#include <io.h>
#include <system.h>
#include <stdio.h>


#define IOWR_VGA_DATA(base, offset, data) \
  IOWR_16DIRECT(base, (offset) * 2, data) 
#define IORD_VGA_DATA(base, offset) \
  IORD_16DIRECT(base, (offset) * 2)  
  
int counter=0;

//Rotary Controller Interrupt 
static void interrupt_rotary (void * context, alt_u32 id)
{
  int flag_right_left;    
  counter ++;
  printf ("%d\n",counter); 
  flag_right_left=IORD_16DIRECT(ROTARY_BASE, 0);
  
  if(flag_right_left==1)
  {printf ("Left\n");}
  
  if(flag_right_left==2)
  {printf ("Right\n");}
  
  IOWR_16DIRECT(ROTARY_BASE, 0, 0);  // reset the interrupt request
}

int main()
{
    int x_ball=21;// x location of ball
    int y_ball=0;// y location of ball
    int delta_x=1;// delta x of ball
    int delta_y=1;// delta y of ball
    int k; //delay counter
    int m=0;//x location of left paddle
    int n=0;//y location of left paddle
    int t=1;// delta x of left paddle 
    int o=1;// delta y of left paddle
    int x_rpad=619;//x location of right paddle
    int y_rpad=0;//y location of right paddle
    int deltax_rpad=1;// delta x of right paddle 
    int deltay_rpad=1;// delta y of right paddle
   
    alt_irq_register( ROTARY_IRQ, NULL,(void*)interrupt_rotary ); // register IRQSOURCE
      
    for(;;)
    {
        for(k=0;k<5000;k++)
        {;}//delay
   
    x_ball=x_ball+delta_x;
    y_ball=y_ball+delta_y;      

    if( x_ball==21)
    delta_x=1;
    if( x_ball==603)
    delta_x=-1; 
    if(y_ball==0)
    delta_y=1;
    if(y_ball==464)
    delta_y=-1;  
    IOWR_VGA_DATA(VGA_BASE, 0, x_ball);  // ball h
    IOWR_VGA_DATA(VGA_BASE, 1, y_ball);  // ball v

    if(n==0)
    o=1;
    if(n==360)
    o=-1;  

    y_rpad=y_rpad+deltay_rpad;
    if(y_rpad==0)
    deltay_rpad=1;
    if(y_rpad==360)
    deltay_rpad=-1;
 
 
    IOWR_VGA_DATA(VGA_BASE, 2, m);  // plot x_lpad
    IOWR_VGA_DATA(VGA_BASE, 3, n);  // plot y_lpad
    IOWR_VGA_DATA(VGA_BASE, 4, x_rpad);  // plot x_rpad
    IOWR_VGA_DATA(VGA_BASE, 5, y_rpad);  // plot y_rpad
    printf ("ball h : %d \n", IORD_VGA_DATA(VGA_BASE, 2));
    printf ("ball v : %d \n", IORD_VGA_DATA(VGA_BASE, 3));
   
  }
}
