primase_core/
material_parameters.rs

1//! Material defaults beyond PBR. Names and meanings belong to the source lowering, not to core.
2use crate::{Component, Entity, Geometry, JsonError, World};
3use serde::{Deserialize, Serialize};
4use serde_json::Value;
5use std::collections::BTreeMap;
6
7/// `core.material_parameters`, on a material: named rest values, one to four finite floats each.
8/// A `ClipTarget::MaterialParameter` channel replaces a named value at its declared width. With
9/// no driving channel the material retains this default. Core assigns no visibility, colour-space,
10/// buffer-address or event-layout meaning to a name; the game's lowering states those separately.
11#[derive(Clone, Debug, Default, PartialEq, Serialize, Deserialize)]
12pub struct MaterialParameters(pub BTreeMap<String, Vec<f32>>);
13
14impl Component for MaterialParameters {
15    const NAME: &'static str = "core.material_parameters";
16    const GEOMETRY: Geometry = Geometry::None;
17    fn to_json(&self) -> Result<Option<Value>, JsonError> {
18        crate::json::to_value(self).map(Some)
19    }
20    fn apply_linear(&self, _l: &crate::Linear) -> crate::world::Linearity<Self> {
21        crate::world::Linearity::Invariant
22    }
23    fn verify(&self, _e: Entity, _w: &World) -> Result<(), String> {
24        for (name, values) in &self.0 {
25            if name.trim().is_empty() {
26                return Err("empty material parameter name".into());
27            }
28            if !(1..=4).contains(&values.len()) {
29                return Err(format!("{name}: {} values, expected 1 to 4", values.len()));
30            }
31            if !values.iter().all(|value| value.is_finite()) {
32                return Err(format!("{name}: non-finite value"));
33            }
34        }
35        Ok(())
36    }
37}
38
39#[cfg(test)]
40mod tests {
41    use super::*;
42    #[test]
43    fn widths_are_one_to_four_and_values_are_finite() {
44        let mut w = World::new();
45        let e = w.spawn();
46        for width in 0..=5 {
47            let p = MaterialParameters(BTreeMap::from([("opaque name".into(), vec![1.; width])]));
48            assert_eq!(p.verify(e, &w).is_ok(), (1..=4).contains(&width));
49        }
50        for value in [f32::NAN, f32::INFINITY, f32::NEG_INFINITY] {
51            let p = MaterialParameters(BTreeMap::from([("value".into(), vec![value])]));
52            assert!(p.verify(e, &w).is_err());
53            assert!(p.to_json().is_err());
54        }
55        assert!(
56            MaterialParameters(BTreeMap::from([(" ".into(), vec![0.])]))
57                .verify(e, &w)
58                .is_err()
59        );
60        assert!(MaterialParameters::default().verify(e, &w).is_ok());
61    }
62    #[test]
63    fn json_round_trip_preserves_names_values_and_signed_zero() {
64        let p = MaterialParameters(BTreeMap::from([
65            ("a tint".into(), vec![0.1, 0.2, 0.3, 1.]),
66            ("a scalar".into(), vec![-0.]),
67        ]));
68        let restored: MaterialParameters = serde_json::from_value(p.to_json().unwrap().unwrap()).unwrap();
69        assert_eq!(restored, p);
70        assert_eq!(restored.0["a scalar"][0].to_bits(), (-0f32).to_bits());
71        // Material parameters describe no primitive or local-space geometry and therefore have no remap.
72        assert!(p.remap_primitives(&[2, 0, 2]).is_none());
73    }
74}
primase_core/material_parameters.rs

primase_core/
material_parameters.rs
