#include <Adafruit_GFX.h>
#include <Adafruit_PCD8544.h>

Adafruit_PCD8544 display = Adafruit_PCD8544(3, 4, 5, 7, 6);

byte e; //represents the X axis in for loops [life(),dispx(),start()]
byte f; //represents the y axis in for loops [life(),dispx(),start()]
byte u; //accumulator to reset the board [loop()]
byte d; //accumulator determines number of living neighbors for each cell [life()]
byte x=48; //X axis [life(),dispx(),start()]
byte y=48; //Y axis [life(),dispx(),start()]
byte xm=x-1; //boundery [life()]
byte ym=y-1; //boundery [life()]
byte a[48][48]; //array for current board [life(),dispx(),start()]
byte b[48][48]; //array for next board [life()]


void start(); //function initializes the current board
void dispx(); //function displays to graphic LCD
void life(); //function is Conway's Game of Life

void setup()
{
  display.begin();
  display.setContrast(50);
  display.fillRect(0,0,84,48,BLACK); //Black margins
}

void loop()
{
  start();
  for (u=0;u<200;u++) //avoid stagnation
  {
    dispx();
    life();
  }
}

void life()
{
  for (e=0;e<x;e++)
  {
    for (f=0;f<y;f++)
    {
      d=0;
      if (a[e-1][f]==1 && e!=0)
      d++;
      if (a[e-1][f-1]==1 && e!=0 && f!=0)
      d++;
      if (a[e-1][f+1]==1 && e!=0 && f!=ym)
      d++;
      if (a[e+1][f]==1 && e!=xm)
      d++;
      if (a[e+1][f-1]==1 && e!=xm && f!=0)
      d++;
      if (a[e+1][f+1]==1 && e!=xm && f!=ym)
      d++;
      if (a[e][f-1]==1 && f!=0)
      d++;
      if (a[e][f+1]==1 && f!=ym)
      d++;
      if (a[e][f]==1)
      {
        if (d<2 || d>3)
        b[e][f]=0;
        if (d==2 || d==3)
        b[e][f]=1;
      }
      if (a[e][f]==0)
      if (d==3)
      b[e][f]=1;
    }
  }
  for (e=0;e<x;e++)
  for (f=0;f<y;f++)
  a[e][f]=b[e][f];
}

void start()
{
  for (e=0;e<x;e++)
  {
    for (f=0;f<y;f++)
    {
      a[e][f]=random(0,2);
    }
  }
}

void dispx()
{
  for (e=0;e<x;e++)
  {
    for (f=0;f<y;f++)
    {
      if (a[e][f]==1)
      {
        display.drawPixel(e+18,f,BLACK); //+18 to have even margins on either side
       }
      if (a[e][f]==0)
      {
        display.drawPixel(e+18,f,WHITE);
      }
    }
  }
  display.display();
  //delay(500);
}