/// <summary>
/// Creates a 2D rotation matrix with the specified angle in radians.
/// </summary>
/// <returns>2D Rotation Matrix</returns>
public static M22f Rotation(float angleInRadians)
{
float cos = Fun.Cos(angleInRadians);
float sin = Fun.Sin(angleInRadians);
return(new M22f(cos, -sin,
sin, cos));
}
/// <summary>
/// Creates a 2D rotation matrix with the specified angle in radians.
/// </summary>
/// <returns>2D Rotation Matrix</returns>
public static M2__x2t__ Rotation(__ft__ angleInRadians)
{
__ft__ cos = Fun.Cos(angleInRadians);
__ft__ sin = Fun.Sin(angleInRadians);
return(new M2__x2t__(cos, -sin,
sin, cos));
}
/// <summary>
/// Creates new rotational matrix for "float value"-radians around Z-Axis.
/// </summary>
/// <returns>Rotational matrix.</returns>
public static M44f RotationZ(float angleRadians)
{
float cos = Fun.Cos(angleRadians);
float sin = Fun.Sin(angleRadians);
return(new M44f(cos, -sin, 0, 0,
sin, cos, 0, 0,
0, 0, 1, 0,
0, 0, 0, 1));
}
/// <summary>
/// Creates new rotational matrix for "double value"-radians around Z-Axis.
/// </summary>
/// <returns>Rotational matrix.</returns>
public static M44d RotationZ(double angleRadians)
{
double cos = Fun.Cos(angleRadians);
double sin = Fun.Sin(angleRadians);
return(new M44d(cos, -sin, 0, 0,
sin, cos, 0, 0,
0, 0, 1, 0,
0, 0, 0, 1));
}
/// <summary>
/// Creates new rotational matrix for "__ft__ value"-radians around Z-Axis.
/// </summary>
/// <returns>Rotational matrix.</returns>
public static M4__x4t__ RotationZ(__ft__ angleRadians)
{
__ft__ cos = Fun.Cos(angleRadians);
__ft__ sin = Fun.Sin(angleRadians);
return(new M4__x4t__(cos, -sin, 0, 0,
sin, cos, 0, 0,
0, 0, 1, 0,
0, 0, 0, 1));
}
/// <summary>
/// Create from Rodrigues axis-angle vactor
/// </summary>
public static __rot3t__ FromAngleAxis(__v3t__ angleAxis)
{
__ft__ theta2 = angleAxis.LengthSquared;
if (theta2 > Constant <__ft__> .PositiveTinyValue)
{
var theta = Fun.Sqrt(theta2);
var thetaHalf = theta / 2;
var k = Fun.Sin(thetaHalf) / theta;
return(new __rot3t__(Fun.Cos(thetaHalf), k * angleAxis));
}
else
{
return(new __rot3t__(1, 0, 0, 0));
}
}
/// <summary>
/// Return an IEnumerable of points on the circle's circumference, optionally repeating the first point as the last.
/// </summary>
/// <param name="tesselation">number of distinct points to generate. the actual number of points returned depends on the <para>duplicateClosePoint</para> parameter. must be 3 or larger.</param>
/// <param name="duplicateClosePoint">if true, the first point is repeated as the last</param>
/// <returns>IEnumerable of points on the circle's circumference. if diplicateClosePoint is true, <para>tesselation</para>+1 points are returned.</returns>
public IEnumerable <V3d> Points(int tesselation, bool duplicateClosePoint = false)
{
if (tesselation < 3)
{
throw new ArgumentOutOfRangeException("tesselation", "tesselation must be at least 3.");
}
var off = 0;
if (duplicateClosePoint)
{
off = 1;
}
for (int i = 0; i < tesselation + off; i++)
{
var angle = ((double)i) / tesselation * Constant.PiTimesTwo;
yield return(Center + AxisU * Fun.Cos(angle) + AxisV * Fun.Sin(angle));
}
}
/// <summary>
/// One real root of the equation: x^3 + c2 x^2 + c1 x + c0 = 0.
/// </summary>
public static double OneRealRootOfNormed(
double c2, double c1, double c0
)
{
// ------ eliminate quadric term (x = y - c2/3): x^3 + p x + q = 0
double d = c2 * c2;
double p3 = 1 / 3.0 * /* p */ (-1 / 3.0 * d + c1);
double q2 = 1 / 2.0 * /* q */ ((2 / 27.0 * d - 1 / 3.0 * c1) * c2 + c0);
double p3c = p3 * p3 * p3;
d = q2 * q2 + p3c;
if (d < 0) // -------------- casus irreducibilis: three real roots
{
return(2 * Fun.Sqrt(-p3) * Fun.Cos(1 / 3.0
* Fun.Acos(-q2 / Fun.Sqrt(-p3c))) - 1 / 3.0 * c2);
}
d = Fun.Sqrt(d); // one triple root or a single and a double root
return(Fun.Cbrt(d - q2) - Fun.Cbrt(d + q2) - 1 / 3.0 * c2);
}
/// <summary>
/// Return real roots of the equation: x^3 + p x + q = 0
/// Double and triple solutions are returned as replicated values.
/// Imaginary and non existing solutions are returned as NaNs.
/// </summary>
public static Triple <double> RealRootsOfDepressed(
double p, double q)
{
double p3 = 1 / 3.0 * p, q2 = 1 / 2.0 * q;
double p3c = p3 * p3 * p3, d = q2 * q2 + p3c;
if (d < 0) // ---------- casus irreducibilis: three real solutions
{
double phi = 1 / 3.0 * Fun.Acos(-q2 / Fun.Sqrt(-p3c));
double t = 2 * Fun.Sqrt(-p3);
double r0 = t * Fun.Cos(phi);
double r1 = -t *Fun.Cos(phi + Constant.Pi / 3.0);
double r2 = -t *Fun.Cos(phi - Constant.Pi / 3.0);
return(Triple.CreateAscending(r0, r1, r2));
}
d = Fun.Sqrt(d); // one triple root or a single and a double root
double s0 = Fun.Cbrt(d - q2) - Fun.Cbrt(d + q2);
double s1 = -0.5 * s0;
return(s0 < s1?Triple.Create(s0, s1, s1)
: Triple.Create(s1, s1, s0));
}
public __vt__ GetPoint(double alpha)
{
return(Center + Axis0 * Fun.Cos(alpha) + Axis1 * Fun.Sin(alpha));
}
public __vt__ GetVector(double alpha)
{
return(Axis0 * Fun.Cos(alpha) + Axis1 * Fun.Sin(alpha));
}
