A simple 2D vector field. More...

#include <VectorField.h>

Inheritance diagram for Menge::VectorField:

Public Member Functions
	VectorField (const std::string &fileName)
	Default constructor. More...

virtual const std::string &	getLabel () const
	Returns a unique resource label to be used to identify different resource types which use the same underlying file data.

void	getCell (const Vector2 &pos, int &r, int &c)
	Reports the cell the a point is in. More...

Vector2	getFieldValue (int row, int col) const
	Returns the value of the field for the given CELL address. More...

Vector2	getFieldValue (const Vector2 &pos)
	Returns the value of the field for the given position. More...

Vector2	getFieldValueInterp (const Vector2 &pos)
	Returns the value of the field for the given position. More...

Vector2	getMinimumPoint () const
	Reports the minimum extent of the field. More...

Vector2	getMaximumPoint () const
	Reports the maximum extent of the field. More...

Vector2	getSize () const
	Reports the size of the field (along both axes). More...

int	getRowCount () const
	Reports the number of rows in the field. More...

int	getColCount () const
	Reports the number of columns in the field. More...

float	getCellSize () const
	Reports the number of rows in the field. More...

Public Member Functions inherited from Menge::Resource
	Resource (const std::string &fileName)
	Constructor. More...

void	destroy ()
	This supplants the destructor. More...

const std::string &	getName () const
	Return the file name for this resource. More...

int	incRef ()
	Increment references to the managed data. More...

int	decRef ()
	Decrement references to the managed data. More...

bool	isUnreferenced () const
	Reports if the data is referenced. More...

Static Public Member Functions
static Resource *	load (const std::string &fileName)
	Parses a vector field definition and returns a pointer to it. More...

Static Public Attributes
static const std::string	LABEL
	The unique label for this data type to be used with resource management.

Protected Member Functions
virtual	~VectorField ()
	Destructor.

void	setDimensions (float width, float height)
	Computes the appropriate resolution of the grid. More...

void	initDataArray ()
	Given the stored resolution, intializes the data array.

void	freeDataArray ()
	frees the data array.

Protected Member Functions inherited from Menge::Resource
virtual	~Resource ()
	Virtual destructor.

Protected Attributes
Vector2	_minPoint
	The minimum extent of the vector field.

int	_resolution [2]
	The resolution (in cells) of the field's grid (rowCount, colCount)

float	_cellSize
	Size of the grid cell.

Vector2 **	_data
	The 2D array of vector data for each cell.

Protected Attributes inherited from Menge::Resource
const std::string	_fileName
	The file which contains the resource's data.

int	_refCount
	The number of data wrappers using this managed data.

SimpleLock	_lock
	Simple lock to handle reference counts safely.

Friends
Logger &	operator<< (Logger &out, const VectorField &vf)
	Overloaded streaming output operator to print the field to an output stream. More...

Detailed Description

A simple 2D vector field.

The field is defined by the location of its bottom, left-hand corner, the size of the space the grid should cover and the size of each, square cell.

Constructor & Destructor Documentation

Menge::VectorField::VectorField ( const std::string & fileName )

Default constructor.

Parameters

fileName The name of the file which contains the vector field definition.

Member Function Documentation

void Menge::VectorField::getCell	(	const Vector2 &	pos,
		int &	r,
		int &	c
	)

Reports the cell the a point is in.

TODO: Determine what happens if pos is off the grid

Parameters

pos	The point to test.
r	A reference to the row index – this is to be set by the function.
c	A reference to the column index – this is to be set by the function.

float Menge::VectorField::getCellSize ( ) const

inline

Reports the number of rows in the field.

Returns: The number of rows.

int Menge::VectorField::getColCount ( ) const

inline

Reports the number of columns in the field.

Returns: The number of columns.

Vector2 Menge::VectorField::getFieldValue	(	int	row,
		int	col
	)		const

Returns the value of the field for the given CELL address.

The row and column values are only validated in debug mode, using an assertion.

Parameters

row	The index of the row
col	The index of the column.

Returns: The vector value of the cell at (row, col)

Vector2 Menge::VectorField::getFieldValue ( const Vector2 & pos )

Returns the value of the field for the given position.

This uses a "nearest" value look-up. The cell center which is closest to the query point is used. That means, points that lie outside the field will get the vector value of the closest cell in the grid.

Parameters

pos	The position to read the field's vector value.

Returns: The vector value of the cell center closest to pos.

Vector2 Menge::VectorField::getFieldValueInterp ( const Vector2 & pos )

Returns the value of the field for the given position.

This uses a bi-linear interpolation value. The four surrounding cells' values are combined linearly based on relative distances. If the point lies outside the field, then only two, or possibly only one cell is used.

Parameters

pos	The position to read the field's vector value.

Returns: The vector value of the cell center closest to pos.

Vector2 Menge::VectorField::getMaximumPoint ( ) const

Reports the maximum extent of the field.

Returns: The maximum extent of the field.

Vector2 Menge::VectorField::getMinimumPoint ( ) const

inline

Reports the minimum extent of the field.

Returns: The minimum extent of the field.

int Menge::VectorField::getRowCount ( ) const

inline

Reports the number of rows in the field.

Returns: The number of rows.

Vector2 Menge::VectorField::getSize ( ) const

Reports the size of the field (along both axes).

Returns: The size of the field.

Resource * Menge::VectorField::load ( const std::string & fileName )

static

Parses a vector field definition and returns a pointer to it.

This function works in conjunction with the ResourceManager. That is why it returns a pointer, not to a VectorField, but to a Resource. The ResourceManager uses it to load and instantiate VectorField instances.

Parameters

fileName The path to the file containing the VectorField definition.

Returns: A pointer to the new VectorField (if the file is valid), NULL if invalid.

void Menge::VectorField::setDimensions	(	float	width,
		float	height
	)

protected

Computes the appropriate resolution of the grid.

It uses the pre-determined cell size to determine the resolution that tightly spans the size given (although, if the size is not an integer multiple of the cell size, the resultant field will be slightly larger (i.e. the extra extent will be less than the cell size).

Parameters

width	The desired size of the field along the x-axis.
height	The desired size of the field along the y-axis.

Friends And Related Function Documentation

Logger& operator<<	(	Logger &	out,
		const VectorField &	vf
	)

friend

Overloaded streaming output operator to print the field to an output stream.

Parameters

out	The output stream.
vf	The vector field to convert to a string.

Returns: The output stream.

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

src/menge/MengeCore/resources/VectorField.h
src/menge/MengeCore/resources/VectorField.cpp

Public Member Functions

Static Public Member Functions

Static Public Attributes

Protected Member Functions

Protected Attributes

Friends

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Friends And Related Function Documentation