godot/modules/mono/glue/GodotSharp/GodotSharp/Core/Quat.cs
2020-02-13 12:37:45 +01:00

388 lines
11 KiB
C#

using System;
using System.Runtime.InteropServices;
#if REAL_T_IS_DOUBLE
using real_t = System.Double;
#else
using real_t = System.Single;
#endif
namespace Godot
{
[Serializable]
[StructLayout(LayoutKind.Sequential)]
public struct Quat : IEquatable<Quat>
{
public real_t x;
public real_t y;
public real_t z;
public real_t w;
public real_t this[int index]
{
get
{
switch (index)
{
case 0:
return x;
case 1:
return y;
case 2:
return z;
case 3:
return w;
default:
throw new IndexOutOfRangeException();
}
}
set
{
switch (index)
{
case 0:
x = value;
break;
case 1:
y = value;
break;
case 2:
z = value;
break;
case 3:
w = value;
break;
default:
throw new IndexOutOfRangeException();
}
}
}
public real_t Length
{
get { return Mathf.Sqrt(LengthSquared); }
}
public real_t LengthSquared
{
get { return Dot(this); }
}
public Quat CubicSlerp(Quat b, Quat preA, Quat postB, real_t t)
{
real_t t2 = (1.0f - t) * t * 2f;
Quat sp = Slerp(b, t);
Quat sq = preA.Slerpni(postB, t);
return sp.Slerpni(sq, t2);
}
public real_t Dot(Quat b)
{
return x * b.x + y * b.y + z * b.z + w * b.w;
}
public Vector3 GetEuler()
{
#if DEBUG
if (!IsNormalized())
throw new InvalidOperationException("Quat is not normalized");
#endif
var basis = new Basis(this);
return basis.GetEuler();
}
public Quat Inverse()
{
#if DEBUG
if (!IsNormalized())
throw new InvalidOperationException("Quat is not normalized");
#endif
return new Quat(-x, -y, -z, w);
}
public Quat Normalized()
{
return this / Length;
}
public Quat Slerp(Quat b, real_t t)
{
#if DEBUG
if (!IsNormalized())
throw new InvalidOperationException("Quat is not normalized");
if (!b.IsNormalized())
throw new ArgumentException("Argument is not normalized", nameof(b));
#endif
// Calculate cosine
real_t cosom = x * b.x + y * b.y + z * b.z + w * b.w;
var to1 = new Quat();
// Adjust signs if necessary
if (cosom < 0.0)
{
cosom = -cosom;
to1.x = -b.x;
to1.y = -b.y;
to1.z = -b.z;
to1.w = -b.w;
}
else
{
to1.x = b.x;
to1.y = b.y;
to1.z = b.z;
to1.w = b.w;
}
real_t sinom, scale0, scale1;
// Calculate coefficients
if (1.0 - cosom > Mathf.Epsilon)
{
// Standard case (Slerp)
real_t omega = Mathf.Acos(cosom);
sinom = Mathf.Sin(omega);
scale0 = Mathf.Sin((1.0f - t) * omega) / sinom;
scale1 = Mathf.Sin(t * omega) / sinom;
}
else
{
// Quaternions are very close so we can do a linear interpolation
scale0 = 1.0f - t;
scale1 = t;
}
// Calculate final values
return new Quat
(
scale0 * x + scale1 * to1.x,
scale0 * y + scale1 * to1.y,
scale0 * z + scale1 * to1.z,
scale0 * w + scale1 * to1.w
);
}
public Quat Slerpni(Quat b, real_t t)
{
real_t dot = Dot(b);
if (Mathf.Abs(dot) > 0.9999f)
{
return this;
}
real_t theta = Mathf.Acos(dot);
real_t sinT = 1.0f / Mathf.Sin(theta);
real_t newFactor = Mathf.Sin(t * theta) * sinT;
real_t invFactor = Mathf.Sin((1.0f - t) * theta) * sinT;
return new Quat
(
invFactor * x + newFactor * b.x,
invFactor * y + newFactor * b.y,
invFactor * z + newFactor * b.z,
invFactor * w + newFactor * b.w
);
}
public Vector3 Xform(Vector3 v)
{
#if DEBUG
if (!IsNormalized())
throw new InvalidOperationException("Quat is not normalized");
#endif
var u = new Vector3(x, y, z);
Vector3 uv = u.Cross(v);
return v + ((uv * w) + u.Cross(uv)) * 2;
}
// Static Readonly Properties
public static Quat Identity { get; } = new Quat(0f, 0f, 0f, 1f);
// Constructors
public Quat(real_t x, real_t y, real_t z, real_t w)
{
this.x = x;
this.y = y;
this.z = z;
this.w = w;
}
public bool IsNormalized()
{
return Mathf.Abs(LengthSquared - 1) <= Mathf.Epsilon;
}
public Quat(Quat q)
{
this = q;
}
public Quat(Basis basis)
{
this = basis.Quat();
}
public Quat(Vector3 eulerYXZ)
{
real_t half_a1 = eulerYXZ.y * 0.5f;
real_t half_a2 = eulerYXZ.x * 0.5f;
real_t half_a3 = eulerYXZ.z * 0.5f;
// R = Y(a1).X(a2).Z(a3) convention for Euler angles.
// Conversion to quaternion as listed in https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19770024290.pdf (page A-6)
// a3 is the angle of the first rotation, following the notation in this reference.
real_t cos_a1 = Mathf.Cos(half_a1);
real_t sin_a1 = Mathf.Sin(half_a1);
real_t cos_a2 = Mathf.Cos(half_a2);
real_t sin_a2 = Mathf.Sin(half_a2);
real_t cos_a3 = Mathf.Cos(half_a3);
real_t sin_a3 = Mathf.Sin(half_a3);
x = sin_a1 * cos_a2 * sin_a3 + cos_a1 * sin_a2 * cos_a3;
y = sin_a1 * cos_a2 * cos_a3 - cos_a1 * sin_a2 * sin_a3;
z = cos_a1 * cos_a2 * sin_a3 - sin_a1 * sin_a2 * cos_a3;
w = sin_a1 * sin_a2 * sin_a3 + cos_a1 * cos_a2 * cos_a3;
}
public Quat(Vector3 axis, real_t angle)
{
#if DEBUG
if (!axis.IsNormalized())
throw new ArgumentException("Argument is not normalized", nameof(axis));
#endif
real_t d = axis.Length();
if (d == 0f)
{
x = 0f;
y = 0f;
z = 0f;
w = 0f;
}
else
{
real_t sinAngle = Mathf.Sin(angle * 0.5f);
real_t cosAngle = Mathf.Cos(angle * 0.5f);
real_t s = sinAngle / d;
x = axis.x * s;
y = axis.y * s;
z = axis.z * s;
w = cosAngle;
}
}
public static Quat operator *(Quat left, Quat right)
{
return new Quat
(
left.w * right.x + left.x * right.w + left.y * right.z - left.z * right.y,
left.w * right.y + left.y * right.w + left.z * right.x - left.x * right.z,
left.w * right.z + left.z * right.w + left.x * right.y - left.y * right.x,
left.w * right.w - left.x * right.x - left.y * right.y - left.z * right.z
);
}
public static Quat operator +(Quat left, Quat right)
{
return new Quat(left.x + right.x, left.y + right.y, left.z + right.z, left.w + right.w);
}
public static Quat operator -(Quat left, Quat right)
{
return new Quat(left.x - right.x, left.y - right.y, left.z - right.z, left.w - right.w);
}
public static Quat operator -(Quat left)
{
return new Quat(-left.x, -left.y, -left.z, -left.w);
}
public static Quat operator *(Quat left, Vector3 right)
{
return new Quat
(
left.w * right.x + left.y * right.z - left.z * right.y,
left.w * right.y + left.z * right.x - left.x * right.z,
left.w * right.z + left.x * right.y - left.y * right.x,
-left.x * right.x - left.y * right.y - left.z * right.z
);
}
public static Quat operator *(Vector3 left, Quat right)
{
return new Quat
(
right.w * left.x + right.y * left.z - right.z * left.y,
right.w * left.y + right.z * left.x - right.x * left.z,
right.w * left.z + right.x * left.y - right.y * left.x,
-right.x * left.x - right.y * left.y - right.z * left.z
);
}
public static Quat operator *(Quat left, real_t right)
{
return new Quat(left.x * right, left.y * right, left.z * right, left.w * right);
}
public static Quat operator *(real_t left, Quat right)
{
return new Quat(right.x * left, right.y * left, right.z * left, right.w * left);
}
public static Quat operator /(Quat left, real_t right)
{
return left * (1.0f / right);
}
public static bool operator ==(Quat left, Quat right)
{
return left.Equals(right);
}
public static bool operator !=(Quat left, Quat right)
{
return !left.Equals(right);
}
public override bool Equals(object obj)
{
if (obj is Quat)
{
return Equals((Quat)obj);
}
return false;
}
public bool Equals(Quat other)
{
return x == other.x && y == other.y && z == other.z && w == other.w;
}
public bool IsEqualApprox(Quat other)
{
return Mathf.IsEqualApprox(x, other.x) && Mathf.IsEqualApprox(y, other.y) && Mathf.IsEqualApprox(z, other.z) && Mathf.IsEqualApprox(w, other.w);
}
public override int GetHashCode()
{
return y.GetHashCode() ^ x.GetHashCode() ^ z.GetHashCode() ^ w.GetHashCode();
}
public override string ToString()
{
return String.Format("({0}, {1}, {2}, {3})", x.ToString(), y.ToString(), z.ToString(), w.ToString());
}
public string ToString(string format)
{
return String.Format("({0}, {1}, {2}, {3})", x.ToString(format), y.ToString(format), z.ToString(format), w.ToString(format));
}
}
}