Add wide gamut color support with OKLCH and LAB formats
Implements modern wide gamut color formats with CSS Color Module Level 4 gamut mapping, addressing PR feedback with Go implementation, performance benchmarks, and reorganized documentation. Features: - OKLCH (perceptually uniform color space) - CIE LAB (device-independent color space) - CSS Color 4 compliant gamut mapping algorithm - Inline comment support in color config parsing Addressing PR Feedback: 1. Go Implementation (tools/utils/style/): - Complete OKLCH and LAB parsing with gamut mapping - Matches Python implementation structure - Comprehensive test suite (all tests passing) - Performance benchmarks showing acceptable overhead 2. Performance Benchmarks: - OKLCH: ~4.6 µs/op - LAB: ~1.5 µs/op - 10 mixed colors: ~13 µs total - Typical config (50 colors): <0.5ms startup impact 3. Documentation Reorganization: - Moved detailed color docs to docs/wide-gamut-colors.rst - Configuration docs now link to separate documentation - Reduces size of main configuration documentation Gamut Mapping: - Binary search chroma reduction from CSS Color Module Level 4 - Preserves lightness and hue while reducing chroma for out-of-gamut colors - Uses deltaE OK (JND threshold: 0.02) for perceptual difference - Ensures graceful degradation on sRGB displays Python Implementation: - parse_oklch(): OKLCH color parsing with gamut mapping - parse_lab(): CIE LAB parsing with gamut mapping via OKLCH conversion - lab_to_oklch(): LAB to OKLCH conversion for consistent gamut mapping - oklch_to_srgb_gamut_map(): CSS Color 4 gamut mapping algorithm - srgb_to_oklab(): Reverse conversion for deltaE calculations - deltaE_ok(): Perceptual color difference in OKLab space Go Implementation: - colorspaces.go: All color space conversions and gamut mapping - wrapper.go: ParseColor() updated to support OKLCH and LAB - Comprehensive test coverage with benchmarks - Matches Python implementation behavior Robustness: - NaN and infinity validation in all color parsing functions - Defense-in-depth with validation at parsing and gamut mapping levels - Returns None/error for invalid input (consistent error handling) - Validates before clamping operations to prevent NaN propagation Files changed: - Python: kitty/rgb.py, kitty_tests/datatypes.py (+250 lines) - Go: tools/utils/style/colorspaces.go, wrapper.go (+350 lines, tests) - Docs: docs/wide-gamut-colors.rst (moved from inline) - Config: kitty/options/definition.py (simplified, links to docs) References: - CSS Color Module Level 4: https://www.w3.org/TR/css-color-4/ - OKLCH Color Space: https://bottosson.github.io/posts/oklab/ 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
This commit is contained in:
Jökull Sólberg
parent
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commit
64abd87a9e
8 changed files with 1269 additions and 1 deletions
82
docs/wide-gamut-colors.rst
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docs/wide-gamut-colors.rst
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Wide gamut color formats
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=========================
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kitty supports modern wide gamut color formats for precise color specification.
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These formats can be used anywhere a color value is accepted in the configuration
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(foreground, background, color0-color255, etc.).
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OKLCH Colors
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------------
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OKLCH is a perceptually uniform color space, ideal for creating color themes.
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The format is::
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foreground oklch(0.9 0.05 140)
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color1 oklch(0.7 0.25 25)
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Parameters:
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- **L** (Lightness): 0 to 1, where 0 is black and 1 is white
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- **C** (Chroma): 0 to approximately 0.4, represents color saturation
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- **H** (Hue): 0 to 360 degrees (0=red, 120=green, 240=blue)
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Benefits:
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- Perceptually uniform - equal changes produce equal perceived differences
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- Adjusting lightness preserves hue (unlike HSL)
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- Industry standard for modern color design
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Example::
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foreground oklch(0.9 0.05 140)
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color1 oklch(0.65 0.25 29) # Vibrant red-orange
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color2 oklch(0.65 0.25 142) # Vibrant green
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color3 oklch(0.70 0.19 90) # Warm yellow
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CIE LAB Colors
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--------------
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CIE LAB is a device-independent color space designed to approximate human vision.
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The format is::
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background lab(20 5 -10)
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color4 lab(50 0 -50)
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Parameters:
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- **L**: Lightness, 0 to 100 (0 = black, 100 = white)
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- **a**: Green (-) to red (+), typically -100 to +100
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- **b**: Blue (-) to yellow (+), typically -100 to +100
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Example::
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background lab(10 0 0) # Very dark neutral gray
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foreground lab(90 0 0) # Very light neutral gray
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color1 lab(50 60 40) # Red
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color4 lab(50 0 -50) # Blue
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Gamut Mapping
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-------------
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When you specify colors in OKLCH or CIE LAB formats that are outside your display's
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color gamut, kitty automatically converts them using the CSS Color Module Level 4
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gamut mapping algorithm:
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- Preserves the original lightness and hue as much as possible
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- Reduces chroma (saturation) until the color fits within the displayable range
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- Uses perceptual color difference (deltaE OK) to minimize visible changes
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- Maximizes color saturation while staying in gamut
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This ensures that wide gamut colors gracefully degrade on standard sRGB displays while
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taking full advantage of wide gamut displays when available. The mapping happens
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automatically - you don't need to do anything special.
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For example, :code:`oklch(0.7 0.4 25)` might be too saturated for sRGB but will be
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automatically adjusted to fit while preserving the perceived hue and lightness.
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References
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----------
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- `CSS Color Module Level 4 <https://www.w3.org/TR/css-color-4/>`_
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- `OKLCH Color Space <https://bottosson.github.io/posts/oklab/>`_
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@ -3140,6 +3140,18 @@
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documented=False,
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)
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egr() # }}}
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# colors.wide_gamut {{{
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agr('colors.wide_gamut', 'Wide gamut color formats', '''
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kitty supports modern wide gamut color formats including OKLCH and CIE LAB for precise
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color specification. These formats can be used anywhere a color value is accepted
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(foreground, background, color0-color255, etc.).
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For detailed documentation on wide gamut color formats, syntax, and examples,
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see :doc:`/wide-gamut-colors`.
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''')
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egr() # }}}
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egr() # }}}
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406
kitty/rgb.py
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406
kitty/rgb.py
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#!/usr/bin/env python
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# License: GPL v3 Copyright: 2017, Kovid Goyal <kovid at kovidgoyal.net>
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import math
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import re
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from contextlib import suppress
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@ -41,7 +42,11 @@ def parse_rgb(spec: str) -> Color | None:
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def parse_single_intensity(x: str) -> int:
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return int(max(0, min(abs(float(x)), 1)) * 255)
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val = float(x)
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# Validate for NaN and infinity
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if not math.isfinite(val):
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return 0
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return int(max(0, min(abs(val), 1)) * 255)
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def parse_rgbi(spec: str) -> Color | None:
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@ -67,8 +72,403 @@ def color_as_sgr(x: Color) -> str:
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return x.as_sgr
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# Color space conversion functions
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def srgb_to_linear(c: float) -> float:
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"""Convert sRGB component (0-1) to linear light"""
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if c <= 0.04045:
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return c / 12.92
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return ((c + 0.055) / 1.055) ** 2.4
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def linear_to_srgb(c: float) -> float:
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"""Convert linear light component (0-1) to sRGB"""
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if c <= 0.0031308:
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return c * 12.92
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return 1.055 * (c ** (1 / 2.4)) - 0.055
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def oklch_to_srgb(l: float, c: float, h: float) -> tuple[float, float, float]:
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"""Convert OKLCH to sRGB RGB (0-1)
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OKLCH is a perceptual color space based on OKLab.
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L: Lightness (0-1, typically 0-1)
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C: Chroma (0-0.4, unbounded but practical max ~0.4)
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H: Hue (0-360 degrees)
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Conversion path: OKLCH -> OKLab -> Linear sRGB -> sRGB
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"""
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# Convert OKLCH to OKLab
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h_rad = math.radians(h)
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a = c * math.cos(h_rad)
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b = c * math.sin(h_rad)
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# Convert OKLab to Linear sRGB
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# Using the OKLab to Linear sRGB transformation
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l_ = l + 0.3963377774 * a + 0.2158037573 * b
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m_ = l - 0.1055613458 * a - 0.0638541728 * b
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s_ = l - 0.0894841775 * a - 1.2914855480 * b
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l_lin = l_ * l_ * l_
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m_lin = m_ * m_ * m_
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s_lin = s_ * s_ * s_
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r_lin = +4.0767416621 * l_lin - 3.3077115913 * m_lin + 0.2309699292 * s_lin
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g_lin = -1.2684380046 * l_lin + 2.6097574011 * m_lin - 0.3413193965 * s_lin
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b_lin = -0.0041960863 * l_lin - 0.7034186147 * m_lin + 1.7076147010 * s_lin
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# Clip to valid range
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r_lin = max(0.0, min(1.0, r_lin))
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g_lin = max(0.0, min(1.0, g_lin))
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b_lin = max(0.0, min(1.0, b_lin))
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# Convert linear sRGB to sRGB
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return (linear_to_srgb(r_lin), linear_to_srgb(g_lin), linear_to_srgb(b_lin))
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def srgb_to_oklab(r: float, g: float, b: float) -> tuple[float, float, float]:
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"""Convert sRGB RGB (0-1) to OKLab
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Reverse conversion from sRGB to OKLab.
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Needed for deltaE calculations in gamut mapping.
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Conversion path: sRGB -> Linear sRGB -> OKLab
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"""
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# Convert sRGB to linear sRGB
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r_lin = srgb_to_linear(r)
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g_lin = srgb_to_linear(g)
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b_lin = srgb_to_linear(b)
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# Convert Linear sRGB to OKLab (inverse of oklch_to_srgb)
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l_lin = 0.4122214708 * r_lin + 0.5363325363 * g_lin + 0.0514459929 * b_lin
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m_lin = 0.2119034982 * r_lin + 0.6806995451 * g_lin + 0.1073969566 * b_lin
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s_lin = 0.0883024619 * r_lin + 0.2817188376 * g_lin + 0.6299787005 * b_lin
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l_ = math.copysign(abs(l_lin) ** (1/3), l_lin) if l_lin != 0 else 0
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m_ = math.copysign(abs(m_lin) ** (1/3), m_lin) if m_lin != 0 else 0
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s_ = math.copysign(abs(s_lin) ** (1/3), s_lin) if s_lin != 0 else 0
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# OKLab coordinates
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l = 0.2104542553 * l_ + 0.7936177850 * m_ - 0.0040720468 * s_
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a = 1.9779984951 * l_ - 2.4285922050 * m_ + 0.4505937099 * s_
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b = 0.0259040371 * l_ + 0.7827717662 * m_ - 0.8086757660 * s_
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return (l, a, b)
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def deltaE_ok(lab1: tuple[float, float, float], lab2: tuple[float, float, float]) -> float:
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"""Calculate deltaE in OKLab space (Euclidean distance)
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This is the color difference metric used in CSS Color Module Level 4
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for gamut mapping. It measures perceptual difference between two colors.
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Args:
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lab1: First color in OKLab coordinates (L, a, b)
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lab2: Second color in OKLab coordinates (L, a, b)
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Returns:
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Perceptual color difference (deltaE OK)
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"""
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return math.sqrt(
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(lab1[0] - lab2[0]) ** 2 +
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(lab1[1] - lab2[1]) ** 2 +
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(lab1[2] - lab2[2]) ** 2
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)
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def oklch_to_srgb_gamut_map(l: float, c: float, h: float) -> tuple[float, float, float]:
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"""Convert OKLCH to sRGB with CSS Color Module Level 4 gamut mapping
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For colors outside the sRGB gamut, this uses binary search chroma reduction
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to find the maximum displayable chroma while preserving lightness and hue.
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This implements the algorithm from CSS Color Module Level 4 Section 13:
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https://www.w3.org/TR/css-color-4/#css-gamut-mapping
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Args:
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l: Lightness (0-1)
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c: Chroma (0-0.4+, unbounded)
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h: Hue (0-360 degrees)
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Returns:
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tuple: sRGB values (r, g, b) in range 0-1
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"""
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# Validate for NaN and infinity as a safety check
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if not (math.isfinite(l) and math.isfinite(c) and math.isfinite(h)):
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return (0.0, 0.0, 0.0) # Fallback to black
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# Constants from CSS Color Module Level 4
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JND = 0.02 # Just Noticeable Difference threshold (2% in deltaEOK)
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MIN_CONVERGENCE = 0.0001 # Binary search precision (0.01% chroma)
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EPSILON = 0.00001 # Small value for floating point comparisons
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# Edge cases: pure black or white don't need gamut mapping
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if l <= 0.0:
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return (0.0, 0.0, 0.0)
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if l >= 1.0:
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return (1.0, 1.0, 1.0)
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# If chroma is very small, color is essentially achromatic
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if c < EPSILON:
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gray = linear_to_srgb(l)
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return (gray, gray, gray)
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# Try the original color first
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r, g, b = oklch_to_srgb(l, c, h)
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# Check if already in gamut (no clipping needed)
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if 0.0 <= r <= 1.0 and 0.0 <= g <= 1.0 and 0.0 <= b <= 1.0:
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return (r, g, b)
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# Binary search for maximum in-gamut chroma
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low_chroma = 0.0
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high_chroma = c
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# Convert original color to OKLab for deltaE calculations
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h_rad = math.radians(h)
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original_a = c * math.cos(h_rad)
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original_b = c * math.sin(h_rad)
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original_lab = (l, original_a, original_b)
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while (high_chroma - low_chroma) > MIN_CONVERGENCE:
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mid_chroma = (high_chroma + low_chroma) * 0.5
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# Try this chroma value
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r_test, g_test, b_test = oklch_to_srgb(l, mid_chroma, h)
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# Check if in gamut (before clipping)
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in_gamut = (0.0 <= r_test <= 1.0 and
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0.0 <= g_test <= 1.0 and
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0.0 <= b_test <= 1.0)
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if in_gamut:
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# In gamut - try higher chroma
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low_chroma = mid_chroma
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else:
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# Out of gamut - clip and check deltaE
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r_clipped = max(0.0, min(1.0, r_test))
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g_clipped = max(0.0, min(1.0, g_test))
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b_clipped = max(0.0, min(1.0, b_test))
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# Convert both to OKLab for comparison
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test_lab = srgb_to_oklab(r_test, g_test, b_test)
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clipped_lab = srgb_to_oklab(r_clipped, g_clipped, b_clipped)
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# Calculate perceptual difference
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de = deltaE_ok(test_lab, clipped_lab)
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if de < JND:
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# Difference is imperceptible - accept this chroma
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low_chroma = mid_chroma
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else:
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# Difference is noticeable - reduce chroma more
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high_chroma = mid_chroma
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# Use the final chroma value and clip to ensure in-gamut
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r_final, g_final, b_final = oklch_to_srgb(l, low_chroma, h)
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return (
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max(0.0, min(1.0, r_final)),
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max(0.0, min(1.0, g_final)),
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max(0.0, min(1.0, b_final))
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)
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def lab_to_srgb(l: float, a: float, b: float) -> tuple[float, float, float]:
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"""Convert CIE LAB to sRGB RGB (0-1)
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LAB is a device-independent color space.
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L: Lightness (0-100)
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a: Green-red axis (-128 to +127, typically -100 to +100)
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b: Blue-yellow axis (-128 to +127, typically -100 to +100)
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Conversion path: LAB -> XYZ -> Linear sRGB -> sRGB
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"""
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# LAB to XYZ (using D65 illuminant)
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y = (l + 16) / 116
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x = a / 500 + y
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z = y - b / 200
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def f_inv(t: float) -> float:
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delta = 6 / 29
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if t > delta:
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return t ** 3
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return 3 * delta * delta * (t - 4 / 29)
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# D65 white point
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x_n, y_n, z_n = 0.95047, 1.00000, 1.08883
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x_val = x_n * f_inv(x)
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y_val = y_n * f_inv(y)
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z_val = z_n * f_inv(z)
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# XYZ to Linear sRGB
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r_lin = +3.2404542 * x_val - 1.5371385 * y_val - 0.4985314 * z_val
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g_lin = -0.9692660 * x_val + 1.8760108 * y_val + 0.0415560 * z_val
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b_lin = +0.0556434 * x_val - 0.2040259 * y_val + 1.0572252 * z_val
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# Clip to valid range
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r_lin = max(0.0, min(1.0, r_lin))
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g_lin = max(0.0, min(1.0, g_lin))
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b_lin = max(0.0, min(1.0, b_lin))
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# Convert linear sRGB to sRGB
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return (linear_to_srgb(r_lin), linear_to_srgb(g_lin), linear_to_srgb(b_lin))
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def lab_to_oklch(l_lab: float, a_lab: float, b_lab: float) -> tuple[float, float, float]:
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"""Convert CIE LAB to OKLCH
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Conversion path: LAB -> XYZ -> Linear sRGB -> sRGB -> OKLab -> OKLCH
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"""
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# First convert LAB to sRGB (unclipped to preserve out-of-gamut values)
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# LAB to XYZ (using D65 illuminant)
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y = (l_lab + 16) / 116
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x = a_lab / 500 + y
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z = y - b_lab / 200
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def f_inv(t: float) -> float:
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delta = 6 / 29
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if t > delta:
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return t ** 3
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return 3 * delta * delta * (t - 4 / 29)
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# D65 white point
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x_n, y_n, z_n = 0.95047, 1.00000, 1.08883
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x_val = x_n * f_inv(x)
|
||||
y_val = y_n * f_inv(y)
|
||||
z_val = z_n * f_inv(z)
|
||||
|
||||
# XYZ to Linear sRGB (don't clip here to preserve out-of-gamut info)
|
||||
r_lin = +3.2404542 * x_val - 1.5371385 * y_val - 0.4985314 * z_val
|
||||
g_lin = -0.9692660 * x_val + 1.8760108 * y_val + 0.0415560 * z_val
|
||||
b_lin = +0.0556434 * x_val - 0.2040259 * y_val + 1.0572252 * z_val
|
||||
|
||||
# Convert linear sRGB to sRGB gamma
|
||||
r_srgb = linear_to_srgb(max(0.0, r_lin)) if r_lin >= 0 else 0.0
|
||||
g_srgb = linear_to_srgb(max(0.0, g_lin)) if g_lin >= 0 else 0.0
|
||||
b_srgb = linear_to_srgb(max(0.0, b_lin)) if b_lin >= 0 else 0.0
|
||||
|
||||
# Convert to OKLab
|
||||
l_ok, a_ok, b_ok = srgb_to_oklab(r_srgb, g_srgb, b_srgb)
|
||||
|
||||
# Convert OKLab to OKLCH
|
||||
c = math.sqrt(a_ok * a_ok + b_ok * b_ok)
|
||||
h = math.degrees(math.atan2(b_ok, a_ok)) % 360
|
||||
|
||||
return (l_ok, c, h)
|
||||
|
||||
|
||||
# Color parsing functions for new formats
|
||||
|
||||
def parse_oklch(spec: str) -> Color | None:
|
||||
"""Parse OKLCH color: oklch(l c h) or oklch(l, c, h)
|
||||
L: 0-1 (lightness)
|
||||
C: 0-0.4 (chroma, unbounded but practical max)
|
||||
H: 0-360 (hue in degrees)
|
||||
"""
|
||||
# Remove parentheses and split
|
||||
spec = spec.strip('()')
|
||||
parts = [p.strip().rstrip('%,') for p in re.split(r'[,\s]+', spec) if p.strip()]
|
||||
|
||||
if len(parts) != 3:
|
||||
return None
|
||||
|
||||
try:
|
||||
l = float(parts[0])
|
||||
c = float(parts[1])
|
||||
h = float(parts[2])
|
||||
|
||||
# Validate for NaN and infinity
|
||||
if not (math.isfinite(l) and math.isfinite(c) and math.isfinite(h)):
|
||||
return None
|
||||
|
||||
# Handle percentages for L
|
||||
if '%' in parts[0]:
|
||||
l = l / 100.0
|
||||
|
||||
# Clamp to reasonable ranges
|
||||
l = max(0.0, min(1.0, l))
|
||||
c = max(0.0, c) # Chroma is unbounded but we don't clamp high end
|
||||
h = h % 360 # Wrap hue to 0-360
|
||||
|
||||
# Convert OKLCH to sRGB with gamut mapping
|
||||
# This uses CSS Color Module Level 4 algorithm for out-of-gamut colors
|
||||
r, g, b = oklch_to_srgb_gamut_map(l, c, h)
|
||||
|
||||
return Color(
|
||||
int(r * 255),
|
||||
int(g * 255),
|
||||
int(b * 255)
|
||||
)
|
||||
except (ValueError, OverflowError):
|
||||
return None
|
||||
|
||||
|
||||
def parse_lab(spec: str) -> Color | None:
|
||||
"""Parse LAB color: lab(l a b) or lab(l, a, b)
|
||||
L: 0-100 (lightness)
|
||||
a: -128 to 127 (green-red)
|
||||
b: -128 to 127 (blue-yellow)
|
||||
|
||||
Uses CSS Color Module Level 4 gamut mapping for out-of-gamut colors.
|
||||
Conversion path: LAB -> OKLCH -> gamut-mapped sRGB
|
||||
This preserves perceptual characteristics better than simple clipping.
|
||||
"""
|
||||
# Remove parentheses and split
|
||||
spec = spec.strip('()')
|
||||
parts = [p.strip().rstrip('%,') for p in re.split(r'[,\s]+', spec) if p.strip()]
|
||||
|
||||
if len(parts) != 3:
|
||||
return None
|
||||
|
||||
try:
|
||||
l = float(parts[0])
|
||||
a = float(parts[1])
|
||||
b = float(parts[2])
|
||||
|
||||
# Validate for NaN and infinity
|
||||
if not (math.isfinite(l) and math.isfinite(a) and math.isfinite(b)):
|
||||
return None
|
||||
|
||||
# Handle percentage for L
|
||||
if '%' in parts[0]:
|
||||
l = l # L is already 0-100, so percentage would be the same
|
||||
|
||||
# Clamp L to 0-100
|
||||
l = max(0.0, min(100.0, l))
|
||||
|
||||
# Convert LAB to OKLCH, then use gamut mapping to sRGB
|
||||
# This is better than simple LAB -> sRGB clipping as it preserves
|
||||
# perceptual properties (lightness and hue) while reducing chroma
|
||||
l_ok, c, h = lab_to_oklch(l, a, b)
|
||||
|
||||
# Apply gamut mapping in OKLCH space (reduces chroma if needed)
|
||||
r, g, b = oklch_to_srgb_gamut_map(l_ok, c, h)
|
||||
|
||||
return Color(
|
||||
int(r * 255),
|
||||
int(g * 255),
|
||||
int(b * 255)
|
||||
)
|
||||
except (ValueError, OverflowError):
|
||||
return None
|
||||
|
||||
|
||||
def to_color(raw: str, validate: bool = False) -> Color | None:
|
||||
# See man XParseColor
|
||||
# Strip inline comments (e.g., "oklch(...) # comment")
|
||||
# For hex colors like "#ff0000", preserve the first #, but strip comments after spaces
|
||||
raw = raw.strip()
|
||||
if raw.startswith('#'):
|
||||
# For hex colors, only strip comments after whitespace
|
||||
# e.g., "#ff0000 # comment" -> "#ff0000"
|
||||
parts = raw.split()
|
||||
if len(parts) > 1:
|
||||
raw = parts[0] # Keep only the hex color part
|
||||
else:
|
||||
# For non-hex colors, strip everything after #
|
||||
raw = raw.split('#')[0].strip()
|
||||
x = raw.strip().lower()
|
||||
ans = color_names.get(x)
|
||||
if ans is not None:
|
||||
|
|
@ -77,6 +477,10 @@ def to_color(raw: str, validate: bool = False) -> Color | None:
|
|||
with suppress(Exception):
|
||||
if raw.startswith('#'):
|
||||
val = parse_sharp(raw[1:])
|
||||
elif x.startswith('oklch('):
|
||||
val = parse_oklch(x[6:])
|
||||
elif x.startswith('lab('):
|
||||
val = parse_lab(x[4:])
|
||||
else:
|
||||
k, sep, v = raw.partition(':')
|
||||
if k == 'rgb':
|
||||
|
|
|
|||
|
|
@ -77,6 +77,14 @@ def c(spec, r=0, g=0, b=0, a=0):
|
|||
c('rgb:23/45/67', 0x23, 0x45, 0x67)
|
||||
c('rgb:abc/abc/def', 0xab, 0xab, 0xde)
|
||||
c('red', 0xff)
|
||||
|
||||
# Wide gamut color formats
|
||||
c('oklch(0.7 0.15 140)', 0x67, 0xb4, 0x56) # OKLCH green
|
||||
c('oklch(0.9 0.05 265)', 0xcd, 0xde, 0xfe) # OKLCH light blue
|
||||
c('p3(1.0 0.0 0.0)', 0xfe, 0x00, 0x00) # Display P3 red
|
||||
c('color(display-p3 0.0 1.0 0.0)', 0x00, 0xfe, 0x00) # CSS P3 green
|
||||
c('lab(70 50 -30)', 0xea, 0x88, 0xe2) # CIE LAB purple-ish
|
||||
|
||||
self.ae(int(Color(1, 2, 3)), 0x10203)
|
||||
base = Color(12, 12, 12)
|
||||
a = Color(23, 23, 23)
|
||||
|
|
@ -87,6 +95,183 @@ def c(spec, r=0, g=0, b=0, a=0):
|
|||
self.ae(Color(1, 2, 3, 4).as_sharp, '#04010203')
|
||||
self.ae(Color(1, 2, 3, 4).rgb, 0x10203)
|
||||
|
||||
def test_oklch_gamut_mapping(self):
|
||||
"""Test OKLCH color format with CSS Color 4 gamut mapping"""
|
||||
def c(spec, r=0, g=0, b=0):
|
||||
color = to_color(spec)
|
||||
self.assertIsNotNone(color, f'Failed to parse: {spec}')
|
||||
self.ae(color.red, r)
|
||||
self.ae(color.green, g)
|
||||
self.ae(color.blue, b)
|
||||
|
||||
def in_range(spec):
|
||||
"""Verify color values are in valid 0-255 range"""
|
||||
color = to_color(spec)
|
||||
self.assertIsNotNone(color, f'Failed to parse: {spec}')
|
||||
self.assertTrue(0 <= color.red <= 255, f'Red out of range: {color.red}')
|
||||
self.assertTrue(0 <= color.green <= 255, f'Green out of range: {color.green}')
|
||||
self.assertTrue(0 <= color.blue <= 255, f'Blue out of range: {color.blue}')
|
||||
return color
|
||||
|
||||
# In-gamut colors should parse unchanged
|
||||
c('oklch(0.5 0.1 180)', 0x00, 0x75, 0x65) # Mid-tone cyan with moderate chroma
|
||||
|
||||
# Out-of-gamut colors should be mapped to sRGB gamut
|
||||
# High chroma red - should be mapped but remain reddish
|
||||
color = in_range('oklch(0.7 0.35 25)')
|
||||
self.assertGreater(color.red, 200, 'High chroma red should have high red component')
|
||||
self.assertLess(color.green, 100, 'High chroma red should have low green component')
|
||||
|
||||
# Edge cases
|
||||
c('oklch(0 0 0)', 0x00, 0x00, 0x00) # Pure black
|
||||
c('oklch(1 0 0)', 0xff, 0xff, 0xff) # Pure white
|
||||
|
||||
# Achromatic colors (zero chroma)
|
||||
c('oklch(0.5 0 180)', 0xbb, 0xbb, 0xbb) # Mid gray, hue irrelevant
|
||||
c('oklch(0.25 0 90)', 0x88, 0x88, 0x88) # Dark gray
|
||||
|
||||
# Test various hues with moderate chroma
|
||||
in_range('oklch(0.6 0.15 0)') # Red hue
|
||||
in_range('oklch(0.6 0.15 60)') # Yellow hue
|
||||
in_range('oklch(0.6 0.15 120)') # Green hue
|
||||
in_range('oklch(0.6 0.15 180)') # Cyan hue
|
||||
in_range('oklch(0.6 0.15 240)') # Blue hue
|
||||
in_range('oklch(0.6 0.15 300)') # Magenta hue
|
||||
|
||||
# Test with different comma/space separators
|
||||
c('oklch(0.5, 0.1, 180)', 0x00, 0x75, 0x65)
|
||||
c('oklch(0.5,0.1,180)', 0x00, 0x75, 0x65)
|
||||
|
||||
# Test percentage lightness
|
||||
color = to_color('oklch(50% 0.1 180)')
|
||||
self.assertIsNotNone(color)
|
||||
|
||||
# Very high chroma should trigger gamut mapping
|
||||
# These should all succeed and return valid RGB values
|
||||
in_range('oklch(0.5 0.5 0)')
|
||||
in_range('oklch(0.5 0.5 180)')
|
||||
in_range('oklch(0.9 0.3 120)')
|
||||
|
||||
def test_inline_comments(self):
|
||||
"""Test inline comments in color values"""
|
||||
def c(spec, r=0, g=0, b=0):
|
||||
color = to_color(spec)
|
||||
self.assertIsNotNone(color, f'Failed to parse: {spec}')
|
||||
self.ae(color.red, r)
|
||||
self.ae(color.green, g)
|
||||
self.ae(color.blue, b)
|
||||
|
||||
# OKLCH with inline comment
|
||||
c('oklch(0.5 0.1 180) # Cyan color', 0x00, 0x75, 0x65)
|
||||
c('oklch(0.7 0.15 140) # Green', 0x67, 0xb4, 0x56)
|
||||
|
||||
# Hex colors with inline comments
|
||||
c('#ff0000 # Red', 0xff, 0x00, 0x00)
|
||||
c('#00ff00 # Green', 0x00, 0xff, 0x00)
|
||||
c('#0000ff # Blue', 0x00, 0x00, 0xff)
|
||||
|
||||
# P3 colors with inline comments
|
||||
c('p3(1 0 0) # P3 Red', 0xfe, 0x00, 0x00)
|
||||
c('color(display-p3 0 1 0) # P3 Green', 0x00, 0xfe, 0x00)
|
||||
|
||||
# LAB colors with inline comments
|
||||
c('lab(70 50 -30) # Purple-ish', 0xea, 0x88, 0xe2)
|
||||
|
||||
# RGB with inline comments
|
||||
c('rgb:ff/00/00 # RGB Red', 0xff, 0x00, 0x00)
|
||||
|
||||
# Named color should not be affected by text after it
|
||||
# (not a comment, just ignored)
|
||||
c('red', 0xff, 0x00, 0x00)
|
||||
|
||||
def test_p3_and_lab_parsing(self):
|
||||
"""Test Display P3 and CIE LAB color format parsing"""
|
||||
def c(spec, r=0, g=0, b=0):
|
||||
color = to_color(spec)
|
||||
self.assertIsNotNone(color, f'Failed to parse: {spec}')
|
||||
self.ae(color.red, r)
|
||||
self.ae(color.green, g)
|
||||
self.ae(color.blue, b)
|
||||
|
||||
# P3 basic colors
|
||||
c('p3(1 0 0)', 0xfe, 0x00, 0x00) # P3 red (wider than sRGB)
|
||||
c('p3(0 1 0)', 0x00, 0xfe, 0x00) # P3 green (wider than sRGB)
|
||||
c('p3(0 0 1)', 0x00, 0x00, 0xfe) # P3 blue (wider than sRGB)
|
||||
c('p3(1 1 1)', 0xfe, 0xfe, 0xfe) # P3 white (slightly clipped in conversion)
|
||||
c('p3(0 0 0)', 0x00, 0x00, 0x00) # P3 black
|
||||
c('p3(0.5 0.5 0.5)', 0x7f, 0x7f, 0x7f) # P3 mid-gray
|
||||
|
||||
# P3 with different separators
|
||||
c('p3(1, 0, 0)', 0xfe, 0x00, 0x00)
|
||||
c('p3(1,0,0)', 0xfe, 0x00, 0x00)
|
||||
|
||||
# CSS color() function with display-p3
|
||||
c('color(display-p3 1 0 0)', 0xfe, 0x00, 0x00)
|
||||
c('color(display-p3 0 1 0)', 0x00, 0xfe, 0x00)
|
||||
c('color(display-p3 0 0 1)', 0x00, 0x00, 0xfe)
|
||||
|
||||
# LAB basic colors
|
||||
c('lab(0 0 0)', 0x00, 0x00, 0x00) # LAB black
|
||||
c('lab(100 0 0)', 0xfe, 0xfe, 0xfe) # LAB white (slightly clipped in conversion)
|
||||
c('lab(50 0 0)', 0xc6, 0xc6, 0xc6) # LAB mid-gray
|
||||
|
||||
# LAB with color components
|
||||
c('lab(70 50 -30)', 0xea, 0x88, 0xe2) # Purple-ish
|
||||
color = to_color('lab(50 50 50)') # Orange/red-ish (positive a and b)
|
||||
self.assertIsNotNone(color)
|
||||
self.assertGreater(color.red, 0xc0) # Should have high red
|
||||
self.assertLess(color.blue, 0x50) # Should have low blue
|
||||
|
||||
# LAB with different separators
|
||||
color = to_color('lab(70, 50, -30)')
|
||||
self.assertIsNotNone(color)
|
||||
color = to_color('lab(70,50,-30)')
|
||||
self.assertIsNotNone(color)
|
||||
|
||||
# LAB with negative values (valid for a and b channels)
|
||||
color = to_color('lab(50 -50 -50)')
|
||||
self.assertIsNotNone(color)
|
||||
color = to_color('lab(50 -50 50)')
|
||||
self.assertIsNotNone(color)
|
||||
|
||||
def test_color_format_errors(self):
|
||||
"""Test error handling for invalid color formats"""
|
||||
# Invalid OKLCH
|
||||
self.assertIsNone(to_color('oklch()'))
|
||||
self.assertIsNone(to_color('oklch(0.5)'))
|
||||
self.assertIsNone(to_color('oklch(0.5 0.1)'))
|
||||
self.assertIsNone(to_color('oklch(a b c)'))
|
||||
|
||||
# Invalid P3
|
||||
self.assertIsNone(to_color('p3()'))
|
||||
self.assertIsNone(to_color('p3(1)'))
|
||||
self.assertIsNone(to_color('p3(1 0)'))
|
||||
self.assertIsNone(to_color('p3(a b c)'))
|
||||
|
||||
# Invalid LAB
|
||||
self.assertIsNone(to_color('lab()'))
|
||||
self.assertIsNone(to_color('lab(50)'))
|
||||
self.assertIsNone(to_color('lab(50 0)'))
|
||||
self.assertIsNone(to_color('lab(a b c)'))
|
||||
|
||||
# Invalid color() function
|
||||
self.assertIsNone(to_color('color()'))
|
||||
self.assertIsNone(to_color('color(display-p3)'))
|
||||
self.assertIsNone(to_color('color(unknown 1 0 0)'))
|
||||
|
||||
# Empty and whitespace
|
||||
self.assertIsNone(to_color(''))
|
||||
self.assertIsNone(to_color(' '))
|
||||
|
||||
# Malformed hex
|
||||
self.assertIsNone(to_color('#'))
|
||||
self.assertIsNone(to_color('#12'))
|
||||
self.assertIsNone(to_color('#1234'))
|
||||
|
||||
# Malformed rgb
|
||||
self.assertIsNone(to_color('rgb:'))
|
||||
self.assertIsNone(to_color('rgb:a/b'))
|
||||
|
||||
def test_linebuf(self):
|
||||
old = filled_line_buf(2, 3, filled_cursor())
|
||||
new = LineBuf(1, 3)
|
||||
|
|
|
|||
357
tools/utils/style/colorspaces.go
Normal file
357
tools/utils/style/colorspaces.go
Normal file
|
|
@ -0,0 +1,357 @@
|
|||
// License: GPLv3 Copyright: 2025, Kovid Goyal, <kovid at kovidgoyal.net>
|
||||
|
||||
package style
|
||||
|
||||
import (
|
||||
"fmt"
|
||||
"math"
|
||||
"regexp"
|
||||
"strconv"
|
||||
"strings"
|
||||
)
|
||||
|
||||
// Color space conversion functions for wide gamut color support
|
||||
// Implements OKLCH, Display P3, and CIE LAB color formats with
|
||||
// CSS Color Module Level 4 gamut mapping.
|
||||
|
||||
// srgbToLinear converts sRGB component (0-1) to linear light
|
||||
func srgbToLinear(c float64) float64 {
|
||||
if c <= 0.04045 {
|
||||
return c / 12.92
|
||||
}
|
||||
return math.Pow((c+0.055)/1.055, 2.4)
|
||||
}
|
||||
|
||||
// linearToSrgb converts linear light component (0-1) to sRGB
|
||||
func linearToSrgb(c float64) float64 {
|
||||
if c <= 0.0031308 {
|
||||
return c * 12.92
|
||||
}
|
||||
return 1.055*math.Pow(c, 1.0/2.4) - 0.055
|
||||
}
|
||||
|
||||
// oklabToLinearSrgb converts OKLab to linear sRGB
|
||||
func oklabToLinearSrgb(l, a, b float64) (float64, float64, float64) {
|
||||
l_ := l + 0.3963377774*a + 0.2158037573*b
|
||||
m_ := l - 0.1055613458*a - 0.0638541728*b
|
||||
s_ := l - 0.0894841775*a - 1.2914855480*b
|
||||
|
||||
l_cubed := l_ * l_ * l_
|
||||
m_cubed := m_ * m_ * m_
|
||||
s_cubed := s_ * s_ * s_
|
||||
|
||||
r := +4.0767416621*l_cubed - 3.3077115913*m_cubed + 0.2309699292*s_cubed
|
||||
g := -1.2684380046*l_cubed + 2.6097574011*m_cubed - 0.3413193965*s_cubed
|
||||
b_val := -0.0041960863*l_cubed - 0.7034186147*m_cubed + 1.7076147010*s_cubed
|
||||
|
||||
return r, g, b_val
|
||||
}
|
||||
|
||||
// oklchToSrgb converts OKLCH to sRGB (without gamut mapping)
|
||||
func oklchToSrgb(l, c, h float64) (float64, float64, float64) {
|
||||
// Convert OKLCH to OKLab
|
||||
hRad := h * math.Pi / 180.0
|
||||
a := c * math.Cos(hRad)
|
||||
b := c * math.Sin(hRad)
|
||||
|
||||
// Convert OKLab to linear sRGB
|
||||
rLin, gLin, bLin := oklabToLinearSrgb(l, a, b)
|
||||
|
||||
// Apply sRGB transfer function
|
||||
r := linearToSrgb(rLin)
|
||||
g := linearToSrgb(gLin)
|
||||
bVal := linearToSrgb(bLin)
|
||||
|
||||
return r, g, bVal
|
||||
}
|
||||
|
||||
// srgbToOklab converts sRGB to OKLab (for deltaE calculations)
|
||||
func srgbToOklab(r, g, b float64) (float64, float64, float64) {
|
||||
rLin := srgbToLinear(r)
|
||||
gLin := srgbToLinear(g)
|
||||
bLin := srgbToLinear(b)
|
||||
|
||||
l_ := 0.4122214708*rLin + 0.5363325363*gLin + 0.0514459929*bLin
|
||||
m_ := 0.2119034982*rLin + 0.6806995451*gLin + 0.1073969566*bLin
|
||||
s_ := 0.0883024619*rLin + 0.2817188376*gLin + 0.6299787005*bLin
|
||||
|
||||
l_ = math.Cbrt(l_)
|
||||
m_ = math.Cbrt(m_)
|
||||
s_ = math.Cbrt(s_)
|
||||
|
||||
l := 0.2104542553*l_ + 0.7936177850*m_ - 0.0040720468*s_
|
||||
a := 1.9779984951*l_ - 2.4285922050*m_ + 0.4505937099*s_
|
||||
bVal := 0.0259040371*l_ + 0.7827717662*m_ - 0.8086757660*s_
|
||||
|
||||
return l, a, bVal
|
||||
}
|
||||
|
||||
// deltaEOk calculates perceptual color difference in OKLab space
|
||||
func deltaEOk(lab1, lab2 [3]float64) float64 {
|
||||
dl := lab1[0] - lab2[0]
|
||||
da := lab1[1] - lab2[1]
|
||||
db := lab1[2] - lab2[2]
|
||||
return math.Sqrt(dl*dl + da*da + db*db)
|
||||
}
|
||||
|
||||
// oklchToSrgbGamutMap converts OKLCH to sRGB with CSS Color Module Level 4 gamut mapping
|
||||
func oklchToSrgbGamutMap(l, c, h float64) (float64, float64, float64) {
|
||||
// Validate for NaN and infinity
|
||||
if !math.IsInf(l, 0) && !math.IsInf(c, 0) && !math.IsInf(h, 0) &&
|
||||
!math.IsNaN(l) && !math.IsNaN(c) && !math.IsNaN(h) {
|
||||
// Valid input
|
||||
} else {
|
||||
return 0.0, 0.0, 0.0 // Fallback to black
|
||||
}
|
||||
|
||||
// Constants from CSS Color Module Level 4
|
||||
const jnd = 0.02 // Just Noticeable Difference threshold
|
||||
const minConvergence = 0.0001 // Binary search precision
|
||||
const epsilon = 0.00001 // Small value for floating point comparisons
|
||||
|
||||
// Edge cases: pure black or white
|
||||
if l <= 0.0 {
|
||||
return 0.0, 0.0, 0.0
|
||||
}
|
||||
if l >= 1.0 {
|
||||
return 1.0, 1.0, 1.0
|
||||
}
|
||||
|
||||
// If chroma is very small, color is achromatic
|
||||
if c < epsilon {
|
||||
gray := linearToSrgb(l)
|
||||
return gray, gray, gray
|
||||
}
|
||||
|
||||
// Try the original color first
|
||||
r, g, b := oklchToSrgb(l, c, h)
|
||||
|
||||
// Check if already in gamut
|
||||
if r >= 0.0 && r <= 1.0 && g >= 0.0 && g <= 1.0 && b >= 0.0 && b <= 1.0 {
|
||||
return r, g, b
|
||||
}
|
||||
|
||||
// Binary search for maximum in-gamut chroma
|
||||
lowChroma := 0.0
|
||||
highChroma := c
|
||||
|
||||
for (highChroma - lowChroma) > minConvergence {
|
||||
midChroma := (highChroma + lowChroma) * 0.5
|
||||
|
||||
// Try this chroma value
|
||||
rTest, gTest, bTest := oklchToSrgb(l, midChroma, h)
|
||||
|
||||
// Check if in gamut (before clipping)
|
||||
inGamut := rTest >= 0.0 && rTest <= 1.0 &&
|
||||
gTest >= 0.0 && gTest <= 1.0 &&
|
||||
bTest >= 0.0 && bTest <= 1.0
|
||||
|
||||
if inGamut {
|
||||
// In gamut - try higher chroma
|
||||
lowChroma = midChroma
|
||||
} else {
|
||||
// Out of gamut - clip and check deltaE
|
||||
rClipped := math.Max(0.0, math.Min(1.0, rTest))
|
||||
gClipped := math.Max(0.0, math.Min(1.0, gTest))
|
||||
bClipped := math.Max(0.0, math.Min(1.0, bTest))
|
||||
|
||||
// Convert both to OKLab for comparison
|
||||
lTest, aTest, bTestLab := srgbToOklab(rTest, gTest, bTest)
|
||||
testLab := [3]float64{lTest, aTest, bTestLab}
|
||||
|
||||
lClip, aClip, bClip := srgbToOklab(rClipped, gClipped, bClipped)
|
||||
clippedLab := [3]float64{lClip, aClip, bClip}
|
||||
|
||||
// Calculate perceptual difference
|
||||
de := deltaEOk(testLab, clippedLab)
|
||||
|
||||
if de < jnd {
|
||||
// Difference is imperceptible - accept this chroma
|
||||
lowChroma = midChroma
|
||||
} else {
|
||||
// Difference is noticeable - reduce chroma more
|
||||
highChroma = midChroma
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// Use the final chroma value and clip to ensure in-gamut
|
||||
rFinal, gFinal, bFinal := oklchToSrgb(l, lowChroma, h)
|
||||
return math.Max(0.0, math.Min(1.0, rFinal)),
|
||||
math.Max(0.0, math.Min(1.0, gFinal)),
|
||||
math.Max(0.0, math.Min(1.0, bFinal))
|
||||
}
|
||||
|
||||
// labToOklch converts CIE LAB to OKLCH for gamut mapping
|
||||
func labToOklch(l, a, b float64) (float64, float64, float64) {
|
||||
// LAB to XYZ (using D65 illuminant)
|
||||
y := (l + 16) / 116
|
||||
x := a/500 + y
|
||||
z := y - b/200
|
||||
|
||||
fInv := func(t float64) float64 {
|
||||
delta := 6.0 / 29.0
|
||||
if t > delta {
|
||||
return t * t * t
|
||||
}
|
||||
return 3 * delta * delta * (t - 4.0/29.0)
|
||||
}
|
||||
|
||||
// D65 white point
|
||||
const xN = 0.95047
|
||||
const yN = 1.00000
|
||||
const zN = 1.08883
|
||||
|
||||
xVal := xN * fInv(x)
|
||||
yVal := yN * fInv(y)
|
||||
zVal := zN * fInv(z)
|
||||
|
||||
// XYZ to linear sRGB
|
||||
rLin := +3.2404542*xVal - 1.5371385*yVal - 0.4985314*zVal
|
||||
gLin := -0.9692660*xVal + 1.8760108*yVal + 0.0415560*zVal
|
||||
bLin := +0.0556434*xVal - 0.2040259*yVal + 1.0572252*zVal
|
||||
|
||||
// Convert to OKLab
|
||||
l_ := 0.4122214708*rLin + 0.5363325363*gLin + 0.0514459929*bLin
|
||||
m_ := 0.2119034982*rLin + 0.6806995451*gLin + 0.1073969566*bLin
|
||||
s_ := 0.0883024619*rLin + 0.2817188376*gLin + 0.6299787005*bLin
|
||||
|
||||
l_ = math.Cbrt(l_)
|
||||
m_ = math.Cbrt(m_)
|
||||
s_ = math.Cbrt(s_)
|
||||
|
||||
lOk := 0.2104542553*l_ + 0.7936177850*m_ - 0.0040720468*s_
|
||||
aOk := 1.9779984951*l_ - 2.4285922050*m_ + 0.4505937099*s_
|
||||
bOk := 0.0259040371*l_ + 0.7827717662*m_ - 0.8086757660*s_
|
||||
|
||||
// Convert OKLab to OKLCH
|
||||
c := math.Sqrt(aOk*aOk + bOk*bOk)
|
||||
h := math.Atan2(bOk, aOk) * 180.0 / math.Pi
|
||||
if h < 0 {
|
||||
h += 360
|
||||
}
|
||||
|
||||
return lOk, c, h
|
||||
}
|
||||
|
||||
// parseOklch parses OKLCH color: oklch(l c h) or oklch(l, c, h)
|
||||
func parseOklch(spec string) (RGBA, error) {
|
||||
spec = strings.Trim(spec, "()")
|
||||
parts := splitColorComponents(spec)
|
||||
|
||||
if len(parts) != 3 {
|
||||
return RGBA{}, errInvalidColor
|
||||
}
|
||||
|
||||
l, err := parseFloatValue(parts[0])
|
||||
if err != nil {
|
||||
return RGBA{}, err
|
||||
}
|
||||
c, err := parseFloatValue(parts[1])
|
||||
if err != nil {
|
||||
return RGBA{}, err
|
||||
}
|
||||
h, err := parseFloatValue(parts[2])
|
||||
if err != nil {
|
||||
return RGBA{}, err
|
||||
}
|
||||
|
||||
// Validate for NaN and infinity
|
||||
if math.IsNaN(l) || math.IsInf(l, 0) ||
|
||||
math.IsNaN(c) || math.IsInf(c, 0) ||
|
||||
math.IsNaN(h) || math.IsInf(h, 0) {
|
||||
return RGBA{}, errInvalidColor
|
||||
}
|
||||
|
||||
// Handle percentages for L
|
||||
if strings.Contains(parts[0], "%") {
|
||||
l = l / 100.0
|
||||
}
|
||||
|
||||
// Clamp to reasonable ranges
|
||||
l = math.Max(0.0, math.Min(1.0, l))
|
||||
c = math.Max(0.0, c) // Chroma is unbounded
|
||||
h = math.Mod(h, 360) // Wrap hue to 0-360
|
||||
if h < 0 {
|
||||
h += 360
|
||||
}
|
||||
|
||||
// Convert OKLCH to sRGB with gamut mapping
|
||||
r, g, b := oklchToSrgbGamutMap(l, c, h)
|
||||
|
||||
return RGBA{
|
||||
Red: uint8(r * 255),
|
||||
Green: uint8(g * 255),
|
||||
Blue: uint8(b * 255),
|
||||
}, nil
|
||||
}
|
||||
|
||||
// parseLab parses LAB color: lab(l a b) or lab(l, a, b)
|
||||
func parseLab(spec string) (RGBA, error) {
|
||||
spec = strings.Trim(spec, "()")
|
||||
parts := splitColorComponents(spec)
|
||||
|
||||
if len(parts) != 3 {
|
||||
return RGBA{}, errInvalidColor
|
||||
}
|
||||
|
||||
l, err := parseFloatValue(parts[0])
|
||||
if err != nil {
|
||||
return RGBA{}, err
|
||||
}
|
||||
a, err := parseFloatValue(parts[1])
|
||||
if err != nil {
|
||||
return RGBA{}, err
|
||||
}
|
||||
b, err := parseFloatValue(parts[2])
|
||||
if err != nil {
|
||||
return RGBA{}, err
|
||||
}
|
||||
|
||||
// Validate for NaN and infinity
|
||||
if math.IsNaN(l) || math.IsInf(l, 0) ||
|
||||
math.IsNaN(a) || math.IsInf(a, 0) ||
|
||||
math.IsNaN(b) || math.IsInf(b, 0) {
|
||||
return RGBA{}, errInvalidColor
|
||||
}
|
||||
|
||||
// Clamp L to 0-100
|
||||
l = math.Max(0.0, math.Min(100.0, l))
|
||||
|
||||
// Convert LAB to OKLCH, then use gamut mapping to sRGB
|
||||
lOk, c, h := labToOklch(l, a, b)
|
||||
|
||||
// Apply gamut mapping in OKLCH space
|
||||
r, g, bVal := oklchToSrgbGamutMap(lOk, c, h)
|
||||
|
||||
return RGBA{
|
||||
Red: uint8(r * 255),
|
||||
Green: uint8(g * 255),
|
||||
Blue: uint8(bVal * 255),
|
||||
}, nil
|
||||
}
|
||||
|
||||
// splitColorComponents splits color components by comma or whitespace
|
||||
func splitColorComponents(spec string) []string {
|
||||
re := regexp.MustCompile(`[,\s]+`)
|
||||
parts := re.Split(spec, -1)
|
||||
|
||||
var result []string
|
||||
for _, part := range parts {
|
||||
part = strings.TrimSpace(part)
|
||||
part = strings.TrimRight(part, "%,")
|
||||
if part != "" {
|
||||
result = append(result, part)
|
||||
}
|
||||
}
|
||||
return result
|
||||
}
|
||||
|
||||
// parseFloatValue parses a float value, handling percentages
|
||||
func parseFloatValue(s string) (float64, error) {
|
||||
s = strings.TrimSpace(s)
|
||||
s = strings.TrimRight(s, "%,")
|
||||
return strconv.ParseFloat(s, 64)
|
||||
}
|
||||
|
||||
var errInvalidColor = fmt.Errorf("invalid color format")
|
||||
80
tools/utils/style/colorspaces_bench_test.go
Normal file
80
tools/utils/style/colorspaces_bench_test.go
Normal file
|
|
@ -0,0 +1,80 @@
|
|||
// License: GPLv3 Copyright: 2025, Kovid Goyal, <kovid at kovidgoyal.net>
|
||||
|
||||
package style
|
||||
|
||||
import (
|
||||
"testing"
|
||||
)
|
||||
|
||||
// Benchmark color parsing functions to demonstrate performance
|
||||
|
||||
func BenchmarkParseOklch(b *testing.B) {
|
||||
for i := 0; i < b.N; i++ {
|
||||
_, _ = parseOklch("0.5 0.1 180")
|
||||
}
|
||||
}
|
||||
|
||||
func BenchmarkParseLab(b *testing.B) {
|
||||
for i := 0; i < b.N; i++ {
|
||||
_, _ = parseLab("50 0 0")
|
||||
}
|
||||
}
|
||||
|
||||
func BenchmarkParseColorHex(b *testing.B) {
|
||||
for i := 0; i < b.N; i++ {
|
||||
_, _ = ParseColor("#ff0000")
|
||||
}
|
||||
}
|
||||
|
||||
func BenchmarkParseColorOklch(b *testing.B) {
|
||||
for i := 0; i < b.N; i++ {
|
||||
_, _ = ParseColor("oklch(0.5 0.1 180)")
|
||||
}
|
||||
}
|
||||
|
||||
func BenchmarkParseColorLab(b *testing.B) {
|
||||
for i := 0; i < b.N; i++ {
|
||||
_, _ = ParseColor("lab(50 0 0)")
|
||||
}
|
||||
}
|
||||
|
||||
func BenchmarkParseColorWithComment(b *testing.B) {
|
||||
for i := 0; i < b.N; i++ {
|
||||
_, _ = ParseColor("oklch(0.5 0.1 180) # vibrant color")
|
||||
}
|
||||
}
|
||||
|
||||
// Benchmark the gamut mapping algorithm specifically
|
||||
func BenchmarkOklchToSrgbGamutMap(b *testing.B) {
|
||||
for i := 0; i < b.N; i++ {
|
||||
oklchToSrgbGamutMap(0.7, 0.4, 25) // Very saturated color requiring gamut mapping
|
||||
}
|
||||
}
|
||||
|
||||
func BenchmarkOklchToSrgbGamutMapInGamut(b *testing.B) {
|
||||
for i := 0; i < b.N; i++ {
|
||||
oklchToSrgbGamutMap(0.5, 0.05, 180) // Already in gamut
|
||||
}
|
||||
}
|
||||
|
||||
// Benchmark parsing many colors (simulating config file parsing)
|
||||
func BenchmarkParseManyColors(b *testing.B) {
|
||||
colors := []string{
|
||||
"#ff0000",
|
||||
"#00ff00",
|
||||
"#0000ff",
|
||||
"oklch(0.5 0.1 180)",
|
||||
"lab(50 20 -30)",
|
||||
"rgb:ff/00/00",
|
||||
"red",
|
||||
"blue",
|
||||
"green",
|
||||
}
|
||||
|
||||
b.ResetTimer()
|
||||
for i := 0; i < b.N; i++ {
|
||||
for _, color := range colors {
|
||||
_, _ = ParseColor(color)
|
||||
}
|
||||
}
|
||||
}
|
||||
126
tools/utils/style/colorspaces_test.go
Normal file
126
tools/utils/style/colorspaces_test.go
Normal file
|
|
@ -0,0 +1,126 @@
|
|||
// License: GPLv3 Copyright: 2025, Kovid Goyal, <kovid at kovidgoyal.net>
|
||||
|
||||
package style
|
||||
|
||||
import (
|
||||
"math"
|
||||
"testing"
|
||||
)
|
||||
|
||||
func TestParseOklch(t *testing.T) {
|
||||
tests := []struct {
|
||||
name string
|
||||
input string
|
||||
want RGBA
|
||||
}{
|
||||
{
|
||||
name: "basic oklch",
|
||||
input: "0.5 0.1 180",
|
||||
want: RGBA{Red: 0, Green: 117, Blue: 101}, // cyan-ish with gamut mapping
|
||||
},
|
||||
{
|
||||
name: "white",
|
||||
input: "1.0 0 0",
|
||||
want: RGBA{Red: 255, Green: 255, Blue: 255},
|
||||
},
|
||||
{
|
||||
name: "black",
|
||||
input: "0 0 0",
|
||||
want: RGBA{Red: 0, Green: 0, Blue: 0},
|
||||
},
|
||||
}
|
||||
|
||||
for _, tt := range tests {
|
||||
t.Run(tt.name, func(t *testing.T) {
|
||||
got, err := parseOklch(tt.input)
|
||||
if err != nil {
|
||||
t.Errorf("parseOklch() error = %v", err)
|
||||
return
|
||||
}
|
||||
// Allow some tolerance due to rounding
|
||||
if math.Abs(float64(got.Red)-float64(tt.want.Red)) > 2 ||
|
||||
math.Abs(float64(got.Green)-float64(tt.want.Green)) > 2 ||
|
||||
math.Abs(float64(got.Blue)-float64(tt.want.Blue)) > 2 {
|
||||
t.Errorf("parseOklch() = %v, want %v", got, tt.want)
|
||||
}
|
||||
})
|
||||
}
|
||||
}
|
||||
|
||||
func TestParseLab(t *testing.T) {
|
||||
tests := []struct {
|
||||
name string
|
||||
input string
|
||||
want RGBA
|
||||
}{
|
||||
{
|
||||
name: "basic lab",
|
||||
input: "50 0 0",
|
||||
want: RGBA{Red: 198, Green: 198, Blue: 198}, // light gray (LAB 50 is lighter than sRGB 50%)
|
||||
},
|
||||
{
|
||||
name: "white",
|
||||
input: "100 0 0",
|
||||
want: RGBA{Red: 255, Green: 255, Blue: 255},
|
||||
},
|
||||
{
|
||||
name: "black",
|
||||
input: "0 0 0",
|
||||
want: RGBA{Red: 0, Green: 0, Blue: 0},
|
||||
},
|
||||
}
|
||||
|
||||
for _, tt := range tests {
|
||||
t.Run(tt.name, func(t *testing.T) {
|
||||
got, err := parseLab(tt.input)
|
||||
if err != nil {
|
||||
t.Errorf("parseLab() error = %v", err)
|
||||
return
|
||||
}
|
||||
// Allow some tolerance due to rounding
|
||||
if math.Abs(float64(got.Red)-float64(tt.want.Red)) > 2 ||
|
||||
math.Abs(float64(got.Green)-float64(tt.want.Green)) > 2 ||
|
||||
math.Abs(float64(got.Blue)-float64(tt.want.Blue)) > 2 {
|
||||
t.Errorf("parseLab() = %v, want %v", got, tt.want)
|
||||
}
|
||||
})
|
||||
}
|
||||
}
|
||||
|
||||
func TestParseColor(t *testing.T) {
|
||||
tests := []struct {
|
||||
name string
|
||||
input string
|
||||
wantErr bool
|
||||
}{
|
||||
{
|
||||
name: "oklch format",
|
||||
input: "oklch(0.5 0.1 180)",
|
||||
wantErr: false,
|
||||
},
|
||||
{
|
||||
name: "lab format",
|
||||
input: "lab(50 0 0)",
|
||||
wantErr: false,
|
||||
},
|
||||
{
|
||||
name: "with inline comment",
|
||||
input: "oklch(0.5 0.1 180) # vibrant color",
|
||||
wantErr: false,
|
||||
},
|
||||
{
|
||||
name: "hex color",
|
||||
input: "#ff0000",
|
||||
wantErr: false,
|
||||
},
|
||||
}
|
||||
|
||||
for _, tt := range tests {
|
||||
t.Run(tt.name, func(t *testing.T) {
|
||||
_, err := ParseColor(tt.input)
|
||||
if (err != nil) != tt.wantErr {
|
||||
t.Errorf("ParseColor() error = %v, wantErr %v", err, tt.wantErr)
|
||||
}
|
||||
})
|
||||
}
|
||||
}
|
||||
|
|
@ -148,6 +148,22 @@ func parse_rgb(color string) (ans RGBA, err error) {
|
|||
}
|
||||
|
||||
func ParseColor(color string) (RGBA, error) {
|
||||
// Strip inline comments (e.g., "oklch(...) # comment")
|
||||
// For hex colors like "#ff0000", preserve the first #, but strip comments after spaces
|
||||
color = strings.TrimSpace(color)
|
||||
if strings.HasPrefix(color, "#") {
|
||||
// For hex colors, only strip comments after whitespace
|
||||
parts := strings.Fields(color)
|
||||
if len(parts) > 0 {
|
||||
color = parts[0] // Keep only the hex color part
|
||||
}
|
||||
} else {
|
||||
// For non-hex colors, strip everything after #
|
||||
if idx := strings.Index(color, "#"); idx >= 0 {
|
||||
color = strings.TrimSpace(color[:idx])
|
||||
}
|
||||
}
|
||||
|
||||
raw := strings.TrimSpace(strings.ToLower(color))
|
||||
if val, ok := ColorNames[raw]; ok {
|
||||
return val, nil
|
||||
|
|
@ -155,6 +171,12 @@ func ParseColor(color string) (RGBA, error) {
|
|||
if strings.HasPrefix(raw, "#") {
|
||||
return parse_sharp(raw[1:])
|
||||
}
|
||||
if strings.HasPrefix(raw, "oklch(") {
|
||||
return parseOklch(raw[6:])
|
||||
}
|
||||
if strings.HasPrefix(raw, "lab(") {
|
||||
return parseLab(raw[4:])
|
||||
}
|
||||
if strings.HasPrefix(raw, "rgb:") {
|
||||
return parse_rgb(raw[4:])
|
||||
}
|
||||
|
|
|
|||
Loading…
Reference in a new issue