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grid Class Reference

A class to solve a basic maze using the flood fill algorithm. More...

#include <grid.h>

Public Member Functions
	grid (void)
	Default constructor.
	grid (int x, int y)
	Constructor specifying size of maze.
CELL_STATE	state (int x, int y) const
CELL_STATE	heading (int x, int y, atomic_rotation) const
void	solve_maze (int cx, int cy, atomic_rotation face, const pose_chain &waypoints, int itarget, motion_chain &path, bool obstacles)
	Solves maze starting from point cx,cy heading direction "face".
void	wall (int x, int y, CELL_STATE ctype)
	Fills specified coordinate with specified cell state. (blocked open, etc.).
int	height (void) const
	Returns height of maze.
int	width (void) const
	Returns width of maze.
void	save_rom_map (long ROM_ADDRESS) const
	Save internal map to ROM (or battery backed RAM).
void	load_rom_map (long ROM_ADDRESS)
	Load internally stored map from ROM/RAM.
bool	obstacles (void)
	Returns whether obstacles are present or not.
void	branches (short)
	Sets how many branches from each map cell.
Private Member Functions
CELL_TYPE	value (int x, int y) const
void	whipitgood (motion_chain &path)
void	generate_bellman_matrix (void)
void	update_frontiers (int, int, atomic_rotation)
void	process_frontiers (int, int)
bool	unique_frontier (int, int)
void	traverse_back2goal (motion_chain &path)
bool	check_heading (atomic_rotation AR, int x, int y, int &imin)
void	init (void)
void	reinit (void)
Private Attributes
pose_chain	_frontiers
pose_chain	_visited
maze_cell	_maze [22][22]
int	_starting_x
int	_starting_y
int	_starting_face
int	_destination_x
int	_destination_y
atomic_rotation	_destination_face
atomic_rotation	_new_face
int	_new_x
int	_new_y
int	_size_x
int	_size_y
bool	_done
bool	_obstacles
short	BRANCHES

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Detailed Description

A class to solve a basic maze using the flood fill algorithm.

Warning:

Maze initialization is very particular to the application; thus, the maze is initialized to all open. be sure to initialize the maze with walls; otherwise, the robot will try to leave the defined grid. Example:

Ref. OGrid for new A* implementation. This grid is no longer supported and will be probably be replaced with the A* with heuristic set to 0 to generate a floodfill.

  void init_maze()
{
  for (int j=0; j<maze.height(); j++)
  {
    for (int i=0; i<maze.width(); i++)
    {
      // this is general micro mouse initialization (just walls around side.)
      if (i == (maze.width()-1)) maze.wall(i,j,WALL);
      if (i == 0) maze.wall(i,j,WALL);
      if (j == 0) maze.wall(i,j,WALL);
      if (j == (maze.height()-1)) maze.wall(i,j,WALL);
    }
  }
}

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Constructor & Destructor Documentation

grid (  void   )

Default constructor.

grid (  int  x, int  y )

Constructor specifying size of maze.

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Member Function Documentation

void branches (  short   )

Sets how many branches from each map cell.

bool check_heading (  atomic_rotation  AR, int  x, int  y, int &  imin )  [private]

void generate_bellman_matrix (  void   )  [private]

CELL_STATE heading (  int  x, int  y, atomic_rotation  )  const

int height (  void   )  const

Returns height of maze.

void init (  void   )  [private]

void load_rom_map (  long  ROM_ADDRESS  )

Load internally stored map from ROM/RAM.

bool obstacles (  void   )

Returns whether obstacles are present or not.

void process_frontiers (  int  , int  )  [private]

void reinit (  void   )  [private]

void save_rom_map (  long  ROM_ADDRESS  )  const

Save internal map to ROM (or battery backed RAM).

void solve_maze (  int  cx, int  cy, atomic_rotation  face, const pose_chain &  waypoints, int  itarget, motion_chain &  path, bool  obstacles )

Solves maze starting from point cx,cy heading direction "face". Parameters: cx  : starting X coordinate cy  : starting Y coordinate face  : starting orientation waypoints  : list of waypoints to go to. itarget  : starts solving from waypoint number specified by itarget. path  : output commands to be executed by a mobilerobot to follow solution path. obstacles:  whether to solve as maze or as a open space where it simply goes from waypoint to waypoint.

CELL_STATE state (  int  x, int  y )  const

Returns state of given cell. Returns state of cell from point x,y and heading in direction specified with atomic_rotation.

void traverse_back2goal (  motion_chain &  path  )  [private]

bool unique_frontier (  int  , int  )  [private]

void update_frontiers (  int  , int  , atomic_rotation  )  [private]

CELL_TYPE value (  int  x, int  y )  const [private]

void wall (  int  x, int  y, CELL_STATE  ctype )

Fills specified coordinate with specified cell state. (blocked open, etc.).

void whipitgood (  motion_chain &  path  )  [private]

int width (  void   )  const

Returns width of maze.

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Field Documentation

atomic_rotation _destination_face [private]

int _destination_x [private]

int _destination_y [private]

bool _done [private]

pose_chain _frontiers [private]

maze_cell _maze[22][22] [private]

atomic_rotation _new_face [private]

int _new_x [private]

int _new_y [private]

bool _obstacles [private]

int _size_x [private]

int _size_y [private]

int _starting_face [private]

int _starting_x [private]

int _starting_y [private]

pose_chain _visited [private]

short BRANCHES [private]

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