/////////////////
//CODE for PONG//
/////////////////


#include <Mega163.h>
#include <stdio.h> // sprintf
#include <delay.h> // delay_ms 
#include <stdlib.h>

//#define t1 104
//#define t2 
#define begin {
#define end   }
#define	PADDLE1	0
#define	BALL    1
#define PADDLE2 2
#define MAX_SCORE 7

/*/flash unsigned char paddle[16]={0x80, 0xb1, 0xda, 0xf6, 0xff, 0xf6, 
0xda, 0xb1, 0x80, 0x4f, 0x26, 0x0a, 0x00, 0x0a, 0x26, 0x4f};  */
flash unsigned char paddle[16]={0x03, 0x06, 0x09, 0x0c, 0x0f, 0x12, 
0x15, 0x18, 0x1b, 0x1e, 0x21, 0x24, 0x27, 0x2b, 0x2f, 0x33}; 

bit statechange,sound;
unsigned char state; 
unsigned char sample, pad1_pos, pad2_pos, ballx, bally, xvel, yvel;
unsigned char p1_score, p2_score, next_point,restart,start, 
pause,ghetto_test;
unsigned char Ain; 
unsigned char counter; 
void initialize (void);   
void task1 (void);
	
//--------------------------------------------------------------------------
void main(void)
{ 
  initialize();
   while (1)
   {         	
   	if (statechange==1) task1();	//call state machine...for state 
transition
	}
}
//---------------------ADC INTERRUPT----------------------------------------     
interrupt [ADC_INT] void adc_done(void)
{ 
	Ain=ADCH;
}
//-------------------TIMER1 COMPARE INTERRUPT-------------------------------     
interrupt [TIM1_COMPA] void cmpA_overflow(void)
{       
	statechange=1;	//interrupt to call state machine
}                                                           
 
//-------------------STATE MACHINE------------------------------------------     
void task1(void)
begin
statechange=0;	//reset state change
switch (state)
	{
	//STATE 'PADDLE1'
	case PADDLE1:	
		if (sample<16){ 
			PORTC=pad1_pos+paddle[sample++];//Draw Paddle1
		}					//paddle1 offset position + paddle table
		else {
		    //sample=0;
			state = BALL;	//next state:  BALL	
			PORTC= bally;	//y-coordinate of ball
			PORTD= ballx;	//x-coordinate of ball
			ADMUX.0=1;		//read ADC1
			ADCSR.6=1;		//ADC START Conversion
			while (ADCSR.6==1){		
			}				//wait for conversion to finish
			pad2_pos=Ain;	//paddle2 offset position = Output of ADC
		}
	break;

	//STATE 'BALL'
	case BALL:
			//if (sample<16){
			//	sample++;
			//}
			//else {
			ADMUX.0=0;		//read ADC0
			ADCSR.6=1;		//ADC START Conversion
			while(ADCSR.6==1){
			}				//wait for conversion to finish
			pad1_pos=Ain;	//paddle1 offset position = Output of ADC
			sample=0;		//reset sample
			PORTC= pad2_pos;//paddle2 offset position  
			PORTD=0xff;		//paddle2 at right side of the screen
			state=PADDLE2;	//next state
			
			//BALL is all the way to the RIGHT of the screen
			if (ballx== 0xfe){	
				//BALL MISSES PADDLE2!!!
				if (((bally+yvel)<pad2_pos) || ((bally+yvel)>(pad2_pos+0x33)) && (xvel==1)){
					ballx=0xff;			//ball stays at right wall
					bally=bally+yvel;	//preserve y position
					if (ghetto_test==1)
						++p1_score;
					else
						ghetto_test=1;			//Increment Player 1 score
					PORTB=(~p1_score<<5)+(~p2_score);//SHOW score on LEDs
					xvel=0;				//STOP Ball
					yvel=0;				//STOP Ball
				}
				//BALL HITS PADDLE2!!!
				else{
					sound=1;
					xvel=-1;	//Reverse the xvel so that the ball bounces off
					if ((bally+ yvel)==pad2_pos){	//DEPENDING on WHERE the ball hits paddle,
						yvel=-3;					//ThERE will be a differet yvel...
					}								//This allows variation in the bounce.
					else if ((bally+ yvel)<=(pad2_pos +0x05)){
						yvel=-2;
					}					
					else if ((bally+ yvel)<=(pad2_pos +0x15)){
						yvel=-1;
					}					
					else if ((bally+ yvel)<=(pad2_pos +0x2d)){
						yvel=1;
					}					
					else if ((bally+ yvel)<=(pad2_pos +0x32)){
						yvel=2;
					}					
					else if ((bally+ yvel)==(pad2_pos +0x33)){
						yvel=3;
					}					
				}
			}
			//BALL is all the way to the LEFT of the screen
			else if (ballx==0x01){  
				//BALL MISSES PADDLE1!!!
				if (((bally+ yvel)< pad1_pos) || ((bally+ yvel) > (pad1_pos + 0x33)) && (xvel==-1)){
					ballx=0x00; bally=bally +yvel; xvel=0; yvel=0; p2_score++;//same comments as above
					if (ghetto_test==0)
						p1_score=0;
					PORTB=(~p1_score<<5)+(~p2_score);
				}
				//BALL HITS PADDLE1!!!
				else{								
					xvel=1;							//same comments as above
					if ((bally+ yvel)==pad1_pos){
						yvel=-3;
					}
					else if ((bally+ yvel)<=(pad1_pos +0x05)){
						yvel=-2;
					}
					else if ((bally+ yvel)<=(pad1_pos +0x15)){
						yvel=-1;
					}					
					else if ((bally+ yvel)<=(pad1_pos +0x2d)){
						yvel=1;
					}					
					else if ((bally+ yvel)<=(pad1_pos +0x32)){
						yvel=2;
					}					
					else if ((bally+ yvel)==(pad1_pos +0x33)){
						yvel=3;
					}					
				}
 			}
			//BALL bounces off TOP and BOTTOM walls
			if ((bally>=0xcc) || (bally<=0)){
				yvel=-yvel;
			}
			//Determine what to do now after a ball has been MISSED
			if ((ballx == 0xff)|| (ballx==0x00)){
				//Reset Game after MAX Score has been reached
				if ((p1_score==MAX_SCORE)|| (p2_score==MAX_SCORE)){
					//Wait for reset command...Button 3
					if (PINB.3==0)
						initialize();
				} 
	
				//Universal Reset
				else if ((PINB.3==0) & (PINB.4==0)) 
					initialize();
				
				//Advance to next point?
				else if (next_point==0){
			  		//wait for another button push
			 		if (PINB.4==0)
						next_point=1;			              
				}
				
				//Serve the ball again, after it has been missed on the right side
				else if (ballx==0xff && (bally>=pad2_pos) &&(bally<=(pad2_pos+0x33))){
					next_point=0;
					xvel=-1;
					ballx=0xfd;
				}

				//Serve the ball again, after it has been missed on the right side
				else if (ballx==0x00 &&(bally>=pad1_pos) &&(bally<=(pad1_pos+0x33))){
					next_point=0;
					xvel=1;
					ballx=0x02;
				}				
			}

			//Ball is in a position in middle the screen, (it is in motion)
			else{
				//Wait for Button 4 to play point
				if (PINB.4==0){
					start=1;			              
				}
				//Ball can only be moving after Button 4 has been pushed during that point
				if (start==1){	
			  		counter=0;			
					ballx= ballx + xvel;
					bally= bally + yvel;
				}
			}
	break;
	
	//STATE 'PADDLE2'
	case PADDLE2:
		if (sample <16){
			PORTC=pad2_pos+paddle[sample++];//DRAW PADDLE2
//			if (sound==1)
//				PORTA.6=(~(PORTA.6));
		}						//paddle2 offset position + paddle table
		else {
			sound=0;
			sample=1;			//reset sample
			PORTC= pad1_pos;	//PORTC= pad1_pos;//paddle2 offset position  
			PORTD= 0;			//paddle1 at left side of the screen
			state = PADDLE1;	//next state
		}
	break;
	}
end  
  
  
//---------------------------------------------------------------
void initialize(void)
begin
	//PORT SET-UP's	                              
		// Analog-Digital Converter does input control 
		// for variable resistor to move the paddles 
  	DDRA = 0x00;            // INPUT (ANALOG PORT) USED
  	DDRB = 0xe7;     		// OUTPUT x-coordinate control				
  	DDRC = 0xff; 			// OUTPUT y-coordinate control
//  	DDRD = 0xe7;			// OUTPUT bit4, bit3 / INPUT bit7:5, bit2:0	- 
//button pushes, lights, speaker
   	 DDRD=0xff;
  
  	//set up timer 1
  	TIMSK= 0x10;		//turn on timer 1 compare match interrupt
  	TCNT1 = 0;     		//and zero the timer 
	OCR1A = 104;   		
	//set to match after 104 cycles=.000208s appx = 100Hz *3 states *16 paddle positions	
	TCCR1B= 0x0a;	//allow clr on match

	
	//initialize values
	PORTD=0x00;
	PORTB=0xff;
	p1_score=0;
	p2_score=0;
   	ballx=0x80;	//start ball in the middle of the screen
  	bally=0x66;
  	start=0;
  	sample = 0;      
	//SET TO 2V
  	xvel=1;   
 	ghetto_test=0;
	//setup ADC
	ADMUX = 0b01100000;	/* makes information left adjusted with regards to AVcc*/ 
	ADCSR = 0x80 + 0x06 + 0x08;
	MCUCR = 0b01010000; //enable sleep and choose ADC modeto AREF pin
	ADCSR.6=1;
	while (ADCSR.6==1){
	}
	pad1_pos=Ain;
	//crank up the ISRs
	#asm
  		sei
	#endasm    
end