RoboticArms/Library/PackageCache/com.unity.splines@d3e1e500c9a0/Runtime/ISpline.cs
2025-11-17 15:16:36 +07:00

100 lines
4.0 KiB
C#

using System;
using System.Collections.Generic;
using Unity.Mathematics;
namespace UnityEngine.Splines
{
/// <summary>
/// A key-value pair associating a distance to interpolation ratio ('t') value. This is used when evaluating Spline
/// attributes to ensure uniform distribution of sampling points.
/// </summary>
/// <seealso cref="CurveUtility.CalculateCurveLengths"/>
[Serializable]
public struct DistanceToInterpolation
{
/// <summary>
/// Distance in Unity units.
/// </summary>
public float Distance;
/// <summary>
/// A normalized interpolation ratio ('t').
/// </summary>
public float T;
internal static readonly DistanceToInterpolation Invalid = new () { Distance = -1f, T = -1f };
}
/// <summary>
/// This interface defines a collection of knot indices that should be considered disconnected from the following
/// knot indices when creating a <see cref="BezierCurve"/>.
/// </summary>
public interface IHasEmptyCurves
{
/// <summary>
/// A collection of knot indices that should be considered degenerate curves for the purpose of creating a
/// non-interpolated gap between curves.
/// </summary>
public IReadOnlyList<int> EmptyCurves { get; }
}
/// <summary>
/// ISpline defines the interface from which Spline types inherit.
/// </summary>
public interface ISpline : IReadOnlyList<BezierKnot>
{
/// <summary>
/// Whether the spline is open (has a start and end point) or closed (forms an unbroken loop).
/// </summary>
bool Closed { get; }
/// <summary>
/// Return the sum of all curve lengths, accounting for <see cref="Closed"/> state.
/// </summary>
/// <returns>
/// Returns the sum length of all curves composing this spline, accounting for closed state.
/// </returns>
float GetLength();
/// <summary>
/// Get a <see cref="BezierCurve"/> from a knot index.
/// </summary>
/// <param name="index">The knot index that serves as the first control point for this curve.</param>
/// <returns>
/// A <see cref="BezierCurve"/> formed by the knot at index and the next knot.
/// </returns>
public BezierCurve GetCurve(int index);
/// <summary>
/// Return the length of a curve.
/// </summary>
/// <param name="index">The index of the curve for which the length needs to be retrieved.</param>
/// <seealso cref="GetLength"/>
/// <returns>
/// Returns the length of the curve of index 'index' in the spline.
/// </returns>
public float GetCurveLength(int index);
/// <summary>
/// Return the up vector for a t ratio on the curve. Contrary to <see cref="SplineUtility.EvaluateUpVector"/>,
/// this method uses cached values when possible for better performance when accessing
/// these values regularly.
/// </summary>
/// <param name="index">The index of the curve for which the length needs to be retrieved.</param>
/// <param name="t">A value between 0 and 1 representing the ratio along the curve.</param>
/// <returns>
/// Returns the up vector at the t ratio of the curve of index 'index'.
/// </returns>
public float3 GetCurveUpVector(int index, float t);
/// <summary>
/// Return the interpolation ratio (0 to 1) corresponding to a distance on a <see cref="BezierCurve"/>. Distance
/// is relative to the curve.
/// </summary>
/// <param name="curveIndex"> The zero-based index of the curve.</param>
/// <param name="curveDistance"> The distance (measuring from the knot at curveIndex) to convert to a normalized interpolation ratio.</param>
/// <returns>The normalized interpolation ratio matching distance on the designated curve. </returns>
public float GetCurveInterpolation(int curveIndex, float curveDistance);
}
}