You're to write a program that randomly fills the entire screen with a character, like an asterisk, with certain foreground/background colors. After you've filled the whole screen with the character, you'll shift foreground/background colors and do it again and again, shifting foreground/background colors for a hypnotic effect! The program will do this endlessly in an infinite loop until the user either stops it with a Ctrl+c keystroke or just forgets to breathe and expires.

Youll need to research how to generate random numbers using the rand function. If you're able to generate a series of random numbers, those numbers can be used to derive random row/column coordinates, which means you'd be able to draw a character to arbitrary positions on the screen until it's eventually filled up. We also considered how you could keep track of which row/column positions had already been used so that you don't keep writing characters to the same locations, by using a 2D array of bools.

cmatrix.h -- This header file contains the declaration for the CMatrix class. The purpose of this class is to fill the screen with a character at random locations. If you look at the class declaration, you'll see that it only has two data members: one to store the total number of rows, and another to save the total number of columns. These data members are initialized by the class constructor, which receives those values in the parameter list. Once the CMatrix object has been initialized, it's ready to have its CMatrix::Fill member function called. This function takes as input a character to draw, and a sleep interval to control the speed with which they're drawn. A loop is entered to draw the character to random locations on the screen until all available positions have been used and the screen is completely filled. (Hmm... how will it keep track of available screen locations? How will it know when the screen has been completely filled?)

cscreen.h -- This header file contains the declaration for the CScreen class. This class has two data members -- one that stores the character to display, and another which saves the sleep interval that can be used as an argument to the usleep function. These data members will get their values from an external file called config.dat, which is read by the class constructor. The constructor will also be responsible for performing any initialization needed by the curses library, which can be handled easily enough by calling the InitCurses member function, which can set up the initialization and colors. The CScreen class only has one other member function, Scatter, which is responsible for the random drawing of characters. As it changes the foreground/background colors, it will use a local CMatrix object to fill the screen with the display character.

main.cpp -- Obviously, this is the main module that drives the whole program. It creates an instance of the CScreen class, passing the name of the configuration file to its constructor. Then calls that object's Scatter function, which takes it from there to randomly fill the screen.

config.dat -- This is the configuration file that the program reads before it begins. If you open it up with a text editor, you'll see that it contains two items: the character to display, and the sleep interval to use when the usleep function is called. Look in the main module and you'll see the name of this file is passed to the CScreen constructor; if you look in the private section of that class, you'll see how the class stores the items in config.dat in its private data members.

scatter -- This is a sample executable, so run the program and see what it does. Try modifying the items in config.dat and see how your changes affect the behavior of the program.

BTW, the only files you should modify are the cmatrix.cpp and cscreen.cpp files, the header files and the main modules are already in a finished state.

cmatrix.cpp

// ============================================================================ // File: cmatrix.cpp // ============================================================================ // This is the implementation file for the CMatrix class. // ============================================================================

#include #include #include #include #include using namespace std; #include "cmatrix.h"

// ==== CMatrix::CMatrix ====================================================== // // This is the CMatrix constructor, it just uses the parameters to initialize // the CMatrix data members so that the screen dimensions are known to the // matrix ADT. // // Input: // numRows [IN] -- the number of rows in the current display // // numCols [IN] -- the number of columns in the current display // // ============================================================================

CMatrix::CMatrix(int numRows, int numCols) { ???

} // end of "CMatrix::CMatrix"

// ==== CMatrix::CMatrix ====================================================== // // This function is responsible for filling the screen at random locations // with the character parameter, and pausing the specified number of micro- // seconds beween the drawing of each character. This drawing of characters // continues until the screen is completely filled, at which point the // function returns to the caller. // // NOTE: It is assumed that the caller has set the foreground and background // colors before making this call. // // Input: // dispChar [IN] -- the character to use to fill the screen // // msecs [IN] -- the number of microseconds to pause between the // drawing of each character // // Output: // Nothing // // ============================================================================

void CMatrix::Fill(char dispChar, int msecs) { ???

} // end of "CMatrix::Fill"

cscreen.cpp

// ============================================================================ // File: cscreen.cpp // ============================================================================ // This is the implementation file for the CScreen class. // ============================================================================

#include #include #include #include #include using namespace std; #include "cscreen.h" #include "cmatrix.h"

// ==== CScreen::CScreen ====================================================== // // This is the constructor for the CScreen class. It uses the parameter to open // the configuration file and fetch the display character and sleep interval to // initialize the object. If values cannot be read from the input file, default // values are used. Then the random number generator is seeded with the current // system time, and the curses library is initialized before returning. // // Input: // fname [IN] -- a cstring containing the name of the configuration // file // // ============================================================================

CScreen::CScreen(const char fname[]) { ???

} // end of "CScreen::CScreen"

// ==== CScreen::InitCurses =================================================== // // This function is responsible for initializing the curses library. It also // establishes the foreground and background colors for all of the color pair // structures. // // Input: // Nothing // // Output: // Nothing // // ============================================================================

void CScreen::InitCurses() { ???

} // end of "CScreen::InitCurses"

// ==== CScreen::Scatter ====================================================== // // This function contains an infinite loop that draws characters to random // locations on the screen. Inside the loop, a COLOR_PAIR is activated, then a // local CMatrix object is used to fill the screen with the display character. // After the screen has been filled, the loop pauses for about a half-second, // before doing it all over again and again, until the user presses Ctrl+c, // which terminates the loop so that the function can return to the caller. // // Input: // Nothing // // Output: // Nothing // // ============================================================================

void CScreen::Scatter() { ???

???

} // end of "CScreen::Scatter"

main.cpp

// ============================================================================ // File: main.cpp // ============================================================================ // This is the main module for the "Scatter" project, which draws characters to // the screen at random locations, over and over again! // ============================================================================

#include "cscreen.h"

// ==== main ================================================================== // // ============================================================================

int main() { // create a screen object CScreen screen("config.dat");

// have the object fill the screen at random locations with colored // characters screen.Scatter(); return 0;

} // end of "main"

cmatrix.h

// ============================================================================ // File: cmatrix.h // ============================================================================ // This header file contains the declaration for the CMatrix class. The class // is used by the CScreen class to help fill the screen display with characters // at random localtions. // ============================================================================

#ifndef CMATRIX_H #define CMATRIX_H

#include #include using namespace std;

// class declaration class CMatrix { public: // constructor CMatrix(int numRows, int numCols);

// member functions void Fill(char dispChar, int msecs);

private: int m_numRows; int m_numCols; };

#endif // CMATRIX_H

cscreen.h

// ============================================================================ // File: cscreen.h // ============================================================================ // This is the header file for the CScreen class. // ============================================================================

#ifndef CSCREEN_H #define CSCREEN_H

#include #include using namespace std;

// defined constants const char DEFAULT_DISPCHAR = '*'; const int DEFAULT_SLEEP = 200; const int LAST_COLOR_PAIR_INDEX = 7;

// class declaration class CScreen { public: // constructor CScreen(const char fname[]);

// member functions void InitCurses(); void Scatter();

private: char m_dispChar; int m_sleep; };

#endif // CSCREEN_H