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/// Color space in which compositing arithmetic is evaluated.
#[derive(Copy, Clone, Debug, Default, Eq, PartialEq)]
pub enum BlendSpace {
/// Convert sRGB-encoded inputs to linear light before blending.
#[default]
LinearLight,
/// Blend directly in sRGB-encoded component space.
SrgbEncoded,
}
impl BlendSpace {
pub(crate) const fn shader_value(self) -> f32 {
match self {
Self::LinearLight => 0.0,
Self::SrgbEncoded => 1.0,
}
}
}
/// RGB blend operation applied before Porter-Duff source-over.
///
/// Formulas follow W3C Compositing and Blending Level 1, evaluated in the renderer's
/// [`BlendSpace`]. The first twelve are separable; `Hue`, `Saturation`, `Color` and
/// `Luminosity` are not. `PlusLighter` is the Level 2 additive operator.
#[derive(Copy, Clone, Debug, Default, Eq, Hash, PartialEq)]
pub enum BlendMode {
/// Preserve the source color.
#[default]
Normal,
/// Multiply source and backdrop components.
Multiply,
/// Inverse-multiply source and backdrop components.
Screen,
/// Multiply dark backdrop regions and screen light regions.
Overlay,
/// The darker of source and backdrop, per channel.
Darken,
/// The lighter of source and backdrop, per channel.
Lighten,
/// Brighten the backdrop to reflect the source.
ColorDodge,
/// Darken the backdrop to reflect the source.
ColorBurn,
/// Multiply or screen, depending on the source.
HardLight,
/// Darken or lighten, depending on the source: a diffused hard light.
SoftLight,
/// The absolute difference of source and backdrop.
Difference,
/// Like difference, with lower contrast.
Exclusion,
/// The source's hue with the backdrop's saturation and luminosity.
Hue,
/// The source's saturation with the backdrop's hue and luminosity.
Saturation,
/// The source's hue and saturation with the backdrop's luminosity.
Color,
/// The source's luminosity with the backdrop's hue and saturation.
Luminosity,
/// Premultiplied source plus backdrop, color and alpha clamped to 1.
PlusLighter,
}
impl BlendMode {
/// Every mode: Level 1 in specification order, then `PlusLighter`.
pub const ALL: [Self; 17] = [
Self::Normal,
Self::Multiply,
Self::Screen,
Self::Overlay,
Self::Darken,
Self::Lighten,
Self::ColorDodge,
Self::ColorBurn,
Self::HardLight,
Self::SoftLight,
Self::Difference,
Self::Exclusion,
Self::Hue,
Self::Saturation,
Self::Color,
Self::Luminosity,
Self::PlusLighter,
];
/// The index `composite.wesl` switches on.
pub(crate) const fn shader_value(self) -> f32 {
match self {
Self::Normal => 0.0,
Self::Multiply => 1.0,
Self::Screen => 2.0,
Self::Overlay => 3.0,
Self::Darken => 4.0,
Self::Lighten => 5.0,
Self::ColorDodge => 6.0,
Self::ColorBurn => 7.0,
Self::HardLight => 8.0,
Self::SoftLight => 9.0,
Self::Difference => 10.0,
Self::Exclusion => 11.0,
Self::Hue => 12.0,
Self::Saturation => 13.0,
Self::Color => 14.0,
Self::Luminosity => 15.0,
Self::PlusLighter => 16.0,
}
}
}