1 /* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
2  * This Source Code Form is subject to the terms of the Mozilla Public
3  * License, v. 2.0. If a copy of the MPL was not distributed with this
4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
5 
6 #ifndef MOZILLA_GFX_QUATERNION_H_
7 #define MOZILLA_GFX_QUATERNION_H_
8 
9 #include "Types.h"
10 #include <math.h>
11 #include <ostream>
12 #include "mozilla/Attributes.h"
13 #include "mozilla/DebugOnly.h"
14 #include "mozilla/gfx/MatrixFwd.h"
15 #include "mozilla/gfx/Point.h"
16 
17 namespace mozilla {
18 namespace gfx {
19 
20 class Quaternion
21 {
22 public:
Quaternion()23   Quaternion()
24     : x(0.0f), y(0.0f), z(0.0f), w(1.0f)
25   {}
26 
Quaternion(Float aX,Float aY,Float aZ,Float aW)27   Quaternion(Float aX, Float aY, Float aZ, Float aW)
28     : x(aX), y(aY), z(aZ), w(aW)
29   {}
30 
31 
Quaternion(const Quaternion & aOther)32   Quaternion(const Quaternion& aOther)
33   {
34     memcpy(this, &aOther, sizeof(*this));
35   }
36 
37   Float x, y, z, w;
38 
39   friend std::ostream& operator<<(std::ostream& aStream, const Quaternion& aQuat);
40 
Set(Float aX,Float aY,Float aZ,Float aW)41   void Set(Float aX, Float aY, Float aZ, Float aW)
42   {
43     x = aX; y = aY; z = aZ; w = aW;
44   }
45 
46   // Assumes upper 3x3 of aMatrix is a pure rotation matrix (no scaling)
47   void SetFromRotationMatrix(const Matrix4x4& aMatrix);
48 
49   // result = this * aQuat
50   Quaternion operator*(const Quaternion &aQuat) const
51   {
52     Quaternion o;
53     const Float bx = aQuat.x, by = aQuat.y, bz = aQuat.z, bw = aQuat.w;
54 
55     o.x = x*bw + w*bx + y*bz - z*by;
56     o.y = y*bw + w*by + z*bx - x*bz;
57     o.z = z*bw + w*bz + x*by - y*bx;
58     o.w = w*bw - x*bx - y*by - z*bz;
59     return o;
60   }
61 
62   Quaternion& operator*=(const Quaternion &aQuat)
63   {
64     *this = *this * aQuat;
65     return *this;
66   }
67 
Length()68   Float Length() const
69   {
70     return sqrt(x*x + y*y + z*z + w*w);
71   }
72 
Conjugate()73   Quaternion& Conjugate()
74   {
75     x *= -1.f; y *= -1.f; z *= -1.f;
76     return *this;
77   }
78 
Normalize()79   Quaternion& Normalize()
80   {
81     Float l = Length();
82     if (l) {
83       l = 1.0f / l;
84       x *= l; y *= l; z *= l; w *= l;
85     } else {
86       x = y = z = 0.f;
87       w = 1.f;
88     }
89     return *this;
90   }
91 
Invert()92   Quaternion& Invert()
93   {
94     return Conjugate().Normalize();
95   }
96 
RotatePoint(const Point3D & aPoint)97   Point3D RotatePoint(const Point3D& aPoint) {
98     Float uvx = Float(2.0) * (y*aPoint.z - z*aPoint.y);
99     Float uvy = Float(2.0) * (z*aPoint.x - x*aPoint.z);
100     Float uvz = Float(2.0) * (x*aPoint.y - y*aPoint.x);
101 
102     return Point3D(aPoint.x + w*uvx + y*uvz - z*uvy,
103                    aPoint.y + w*uvy + z*uvx - x*uvz,
104                    aPoint.z + w*uvz + x*uvy - y*uvx);
105   }
106 };
107 
108 } // namespace gfx
109 } // namespace mozilla
110 
111 #endif
112