OccupancyGrid Class Reference

Class representing an occupancy grid. More...

#include <gz/math/OccupancyGrid.hh>

Public Member Functions
	OccupancyGrid (double _resolutionMeters, int _widthCells, int _heightCells, double _originX=0.0, double _originY=0.0)
	Constructor.
int	CalculateIGain (int _x0, int _y0, int _x1, int _y1)
	Calculate information gain along a line. This is useful when implementing safe frontier exploration algorithms.
OccupancyCellState	CellState (int _gridX, int _gridY) const
	Get the state of a cell.
void	CellState (int _gridX, int _gridY, OccupancyCellState _state)
	Set the state of a cell.
void	ExportToRGBImage (std::vector< uint8_t > &_pixels) const
	Export the occupancy grid to a RGB image buffer.
void	GridToWorld (int _gridX, int _gridY, double &_worldX, double &_worldY) const
	Convert grid coordinates (cells) to world coordinates (meters - center of cell).
int	Height () const
	Get the number of cells in height.
bool	IsValidGridCoordinate (int _gridX, int _gridY) const
	Check if grid coordinates are within bounds.
bool	MarkFree (double _worldX0, double _worldY0, double _worldX1, double _worldY1)
	Mark a path as free (e.g., a clear line of sight).
void	MarkLine (int _x0, int _y0, int _x1, int _y1, OccupancyCellState _state)
	Use Bresenham's Line Algorithm to mark cells along a line. This function will not modify cells that are already marked as Occupied. It marks cells from (_x0, _y0) to (_x1, _y1) with the specified state.
bool	MarkOccupied (double _worldX, double _worldY)
	Mark a single point as occupied (e.g., an obstacle detection).
double	OriginX () const
	Get the origin X position.
double	OriginY () const
	Get the origin Y position.
void	RawOccupancy (std::vector< int8_t > &_data) const
	Export the occupancy grid to a raw buffer.
double	Resolution () const
	Get the resolution of the occupancy grid.
int	Width () const
	Get the number of cells in width.
bool	WorldToGrid (double _worldX, double _worldY, int &_gridX, int &_gridY) const
	Convert world coordinates (meters) to grid coordinates (cells).

Detailed Description

Class representing an occupancy grid.

Constructor & Destructor Documentation

OccupancyGrid()

OccupancyGrid	(	double	_resolutionMeters,
		int	_widthCells,
		int	_heightCells,
		double	_originX = 0.0,
		double	_originY = 0.0
	)

Constructor.

Parameters

[in]	_resolutionMeters	Resolution of the grid in meters per cell.
[in]	_widthCells	Width of the grid in cells.
[in]	_heightCells	Height of the grid in cells.
[in]	_originX	X-coordinate of the grid's origin in world coordinates.
[in]	_originY	Y-coordinate of the grid's origin in world coordinates.

Member Function Documentation

CalculateIGain()

int CalculateIGain	(	int	_x0,
		int	_y0,
		int	_x1,
		int	_y1
	)

Calculate information gain along a line. This is useful when implementing safe frontier exploration algorithms.

Parameters

[in]	_x0	X coordinate of the start point in cells.
[in]	_y0	Y coordinate of the start point in cells.
[in]	_x1	X coordinate of the end point in cells.
[in]	_y1	Y coordinate of the end point in cells.

Returns

The information gain.

CellState() [1/2]

OccupancyCellState CellState	(	int	_gridX,
		int	_gridY
	)		const

Get the state of a cell.

Parameters

[in]	_gridX	Grid X coordinate in cells.
[in]	_gridY	Grid Y coordinate in cells.

Returns

The state of the cell.

CellState() [2/2]

void CellState	(	int	_gridX,
		int	_gridY,
		OccupancyCellState	_state
	)

Set the state of a cell.

Parameters

[in]	_gridX	Grid X coordinate in cells.
[in]	_gridY	Grid Y coordinate in cells.
[in]	_state	The new state of the cell.

ExportToRGBImage()

void ExportToRGBImage

(

std::vector< uint8_t > &

_pixels

)

const

Export the occupancy grid to a RGB image buffer.

Parameters

[out]

_pixels

The output buffer to store the RGB image data.

GridToWorld()

void GridToWorld	(	int	_gridX,
		int	_gridY,
		double &	_worldX,
		double &	_worldY
	)		const

Convert grid coordinates (cells) to world coordinates (meters - center of cell).

Parameters

[in]	_gridX	Grid X coordinate in cells.
[in]	_gridY	Grid Y coordinate in cells.
[out]	_worldX	World X coordinate in meters.
[out]	_worldY	World Y coordinate in meters.

Height()

int Height

(

)

const

Get the number of cells in height.

Returns

The height of the grid in cells.

IsValidGridCoordinate()

bool IsValidGridCoordinate	(	int	_gridX,
		int	_gridY
	)		const

Check if grid coordinates are within bounds.

Parameters

[in]	_gridX	Grid X coordinate in cells.
[in]	_gridY	Grid Y coordinate in cells.

Returns

True if the coordinates are valid, false otherwise.

MarkFree()

bool MarkFree	(	double	_worldX0,
		double	_worldY0,
		double	_worldX1,
		double	_worldY1
	)

Mark a path as free (e.g., a clear line of sight).

Parameters

[in]	_worldX0	World X coordinate of the start point in meters.
[in]	_worldY0	World Y coordinate of the start point in meters.
[in]	_worldX1	World X coordinate of the end point in meters.
[in]	_worldY1	World Y coordinate of the end point in meters.

Returns

true if the grid was inside the coordinates, false otherwise

MarkLine()

void MarkLine	(	int	_x0,
		int	_y0,
		int	_x1,
		int	_y1,
		OccupancyCellState	_state
	)

Use Bresenham's Line Algorithm to mark cells along a line. This function will not modify cells that are already marked as Occupied. It marks cells from (_x0, _y0) to (_x1, _y1) with the specified state.

Parameters

[in]	_x0	X coordinate of the start point in cells.
[in]	_y0	Y coordinate of the start point in cells.
[in]	_x1	X coordinate of the end point in cells.
[in]	_y1	Y coordinate of the end point in cells.
[in]	_state	The state to mark the cells with.

MarkOccupied()

bool MarkOccupied	(	double	_worldX,
		double	_worldY
	)

Mark a single point as occupied (e.g., an obstacle detection).

Parameters

[in]	_worldX	World X coordinate in meters.
[in]	_worldY	World Y coordinate in meters.

Returns

true if the grid was inside the coordinates, false otherwise

OriginX()

double OriginX

(

)

const

Get the origin X position.

Returns

The X-coordinate of the grid's origin in world coordinates.

OriginY()

double OriginY

(

)

const

Get the origin Y position.

Returns

The Y-coordinate of the grid's origin in world coordinates.

RawOccupancy()

void RawOccupancy

(

std::vector< int8_t > &

_data

)

const

Export the occupancy grid to a raw buffer.

Parameters

[out]

_data

The output buffer to store the raw occupancy data.

Resolution()

double Resolution

(

)

const

Get the resolution of the occupancy grid.

Returns

The resolution in meters per cell.

Width()

int Width

(

)

const

Get the number of cells in width.

Returns

The width of the grid in cells.

WorldToGrid()

bool WorldToGrid	(	double	_worldX,
		double	_worldY,
		int &	_gridX,
		int &	_gridY
	)		const

Convert world coordinates (meters) to grid coordinates (cells).

Parameters

[in]	_worldX	World X coordinate in meters.
[in]	_worldY	World Y coordinate in meters.
[out]	_gridX	Grid X coordinate in cells.
[out]	_gridY	Grid Y coordinate in cells.

Returns

True if coordinates are within bounds, false otherwise. May also

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

• OccupancyGrid.hh