1 /*************************************************************************/
2 /*  quat.h                                                               */
3 /*************************************************************************/
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5 /*                           GODOT ENGINE                                */
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8 /* Copyright (c) 2007-2019 Juan Linietsky, Ariel Manzur.                 */
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30 #ifndef QUAT_H
31 #define QUAT_H
32 
33 #include "math_defs.h"
34 #include "math_funcs.h"
35 #include "ustring.h"
36 #include "vector3.h"
37 
38 /**
39 	@author Juan Linietsky <reduzio@gmail.com>
40 */
41 class Quat {
42 public:
43 	real_t x, y, z, w;
44 
45 	_FORCE_INLINE_ real_t length_squared() const;
46 	real_t length() const;
47 	void normalize();
48 	Quat normalized() const;
49 	Quat inverse() const;
50 	_FORCE_INLINE_ real_t dot(const Quat &q) const;
51 	void set_euler(const Vector3 &p_euler);
52 	Quat slerp(const Quat &q, const real_t &t) const;
53 	Quat slerpni(const Quat &q, const real_t &t) const;
54 	Quat cubic_slerp(const Quat &q, const Quat &prep, const Quat &postq, const real_t &t) const;
55 
get_axis_and_angle(Vector3 & r_axis,real_t & r_angle)56 	_FORCE_INLINE_ void get_axis_and_angle(Vector3 &r_axis, real_t &r_angle) const {
57 		r_angle = 2 * Math::acos(w);
58 		r_axis.x = -x / Math::sqrt(1 - w * w);
59 		r_axis.y = -y / Math::sqrt(1 - w * w);
60 		r_axis.z = -z / Math::sqrt(1 - w * w);
61 	}
62 
63 	void operator*=(const Quat &q);
64 	Quat operator*(const Quat &q) const;
65 
66 	Quat operator*(const Vector3 &v) const {
67 		return Quat(w * v.x + y * v.z - z * v.y,
68 				w * v.y + z * v.x - x * v.z,
69 				w * v.z + x * v.y - y * v.x,
70 				-x * v.x - y * v.y - z * v.z);
71 	}
72 
xform(const Vector3 & v)73 	_FORCE_INLINE_ Vector3 xform(const Vector3 &v) const {
74 
75 		Quat q = *this * v;
76 		q *= this->inverse();
77 		return Vector3(q.x, q.y, q.z);
78 	}
79 
80 	_FORCE_INLINE_ void operator+=(const Quat &q);
81 	_FORCE_INLINE_ void operator-=(const Quat &q);
82 	_FORCE_INLINE_ void operator*=(const real_t &s);
83 	_FORCE_INLINE_ void operator/=(const real_t &s);
84 	_FORCE_INLINE_ Quat operator+(const Quat &q2) const;
85 	_FORCE_INLINE_ Quat operator-(const Quat &q2) const;
86 	_FORCE_INLINE_ Quat operator-() const;
87 	_FORCE_INLINE_ Quat operator*(const real_t &s) const;
88 	_FORCE_INLINE_ Quat operator/(const real_t &s) const;
89 
90 	_FORCE_INLINE_ bool operator==(const Quat &p_quat) const;
91 	_FORCE_INLINE_ bool operator!=(const Quat &p_quat) const;
92 
93 	operator String() const;
94 
set(real_t p_x,real_t p_y,real_t p_z,real_t p_w)95 	inline void set(real_t p_x, real_t p_y, real_t p_z, real_t p_w) {
96 		x = p_x;
97 		y = p_y;
98 		z = p_z;
99 		w = p_w;
100 	}
Quat(real_t p_x,real_t p_y,real_t p_z,real_t p_w)101 	inline Quat(real_t p_x, real_t p_y, real_t p_z, real_t p_w) {
102 		x = p_x;
103 		y = p_y;
104 		z = p_z;
105 		w = p_w;
106 	}
107 	Quat(const Vector3 &axis, const real_t &angle);
108 
Quat(const Vector3 & v0,const Vector3 & v1)109 	Quat(const Vector3 &v0, const Vector3 &v1) // shortest arc
110 	{
111 		Vector3 c = v0.cross(v1);
112 		real_t d = v0.dot(v1);
113 
114 		if (d < -1.0 + CMP_EPSILON) {
115 			x = 0;
116 			y = 1;
117 			z = 0;
118 			w = 0;
119 		} else {
120 
121 			real_t s = Math::sqrt((1.0f + d) * 2.0f);
122 			real_t rs = 1.0f / s;
123 
124 			x = c.x * rs;
125 			y = c.y * rs;
126 			z = c.z * rs;
127 			w = s * 0.5;
128 		}
129 	}
130 
Quat()131 	inline Quat() {
132 		x = y = z = 0;
133 		w = 1;
134 	}
135 };
136 
dot(const Quat & q)137 real_t Quat::dot(const Quat &q) const {
138 	return x * q.x + y * q.y + z * q.z + w * q.w;
139 }
140 
length_squared()141 real_t Quat::length_squared() const {
142 	return dot(*this);
143 }
144 
145 void Quat::operator+=(const Quat &q) {
146 	x += q.x;
147 	y += q.y;
148 	z += q.z;
149 	w += q.w;
150 }
151 
152 void Quat::operator-=(const Quat &q) {
153 	x -= q.x;
154 	y -= q.y;
155 	z -= q.z;
156 	w -= q.w;
157 }
158 
159 void Quat::operator*=(const real_t &s) {
160 	x *= s;
161 	y *= s;
162 	z *= s;
163 	w *= s;
164 }
165 
166 void Quat::operator/=(const real_t &s) {
167 
168 	*this *= 1.0 / s;
169 }
170 
171 Quat Quat::operator+(const Quat &q2) const {
172 	const Quat &q1 = *this;
173 	return Quat(q1.x + q2.x, q1.y + q2.y, q1.z + q2.z, q1.w + q2.w);
174 }
175 
176 Quat Quat::operator-(const Quat &q2) const {
177 	const Quat &q1 = *this;
178 	return Quat(q1.x - q2.x, q1.y - q2.y, q1.z - q2.z, q1.w - q2.w);
179 }
180 
181 Quat Quat::operator-() const {
182 	const Quat &q2 = *this;
183 	return Quat(-q2.x, -q2.y, -q2.z, -q2.w);
184 }
185 
186 Quat Quat::operator*(const real_t &s) const {
187 	return Quat(x * s, y * s, z * s, w * s);
188 }
189 
190 Quat Quat::operator/(const real_t &s) const {
191 	return *this * (1.0 / s);
192 }
193 
194 bool Quat::operator==(const Quat &p_quat) const {
195 
196 	return x == p_quat.x && y == p_quat.y && z == p_quat.z && w == p_quat.w;
197 }
198 
199 bool Quat::operator!=(const Quat &p_quat) const {
200 
201 	return x != p_quat.x || y != p_quat.y || z != p_quat.z || w != p_quat.w;
202 }
203 
204 #endif
205