animsmith-core 0.1.0

//! Measurements: the raw per-clip metric map that `measure` emits and
//! `lint` judges. Kept separate from findings so pipelines (e.g. a
//! bake's measured sidecar) can pin their own contracts to the numbers.

use crate::config::Config;
use crate::metrics::{MetricGrids, foot_cycle_metrics, root_motion_speed_mps, rotation_range_deg};
use crate::model::SceneAssets;
use crate::profile::ResolvedRoles;
use serde::{Deserialize, Serialize};
use std::collections::{BTreeMap, BTreeSet};

/// Rotation ranges below this are not recorded (matches the incubating
/// pipeline's convention).
pub const MIN_RECORDED_ROTATION_DEG: f64 = 0.1;

/// Axis-aligned bounding box of a mesh's positions, in scene units
/// (metres, Y-up — the converted space every loader hands over).
#[derive(Debug, Clone, Serialize, Deserialize)]
#[non_exhaustive]
pub struct Aabb {
    /// Minimum XYZ corner.
    pub min: [f32; 3],
    /// Maximum XYZ corner.
    pub max: [f32; 3],
}

/// Static (animation-independent) measurements of one mesh carried in
/// [`SceneAssets`]. Emitted by `measure` when the input carried geometry
/// (both the FBX and glTF loaders fill `SceneAssets`). Vertex data is
/// read as authored — indexed meshes count their unique vertices,
/// unindexed meshes count every triangle corner.
#[derive(Debug, Clone, Serialize, Deserialize)]
#[non_exhaustive]
pub struct MeshMeasurements {
    /// Mesh name.
    pub name: String,
    /// Total position count across the mesh's primitives.
    pub vertex_count: u32,
    /// Bounding box over every primitive position; `None` for a mesh
    /// with no positions.
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub aabb: Option<Aabb>,
    /// Highest number of non-zero skin influences on any single vertex
    /// (`0` for an unskinned mesh).
    pub max_joints_per_vertex: u32,
    /// Min/max of the per-vertex skin-weight sums (≈1.0 for a
    /// well-formed skin); `None` for an unskinned mesh.
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub weight_sum_min: Option<f64>,
    /// Maximum finite per-vertex skin-weight sum; `None` for an
    /// unskinned mesh.
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub weight_sum_max: Option<f64>,
}

/// Measure every mesh in the document's [`SceneAssets`], in document
/// order. Returns an empty vector when no geometry was loaded (the
/// lint/inspect path and asset-less files), so callers that don't carry
/// assets emit nothing extra. Hostile geometry never crashes or leaks a
/// non-finite bound: non-finite positions and weight sums are dropped
/// from the AABB / weight-sum stats (and still flow to the `nan` check),
/// so the emitted numbers are always finite.
pub fn measure_meshes(assets: &SceneAssets) -> Vec<MeshMeasurements> {
    assets
        .meshes
        .iter()
        .map(|mesh| {
            let mut vertex_count = 0u32;
            let mut min = [f32::INFINITY; 3];
            let mut max = [f32::NEG_INFINITY; 3];
            let mut any_finite_position = false;
            let mut max_joints_per_vertex = 0u32;
            let mut weight_sum_min = f64::INFINITY;
            let mut weight_sum_max = f64::NEG_INFINITY;
            let mut any_finite_weight = false;

            for prim in &mesh.primitives {
                vertex_count = vertex_count.saturating_add(prim.positions.len() as u32);
                for p in &prim.positions {
                    let a = p.to_array();
                    // Only finite vertices contribute to the box; a NaN
                    // or infinite coordinate is garbage geometry (it
                    // still lints via the `nan` check) and must never
                    // reach the output — a non-finite bound serializes to
                    // JSON `null`, which violates the numeric schema.
                    if a.iter().all(|c| c.is_finite()) {
                        any_finite_position = true;
                        for i in 0..3 {
                            min[i] = min[i].min(a[i]);
                            max[i] = max[i].max(a[i]);
                        }
                    }
                }
                for w in &prim.weights {
                    let influences = w.iter().filter(|&&x| x > 0.0).count() as u32;
                    max_joints_per_vertex = max_joints_per_vertex.max(influences);
                    let sum: f64 = w.iter().map(|&x| x as f64).sum();
                    if sum.is_finite() {
                        any_finite_weight = true;
                        weight_sum_min = weight_sum_min.min(sum);
                        weight_sum_max = weight_sum_max.max(sum);
                    }
                }
            }

            MeshMeasurements {
                name: mesh.name.clone(),
                vertex_count,
                aabb: any_finite_position.then_some(Aabb { min, max }),
                max_joints_per_vertex,
                weight_sum_min: any_finite_weight.then_some(weight_sum_min),
                weight_sum_max: any_finite_weight.then_some(weight_sum_max),
            }
        })
        .collect()
}

/// Role-dependent gait metrics for one clip.
#[derive(Debug, Clone, Serialize, Deserialize)]
#[non_exhaustive]
pub struct GaitMeasurement {
    /// Stride-anchor phase in `[0,1)`; see
    /// [`crate::metrics::FootCycleMetrics::gait_phase`].
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub phase: Option<f64>,
    /// Peak-to-peak L−R foot-height swing (metres).
    pub lr_amplitude_m: f64,
}

/// Measurements for one clip in the `measure` output map.
#[derive(Debug, Clone, Serialize, Deserialize)]
#[non_exhaustive]
pub struct ClipMeasurements {
    /// Clip duration in seconds.
    pub duration_s: f64,
    /// Keyframe count of the longest channel. This also selects the uniform
    /// metric-grid resolution, but it is not an authored frame-rate value.
    pub frame_count: u32,
    /// Bones with at least one keyframed channel, sorted.
    pub animated_bones: Vec<String>,
    /// Max rotation deviation (degrees) of each bone from its first
    /// keyed rotation. Bones under [`MIN_RECORDED_ROTATION_DEG`] are
    /// omitted.
    pub bone_rotation_range_deg: BTreeMap<String, f64>,
    /// Loop wrap discontinuity ratio; needs hips + foot roles and a
    /// real stride. See [`crate::metrics::FootCycleMetrics`].
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub loop_seam_ratio: Option<f64>,
    /// Gait stride anchor; needs a left and a right foot role.
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub gait: Option<GaitMeasurement>,
    /// Horizontal root displacement ÷ duration (m/s); needs the Root
    /// (or Hips) role.
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub speed_mps: Option<f64>,
}

/// Measure every clip using shared metric pose grids. Role-dependent
/// metrics (loop seam, gait, root-motion speed) are present only where
/// the roles resolve; pass an empty [`ResolvedRoles`] to skip them.
///
/// This returns clip measurements only. Call [`measure_meshes`] separately
/// when the pipeline also needs geometry measurements. Clip names are map
/// keys and therefore must be unique; a later duplicate replaces an earlier
/// entry.
pub fn measure_document(
    grids: &MetricGrids<'_>,
    roles: &ResolvedRoles,
    config: &Config,
) -> BTreeMap<String, ClipMeasurements> {
    let doc = grids.document();
    let min_stride_step_m = config.loop_seam_min_stride_step_m();
    doc.clips
        .iter()
        .enumerate()
        .map(|(clip_index, clip)| {
            let mut animated: BTreeSet<String> = BTreeSet::new();
            let mut rotation_range: BTreeMap<String, f64> = BTreeMap::new();
            let mut frame_count = 0usize;

            for track in &clip.tracks {
                let Some(bone) = doc.skeleton.bones.get(track.bone) else {
                    continue;
                };
                if track.key_count() == 0 {
                    continue;
                }
                animated.insert(bone.name.clone());
                frame_count = frame_count.max(track.key_count());

                if let Some(max_deg) = rotation_range_deg(track)
                    && max_deg >= MIN_RECORDED_ROTATION_DEG
                {
                    let entry = rotation_range.entry(bone.name.clone()).or_insert(0.0);
                    *entry = entry.max(max_deg);
                }
            }

            let grid = grids.grid(clip_index);
            let cycle = grid
                .as_ref()
                .and_then(|g| foot_cycle_metrics(g, roles, min_stride_step_m));
            let speed_mps = grid.as_ref().and_then(|g| root_motion_speed_mps(g, roles));

            (
                clip.name.clone(),
                ClipMeasurements {
                    duration_s: clip.duration_s,
                    frame_count: frame_count as u32,
                    animated_bones: animated.into_iter().collect(),
                    bone_rotation_range_deg: rotation_range,
                    loop_seam_ratio: cycle.as_ref().and_then(|c| c.loop_seam_ratio),
                    gait: cycle.map(|c| GaitMeasurement {
                        phase: c.gait_phase,
                        lr_amplitude_m: c.lr_amplitude_m,
                    }),
                    speed_mps,
                },
            )
        })
        .collect()
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::model::{
        Bone, Clip, Document, Interpolation, MeshAsset, Primitive, Property, Skeleton, Track,
        TrackValues, Transform,
    };
    use crate::profile::Role;
    use glam::{Quat, Vec3};

    fn mesh(name: &str, primitives: Vec<Primitive>) -> SceneAssets {
        SceneAssets {
            meshes: vec![MeshAsset {
                name: name.into(),
                node: 0,
                primitives,
                skin_joints: vec![],
                skin_ibms: vec![],
            }],
            materials: vec![],
        }
    }

    #[test]
    fn skinned_mesh_measures_bbox_joints_and_weight_sums() {
        // Four positions with an analytic AABB of (0,0,0)..(2,3,4).
        let prim = Primitive {
            positions: vec![
                Vec3::new(0.0, 0.0, 0.0),
                Vec3::new(2.0, 0.0, 0.0),
                Vec3::new(0.0, 3.0, 0.0),
                Vec3::new(0.0, 0.0, 4.0),
            ],
            // Influence counts 1, 2, 3, 3 → max 3; weight sums 1.0, 1.0,
            // 1.0, 0.9 → min 0.9, max 1.0.
            weights: vec![
                [1.0, 0.0, 0.0, 0.0],
                [0.5, 0.5, 0.0, 0.0],
                [0.4, 0.3, 0.3, 0.0],
                [0.3, 0.3, 0.3, 0.0],
            ],
            joints: vec![[0, 0, 0, 0]; 4],
            ..Primitive::default()
        };
        let m = &measure_meshes(&mesh("body", vec![prim]))[0];

        assert_eq!(m.name, "body");
        assert_eq!(m.vertex_count, 4);
        let aabb = m.aabb.as_ref().expect("positions present");
        assert_eq!(aabb.min, [0.0, 0.0, 0.0]);
        assert_eq!(aabb.max, [2.0, 3.0, 4.0]);
        assert_eq!(m.max_joints_per_vertex, 3);
        // f32 weights summed in f64 carry rounding; compare with tolerance.
        assert!((m.weight_sum_min.unwrap() - 0.9).abs() < 1e-6);
        assert!((m.weight_sum_max.unwrap() - 1.0).abs() < 1e-6);
    }

    #[test]
    fn unskinned_mesh_has_bbox_but_no_weight_stats() {
        let prim = Primitive {
            positions: vec![Vec3::new(-1.0, -2.0, -3.0), Vec3::new(1.0, 2.0, 3.0)],
            ..Primitive::default()
        };
        let m = &measure_meshes(&mesh("prop", vec![prim]))[0];

        assert_eq!(m.vertex_count, 2);
        assert_eq!(m.aabb.as_ref().unwrap().min, [-1.0, -2.0, -3.0]);
        assert_eq!(m.max_joints_per_vertex, 0);
        assert_eq!(m.weight_sum_min, None, "no skin ⇒ no weight-sum");
        assert_eq!(m.weight_sum_max, None);
    }

    #[test]
    fn empty_mesh_reports_no_bbox() {
        let m = &measure_meshes(&mesh("hollow", vec![Primitive::default()]))[0];
        assert_eq!(m.vertex_count, 0);
        assert!(m.aabb.is_none(), "no positions ⇒ no bounding box");
    }

    #[test]
    fn non_finite_position_is_dropped_from_the_bbox() {
        // A vertex with any non-finite coordinate is garbage geometry:
        // it is dropped whole (not folded per-axis), so the box stays
        // the finite extent — and never emits a non-finite bound.
        let prim = Primitive {
            positions: vec![
                Vec3::new(0.0, 0.0, 0.0),
                Vec3::new(f32::NAN, 5.0, 0.0),
                Vec3::new(f32::INFINITY, 9.0, 0.0),
                Vec3::new(2.0, 3.0, 0.0),
            ],
            ..Primitive::default()
        };
        let m = &measure_meshes(&mesh("nan", vec![prim]))[0];
        let aabb = m.aabb.as_ref().unwrap();
        // Only the two finite vertices contribute; the NaN/Inf rows drop
        // out, so their 5.0 / 9.0 do NOT reach the box.
        assert_eq!(aabb.min, [0.0, 0.0, 0.0]);
        assert_eq!(aabb.max, [2.0, 3.0, 0.0]);
        assert!(
            aabb.min.iter().chain(&aabb.max).all(|c| c.is_finite()),
            "no non-finite bound is ever emitted"
        );
    }

    #[test]
    fn all_non_finite_positions_yield_no_bbox() {
        // Every vertex non-finite ⇒ no finite contribution ⇒ `aabb` is
        // omitted, not an inf/-inf box that serializes to JSON `null`.
        let prim = Primitive {
            positions: vec![Vec3::splat(f32::NAN), Vec3::splat(f32::INFINITY)],
            ..Primitive::default()
        };
        let m = &measure_meshes(&mesh("allnan", vec![prim]))[0];
        assert_eq!(m.vertex_count, 2, "count still reflects the vertices");
        assert!(
            m.aabb.is_none(),
            "no finite vertex ⇒ no box (never null bounds)"
        );
    }

    #[test]
    fn non_finite_weight_sum_is_omitted() {
        // A NaN weight makes its sum non-finite; it must not surface as a
        // JSON-null weight-sum bound.
        let prim = Primitive {
            positions: vec![Vec3::ZERO, Vec3::ONE],
            weights: vec![[0.5, 0.5, 0.0, 0.0], [f32::NAN, 0.0, 0.0, 0.0]],
            ..Primitive::default()
        };
        let m = &measure_meshes(&mesh("nanw", vec![prim]))[0];
        // The one finite sum (1.0) is kept; the NaN sum is skipped.
        assert_eq!(m.weight_sum_min, Some(1.0));
        assert_eq!(m.weight_sum_max, Some(1.0));
    }

    #[test]
    fn all_non_finite_weight_sums_yield_no_weight_stats() {
        // Every weight sum non-finite ⇒ no finite contribution ⇒ both
        // bounds omitted, not an inf/-inf pair that serializes to `null`.
        let prim = Primitive {
            positions: vec![Vec3::ZERO, Vec3::ONE],
            weights: vec![[f32::NAN, 0.0, 0.0, 0.0], [f32::INFINITY, 0.0, 0.0, 0.0]],
            ..Primitive::default()
        };
        let m = &measure_meshes(&mesh("allnanw", vec![prim]))[0];
        assert_eq!(m.weight_sum_min, None, "no finite weight sum ⇒ omitted");
        assert_eq!(m.weight_sum_max, None);
        // max_joints_per_vertex still counts the non-zero influences.
        assert_eq!(m.max_joints_per_vertex, 1);
    }

    #[test]
    fn vertex_count_sums_across_primitives() {
        let a = Primitive {
            positions: vec![Vec3::ZERO; 3],
            ..Primitive::default()
        };
        let b = Primitive {
            positions: vec![Vec3::ONE; 5],
            ..Primitive::default()
        };
        let m = &measure_meshes(&mesh("multi", vec![a, b]))[0];
        assert_eq!(m.vertex_count, 8, "3 + 5 corners across two primitives");
    }

    #[test]
    fn later_duplicate_clip_name_replaces_earlier_measurement() {
        let earlier = Clip {
            name: "duplicate".into(),
            duration_s: 1.0,
            tracks: vec![
                Track {
                    bone: 0,
                    property: Property::Rotation,
                    interpolation: Interpolation::Linear,
                    times: vec![0.0, 0.5, 1.0],
                    values: TrackValues::Quats(vec![
                        Quat::IDENTITY,
                        Quat::from_rotation_x(0.25),
                        Quat::from_rotation_x(0.5),
                    ]),
                },
                Track {
                    bone: 0,
                    property: Property::Translation,
                    interpolation: Interpolation::Linear,
                    times: vec![0.0, 0.5, 1.0],
                    values: TrackValues::Vec3s(vec![Vec3::ZERO, Vec3::Z * 0.5, Vec3::Z]),
                },
                Track {
                    bone: 1,
                    property: Property::Translation,
                    interpolation: Interpolation::Linear,
                    times: vec![0.0, 0.5, 1.0],
                    values: TrackValues::Vec3s(vec![
                        Vec3::new(-0.1, -1.0, 0.0),
                        Vec3::new(-0.1, -0.9, 0.15),
                        Vec3::new(-0.1, -1.0, 0.0),
                    ]),
                },
                Track {
                    bone: 2,
                    property: Property::Translation,
                    interpolation: Interpolation::Linear,
                    times: vec![0.0, 0.5, 1.0],
                    values: TrackValues::Vec3s(vec![
                        Vec3::new(0.1, -1.0, 0.0),
                        Vec3::new(0.1, -1.1, -0.15),
                        Vec3::new(0.1, -1.0, 0.0),
                    ]),
                },
            ],
        };
        let later = Clip {
            name: "duplicate".into(),
            duration_s: 2.0,
            tracks: vec![Track {
                bone: 0,
                property: Property::Translation,
                interpolation: Interpolation::Linear,
                times: vec![0.0, 2.0],
                values: TrackValues::Vec3s(vec![Vec3::ZERO, Vec3::X]),
            }],
        };
        let skeleton = Skeleton {
            bones: vec![
                Bone {
                    name: "hips".into(),
                    parent: None,
                    rest: Transform::IDENTITY,
                    inverse_bind: None,
                },
                Bone {
                    name: "left_foot".into(),
                    parent: Some(0),
                    rest: Transform::IDENTITY,
                    inverse_bind: None,
                },
                Bone {
                    name: "right_foot".into(),
                    parent: Some(0),
                    rest: Transform::IDENTITY,
                    inverse_bind: None,
                },
            ],
        };
        let roles = ResolvedRoles::from_names(
            &skeleton,
            [
                (Role::Hips, "hips".into()),
                (Role::LeftFoot, "left_foot".into()),
                (Role::RightFoot, "right_foot".into()),
            ],
        );
        let earlier_doc = Document {
            skeleton: skeleton.clone(),
            clips: vec![earlier.clone()],
            ..Document::default()
        };
        let earlier_grids = MetricGrids::new(&earlier_doc);
        let earlier_measurement =
            &measure_document(&earlier_grids, &roles, &Config::default())["duplicate"];
        assert!(earlier_measurement.loop_seam_ratio.is_some());
        assert!(earlier_measurement.gait.is_some());
        assert!(earlier_measurement.speed_mps.is_some());

        let doc = Document {
            skeleton,
            clips: vec![earlier, later],
            ..Document::default()
        };
        let grids = MetricGrids::new(&doc);
        let measurements = measure_document(&grids, &roles, &Config::default());

        assert_eq!(
            serde_json::to_value(measurements).expect("duplicate measurements serialize"),
            serde_json::json!({
                "duplicate": {
                    "duration_s": 2.0,
                    "frame_count": 2,
                    "animated_bones": ["hips"],
                    "bone_rotation_range_deg": {},
                }
            })
        );
    }
}