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use std::collections::BTreeMap;
use crate::{Animated, EffectResourceId, Interpolation};
use serde::{Deserialize, Serialize};
/// Artistic blend operation stored independently from a renderer implementation.
///
/// The modes are those of W3C Compositing and Blending Level 1 (the CSS
/// `mix-blend-mode` values), with the specification's formulas.
#[derive(Copy, Clone, Debug, Default, Deserialize, Eq, PartialEq, Serialize)]
#[cfg_attr(feature = "schema", derive(schemars::JsonSchema))]
#[serde(rename_all = "snake_case")]
pub enum ClipBlendMode {
/// Preserve source color and apply source-over coverage.
#[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,
}
/// Serializable value supplied to one runtime effect parameter.
#[derive(Copy, Clone, Debug, Deserialize, PartialEq, Serialize)]
#[cfg_attr(feature = "schema", derive(schemars::JsonSchema))]
#[serde(deny_unknown_fields)]
#[serde(tag = "type", content = "value", rename_all = "snake_case")]
pub enum EffectValue {
/// One finite scalar.
Float(f32),
/// Two finite components, normally in normalized coordinates.
Vec2([f32; 2]),
/// Four finite components that are not a color, such as per-channel
/// thresholds; they keyframe component by component.
Vec4([f32; 4]),
/// Straight (not premultiplied), sRGB-encoded RGBA components in the
/// inclusive unit interval, as a color picker shows them.
Color([f32; 4]),
/// Index into an effect definition's enum choices.
Enum(u32),
/// Boolean toggle.
Bool(bool),
}
impl EffectValue {
/// Whether keyframes of this type interpolate. `Enum` and `Bool` values
/// have nothing between them, so their keyframes only hold.
#[must_use]
pub const fn interpolates(&self) -> bool {
matches!(
self,
Self::Float(_) | Self::Vec2(_) | Self::Vec4(_) | Self::Color(_)
)
}
/// Whether `other` is the same type of value.
#[must_use]
pub fn same_type(&self, other: &Self) -> bool {
core::mem::discriminant(self) == core::mem::discriminant(other)
}
pub(crate) fn is_valid(&self) -> bool {
match self {
Self::Float(value) => value.is_finite(),
Self::Vec2(values) => values.iter().all(|value| value.is_finite()),
Self::Vec4(values) => values.iter().all(|value| value.is_finite()),
Self::Color(values) => values
.iter()
.all(|value| value.is_finite() && (0.0..=1.0).contains(value)),
Self::Enum(_) | Self::Bool(_) => true,
}
}
}
/// One versioned runtime effect invocation: a composition's effect or
/// transition node, or a timeline transition.
#[derive(Clone, Debug, Deserialize, PartialEq, Serialize)]
#[cfg_attr(feature = "schema", derive(schemars::JsonSchema))]
#[serde(deny_unknown_fields)]
pub struct ClipEffect {
/// Stable effect definition identifier.
pub id: String,
/// Exact effect definition version required by the project.
pub version: u32,
/// Named parameter values, constant or keyframed. Omitted entries use
/// definition defaults.
///
/// Keyframe times are composition times in a composition node and
/// timeline times in a timeline transition. A parameter's keyframes all
/// have one value type, and `enum` and `bool` keyframes only hold. An
/// interpolated value that a timing curve carries past the parameter's
/// range is clamped to it; an authored value outside it is an error.
#[serde(default)]
pub params: BTreeMap<String, Animated<EffectValue>>,
/// Named external resources matched against the effect definition.
#[serde(default)]
pub resources: BTreeMap<String, EffectResourceId>,
}
impl ClipEffect {
pub(crate) fn is_valid(&self) -> bool {
!self.id.is_empty()
&& self.version > 0
&& self
.params
.iter()
.all(|(name, value)| valid_binding_name(name) && valid_param(value))
&& self
.resources
.iter()
.all(|(name, id)| valid_binding_name(name) && !id.as_str().is_empty())
}
}
/// Whether `name` can name what an effect binds: a parameter, a resource, or
/// a named input. An ASCII letter or `_`, then letters, digits, or `_`.
pub(crate) fn valid_binding_name(name: &str) -> bool {
let mut bytes = name.bytes();
bytes
.next()
.is_some_and(|byte| byte.is_ascii_alphabetic() || byte == b'_')
&& bytes.all(|byte| byte.is_ascii_alphanumeric() || byte == b'_')
}
pub(crate) fn valid_param(animation: &Animated<EffectValue>) -> bool {
match animation {
Animated::Constant { value } => value.is_valid(),
Animated::Keyframes { keyframes } => {
let Some(first) = keyframes.first() else {
return false;
};
crate::animation::valid_keyframes(keyframes)
&& keyframes.iter().all(|keyframe| {
keyframe.value.is_valid()
&& keyframe.value.same_type(&first.value)
&& (first.value.interpolates()
|| keyframe.interpolation == Interpolation::Hold)
})
}
}
}