16 bit xor shift rng

// XOR SHIFT 16 bit RNG (Modified version of George Marsaglia's xorshift)
// http://www.arklyffe.com/main/2010/08/29/xorshift-pseudorandom-number-generator/
//
//
/* 60 Values that work for A,B,C in the 16-bit XORShift RNG.
(1,  1, 14)     (1,  1, 15)     (1, 5, 2 )  (1,  7, 4 )     (1,  7, 11)     (1, 11, 3 )
(1, 15, 6 )     (1, 15, 7 )     (2, 5, 1 )  (2,  5, 13)     (2,  5, 15)     (2,  7, 13)
(2,  7, 15)     (3,  1, 12)     (3, 1, 15)  (3,  5, 11)     (3, 11, 1 )     (3, 11, 11)
(3, 13, 9 )     (4,  3, 7 )     (4, 7, 1 )  (4, 11, 11)     (5,  7, 14)     (5,  9, 8 )
(5, 11, 6 )     (5, 11, 11)     (6, 7, 13)  (6, 11, 5 )     (6, 15, 1 )     (7,  1, 11)
(7,  3, 4 )     (7,  9, 8 )     (7, 9, 13)  (7, 15, 1 )     (8,  9, 5 )     (8,  9, 7 )
(9,  7, 13)     (9, 13, 3 )     (11, 1, 7)  (11, 3, 13)     (11, 5, 3 )     (11, 7, 1 )
(11,11, 3 )     (11,11, 4 )     (11,11, 5)  (12, 1, 3 )     (12, 3, 13)     (13, 3, 11)
(13, 3, 12)     (13, 5, 2 )     (13, 7, 2)  (13, 7, 6 )     (13, 7, 9 )     (13, 9, 7 )
(14, 1, 1 )     (14, 7, 5 )     (15, 1, 1)  (15, 1, 3 )     (15, 5, 2 )     (15, 7, 2 )
*/

int PR_Y = 1; //Seed, must not be zero.
#define PR_A 13
#define PR_B 9
#define PR_C 7

function int PRandom(int min, int max) //Dont use negative values with this function
{
  int value;

  if(min == max) return min;
  if(max < min)
  {   //Swap values
    value = max;
    max = min;
    min = value;
  }

  PR_Y ^= (PR_Y << PR_A);
  PR_Y ^= (PR_Y >> PR_B);
  PR_Y ^= (PR_Y << PR_C);
  value = PR_Y;

  if (value < 0) value = -value;
  value = value % (max - min + 1);
  value += min;

  return value;
}