HumanoidRetargeter/Core/Formats/Gltf/GltfChannel.cs
A small internal class representing a decoded GLTF animation channel. It stores the target node index, whether the channel is a rotation or translation, arrays of keyframe times and flattened values, interpolation mode, and provides computed properties for component count, elements per key, and key count.
#nullable enable annotations
using System;
using System.Collections.Generic;
using System.Numerics;
using System.Text;
using System.Text.Json;
namespace HumanoidRetargeter.Core.Formats.Gltf;
using Vector3 = System.Numerics.Vector3; // s&box compat: shadow engine's global-namespace Vector3 (see Code/HumanoidRetargeter/Assembly.cs)
/// <summary>One decoded animation channel: keyframe times + values for one node property.</summary>
internal sealed class GltfChannel
{
public required int NodeIndex;
public required bool IsRotation; // true = rotation (VEC4 quat), false = translation (VEC3)
public required float[] Times; // seconds, ascending
public required float[] Values; // flattened; 4 (or 3) floats per element
public required string Interpolation; // LINEAR / STEP / CUBICSPLINE
/// <summary>Floats per element (3 translation / 4 rotation).</summary>
public int Comps => IsRotation ? 4 : 3;
/// <summary>Elements stored per key: CUBICSPLINE keys carry in-tangent/value/out-tangent.</summary>
public int ElementsPerKey => Interpolation == "CUBICSPLINE" ? 3 : 1;
/// <summary>Number of keys.</summary>
public int KeyCount => Times.Length;
}