Beatmup::AffineMapping Class Reference

2x3 affine mapping containing a 2x2 matrix and a 2D point More...

#include <geometry.h>

Public Member Functions
	AffineMapping ()
	AffineMapping (const Matrix2 &aMatrix, const Point &aPosition)
	AffineMapping (const Rectangle &rectangle)
	Creates a mapping of unit square to a given rectangle. More...
Point	getPosition () const
Matrix2	getMatrix () const
Point	operator() (const Point &point) const
	Maps a point. More...
AffineMapping	operator* (const AffineMapping &mapping) const
	Composition of two mappings. More...
void	setIdentity ()
void	invert ()
	Inverts the mapping. More...
AffineMapping	getInverse () const
	Returns inverse mapping. More...
Point	getInverse (const Point &pos) const
	Computes inverse mapping of a point. More...
Point	getInverse (float x, float y) const
void	setCenterPosition (const Point &newPos)
	Adjusts the mapping origin so that the center of the axes box matches a given point. More...
void	translate (const Point &shift)
	Translates the mapping. More...
void	scale (float factor, const Point &fixedPoint=Point::ZERO)
	Scales the mapping around a given point in target domain. More...
void	rotateDegrees (float angle, const Point &fixedPoint=Point::ZERO)
	Rotates the mapping around a given point in target domain. More...
bool	isPointInside (const Point &point) const
	Tests whether a point from the output domain is inside the input axes span. More...
bool	isPointInside (float x, float y) const
bool	isPointInside (float x, float y, float width, float height) const

Public Attributes
Matrix2	matrix
Point	position

Static Public Attributes
static const AffineMapping	IDENTITY

Detailed Description

2x3 affine mapping containing a 2x2 matrix and a 2D point

Definition at line 639 of file geometry.h.

Constructor & Destructor Documentation

AffineMapping() [1/3]

AffineMapping::AffineMapping

(

)

Definition at line 27 of file geometry.cpp.

{}

AffineMapping() [2/3]

AffineMapping::AffineMapping	(	const Matrix2 &	aMatrix,
		const Point &	aPosition
	)

Definition at line 29 of file geometry.cpp.

                                                                           :
    matrix(aMatrix), position(aPosition)
{}

AffineMapping() [3/3]

AffineMapping::AffineMapping

(

const Rectangle &

rectangle

)

Creates a mapping of unit square to a given rectangle.

Parameters

[in]

rectangle

The rectangle

Definition at line 33 of file geometry.cpp.

                                                      :
    matrix(rectangle.width(), rectangle.height()), position(rectangle.getX1(), rectangle.getY1())
{}

Member Function Documentation

getPosition()

Point Beatmup::AffineMapping::getPosition ( ) const

inline

Definition at line 653 of file geometry.h.

                                         {
            return position;
        }

getMatrix()

Matrix2 Beatmup::AffineMapping::getMatrix ( ) const

inline

Definition at line 657 of file geometry.h.

                                         {
            return matrix;
        }

operator()()

Point Beatmup::AffineMapping::operator() ( const Point &  point ) const

inline

Maps a point.

Definition at line 664 of file geometry.h.

                                                          {
            return matrix(point) + position;
        }

operator*()

AffineMapping AffineMapping::operator*

(

const AffineMapping &

mapping

)

const

Composition of two mappings.

Definition at line 38 of file geometry.cpp.

                                                                         {
    return AffineMapping(matrix * mapping.matrix, position + matrix * mapping.position);
}

setIdentity()

void AffineMapping::setIdentity

(

)

Definition at line 42 of file geometry.cpp.

                                {
    matrix.setElements(1.0f, 0.0f, 0.0f, 1.0f);
    position = Point::ZERO;
}

invert()

void AffineMapping::invert

(

)

Inverts the mapping.

Definition at line 47 of file geometry.cpp.

                           {
    matrix = matrix.getInverse();
    position = -(matrix * position);
}

getInverse() [1/3]

AffineMapping AffineMapping::getInverse

(

)

const

Returns inverse mapping.

Definition at line 52 of file geometry.cpp.

                                              {
    AffineMapping inverse;
    inverse.matrix = matrix.getInverse();
    inverse.position = - ( inverse.matrix * position );
    return inverse;
}

getInverse() [2/3]

Point AffineMapping::getInverse

(

const Point &

pos

)

const

Computes inverse mapping of a point.

Definition at line 59 of file geometry.cpp.

                                                        {
    return matrix.getInverse(point.x - position.x, point.y - position.y);
}

getInverse() [3/3]

Point AffineMapping::getInverse	(	float	x,
		float	y
	)		const

Definition at line 63 of file geometry.cpp.

                                                      {
    return matrix.getInverse(x - position.x, y - position.y);
}

setCenterPosition()

void AffineMapping::setCenterPosition

(

const Point &

newPos

)

Adjusts the mapping origin so that the center of the axes box matches a given point.

Definition at line 67 of file geometry.cpp.

                                                         {
    position = newPos - matrix(0.5f, 0.5f);
}

translate()

void AffineMapping::translate

(

const Point &

shift

)

Translates the mapping.

Definition at line 71 of file geometry.cpp.

                                                {
    position = position + shift;
}

scale()

void AffineMapping::scale	(	float	factor,
		const Point &	fixedPoint = Point::ZERO
	)

Scales the mapping around a given point in target domain.

Definition at line 75 of file geometry.cpp.

                                                               {
    const Point pos0 = matrix(fixedPoint);
    matrix.scale(factor);
    position = position + pos0 - matrix * fixedPoint;
}

rotateDegrees()

void AffineMapping::rotateDegrees	(	float	angle,
		const Point &	fixedPoint = Point::ZERO
	)

Rotates the mapping around a given point in target domain.

Definition at line 81 of file geometry.cpp.

                                                                      {
    const Point pos0 = matrix(fixedPoint);
    matrix.rotateDegrees(angle);
    position = position + pos0 - matrix * fixedPoint;
}

isPointInside() [1/3]

bool AffineMapping::isPointInside

(

const Point &

point

)

const

Tests whether a point from the output domain is inside the input axes span.

Definition at line 87 of file geometry.cpp.

                                                          {
    return isPointInside(point.x, point.y);
}

isPointInside() [2/3]

bool AffineMapping::isPointInside	(	float	x,
		float	y
	)		const

Definition at line 91 of file geometry.cpp.

                                                        {
    return matrix.getInverse().isPointInsideAxes(x - position.x, y - position.y);
}

isPointInside() [3/3]

bool AffineMapping::isPointInside	(	float	x,
		float	y,
		float	width,
		float	height
	)		const

Definition at line 95 of file geometry.cpp.

                                                                                   {
    return matrix.getInverse().isPointInsideAxes(x - position.x, y - position.y, width, height);
}

Member Data Documentation

matrix

Matrix2 Beatmup::AffineMapping::matrix

Definition at line 641 of file geometry.h.

position

Point Beatmup::AffineMapping::position

Definition at line 642 of file geometry.h.

IDENTITY

const AffineMapping AffineMapping::IDENTITY

static

Definition at line 717 of file geometry.h.

---

The documentation for this class was generated from the following files:

• core/geometry.h
• core/geometry.cpp