/' (c) 2021, 2005 cepstrum.co.jp '/
' FreeBASIC GUI program
' >fbc -s gui 
'--------------------------------------------------------------------------
' xorshift random number generator 

function uint_xorshift(a as uinteger, b as uinteger, c as uinteger) as uinteger<32>
  static r as uinteger<32> = &Hffffffff

  r=r xor (r shl a)
  r=r xor (r shr b)
  r=r xor (r shl c)
  return r
end function

'--------------------------------------------------------------------------

dim x   as uinteger
dim y   as uinteger
dim a   as uinteger = 3
dim b   as uinteger = 13
dim c   as uinteger = 7
dim sft as uinteger = 9

screenres 1024, 1024

while inkey$<>""
wend
sleep 300

while inkey$=""
  x=(uint_xorshift(a, b, c) shr sft) mod 1024
  y=(uint_xorshift(a, b, c) shr sft) mod 1024
  line (x, y)-(x, y), (uint_xorshift(a, b, c) shr sft) mod 64
wend