Task

You will write a class called Grid, and test it with a couple of programs. A Grid object will be made up of a grid of positions, numbered with rows and columns. Row and column numbering start at 0, at the top left corner of the grid. A grid object also has a "mover", which can move around to different locations on the grid. Obstacles (which block the mover) and other objects (that can be placed or picked up) are also available. Here is a sample picture of a Grid object in its display format:

0 . . . This is a Grid object with 4 rows and 4 columns (numbered 0 - 3). . . > . The mover '>' is at row 1, column 2, facing east. . . . . The obstacle '#' is at row 3, column 1 . # . . The other item '0' is at row 0, column 0 

The @ character indicates that the mover and an item (0) currently occupy the same position on the grid.

Program Details and Requirements

1) Grid class

Download this starter file: grid_starter.h and rename it as grid.h. Your member function prototypes are already given in this file. You will need to add appropriate member data. You will also need to define each of the member functions in the file grid.cpp. You may add whatever member data you need, but you must store the grid itself as a two-dimensional array. Maximum grid size will be 40 rows and 40 columns. (Note that this means dynamic allocation will NOT be needed for this assignment).

Meaning of Grid symbols

. empty spot on the grid 0 an item that can be placed, or picked up # a block (an obstacle). Mover cannot move through it  mover facing EAST ^ mover facing NORTH v mover facing SOUTH @ mover occupying same place as item (0) 

A printed space ' ' in a grid position represents a spot that the mover has already moved through when the path display is toggled on

Member function descriptions

Grid() The default constructor should create a 1 x 1 grid, with the mover in the only position, facing EAST

Grid(int r, int c) The two-parameter constructor will accept two integers, representing rows and columns. Create a grid with r rows and c columns. If either of these is less than 3, default to 3. If either is greater than the max number of rows or columns, default to the max. This grid should be built such that blocks are placed all around the edge, with one random exit (i.e. with no block). The mover should be in a random position and facing a random direction within the grid. When setting up the randomness, make sure each possibility has an equal chance of happening. For example, the random direction has 4 possibilities, so each one should happen about 25% of the time. For the random exit, it will be sufficient to pick a random wall first, then pick a random location on that wall (note that the exit cannot be in a corner spot).

You'll need the library cstdlib for the srand and rand functions. While it's not normally the best place to do it, you can go ahead and seed the random number generator here in the constructor in some appropriate way so that it's different for seperate program runs.

If you need a refresher on pseudo-random number generation, see this notes set from COP 3014: http://www.cs.fsu.edu/~myers/c++otes/rand.html

Grid(int r, int c, int mr, int mc, int d) This constructor (5 parameters) takes in the following information, in this order:

number of starting rows for the grid (if out of range, adjust like in the 2-parameter constructor, although minimum in this case is 1)

number of starting columns for the grid (if out of range, adjust like in the 2-parameter constructor, although minimum in this case is 1)

The starting row position of the mover (if out of range, adjust to the first or last row, whichever is closer)

The starting column position of the mover (if out of range, adjust to the first or last column, whichever is closer)

The starting direction of the mover

Build the starting grid based on the incoming parameters and their descriptions above. Other than the mover, this grid starts out empty.

Display() This function should print out "The Grid:" on one line, then output the full grid below it -- place spaces between columns so that outputs line up more evenly. End with a newline (so that any next output will be on a separate line). If the path setting is toggled to ON, then any position the mover has already moved through should show up blank. If the path setting is toggled to OFF, then all empty grid spaces show up as dots '.' Examples of the full Display format can be seen in the sample run for test1.cpp linked below under "Test Programs". For description of the path setting, see the funtion TogglePath() below

TogglePath() This function, when called, should reverse whatever the current "path" setting is. The path setting can be either ON or OFF. If it's ON, it means that displays of the grid should indicate where the mover has been by showing those positions as spaces. If the path is OFF, then all blank spots on the grid show as the dot character '.' no matter what. The initial default setting for any grid should be ON.

Simple Accessors These are accessor functions that should return the requested information:

GetRow() should return the current row of the mover

GetCol() should return the current column of the mover

GetNumRows() should return the number of rows in the grid

GetNumCols() should return the number of columns in the grid

Predicate functions These two functions return boolean values (true or false) to answer simple questions:

FrontIsClear() should return an indication of whether the space in front of the mover is clear (i.e. not blocked)

RightIsClear() should return an indication of whether the space to the right of the mover is clear (i.e. not blocked)

Placing blocks and/or items These functions involve placing things on the grid:

PutDown(): This function should place an "item" at the current location of the mover. If the location already contains an item, then nothing changes (i.e. the item is still there)

PutDown(int r, int c): This function should place an "item" at position (r,c) where r is the row and c is the column. This function should return true for a successful placement, and false for failure. For successful placement, the position has to exist within the grid boundaries and not already contain a block or another item. (It can, however, be placed in a spot where only the mover is located).

PlaceBlock(int r, int c): This function should place a "block" at position (r,c) where r is the row and c is the column. This function should return true for a successful placement, and false for failure. For successful placement, the position has to exist within the grid boundaries and be an empty space (i.e. not containing a block, an item, or the mover)

PickUp() This function should pick up the "item" at the mover's position. This means removing it from the grid. This function should return true for a successful pick-up (i.e. the item is at the mover's current position), and false for failure (there is no item there).

Move(int s) This function should move the mover forward, in the current direction, for s spaces. Return true for success, false for failure. A successful move must be a positive number of spaces, must remain on the grid, and must not attempt to move through a "block". On a failed move, the mover should remain in the original position. (i.e. the move must be all or nothing, based on the number of spaces given by the parameter).

TurnLeft() This function will cause the mover to turn 90 degrees to the left, from whichever way it is currently facing. (example: if the mover is facing NORTH, then TurnLeft() will make it face WEST).

void Grow(int gr, int gc) This function should increase the size of the grid by gr rows and gc columns. If the increase causes either the number of rows or columns to exceed the maximum, simply set that (rows or columns) to the maximum. The grow should not change the current position of any item, mover, or block on the grid.

Note that the list of member functions given in the provided starter file (and described above) constitute the entire public interface of the class. These should be the ONLY public member functions in your class. If you create any extra member functions as helpers, put them in the private section of the class

**Help with function definitions. Declarations included in image. **

class Grid public: // public static class constants, for direction indicators static const int NORTH = 0; static const int WEST1 static const int SOUTH = 2; static const int EAST = 3; // public member funcitons Grid); Grid(int r, int c) // build 1 x1grid with mover in only square, facing east // build grid with r rows, c cols, // blocks around edge with random exit // and random mover position and direction Grid(int r, int c, int mr, int mc, int d); // build empty grid with r rows, c cols, and mover // at row mr, col mc, and facing direction d // move forward s spaces, if possible // toggle whether or not moved path is shown / turn the mover to the left bool Move (int s); void TogglePath); void TurnLeft); void PutDown ) bool PutDown (int r, int c); I/ put down an item at (r,c), if possible bool PickUp); bool PlaceBlock(int r, int c); // put a block at (r,c), if possible void Grow(int gr, int gc); // grow the grid by gr rows, gc columns // put down an item at the mover's position // pick up item at current position void Display) const; // display the grid on screen // Accessors bool FrontIsClear) const; I1 check to see if space in front of // mover is clear bool RightIsClear) const; II check to see if space to right of / mover is clear int GetRow() const int GetCol) const int GetNumRows) const; // return number of rows in the grid int GetNumCols() const // return number of columns in the grid // return row of the mover // return column of the mover private: int row, col, rowmover, colmover, dir char mover, fill; char grid[401[48] class Grid public: // public static class constants, for direction indicators static const int NORTH = 0; static const int WEST1 static const int SOUTH = 2; static const int EAST = 3; // public member funcitons Grid); Grid(int r, int c) // build 1 x1grid with mover in only square, facing east // build grid with r rows, c cols, // blocks around edge with random exit // and random mover position and direction Grid(int r, int c, int mr, int mc, int d); // build empty grid with r rows, c cols, and mover // at row mr, col mc, and facing direction d // move forward s spaces, if possible // toggle whether or not moved path is shown / turn the mover to the left bool Move (int s); void TogglePath); void TurnLeft); void PutDown ) bool PutDown (int r, int c); I/ put down an item at (r,c), if possible bool PickUp); bool PlaceBlock(int r, int c); // put a block at (r,c), if possible void Grow(int gr, int gc); // grow the grid by gr rows, gc columns // put down an item at the mover's position // pick up item at current position void Display) const; // display the grid on screen // Accessors bool FrontIsClear) const; I1 check to see if space in front of // mover is clear bool RightIsClear) const; II check to see if space to right of / mover is clear int GetRow() const int GetCol) const int GetNumRows) const; // return number of rows in the grid int GetNumCols() const // return number of columns in the grid // return row of the mover // return column of the mover private: int row, col, rowmover, colmover, dir char mover, fill; char grid[401[48]