2025-02-25 15:46:58 +01:00

72 lines
2.7 KiB
C#

using System;
using Quaternion = UnityEngine.Quaternion;
namespace Passer.LinearAlgebra {
public class QuaternionOf<T> {
public T x;
public T y;
public T z;
public T w;
public QuaternionOf(T x, T y, T z, T w) {
this.x = x;
this.y = y;
this.z = z;
this.w = w;
}
public static Matrix2 ToRotationMatrix(Quaternion q) {
float w = q.x, x = q.y, y = q.z, z = q.w;
float[,] result = new float[,]
{
{ 1 - 2 * (y * y + z * z), 2 * (x * y - w * z), 2 * (x * z + w * y) },
{ 2 * (x * y + w * z), 1 - 2 * (x * x + z * z), 2 * (y * z - w * x) },
{ 2 * (x * z - w * y), 2 * (y * z + w * x), 1 - 2 * (x * x + y * y) }
};
return new Matrix2(result);
}
public static Quaternion FromRotationMatrix(Matrix2 m) {
float trace = m.data[0, 0] + m.data[1, 1] + m.data[2, 2];
float w, x, y, z;
if (trace > 0) {
float s = 0.5f / (float)Math.Sqrt(trace + 1.0f);
w = 0.25f / s;
x = (m.data[2, 1] - m.data[1, 2]) * s;
y = (m.data[0, 2] - m.data[2, 0]) * s;
z = (m.data[1, 0] - m.data[0, 1]) * s;
}
else {
if (m.data[0, 0] > m.data[1, 1] && m.data[0, 0] > m.data[2, 2]) {
float s = 2.0f * (float)Math.Sqrt(1.0f + m.data[0, 0] - m.data[1, 1] - m.data[2, 2]);
w = (m.data[2, 1] - m.data[1, 2]) / s;
x = 0.25f * s;
y = (m.data[0, 1] + m.data[1, 0]) / s;
z = (m.data[0, 2] + m.data[2, 0]) / s;
}
else if (m.data[1, 1] > m.data[2, 2]) {
float s = 2.0f * (float)Math.Sqrt(1.0f + m.data[1, 1] - m.data[0, 0] - m.data[2, 2]);
w = (m.data[0, 2] - m.data[2, 0]) / s;
x = (m.data[0, 1] + m.data[1, 0]) / s;
y = 0.25f * s;
z = (m.data[1, 2] + m.data[2, 1]) / s;
}
else {
float s = 2.0f * (float)Math.Sqrt(1.0f + m.data[2, 2] - m.data[0, 0] - m.data[1, 1]);
w = (m.data[1, 0] - m.data[0, 1]) / s;
x = (m.data[0, 2] + m.data[2, 0]) / s;
y = (m.data[1, 2] + m.data[2, 1]) / s;
z = 0.25f * s;
}
}
return new Quaternion(x, y, z, w);
}
}
// public class Quaternion : QuaternionOf<float> {
// public Quaternion(float x, float y, float z, float w) : base(x, y, z, w) { }
// }
}