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/*************************************************************************/
/* quat.cpp */
/*************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* https://godotengine.org */
/*************************************************************************/
/* Copyright (c) 2007-2018 Juan Linietsky, Ariel Manzur. */
/* Copyright (c) 2014-2018 Godot Engine contributors (cf. AUTHORS.md) */
/* */
/* Permission is hereby granted, free of charge, to any person obtaining */
/* a copy of this software and associated documentation files (the */
/* "Software"), to deal in the Software without restriction, including */
/* without limitation the rights to use, copy, modify, merge, publish, */
/* distribute, sublicense, and/or sell copies of the Software, and to */
/* permit persons to whom the Software is furnished to do so, subject to */
/* the following conditions: */
/* */
/* The above copyright notice and this permission notice shall be */
/* included in all copies or substantial portions of the Software. */
/* */
/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, */
/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF */
/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY */
/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, */
/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE */
/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
/*************************************************************************/
#include "quat.h"
#include "matrix3.h"
#include "print_string.h"
// set_euler_xyz expects a vector containing the Euler angles in the format
// (ax,ay,az), where ax is the angle of rotation around x axis,
// and similar for other axes.
// This implementation uses XYZ convention (Z is the first rotation).
void Quat::set_euler_xyz(const Vector3 &p_euler) {
real_t half_a1 = p_euler.x * 0.5;
real_t half_a2 = p_euler.y * 0.5;
real_t half_a3 = p_euler.z * 0.5;
// R = X(a1).Y(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-2)
// a3 is the angle of the first rotation, following the notation in this reference.
real_t cos_a1 = Math::cos(half_a1);
real_t sin_a1 = Math::sin(half_a1);
real_t cos_a2 = Math::cos(half_a2);
real_t sin_a2 = Math::sin(half_a2);
real_t cos_a3 = Math::cos(half_a3);
real_t sin_a3 = Math::sin(half_a3);
set(sin_a1 * cos_a2 * cos_a3 + sin_a2 * sin_a3 * cos_a1,
-sin_a1 * sin_a3 * cos_a2 + sin_a2 * cos_a1 * cos_a3,
sin_a1 * sin_a2 * cos_a3 + sin_a3 * cos_a1 * cos_a2,
-sin_a1 * sin_a2 * sin_a3 + cos_a1 * cos_a2 * cos_a3);
}
// get_euler_xyz returns a vector containing the Euler angles in the format
// (ax,ay,az), where ax is the angle of rotation around x axis,
// and similar for other axes.
// This implementation uses XYZ convention (Z is the first rotation).
Vector3 Quat::get_euler_xyz() const {
Basis m(*this);
return m.get_euler_xyz();
}
// set_euler_yxz expects a vector containing the Euler angles in the format
// (ax,ay,az), where ax is the angle of rotation around x axis,
// and similar for other axes.
// This implementation uses YXZ convention (Z is the first rotation).
void Quat::set_euler_yxz(const Vector3 &p_euler) {
real_t half_a1 = p_euler.y * 0.5;
real_t half_a2 = p_euler.x * 0.5;
real_t half_a3 = p_euler.z * 0.5;
// 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 = Math::cos(half_a1);
real_t sin_a1 = Math::sin(half_a1);
real_t cos_a2 = Math::cos(half_a2);
real_t sin_a2 = Math::sin(half_a2);
real_t cos_a3 = Math::cos(half_a3);
real_t sin_a3 = Math::sin(half_a3);
set(sin_a1 * cos_a2 * sin_a3 + cos_a1 * sin_a2 * cos_a3,
sin_a1 * cos_a2 * cos_a3 - cos_a1 * sin_a2 * sin_a3,
-sin_a1 * sin_a2 * cos_a3 + cos_a1 * sin_a2 * sin_a3,
sin_a1 * sin_a2 * sin_a3 + cos_a1 * cos_a2 * cos_a3);
}
// get_euler_yxz returns a vector containing the Euler angles in the format
// (ax,ay,az), where ax is the angle of rotation around x axis,
// and similar for other axes.
// This implementation uses YXZ convention (Z is the first rotation).
Vector3 Quat::get_euler_yxz() const {
Basis m(*this);
return m.get_euler_yxz();
}
void Quat::operator*=(const Quat &q) {
set(w * q.x + x * q.w + y * q.z - z * q.y,
w * q.y + y * q.w + z * q.x - x * q.z,
w * q.z + z * q.w + x * q.y - y * q.x,
w * q.w - x * q.x - y * q.y - z * q.z);
}
Quat Quat::operator*(const Quat &q) const {
Quat r = *this;
r *= q;
return r;
}
real_t Quat::length() const {
return Math::sqrt(length_squared());
}
void Quat::normalize() {
*this /= length();
}
Quat Quat::normalized() const {
return *this / length();
}
bool Quat::is_normalized() const {
return Math::is_equal_approx(length(), 1.0);
}
Quat Quat::inverse() const {
return Quat(-x, -y, -z, w);
}
Quat Quat::slerp(const Quat &q, const real_t &t) const {
Quat to1;
real_t omega, cosom, sinom, scale0, scale1;
// calc cosine
cosom = dot(q);
// adjust signs (if necessary)
if (cosom < 0.0) {
cosom = -cosom;
to1.x = -q.x;
to1.y = -q.y;
to1.z = -q.z;
to1.w = -q.w;
} else {
to1.x = q.x;
to1.y = q.y;
to1.z = q.z;
to1.w = q.w;
}
// calculate coefficients
if ((1.0 - cosom) > CMP_EPSILON) {
// standard case (slerp)
omega = Math::acos(cosom);
sinom = Math::sin(omega);
scale0 = Math::sin((1.0 - t) * omega) / sinom;
scale1 = Math::sin(t * omega) / sinom;
} else {
// "from" and "to" quaternions are very close
// ... so we can do a linear interpolation
scale0 = 1.0 - t;
scale1 = t;
}
// calculate final values
return Quat(
scale0 * x + scale1 * to1.x,
scale0 * y + scale1 * to1.y,
scale0 * z + scale1 * to1.z,
scale0 * w + scale1 * to1.w);
}
Quat Quat::slerpni(const Quat &q, const real_t &t) const {
const Quat &from = *this;
real_t dot = from.dot(q);
if (Math::absf(dot) > 0.9999) return from;
real_t theta = Math::acos(dot),
sinT = 1.0 / Math::sin(theta),
newFactor = Math::sin(t * theta) * sinT,
invFactor = Math::sin((1.0 - t) * theta) * sinT;
return Quat(invFactor * from.x + newFactor * q.x,
invFactor * from.y + newFactor * q.y,
invFactor * from.z + newFactor * q.z,
invFactor * from.w + newFactor * q.w);
}
Quat Quat::cubic_slerp(const Quat &q, const Quat &prep, const Quat &postq, const real_t &t) const {
//the only way to do slerp :|
real_t t2 = (1.0 - t) * t * 2;
Quat sp = this->slerp(q, t);
Quat sq = prep.slerpni(postq, t);
return sp.slerpni(sq, t2);
}
Quat::operator String() const {
return String::num(x) + ", " + String::num(y) + ", " + String::num(z) + ", " + String::num(w);
}
Quat::Quat(const Vector3 &axis, const real_t &angle) {
real_t d = axis.length();
if (d == 0)
set(0, 0, 0, 0);
else {
real_t sin_angle = Math::sin(angle * 0.5);
real_t cos_angle = Math::cos(angle * 0.5);
real_t s = sin_angle / d;
set(axis.x * s, axis.y * s, axis.z * s,
cos_angle);
}
}
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