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Diffstat (limited to 'servo/components/style/color/mod.rs')
| -rw-r--r-- | servo/components/style/color/mod.rs | 465 |
1 files changed, 465 insertions, 0 deletions
diff --git a/servo/components/style/color/mod.rs b/servo/components/style/color/mod.rs new file mode 100644 index 0000000000..f8ceee9703 --- /dev/null +++ b/servo/components/style/color/mod.rs @@ -0,0 +1,465 @@ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at https://mozilla.org/MPL/2.0/. */ + +//! Color support functions. + +/// cbindgen:ignore +pub mod convert; +pub mod mix; + +use std::fmt::{self, Write}; +use style_traits::{CssWriter, ToCss}; + +/// The 3 components that make up a color. (Does not include the alpha component) +#[derive(Copy, Clone, Debug, MallocSizeOf, PartialEq, ToShmem)] +#[repr(C)] +pub struct ColorComponents(pub f32, pub f32, pub f32); + +impl ColorComponents { + /// Apply a function to each of the 3 components of the color. + pub fn map(self, f: impl Fn(f32) -> f32) -> Self { + Self(f(self.0), f(self.1), f(self.2)) + } +} + +/// A color space representation in the CSS specification. +/// +/// https://drafts.csswg.org/css-color-4/#typedef-color-space +#[derive( + Clone, + Copy, + Debug, + Eq, + MallocSizeOf, + Parse, + PartialEq, + ToAnimatedValue, + ToComputedValue, + ToCss, + ToResolvedValue, + ToShmem, +)] +#[repr(u8)] +pub enum ColorSpace { + /// A color specified in the sRGB color space with either the rgb/rgba(..) + /// functions or the newer color(srgb ..) function. If the color(..) + /// function is used, the AS_COLOR_FUNCTION flag will be set. Examples: + /// "color(srgb 0.691 0.139 0.259)", "rgb(176, 35, 66)" + Srgb = 0, + /// A color specified in the Hsl notation in the sRGB color space, e.g. + /// "hsl(289.18 93.136% 65.531%)" + /// https://drafts.csswg.org/css-color-4/#the-hsl-notation + Hsl, + /// A color specified in the Hwb notation in the sRGB color space, e.g. + /// "hwb(740deg 20% 30%)" + /// https://drafts.csswg.org/css-color-4/#the-hwb-notation + Hwb, + /// A color specified in the Lab color format, e.g. + /// "lab(29.2345% 39.3825 20.0664)". + /// https://w3c.github.io/csswg-drafts/css-color-4/#lab-colors + Lab, + /// A color specified in the Lch color format, e.g. + /// "lch(29.2345% 44.2 27)". + /// https://w3c.github.io/csswg-drafts/css-color-4/#lch-colors + Lch, + /// A color specified in the Oklab color format, e.g. + /// "oklab(40.101% 0.1147 0.0453)". + /// https://w3c.github.io/csswg-drafts/css-color-4/#lab-colors + Oklab, + /// A color specified in the Oklch color format, e.g. + /// "oklch(40.101% 0.12332 21.555)". + /// https://w3c.github.io/csswg-drafts/css-color-4/#lch-colors + Oklch, + /// A color specified with the color(..) function and the "srgb-linear" + /// color space, e.g. "color(srgb-linear 0.435 0.017 0.055)". + SrgbLinear, + /// A color specified with the color(..) function and the "display-p3" + /// color space, e.g. "color(display-p3 0.84 0.19 0.72)". + DisplayP3, + /// A color specified with the color(..) function and the "a98-rgb" color + /// space, e.g. "color(a98-rgb 0.44091 0.49971 0.37408)". + A98Rgb, + /// A color specified with the color(..) function and the "prophoto-rgb" + /// color space, e.g. "color(prophoto-rgb 0.36589 0.41717 0.31333)". + ProphotoRgb, + /// A color specified with the color(..) function and the "rec2020" color + /// space, e.g. "color(rec2020 0.42210 0.47580 0.35605)". + Rec2020, + /// A color specified with the color(..) function and the "xyz-d50" color + /// space, e.g. "color(xyz-d50 0.2005 0.14089 0.4472)". + XyzD50, + /// A color specified with the color(..) function and the "xyz-d65" or "xyz" + /// color space, e.g. "color(xyz-d65 0.21661 0.14602 0.59452)". + /// NOTE: https://drafts.csswg.org/css-color-4/#resolving-color-function-values + /// specifies that `xyz` is an alias for the `xyz-d65` color space. + #[parse(aliases = "xyz")] + XyzD65, +} + +impl ColorSpace { + /// Returns whether this is a `<rectangular-color-space>`. + #[inline] + pub fn is_rectangular(&self) -> bool { + !self.is_polar() + } + + /// Returns whether this is a `<polar-color-space>`. + #[inline] + pub fn is_polar(&self) -> bool { + matches!(self, Self::Hsl | Self::Hwb | Self::Lch | Self::Oklch) + } + + /// Returns an index of the hue component in the color space, otherwise + /// `None`. + #[inline] + pub fn hue_index(&self) -> Option<usize> { + match self { + Self::Hsl | Self::Hwb => Some(0), + Self::Lch | Self::Oklch => Some(2), + + _ => { + debug_assert!(!self.is_polar()); + None + }, + } + } +} + +bitflags! { + /// Flags used when serializing colors. + #[derive(Clone, Copy, Default, MallocSizeOf, PartialEq, ToShmem)] + #[repr(C)] + pub struct ColorFlags : u8 { + /// If set, serializes sRGB colors into `color(srgb ...)` instead of + /// `rgba(...)`. + const AS_COLOR_FUNCTION = 1 << 0; + /// Whether the 1st color component is `none`. + const C1_IS_NONE = 1 << 1; + /// Whether the 2nd color component is `none`. + const C2_IS_NONE = 1 << 2; + /// Whether the 3rd color component is `none`. + const C3_IS_NONE = 1 << 3; + /// Whether the alpha component is `none`. + const ALPHA_IS_NONE = 1 << 4; + } +} + +/// An absolutely specified color, using either rgb(), rgba(), lab(), lch(), +/// oklab(), oklch() or color(). +#[derive(Copy, Clone, Debug, MallocSizeOf, PartialEq, ToShmem)] +#[repr(C)] +pub struct AbsoluteColor { + /// The 3 components that make up colors in any color space. + pub components: ColorComponents, + /// The alpha component of the color. + pub alpha: f32, + /// The current color space that the components represent. + pub color_space: ColorSpace, + /// Extra flags used durring serialization of this color. + pub flags: ColorFlags, +} + +/// Given an [`AbsoluteColor`], return the 4 float components as the type given, +/// e.g.: +/// +/// ```rust +/// let srgb = AbsoluteColor::new(ColorSpace::Srgb, 1.0, 0.0, 0.0, 0.0); +/// let floats = color_components_as!(&srgb, [f32; 4]); // [1.0, 0.0, 0.0, 0.0] +/// ``` +macro_rules! color_components_as { + ($c:expr, $t:ty) => {{ + // This macro is not an inline function, because we can't use the + // generic type ($t) in a constant expression as per: + // https://github.com/rust-lang/rust/issues/76560 + const_assert_eq!(std::mem::size_of::<$t>(), std::mem::size_of::<[f32; 4]>()); + const_assert_eq!(std::mem::align_of::<$t>(), std::mem::align_of::<[f32; 4]>()); + const_assert!(std::mem::size_of::<AbsoluteColor>() >= std::mem::size_of::<$t>()); + const_assert_eq!( + std::mem::align_of::<AbsoluteColor>(), + std::mem::align_of::<$t>() + ); + + std::mem::transmute::<&ColorComponents, &$t>(&$c.components) + }}; +} + +impl AbsoluteColor { + /// Create a new [`AbsoluteColor`] with the given [`ColorSpace`] and + /// components. + pub fn new(color_space: ColorSpace, components: ColorComponents, alpha: f32) -> Self { + let mut components = components; + + // Lightness must not be less than 0. + if matches!( + color_space, + ColorSpace::Lab | ColorSpace::Lch | ColorSpace::Oklab | ColorSpace::Oklch + ) { + components.0 = components.0.max(0.0); + } + + // Chroma must not be less than 0. + if matches!(color_space, ColorSpace::Lch | ColorSpace::Oklch) { + components.1 = components.1.max(0.0); + } + + Self { + components, + alpha: alpha.clamp(0.0, 1.0), + color_space, + flags: ColorFlags::empty(), + } + } + + /// Create a new [`AbsoluteColor`] from rgba values in the sRGB color space. + pub fn srgb(red: f32, green: f32, blue: f32, alpha: f32) -> Self { + Self::new(ColorSpace::Srgb, ColorComponents(red, green, blue), alpha) + } + + /// Create a new transparent color. + pub fn transparent() -> Self { + Self::srgb(0.0, 0.0, 0.0, 0.0) + } + + /// Create a new opaque black color. + pub fn black() -> Self { + Self::srgb(0.0, 0.0, 0.0, 1.0) + } + + /// Create a new opaque white color. + pub fn white() -> Self { + Self::srgb(1.0, 1.0, 1.0, 1.0) + } + + /// Return all the components of the color in an array. (Includes alpha) + #[inline] + pub fn raw_components(&self) -> &[f32; 4] { + unsafe { color_components_as!(self, [f32; 4]) } + } + + /// Returns true if this color is in one of the legacy color formats. + #[inline] + pub fn is_legacy_color(&self) -> bool { + // rgb(), rgba(), hsl(), hsla(), hwb(), hwba() + match self.color_space { + ColorSpace::Srgb => !self.flags.contains(ColorFlags::AS_COLOR_FUNCTION), + ColorSpace::Hsl | ColorSpace::Hwb => true, + _ => false, + } + } + + /// Return the alpha component. + #[inline] + pub fn alpha(&self) -> f32 { + self.alpha + } + + /// Convert this color to the specified color space. + pub fn to_color_space(&self, color_space: ColorSpace) -> Self { + use ColorSpace::*; + + if self.color_space == color_space { + return self.clone(); + } + + // We have simplified conversions that do not need to convert to XYZ + // first. This improves performance, because it skips 2 matrix + // multiplications and reduces float rounding errors. + match (self.color_space, color_space) { + (Srgb, Hsl) => { + return Self::new( + color_space, + convert::rgb_to_hsl(&self.components), + self.alpha, + ); + }, + + (Srgb, Hwb) => { + return Self::new( + color_space, + convert::rgb_to_hwb(&self.components), + self.alpha, + ); + }, + + (Hsl, Srgb) => { + return Self::new( + color_space, + convert::hsl_to_rgb(&self.components), + self.alpha, + ); + }, + + (Hwb, Srgb) => { + return Self::new( + color_space, + convert::hwb_to_rgb(&self.components), + self.alpha, + ); + }, + + (Lab, Lch) | (Oklab, Oklch) => { + return Self::new( + color_space, + convert::lab_to_lch(&self.components), + self.alpha, + ); + }, + + (Lch, Lab) | (Oklch, Oklab) => { + return Self::new( + color_space, + convert::lch_to_lab(&self.components), + self.alpha, + ); + }, + + _ => {}, + } + + let (xyz, white_point) = match self.color_space { + Lab => convert::to_xyz::<convert::Lab>(&self.components), + Lch => convert::to_xyz::<convert::Lch>(&self.components), + Oklab => convert::to_xyz::<convert::Oklab>(&self.components), + Oklch => convert::to_xyz::<convert::Oklch>(&self.components), + Srgb => convert::to_xyz::<convert::Srgb>(&self.components), + Hsl => convert::to_xyz::<convert::Hsl>(&self.components), + Hwb => convert::to_xyz::<convert::Hwb>(&self.components), + SrgbLinear => convert::to_xyz::<convert::SrgbLinear>(&self.components), + DisplayP3 => convert::to_xyz::<convert::DisplayP3>(&self.components), + A98Rgb => convert::to_xyz::<convert::A98Rgb>(&self.components), + ProphotoRgb => convert::to_xyz::<convert::ProphotoRgb>(&self.components), + Rec2020 => convert::to_xyz::<convert::Rec2020>(&self.components), + XyzD50 => convert::to_xyz::<convert::XyzD50>(&self.components), + XyzD65 => convert::to_xyz::<convert::XyzD65>(&self.components), + }; + + let result = match color_space { + Lab => convert::from_xyz::<convert::Lab>(&xyz, white_point), + Lch => convert::from_xyz::<convert::Lch>(&xyz, white_point), + Oklab => convert::from_xyz::<convert::Oklab>(&xyz, white_point), + Oklch => convert::from_xyz::<convert::Oklch>(&xyz, white_point), + Srgb => convert::from_xyz::<convert::Srgb>(&xyz, white_point), + Hsl => convert::from_xyz::<convert::Hsl>(&xyz, white_point), + Hwb => convert::from_xyz::<convert::Hwb>(&xyz, white_point), + SrgbLinear => convert::from_xyz::<convert::SrgbLinear>(&xyz, white_point), + DisplayP3 => convert::from_xyz::<convert::DisplayP3>(&xyz, white_point), + A98Rgb => convert::from_xyz::<convert::A98Rgb>(&xyz, white_point), + ProphotoRgb => convert::from_xyz::<convert::ProphotoRgb>(&xyz, white_point), + Rec2020 => convert::from_xyz::<convert::Rec2020>(&xyz, white_point), + XyzD50 => convert::from_xyz::<convert::XyzD50>(&xyz, white_point), + XyzD65 => convert::from_xyz::<convert::XyzD65>(&xyz, white_point), + }; + + Self::new(color_space, result, self.alpha) + } +} + +impl From<cssparser::PredefinedColorSpace> for ColorSpace { + fn from(value: cssparser::PredefinedColorSpace) -> Self { + match value { + cssparser::PredefinedColorSpace::Srgb => ColorSpace::Srgb, + cssparser::PredefinedColorSpace::SrgbLinear => ColorSpace::SrgbLinear, + cssparser::PredefinedColorSpace::DisplayP3 => ColorSpace::DisplayP3, + cssparser::PredefinedColorSpace::A98Rgb => ColorSpace::A98Rgb, + cssparser::PredefinedColorSpace::ProphotoRgb => ColorSpace::ProphotoRgb, + cssparser::PredefinedColorSpace::Rec2020 => ColorSpace::Rec2020, + cssparser::PredefinedColorSpace::XyzD50 => ColorSpace::XyzD50, + cssparser::PredefinedColorSpace::XyzD65 => ColorSpace::XyzD65, + } + } +} + +impl ToCss for AbsoluteColor { + fn to_css<W>(&self, dest: &mut CssWriter<W>) -> fmt::Result + where + W: Write, + { + macro_rules! value_or_none { + ($v:expr,$flag:tt) => {{ + if self.flags.contains(ColorFlags::$flag) { + None + } else { + Some($v) + } + }}; + } + + let maybe_c1 = value_or_none!(self.components.0, C1_IS_NONE); + let maybe_c2 = value_or_none!(self.components.1, C2_IS_NONE); + let maybe_c3 = value_or_none!(self.components.2, C3_IS_NONE); + let maybe_alpha = value_or_none!(self.alpha, ALPHA_IS_NONE); + + match self.color_space { + ColorSpace::Hsl => { + let rgb = convert::hsl_to_rgb(&self.components); + Self::new(ColorSpace::Srgb, rgb, self.alpha).to_css(dest) + }, + + ColorSpace::Hwb => { + let rgb = convert::hwb_to_rgb(&self.components); + + Self::new(ColorSpace::Srgb, rgb, self.alpha).to_css(dest) + }, + + ColorSpace::Srgb if !self.flags.contains(ColorFlags::AS_COLOR_FUNCTION) => { + // Althought we are passing Option<_> in here, the to_css fn + // knows that the "none" keyword is not supported in the + // rgb/rgba legacy syntax. + cssparser::ToCss::to_css( + &cssparser::RGBA::from_floats(maybe_c1, maybe_c2, maybe_c3, maybe_alpha), + dest, + ) + }, + ColorSpace::Lab => cssparser::ToCss::to_css( + &cssparser::Lab::new(maybe_c1, maybe_c2, maybe_c3, maybe_alpha), + dest, + ), + ColorSpace::Lch => cssparser::ToCss::to_css( + &cssparser::Lch::new(maybe_c1, maybe_c2, maybe_c3, maybe_alpha), + dest, + ), + ColorSpace::Oklab => cssparser::ToCss::to_css( + &cssparser::Oklab::new(maybe_c1, maybe_c2, maybe_c3, maybe_alpha), + dest, + ), + ColorSpace::Oklch => cssparser::ToCss::to_css( + &cssparser::Oklch::new(maybe_c1, maybe_c2, maybe_c3, maybe_alpha), + dest, + ), + _ => { + let color_space = match self.color_space { + ColorSpace::Srgb => { + debug_assert!( + self.flags.contains(ColorFlags::AS_COLOR_FUNCTION), + "The case without this flag should be handled in the wrapping match case!!" + ); + + cssparser::PredefinedColorSpace::Srgb + }, + ColorSpace::SrgbLinear => cssparser::PredefinedColorSpace::SrgbLinear, + ColorSpace::DisplayP3 => cssparser::PredefinedColorSpace::DisplayP3, + ColorSpace::A98Rgb => cssparser::PredefinedColorSpace::A98Rgb, + ColorSpace::ProphotoRgb => cssparser::PredefinedColorSpace::ProphotoRgb, + ColorSpace::Rec2020 => cssparser::PredefinedColorSpace::Rec2020, + ColorSpace::XyzD50 => cssparser::PredefinedColorSpace::XyzD50, + ColorSpace::XyzD65 => cssparser::PredefinedColorSpace::XyzD65, + + _ => { + unreachable!("other color spaces do not support color() syntax") + }, + }; + + let color_function = cssparser::ColorFunction { + color_space, + c1: maybe_c1, + c2: maybe_c2, + c3: maybe_c3, + alpha: maybe_alpha, + }; + let color = cssparser::Color::ColorFunction(color_function); + cssparser::ToCss::to_css(&color, dest) + }, + } + } +} |