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Diffstat (limited to 'core/math/quaternion.cpp')
-rw-r--r-- | core/math/quaternion.cpp | 237 |
1 files changed, 237 insertions, 0 deletions
diff --git a/core/math/quaternion.cpp b/core/math/quaternion.cpp new file mode 100644 index 0000000000..3f1d2c58e5 --- /dev/null +++ b/core/math/quaternion.cpp @@ -0,0 +1,237 @@ +/*************************************************************************/ +/* quaternion.cpp */ +/*************************************************************************/ +/* This file is part of: */ +/* GODOT ENGINE */ +/* https://godotengine.org */ +/*************************************************************************/ +/* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur. */ +/* Copyright (c) 2014-2021 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 "quaternion.h" + +#include "core/math/basis.h" +#include "core/string/print_string.h" + +real_t Quaternion::angle_to(const Quaternion &p_to) const { + real_t d = dot(p_to); + return Math::acos(CLAMP(d * d * 2 - 1, -1, 1)); +} + +// 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 Quaternion::get_euler_xyz() const { + Basis m(*this); + return m.get_euler_xyz(); +} + +// 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 Quaternion::get_euler_yxz() const { +#ifdef MATH_CHECKS + ERR_FAIL_COND_V_MSG(!is_normalized(), Vector3(0, 0, 0), "The quaternion must be normalized."); +#endif + Basis m(*this); + return m.get_euler_yxz(); +} + +void Quaternion::operator*=(const Quaternion &p_q) { + real_t xx = w * p_q.x + x * p_q.w + y * p_q.z - z * p_q.y; + real_t yy = w * p_q.y + y * p_q.w + z * p_q.x - x * p_q.z; + real_t zz = w * p_q.z + z * p_q.w + x * p_q.y - y * p_q.x; + w = w * p_q.w - x * p_q.x - y * p_q.y - z * p_q.z; + x = xx; + y = yy; + z = zz; +} + +Quaternion Quaternion::operator*(const Quaternion &p_q) const { + Quaternion r = *this; + r *= p_q; + return r; +} + +bool Quaternion::is_equal_approx(const Quaternion &p_quaternion) const { + return Math::is_equal_approx(x, p_quaternion.x) && Math::is_equal_approx(y, p_quaternion.y) && Math::is_equal_approx(z, p_quaternion.z) && Math::is_equal_approx(w, p_quaternion.w); +} + +real_t Quaternion::length() const { + return Math::sqrt(length_squared()); +} + +void Quaternion::normalize() { + *this /= length(); +} + +Quaternion Quaternion::normalized() const { + return *this / length(); +} + +bool Quaternion::is_normalized() const { + return Math::is_equal_approx(length_squared(), 1, (real_t)UNIT_EPSILON); //use less epsilon +} + +Quaternion Quaternion::inverse() const { +#ifdef MATH_CHECKS + ERR_FAIL_COND_V_MSG(!is_normalized(), Quaternion(), "The quaternion must be normalized."); +#endif + return Quaternion(-x, -y, -z, w); +} + +Quaternion Quaternion::slerp(const Quaternion &p_to, const real_t &p_weight) const { +#ifdef MATH_CHECKS + ERR_FAIL_COND_V_MSG(!is_normalized(), Quaternion(), "The start quaternion must be normalized."); + ERR_FAIL_COND_V_MSG(!p_to.is_normalized(), Quaternion(), "The end quaternion must be normalized."); +#endif + Quaternion to1; + real_t omega, cosom, sinom, scale0, scale1; + + // calc cosine + cosom = dot(p_to); + + // adjust signs (if necessary) + if (cosom < 0.0) { + cosom = -cosom; + to1.x = -p_to.x; + to1.y = -p_to.y; + to1.z = -p_to.z; + to1.w = -p_to.w; + } else { + to1.x = p_to.x; + to1.y = p_to.y; + to1.z = p_to.z; + to1.w = p_to.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 - p_weight) * omega) / sinom; + scale1 = Math::sin(p_weight * omega) / sinom; + } else { + // "from" and "to" quaternions are very close + // ... so we can do a linear interpolation + scale0 = 1.0 - p_weight; + scale1 = p_weight; + } + // calculate final values + return Quaternion( + scale0 * x + scale1 * to1.x, + scale0 * y + scale1 * to1.y, + scale0 * z + scale1 * to1.z, + scale0 * w + scale1 * to1.w); +} + +Quaternion Quaternion::slerpni(const Quaternion &p_to, const real_t &p_weight) const { +#ifdef MATH_CHECKS + ERR_FAIL_COND_V_MSG(!is_normalized(), Quaternion(), "The start quaternion must be normalized."); + ERR_FAIL_COND_V_MSG(!p_to.is_normalized(), Quaternion(), "The end quaternion must be normalized."); +#endif + const Quaternion &from = *this; + + real_t dot = from.dot(p_to); + + if (Math::absf(dot) > 0.9999) { + return from; + } + + real_t theta = Math::acos(dot), + sinT = 1.0 / Math::sin(theta), + newFactor = Math::sin(p_weight * theta) * sinT, + invFactor = Math::sin((1.0 - p_weight) * theta) * sinT; + + return Quaternion(invFactor * from.x + newFactor * p_to.x, + invFactor * from.y + newFactor * p_to.y, + invFactor * from.z + newFactor * p_to.z, + invFactor * from.w + newFactor * p_to.w); +} + +Quaternion Quaternion::cubic_slerp(const Quaternion &p_b, const Quaternion &p_pre_a, const Quaternion &p_post_b, const real_t &p_weight) const { +#ifdef MATH_CHECKS + ERR_FAIL_COND_V_MSG(!is_normalized(), Quaternion(), "The start quaternion must be normalized."); + ERR_FAIL_COND_V_MSG(!p_b.is_normalized(), Quaternion(), "The end quaternion must be normalized."); +#endif + //the only way to do slerp :| + real_t t2 = (1.0 - p_weight) * p_weight * 2; + Quaternion sp = this->slerp(p_b, p_weight); + Quaternion sq = p_pre_a.slerpni(p_post_b, p_weight); + return sp.slerpni(sq, t2); +} + +Quaternion::operator String() const { + return "(" + String::num_real(x, false) + ", " + String::num_real(y, false) + ", " + String::num_real(z, false) + ", " + String::num_real(w, false) + ")"; +} + +Quaternion::Quaternion(const Vector3 &p_axis, real_t p_angle) { +#ifdef MATH_CHECKS + ERR_FAIL_COND_MSG(!p_axis.is_normalized(), "The axis Vector3 must be normalized."); +#endif + real_t d = p_axis.length(); + if (d == 0) { + x = 0; + y = 0; + z = 0; + w = 0; + } else { + real_t sin_angle = Math::sin(p_angle * 0.5); + real_t cos_angle = Math::cos(p_angle * 0.5); + real_t s = sin_angle / d; + x = p_axis.x * s; + y = p_axis.y * s; + z = p_axis.z * s; + w = cos_angle; + } +} + +// Euler constructor 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). +Quaternion::Quaternion(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); + + 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 = -sin_a1 * sin_a2 * cos_a3 + cos_a1 * cos_a2 * sin_a3; + w = sin_a1 * sin_a2 * sin_a3 + cos_a1 * cos_a2 * cos_a3; +} |