private static TurtleDirection NewDirection(TurtleDirection facing, TurtleCommands turnCommand)
{
if (turnCommand == TurtleCommands.TurnRight)
{
switch (facing)
{
case TurtleDirection.UP:
return(TurtleDirection.RIGHT);
case TurtleDirection.DOWN:
return(TurtleDirection.LEFT);
case TurtleDirection.LEFT:
return(TurtleDirection.UP);
case TurtleDirection.RIGHT:
return(TurtleDirection.DOWN);
default:
return(facing);
}
}
else
{
switch (facing)
{
case TurtleDirection.UP:
return(TurtleDirection.LEFT);
case TurtleDirection.DOWN:
return(TurtleDirection.RIGHT);
case TurtleDirection.LEFT:
return(TurtleDirection.DOWN);
case TurtleDirection.RIGHT:
return(TurtleDirection.UP);
default:
return(facing);
}
}
}
static void Execute(int[,] turtleProgram)
{
//a 20x20 array floor initialized to 0's
int[,] floor = new int[20, 20];
char [,] displayFloor = new char [20, 20];
ClearFloor(floor);
//turtle properties
bool penDown = false;
TurtleDirection facing = TurtleDirection.RIGHT;
int xCoord = 0;
int yCoord = 0;
//control variables
int moveCounter = 0;
int commandIndex = 0;
TurtleCommands nextCommand = (TurtleCommands)turtleProgram[commandIndex, 0];
while (nextCommand != TurtleCommands.End)
{
//execute command
switch (nextCommand)
{
case TurtleCommands.PenUp: //raises the turtle's pen
penDown = false;
break;
case TurtleCommands.PenDown: //lowers the turtle's pen
penDown = true;
break;
case TurtleCommands.TurnRight: //turns the turtle right 90 degrees
facing = NewDirection(facing, TurtleCommands.TurnRight);
break;
case TurtleCommands.TurnLeft: //turns the turtle left 90 degrees
facing = NewDirection(facing, TurtleCommands.TurnLeft);
break;
case TurtleCommands.Move: //moves the turtle the indicated number of spaces
switch (facing)
{
case TurtleDirection.UP:
moveCounter = turtleProgram[commandIndex, 1]; //get number of spaces to move. This code is repeated for each of the directions.
if (yCoord > 0) //check to see if at edge of floor
{
while (moveCounter > 0) //check for moves remaining
{
if (penDown) //check for pen down
{
floor[xCoord, yCoord] = 1;
}
if (yCoord > 0) //check if movement has caused turtle to reach end of floor.
//required due to movement near end of loop
{
yCoord--;
}
moveCounter--;
}
}
break;
case TurtleDirection.DOWN:
moveCounter = turtleProgram[commandIndex, 1];
if (yCoord < 19)
{
while (moveCounter > 0)
{
if (penDown)
{
floor[xCoord, yCoord] = 1;
}
if (yCoord < 19)
{
yCoord++;
}
moveCounter--;
}
}
break;
case TurtleDirection.LEFT:
moveCounter = turtleProgram[commandIndex, 1];
if (xCoord > 0)
{
while (moveCounter > 0)
{
if (penDown)
{
floor[xCoord, yCoord] = 1;
}
if (xCoord > 0)
{
xCoord--;
}
moveCounter--;
}
}
break;
case TurtleDirection.RIGHT:
moveCounter = turtleProgram[commandIndex, 1];
if (xCoord < 19)
{
while (moveCounter > 0)
{
if (penDown)
{
floor[xCoord, yCoord] = 1;
}
if (xCoord < 19)
{
xCoord++;
}
moveCounter--;
}
}
break;
default:
Console.WriteLine("Something went wrong in Execute(move command)");
break;
}
break;
case TurtleCommands.Print: //creates secondary array of characters that mirrors the floor and prints it
for (int x = 0; x < floor.GetUpperBound(0); x++)
{
for (int y = 0; y < floor.GetUpperBound(1); y++)
{
if (floor[x, y] == 0)
{
displayFloor[x, y] = ' ';
}
else
{
displayFloor[x, y] = '*';
}
}
}
for (int x = 0; x < displayFloor.GetUpperBound(0); x++)
{
for (int y = 0; y < displayFloor.GetUpperBound(1); y++)
{
if (x != 19)
{
Console.Write(displayFloor[x, y]);
}
else
{
Console.WriteLine(displayFloor[x, y]);
}
}
}
break;
case TurtleCommands.End:
Console.WriteLine("END OF PROGRAM");
break;
default:
Console.WriteLine("Something went wrong in Execute (unknown command)");
break;
}
commandIndex++; //move control variable
nextCommand = (TurtleCommands)turtleProgram[commandIndex, 0]; //change which command is being evaluated
}
}