b2Mat22 Struct Reference

A 2-by-2 matrix. Stored in column-major order. More...

#include <b2Math.h>

List of all members.

Public Member Functions
	b2Mat22 ()
	The default constructor does nothing (for performance).
	b2Mat22 (const b2Vec2 &c1, const b2Vec2 &c2)
	Construct this matrix using columns.
	b2Mat22 (float32 a11, float32 a12, float32 a21, float32 a22)
	Construct this matrix using scalars.
	b2Mat22 (float32 angle)
void	Set (const b2Vec2 &c1, const b2Vec2 &c2)
	Initialize this matrix using columns.
void	Set (float32 angle)
void	SetIdentity ()
	Set this to the identity matrix.
void	SetZero ()
	Set this matrix to all zeros.
float32	GetAngle () const
b2Mat22	GetInverse () const
b2Vec2	Solve (const b2Vec2 &b) const
Public Attributes
b2Vec2	col1
b2Vec2	col2

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Detailed Description

A 2-by-2 matrix. Stored in column-major order.

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Constructor & Destructor Documentation

b2Mat22::b2Mat22

(

)

[inline]

The default constructor does nothing (for performance).

b2Mat22::b2Mat22	(	const b2Vec2 &	c1,
		const b2Vec2 &	c2
	)			[inline]

Construct this matrix using columns.

b2Mat22::b2Mat22	(	float32	a11,
		float32	a12,
		float32	a21,
		float32	a22
	)			[inline]

Construct this matrix using scalars.

b2Mat22::b2Mat22

(

float32

angle

)

[inline, explicit]

Construct this matrix using an angle. This matrix becomes an orthonormal rotation matrix.

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Member Function Documentation

float32 b2Mat22::GetAngle

(

)

const [inline]

Extract the angle from this matrix (assumed to be a rotation matrix).

b2Mat22 b2Mat22::GetInverse

(

)

const [inline]

void b2Mat22::Set

(

float32

angle

)

[inline]

Initialize this matrix using an angle. This matrix becomes an orthonormal rotation matrix.

void b2Mat22::Set	(	const b2Vec2 &	c1,
		const b2Vec2 &	c2
	)			[inline]

Initialize this matrix using columns.

void b2Mat22::SetIdentity

(

)

[inline]

Set this to the identity matrix.

void b2Mat22::SetZero

(

)

[inline]

Set this matrix to all zeros.

b2Vec2 b2Mat22::Solve

(

const b2Vec2 &

b

)

const [inline]

Solve A * x = b, where b is a column vector. This is more efficient than computing the inverse in one-shot cases.

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Member Data Documentation

b2Vec2 b2Mat22::col1

b2Vec2 b2Mat22::col2

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The documentation for this struct was generated from the following file:

• Box2D/Box2D/Common/b2Math.h