1 /*************************************************************************/
2 /*  quat.h                                                               */
3 /*************************************************************************/
4 /*                       This file is part of:                           */
5 /*                           GODOT ENGINE                                */
6 /*                      https://godotengine.org                          */
7 /*************************************************************************/
8 /* Copyright (c) 2007-2020 Juan Linietsky, Ariel Manzur.                 */
9 /* Copyright (c) 2014-2020 Godot Engine contributors (cf. AUTHORS.md).   */
10 /*                                                                       */
11 /* Permission is hereby granted, free of charge, to any person obtaining */
12 /* a copy of this software and associated documentation files (the       */
13 /* "Software"), to deal in the Software without restriction, including   */
14 /* without limitation the rights to use, copy, modify, merge, publish,   */
15 /* distribute, sublicense, and/or sell copies of the Software, and to    */
16 /* permit persons to whom the Software is furnished to do so, subject to */
17 /* the following conditions:                                             */
18 /*                                                                       */
19 /* The above copyright notice and this permission notice shall be        */
20 /* included in all copies or substantial portions of the Software.       */
21 /*                                                                       */
22 /* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
23 /* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
24 /* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
25 /* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
26 /* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
27 /* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
28 /* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
29 /*************************************************************************/
30 
31 // Circular dependency between Vector3 and Basis :/
32 #include "core/math/vector3.h"
33 
34 #ifndef QUAT_H
35 #define QUAT_H
36 
37 #include "core/math/math_defs.h"
38 #include "core/math/math_funcs.h"
39 #include "core/ustring.h"
40 
41 class Quat {
42 public:
43 	real_t x, y, z, w;
44 
45 	_FORCE_INLINE_ real_t length_squared() const;
46 	bool is_equal_approx(const Quat &p_quat) const;
47 	real_t length() const;
48 	void normalize();
49 	Quat normalized() const;
50 	bool is_normalized() const;
51 	Quat inverse() const;
52 	_FORCE_INLINE_ real_t dot(const Quat &q) const;
53 
54 	void set_euler_xyz(const Vector3 &p_euler);
55 	Vector3 get_euler_xyz() const;
56 	void set_euler_yxz(const Vector3 &p_euler);
57 	Vector3 get_euler_yxz() const;
58 
set_euler(const Vector3 & p_euler)59 	void set_euler(const Vector3 &p_euler) { set_euler_yxz(p_euler); };
get_euler()60 	Vector3 get_euler() const { return get_euler_yxz(); };
61 
62 	Quat slerp(const Quat &q, const real_t &t) const;
63 	Quat slerpni(const Quat &q, const real_t &t) const;
64 	Quat cubic_slerp(const Quat &q, const Quat &prep, const Quat &postq, const real_t &t) const;
65 
66 	void set_axis_angle(const Vector3 &axis, const real_t &angle);
get_axis_angle(Vector3 & r_axis,real_t & r_angle)67 	_FORCE_INLINE_ void get_axis_angle(Vector3 &r_axis, real_t &r_angle) const {
68 		r_angle = 2 * Math::acos(w);
69 		real_t r = ((real_t)1) / Math::sqrt(1 - w * w);
70 		r_axis.x = x * r;
71 		r_axis.y = y * r;
72 		r_axis.z = z * r;
73 	}
74 
75 	void operator*=(const Quat &q);
76 	Quat operator*(const Quat &q) const;
77 
78 	Quat operator*(const Vector3 &v) const {
79 		return Quat(w * v.x + y * v.z - z * v.y,
80 				w * v.y + z * v.x - x * v.z,
81 				w * v.z + x * v.y - y * v.x,
82 				-x * v.x - y * v.y - z * v.z);
83 	}
84 
xform(const Vector3 & v)85 	_FORCE_INLINE_ Vector3 xform(const Vector3 &v) const {
86 #ifdef MATH_CHECKS
87 		ERR_FAIL_COND_V_MSG(!is_normalized(), v, "The quaternion must be normalized.");
88 #endif
89 		Vector3 u(x, y, z);
90 		Vector3 uv = u.cross(v);
91 		return v + ((uv * w) + u.cross(uv)) * ((real_t)2);
92 	}
93 
94 	_FORCE_INLINE_ void operator+=(const Quat &q);
95 	_FORCE_INLINE_ void operator-=(const Quat &q);
96 	_FORCE_INLINE_ void operator*=(const real_t &s);
97 	_FORCE_INLINE_ void operator/=(const real_t &s);
98 	_FORCE_INLINE_ Quat operator+(const Quat &q2) const;
99 	_FORCE_INLINE_ Quat operator-(const Quat &q2) const;
100 	_FORCE_INLINE_ Quat operator-() const;
101 	_FORCE_INLINE_ Quat operator*(const real_t &s) const;
102 	_FORCE_INLINE_ Quat operator/(const real_t &s) const;
103 
104 	_FORCE_INLINE_ bool operator==(const Quat &p_quat) const;
105 	_FORCE_INLINE_ bool operator!=(const Quat &p_quat) const;
106 
107 	operator String() const;
108 
set(real_t p_x,real_t p_y,real_t p_z,real_t p_w)109 	inline void set(real_t p_x, real_t p_y, real_t p_z, real_t p_w) {
110 		x = p_x;
111 		y = p_y;
112 		z = p_z;
113 		w = p_w;
114 	}
Quat(real_t p_x,real_t p_y,real_t p_z,real_t p_w)115 	inline Quat(real_t p_x, real_t p_y, real_t p_z, real_t p_w) :
116 			x(p_x),
117 			y(p_y),
118 			z(p_z),
119 			w(p_w) {
120 	}
Quat(const Vector3 & axis,const real_t & angle)121 	Quat(const Vector3 &axis, const real_t &angle) { set_axis_angle(axis, angle); }
122 
Quat(const Vector3 & euler)123 	Quat(const Vector3 &euler) { set_euler(euler); }
Quat(const Quat & q)124 	Quat(const Quat &q) :
125 			x(q.x),
126 			y(q.y),
127 			z(q.z),
128 			w(q.w) {
129 	}
130 
131 	Quat operator=(const Quat &q) {
132 		x = q.x;
133 		y = q.y;
134 		z = q.z;
135 		w = q.w;
136 		return *this;
137 	}
138 
Quat(const Vector3 & v0,const Vector3 & v1)139 	Quat(const Vector3 &v0, const Vector3 &v1) // shortest arc
140 	{
141 		Vector3 c = v0.cross(v1);
142 		real_t d = v0.dot(v1);
143 
144 		if (d < -1.0 + CMP_EPSILON) {
145 			x = 0;
146 			y = 1;
147 			z = 0;
148 			w = 0;
149 		} else {
150 
151 			real_t s = Math::sqrt((1.0 + d) * 2.0);
152 			real_t rs = 1.0 / s;
153 
154 			x = c.x * rs;
155 			y = c.y * rs;
156 			z = c.z * rs;
157 			w = s * 0.5;
158 		}
159 	}
160 
Quat()161 	inline Quat() :
162 			x(0),
163 			y(0),
164 			z(0),
165 			w(1) {
166 	}
167 };
168 
dot(const Quat & q)169 real_t Quat::dot(const Quat &q) const {
170 	return x * q.x + y * q.y + z * q.z + w * q.w;
171 }
172 
length_squared()173 real_t Quat::length_squared() const {
174 	return dot(*this);
175 }
176 
177 void Quat::operator+=(const Quat &q) {
178 	x += q.x;
179 	y += q.y;
180 	z += q.z;
181 	w += q.w;
182 }
183 
184 void Quat::operator-=(const Quat &q) {
185 	x -= q.x;
186 	y -= q.y;
187 	z -= q.z;
188 	w -= q.w;
189 }
190 
191 void Quat::operator*=(const real_t &s) {
192 	x *= s;
193 	y *= s;
194 	z *= s;
195 	w *= s;
196 }
197 
198 void Quat::operator/=(const real_t &s) {
199 
200 	*this *= 1.0 / s;
201 }
202 
203 Quat Quat::operator+(const Quat &q2) const {
204 	const Quat &q1 = *this;
205 	return Quat(q1.x + q2.x, q1.y + q2.y, q1.z + q2.z, q1.w + q2.w);
206 }
207 
208 Quat Quat::operator-(const Quat &q2) const {
209 	const Quat &q1 = *this;
210 	return Quat(q1.x - q2.x, q1.y - q2.y, q1.z - q2.z, q1.w - q2.w);
211 }
212 
213 Quat Quat::operator-() const {
214 	const Quat &q2 = *this;
215 	return Quat(-q2.x, -q2.y, -q2.z, -q2.w);
216 }
217 
218 Quat Quat::operator*(const real_t &s) const {
219 	return Quat(x * s, y * s, z * s, w * s);
220 }
221 
222 Quat Quat::operator/(const real_t &s) const {
223 	return *this * (1.0 / s);
224 }
225 
226 bool Quat::operator==(const Quat &p_quat) const {
227 	return x == p_quat.x && y == p_quat.y && z == p_quat.z && w == p_quat.w;
228 }
229 
230 bool Quat::operator!=(const Quat &p_quat) const {
231 	return x != p_quat.x || y != p_quat.y || z != p_quat.z || w != p_quat.w;
232 }
233 
234 #endif
235