// Lab 2 part 1
// USE LEDREG.BIT

#include <reg51.h>
#include <stdlib.h>
char xdata *ledaddress;


bit En;
bit Done;

int Diamond;


//Data before sign change
int PreXData;
int PreYData;



//Data to PS/2
char XData;
char YData;
char Sign;


void init () {

	Done = 1;
	Sign = 0;
	Diamond = 1;
	En = 0;

 
}

char FindSign ( int X, int Y )
{

	char tempSign;
	tempSign = 0;

	if (X > 0 && Y > 0 )			// X > 0 and Y > 0			//abs(X) == X && abs(Y) == Y
	{
		tempSign = 1;							// Quadrant 1
	}

	else if (X < 0 && Y > 0)			// Quadrant 2
	{
		tempSign = 2;	
	}

	else if (X < 0 && Y < 0)			// Quadrant 3
	{
		tempSign = 3;	
	}

	else if (X > 0 && Y < 0)			// Quadrant 4
	{
		tempSign = 4;	
	}

	else				// ERROR CONDITION!!
	{
		tempSign = 0;
	}

	return (tempSign);
		
}

void main() {

	init();

	while (1)				// All programs run forever
	{
		if (Done && !En)	// I can put new data in the variables to send to the PS/2 port
		{
			switch(Diamond) 
			{
				case 1:
					Done = 0;		// reset done
					PreXData = 150;
					PreYData = 150;
					Diamond = 2;
					break;
				case 2:
					Done = 0;		// reset done
					PreXData = 150;
					PreYData = -150;
					Diamond = 3;
					break;
				case 3:
					Done = 0;		// reset done
					PreXData = -150;
					PreYData = -150;
					Diamond = 4;
					break;
				case 4:
					Done = 0;		// reset done
					PreXData = -150;
					PreYData = 150;
					Diamond = 1;
					break;
			}

			XData = abs(PreXData);
			YData = abs(PreYData);	
			Sign = FindSign(PreXData, PreYData);
			En = 1; 					// Set En high to let PS/2 port know that we have data in the variables

		}			
	}					
}