public quat(AxisAngle aa)
{
angle half = aa.angle * 0.5f;
vec = aa.axis * half.Sin;
w = half.Cos;
normalize();
}
public quat rotation(vec2 from, vec2 to)
{
vec3 f = transform(from);
vec3 t = transform(to);
vec3 axis = vec3.cross(f, t).Normalized;
angle angle = vec3.AngleBetween(f, t);
return(new quat(AxisAngle.RightHandAround(axis, angle)));
}
public static quat Slerp(quat a, float v, quat b)
{
float d = dot(a, b);
if (d > 0.9995f)
{
return(lerp(a, v, b));
}
d = math1.Within(-1, d, 1);
angle theta0 = angle.Acos(d);
angle theta = theta0 * v;
quat q = (b - a * d).Normalized;
return(a * theta.Cos + q * theta.Sin);/*
* float cosOmega = a.x * b.x +
* a.y * b.y +
* a.z * b.z +
* a.w * b.w;
*
* float sign = (cosOmega < 0.0f) ? (-1.0f) : (1.0f);
* cosOmega *= sign;
*
* float scaleFrom;
* float scaleTo;
* const float DELTA = 0.0001f;
* if ((1.0f - cosOmega) > DELTA)
* {
* // regular slerp
* angle omega = angle.Acos(cosOmega);
* float sinOmega = omega.Sin;
* scaleFrom = (float)Math.Sin((1.0f - v) * omega.inRadians) / sinOmega;
* scaleTo = (float)Math.Sin(v * omega.inRadians) / sinOmega;
* }
* else
* {
* // from and to are close, do a linear interpolation to speed things up a little
* scaleFrom = 1.0f - v;
* scaleTo = v;
* }
* scaleTo *= sign;
*
* return new quat(
* scaleFrom * a.w + scaleTo * b.w, new vec3(
* scaleFrom * a.x + scaleTo * b.x,
* scaleFrom * a.y + scaleTo * b.y,
* scaleFrom * a.z + scaleTo * b.z));*/
}
private AxisAngle(vec3 axis, angle angle)
{
this.axis = axis;
this.angle = angle;
}
public static AxisAngle RightHandAround(vec3 axis, angle angle)
{
return(new AxisAngle(axis, angle));
}