/*
  Filename: 8x8dice.c

  Turns on and off LEDs at to display the roll of 2 dice in an 8x8 matrix.

  Pins 0-7 are the row pins, on if HIGH.
  Pins 8-15 are the column pins, on if LOW.

  Pin 16 is a pushbutton switch.  
  It is connected between pin 16 and ground.
  There is a 10K pull up resistor connected between pin 16 and +3.3 Volts.
*/

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <wiringPi.h>

/*
  3x3 matrix arrays for dice
*/

int die_1[3][3] = { {0,0,0},   // Die rolled 1
		    {0,1,0},
		    {0,0,0} };

int die_2[3][3] = { {1,0,0},   // Die rolled 2
		    {0,0,0},
		    {0,0,1} };

int die_3[3][3] = { {1,0,0},   // Die rolled 3
		    {0,1,0},
		    {0,0,1} };

int die_4[3][3] = { {1,0,1},   // Die rolled 4
		    {0,0,0},
		    {1,0,1} };

int die_5[3][3] = { {1,0,1},   // Die rolled 5
		    {0,1,0},
		    {1,0,1} };

int die_6[3][3] = { {1,0,1},   // Die rolled 6
		    {1,0,1},
		    {1,0,1} };

int rowPin[8] = {0,1,2,3,4,5,6,7};
int columnPin[8] = {8,9,10,11,12,13,14,15}; 

int LED[8][8]; //8 rows, 8 columns - used to pass data between threads.

void setup(void)
{
  int i;

  if (geteuid() != 0)
  {
    fprintf (stderr, "You need to be root to run this program. (sudo?)\n") ;
    exit(0) ;
  }

  if (wiringPiSetup() == -1)
  {
    printf("wiringPiSetup error\n");
    exit(1) ;
  }

  for(i = 0; i < 16; i++)
  {                            
    pinMode(i,OUTPUT);  // Set pins 0 - 15 for output.
  }                                  

  pinMode(16,INPUT);    // Set pin 16 for input. 

  srand(millis());      // Seed random number generator.
}

/*
 This thread reads the LED array and performs the multiplex.  
 It turns on the pins for one LED at a time. 

 Row 1 LED 1 - 2 - 3 ...
 Row 2 LED 1 - 2 - 3 ...

 The code here runs concurrently with the main program in an infinite loop.
*/
PI_THREAD (display)
{
  int i,j;

//  int x = piHiPri(1); // Raise priority.

  while(1)
  {
    for(i = 0; i < 8; i++)                     // Row, HIGH is on. 
    {
      if(i==0) digitalWrite(rowPin[7],0);      // Turn off previous row.
      else digitalWrite(rowPin[i-1],0);
      digitalWrite(columnPin[7],1);            // Turn off column 7 pin.
   
      digitalWrite(rowPin[i],1);               // Turn on current row.

      for(j = 0; j < 8; j++)                   // Column, LOW is on.
      {
        if(j==0) digitalWrite(columnPin[7],1); // Turn off previous column.
        else digitalWrite(columnPin[j-1],1);
        
        if (LED[i][j]==1)
        {
          digitalWrite(columnPin[j],0);        // Turn on current column.
        }
      }
    }
  }
}

/*
 Function to display the first die in the 
 upper left corner of 8x8 LED matrix.
*/
void dspDie1(int die[3][3])
{
int i,j;
  for(i=0;i<3;i++)
  {
    for(j=0;j<3;j++)
    {
      LED[i][j] = die[i][j]; //Move die to LED for display
    }
  }
}

/*
 Function to display the Second die in the 
 bottom left corner of 8x8 LED matrix.
*/
void dspDie2(int die[3][3])
{
int i,j;
  for(i=5;i<8;i++)
  {
    for(j=0;j<3;j++)
    {
      LED[i][j] = die[i-5][j]; //Move die to LED for display
    }
  }
}

/*
  Displays random points in 8x8 matrix to simulate rolling dice.
*/
void rolling(void)
{
  int i,j;

    for(i = 0; i < 8; i++)
    {
      for(j = 0; j < 8; j++)
      {
        int pick = rand();  // Get random number
        if((pick % 4) == 0) // 1 in 4 chance.
        {
          LED[i][j] = 1;    // If random number is divisable by 4 set HIGH
        }
        else
        {
          LED[i][j] = 0;    // Else set LOW
        }
      }
    }
    delay(10);
}

/*
 The loop function lights random LEDS to simulate rolling dice.
 Then it clears the matrix, rolls the dice and passes the 
 correct array to the display dice functions.
*/
void loop()
{
int i,j;

  rolling(); // Display random LEDs to simulate rolling dice.

  for(i = 0; i < 8; i++)
  {
    for(j = 0; j < 8; j++)
    {
      LED[i][j] = 0;    // Turn off all LEDs.
    }
  }

  srand(millis());      // Seed random number generator.
  int pick = rand();         // Get random number
  int die1 = (pick % 6) + 1; // First die 1 - 6
 
  pick = rand();             // Get random number
  int die2 = (pick % 6) + 1; // Second die 1 - 6
 
   switch(die1)              // Display first die.
   {
     case 1:
       dspDie1(die_1);
       break;
     case 2:
       dspDie1(die_2);
       break;
     case 3:
       dspDie1(die_3);
       break;
     case 4:  
       dspDie1(die_4);
       break;
     case 5:  
       dspDie1(die_5);
       break;
     case 6:  
       dspDie1(die_6);
       break;
   }

   switch(die2)             // Display second die.
   {
     case 1:
       dspDie2(die_1);
       break;
     case 2:
       dspDie2(die_2);
       break;
     case 3:
       dspDie2(die_3);
       break;
     case 4:  
       dspDie2(die_4);
       break;
     case 5:  
       dspDie2(die_5);
       break;
     case 6:  
       dspDie2(die_6);
       break;
   }
}

int main(void)
{

  int x = piThreadCreate (display) ;             // Start second thread.
  if (x != 0) printf ("It didn't start.\n");

  setup();

  int count = 0;

  while(1)
  {
    while(digitalRead(16)==LOW)
    {
      loop();
      count++;
      if(count==10)
      {
        srand(millis());      // Seed random number generator.
        count=0;
      }

    }
  }
  return(0);
}