b2Math.cpp
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1 /*
2 * Copyright (c) 2007-2009 Erin Catto http://www.box2d.org
3 *
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18 
19 #include <Box2D/Common/b2Math.h>
20 
21 const b2Vec2 b2Vec2_zero(0.0f, 0.0f);
22 
26 {
27  float32 det = b2Dot(ex, b2Cross(ey, ez));
28  if (det != 0.0f)
29  {
30  det = 1.0f / det;
31  }
32  b2Vec3 x;
33  x.x = det * b2Dot(b, b2Cross(ey, ez));
34  x.y = det * b2Dot(ex, b2Cross(b, ez));
35  x.z = det * b2Dot(ex, b2Cross(ey, b));
36  return x;
37 }
38 
42 {
43  float32 a11 = ex.x, a12 = ey.x, a21 = ex.y, a22 = ey.y;
44  float32 det = a11 * a22 - a12 * a21;
45  if (det != 0.0f)
46  {
47  det = 1.0f / det;
48  }
49  b2Vec2 x;
50  x.x = det * (a22 * b.x - a12 * b.y);
51  x.y = det * (a11 * b.y - a21 * b.x);
52  return x;
53 }
54 
57 {
58  float32 a = ex.x, b = ey.x, c = ex.y, d = ey.y;
59  float32 det = a * d - b * c;
60  if (det != 0.0f)
61  {
62  det = 1.0f / det;
63  }
64 
65  M->ex.x = det * d; M->ey.x = -det * b; M->ex.z = 0.0f;
66  M->ex.y = -det * c; M->ey.y = det * a; M->ey.z = 0.0f;
67  M->ez.x = 0.0f; M->ez.y = 0.0f; M->ez.z = 0.0f;
68 }
69 
72 {
73  float32 det = b2Dot(ex, b2Cross(ey, ez));
74  if (det != 0.0f)
75  {
76  det = 1.0f / det;
77  }
78 
79  float32 a11 = ex.x, a12 = ey.x, a13 = ez.x;
80  float32 a22 = ey.y, a23 = ez.y;
81  float32 a33 = ez.z;
82 
83  M->ex.x = det * (a22 * a33 - a23 * a23);
84  M->ex.y = det * (a13 * a23 - a12 * a33);
85  M->ex.z = det * (a12 * a23 - a13 * a22);
86 
87  M->ey.x = M->ex.y;
88  M->ey.y = det * (a11 * a33 - a13 * a13);
89  M->ey.z = det * (a13 * a12 - a11 * a23);
90 
91  M->ez.x = M->ex.z;
92  M->ez.y = M->ey.z;
93  M->ez.z = det * (a11 * a22 - a12 * a12);
94 }
d
float32 b2Dot(const b2Vec2 &a, const b2Vec2 &b)
Perform the dot product on two vectors.
Definition: b2Math.h:406
const b2Vec2 b2Vec2_zero(0.0f, 0.0f)
Useful constant.
b2Vec3 ex
Definition: b2Math.h:295
void GetInverse22(b2Mat33 *M) const
Definition: b2Math.cpp:56
f
float32 y
Definition: b2Math.h:179
b2Vec3 ez
Definition: b2Math.h:295
A 2D column vector.
Definition: b2Math.h:53
float32 b2Cross(const b2Vec2 &a, const b2Vec2 &b)
Perform the cross product on two vectors. In 2D this produces a scalar.
Definition: b2Math.h:412
A 2D column vector with 3 elements.
Definition: b2Math.h:144
b2Vec3 ey
Definition: b2Math.h:295
float32 x
Definition: b2Math.h:179
TFSIMD_FORCE_INLINE const tfScalar & x() const
A 3-by-3 matrix. Stored in column-major order.
Definition: b2Math.h:257
float32 y
Definition: b2Math.h:140
b2Vec2 Solve22(const b2Vec2 &b) const
Definition: b2Math.cpp:41
b2Vec3 Solve33(const b2Vec3 &b) const
Definition: b2Math.cpp:25
void GetSymInverse33(b2Mat33 *M) const
Returns the zero matrix if singular.
Definition: b2Math.cpp:71
float32 z
Definition: b2Math.h:179
float32 x
Definition: b2Math.h:140
float float32
Definition: b2Settings.h:35


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autogenerated on Thu Jun 6 2019 19:36:40