Turtle

/* PROGRAM:  turtle_A.c

   AUTHOR:

   DATE:

   TOPIC:

   PURPOSE:  Simple Turtle Graphic

   LEVEL OF DIFFICULTY:

   CHALLENGES:

   HOURS SPENT:

   NOTES:





*/

/**************************************************************************/

/* Declare include files

 **************************************************************************/

#include <stdio.h>



/**************************************************************************/

/* Defines

 **************************************************************************/

#define TRUE 1

#define FALSE 0

#define MAX 200

#define SIZE 40



#define RIGHT 0

#define DOWN  1

#define LEFT  2

#define UP    3

#define TOTAL_DIR 3



/**************************************************************************/

/* Function Prototypes

 **************************************************************************/

int readCommands( char c[ ] );

int execCommands( char c[ ], int n );

int turnRight( int d );

int turnLeft( int d );

void moveTurtle( int down, int a[][ SIZE ], int dir, int dist, int ver, int horz );

void printFloor( int a[][ SIZE ], char c );



/**************************************************************************/

/* Main`

/* Read commands from stdin or file

/* Execute the commands

 **************************************************************************/

int main( void ) {



    char commands[ MAX ] = { 0 };

    int ncmds;



    ncmds = readCommands( commands );

    int count = 0;

    for(count;count<ncmds;count++){

        fprintf(stdout,"%c\n",commands[count]);

    }

    execCommands( commands, ncmds );



   return 0;

}



/**************************************************************************

 readCommands

 Read one command at a time and store it in the commands arrays

 Reads until the EOF ( CTL-D ) or the MAX maximun number of commands is

 reached



 ARGUMENTS:

    commands:  An empty array of chars to store the commands read

               commands is modified in this function



 RETURN:

     number of commands read

**************************************************************************/

int readCommands( char commands[] ) {

    int ncmds = 0;

    char val;



    while(fscanf(stdin,"%c\n",&val)!= EOF){

        commands[ncmds] = val;

        ++ncmds;

    }



    return ncmds;

}

/**************************************************************************

 execCommands

 execute one command at a time



 ARGUMENTS:

    commands:  an array containing valid turtle commands

    ncmds   :  number of commands stored in commands

              0 <= ncmds < MAX

 **************************************************************************/

 int execCommands( char commands[], int ncmds ) {

  int ver = 0;

  int horz = 0;



  int i = 0;

    char cmd;

    int dir = 0;

    int floor[ SIZE ][ SIZE ] = { { 0 } };

    int penDown = FALSE;



    cmd = commands[ i ];



    while ( ncmds-- ) {

            switch ( cmd ) {

                case 'U':

                    penDown = FALSE;

                    break;

                    case 'D':

                        penDown = TRUE;

                        break;

                case 'R':

                    dir = turnRight( dir );

                        break;

                case 'L':

                    dir = turnLeft( dir );

                        break;

                case 'F':

            if(dir == UP){

              ver--;

            }

            if(dir == DOWN){

              ver++;

            }

            if(dir == RIGHT){

              horz++;

            }

            if(dir == LEFT){

              horz--;

            }

                moveTurtle( penDown, floor, dir, 1, ver, horz );

                        break;

                case 'P':

                    printFloor( floor, '*' );

                        break;

                    default:

                        break;

            }

            cmd = commands[ i++ ];

    }



    return 0;



 }

/**************************************************************************

 turnRight

 Turn the turtle direction to the right ( 90 degres counterclock wise )

 Think about 4 directions:

 >  ( RIGHT )

  \/ ( DOWN )

  <  ( LEFT }

  ^  ( UP )

 **************************************************************************/

int turnRight( int d ) {



  if (d == DOWN){

    d = RIGHT;

  }

  if( d == RIGHT){

    d = UP;

  }

  if( d == UP ){

    d = LEFT;

  }

  if ( d == LEFT){

    d = DOWN;

  }

  else {

    printf("Out of Range!");

  }

  return d;



}





/**************************************************************************

 turnRight

 Turn the turtle direction to the left ( -90 degres counterclock wise )

 Think about 4 directions:

  >  ( RIGHT )

  \/ ( DOWN )

  <  ( LEFT }

  ^  ( UP )

 *************************************************************************/

int turnLeft( int d ) {

    if( d == DOWN){

      d = LEFT;

    }

    if( d == LEFT){

      d = UP;

    }

    if( d == UP){

      d = RIGHT;

    }

    if(d == RIGHT){

      d = DOWN;

    }

    else {

      printf("Out of Range" );

    }

    return d;



}



/**************************************************************************

 movePen

 move the turtle a distance dis in the direction dir from current pos

 if the pen is

 down, place a 1 in floor position

 ARGUMENTS:

    a   :  floor

    down:  1

    if pen is down    dir :  direction turtle is facing

    dist:  How far to walk

 *************************************************************************/

void moveTurtle( int down, int a[][ SIZE ], int dir, int dist, int ver, int horz ) {



if ( down == TRUE){

  a[ver][horz] = dist;

}



    return;

}



/*************************************************************************

 printFloor

 Print the floor

 ARGUMENTS:

    a   :  floor

    c   :  char to use to print the floor

 *************************************************************************/

void printFloor( int a[][ SIZE ], char c ){

    int j = 0;

    int i = 0;

    for (i;i<SIZE;i++){



      for(j;j<SIZE;j++){

        if(a[i][j] != 0){

          printf("%c\n", c);

        }

      }

    }





    return;

}