 @@ def parse_version(ver: str) -> Version:
     return Version(major, minor, micro, release, pre, post, dev)
 
 
-__version_info__ = Version(4, 0, 0, "final")
+__version_info__ = Version(4, 0, 1, "final")
 __version__ = __version_info__._get_canonical()

coloraide/color.py

@@ -386,7 +386,7 @@ def register(
                     cls._get_convert_chain.cache_clear()
                 raise TypeError(f"Cannot register plugin of type '{type(i)}'")
 
-            if p.NAME != "*" and p.NAME not in mapping or overwrite:
+            if p.NAME != "*" and (p.NAME not in mapping or overwrite):
                 mapping[p.NAME] = p
             elif not silent:
                 if reset_convert_cache:  # pragma: no cover

coloraide/interpolate/continuous.py

@@ -90,7 +90,7 @@ def normalize_hue(
         else:
             raise ValueError(f"Unknown hue adjuster '{hue}'")
 
-        c1 = color1[index] + offset
+        c1 = color1[index]
         c2 = (color2[index] % 360) + offset
 
         # Adjust hue, handle gaps across `NaN`s
@@ -156,7 +156,8 @@ def handle_undefined(self) -> None:
                 # Two good values, store the last good value and continue
                 if not a_nan and not b_nan:
                     if self.premultiplied and i == alpha:
-                        self.premultiply(c1)
+                        if x == 1:
+                            self.premultiply(c1)
                         self.premultiply(c2)
                     last = b
                     continue

docs/src/markdown/about/changelog.md

@@ -1,5 +1,12 @@
 # Changelog
 
+## 4.0.1
+
+-   **FIX**: Fix issue with `continuous` interpolation (and any that are derived from it, e.g., cubic spline
+    interpolations) that can cause bad hue fixup calculations.
+-   **FIX**: Fix issue with `continuous` interpolation (and any that are derived from it, e.g., cubic spline
+    interpolations) that can cause premultiplication to be applied to a color twice.
+
 ## 4.0
 
 -   **NEW**: Officially support Python 3.13.

docs/src/markdown/demos/3d_models.html

@@ -905,7 +905,7 @@ <h1>ColorAide Color Space Models</h1>
 let colorSpaces = null
 let colorGamuts = null
 let lastModel = null
-let package = 'coloraide-4.0-py3-none-any.whl'
+let package = 'coloraide-4.0.1-py3-none-any.whl'
 const defaultSpace = 'lab'
 const defaultGamut = 'srgb'
 const exceptions = new Set(['hwb', 'ryb', 'ryb-biased'])

docs/src/markdown/demos/colorpicker.html

@@ -421,7 +421,7 @@ <h1>ColorAide Color Picker</h1>
     let pyodide = null
     let webspace = ''
     let initial = 'oklab(0.69 0.13 -0.1 / 0.85)'
-    let package = 'coloraide-4.0-py3-none-any.whl'
+    let package = 'coloraide-4.0.1-py3-none-any.whl'
 
     const base = `${window.location.origin}/${window.location.pathname.split('/')[1]}/playground/`
     package = base + package

docs/src/mkdocs.yml

@@ -309,7 +309,7 @@ extra_css:
   - assets/coloraide-extras/extra.css
 extra_javascript:
   - https://unpkg.com/[email protected]/dist/mermaid.min.js
-  - playground-config-70f29cae.js
+  - playground-config-4f0f586c.js
   - https://cdn.jsdelivr.net/pyodide/v0.26.2/full/pyodide.js
   - assets/coloraide-extras/extra-notebook.js
 

docs/theme/playground-config-70f29cae.js → docs/theme/playground-config-4f0f586c.js

@@ -1,5 +1,5 @@
 var colorNotebook = {
-    "playgroundWheels": ['pygments-2.17.2-py3-none-any.whl', 'coloraide-4.0-py3-none-any.whl'],
-    "notebookWheels": ['pyyaml', 'Markdown-3.6-py3-none-any.whl', 'pymdown_extensions-10.10.1-py3-none-any.whl', 'pygments-2.17.2-py3-none-any.whl', 'coloraide-4.0-py3-none-any.whl'],
+    "playgroundWheels": ['pygments-2.17.2-py3-none-any.whl', 'coloraide-4.0.1-py3-none-any.whl'],
+    "notebookWheels": ['pyyaml', 'Markdown-3.6-py3-none-any.whl', 'pymdown_extensions-10.10.1-py3-none-any.whl', 'pygments-2.17.2-py3-none-any.whl', 'coloraide-4.0.1-py3-none-any.whl'],
     "defaultPlayground": "import coloraide\ncoloraide.__version__\nColor('red')"
 }

mkdocs.yml

@@ -309,9 +309,9 @@ extra_css:
   - assets/coloraide-extras/extra-696a2734c9.css
 extra_javascript:
   - https://unpkg.com/[email protected]/dist/mermaid.min.js
-  - playground-config-70f29cae.js
+  - playground-config-4f0f586c.js
   - https://cdn.jsdelivr.net/pyodide/v0.26.2/full/pyodide.js
-  - assets/coloraide-extras/extra-notebook-DQWpIrCE.js
+  - assets/coloraide-extras/extra-notebook-UmZ-G8NV.js
 
 extra:
   social:

pyproject.toml

@@ -118,6 +118,8 @@ lint.ignore = [
     "RUF012",
     "RUF005",
     "PGH004",
+    "RUF022",
+    "RUF023",
     "RUF100",
     "B905"
 ]

tests/test_interpolation.py

@@ -1563,7 +1563,7 @@ def test_bspline_undefined_alpha(self):
                 space='srgb',
                 method='bspline'
             )(0.75),
-            Color('rgb(3.4932 38.425 174.66 / 0.76042)')
+            Color('rgb(3.4932 76.849 174.66 / 0.76042)')
         )
 
         self.assertColorEqual(