Struct Requirements 

pub struct Requirements {
    pub required: Vec<PropertyId>,
    pub optional_with_defaults: Vec<(PropertyId, MaterialValue)>,
}

Declares what a ShadingStrategy needs from a Material before it can pack it. Checked once when a material is assigned to a strategy, so mistakes surface immediately instead of as a panic deep in pack().

Fields

required: Vec<PropertyId>

optional_with_defaults: Vec<(PropertyId, MaterialValue)>

Implementations

impl Requirements

pub fn new() -> Self

pub fn require(self, id: PropertyId) -> Self

pub fn optional(self, id: PropertyId, default: MaterialValue) -> Self

pub fn validate( &self, material: &Material, strategy_name: &'static str, ) -> Result<(), MaterialError>

Validates that material has every required property. Does not check types - individual MaterialValue::as_* accessors are the source of truth for type coercion inside pack().

pub fn get_or_default<'a>( &'a self, material: &'a Material, id: PropertyId, ) -> Option<&'a MaterialValue>

Reads a property from material, falling back to this requirement’s declared default for optional properties. Returns None if the property is neither present nor has a declared default.

Trait Implementations

impl Clone for Requirements

fn clone(&self) -> Requirements

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Requirements

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for Requirements

fn default() -> Requirements

Returns the “default value” for a type.