fortunes_foundation/seeds.lua

seeds={}
add(modules,seeds)
function seeds:init()
 self.l4=seed_pool:new(seed_constants.l4_start,seed_constants.l4_end,_naive_16b,true)
 self.l5=seed_pool:new(seed_constants.l5_start,seed_constants.l5_end,_delta_4b,true)
 self.ff=seed_pool:new(seed_constants.ff_start,seed_constants.ff_end,_delta_4b)
 self.l7=seed_pool:new(seed_constants.l7_start,seed_constants.l7_end,_delta_4b)
end
function seeds:choose(pool)
 if (pool) return self[pool]:choose()
 return rnd(5000>>16)
end

seed_pool=klass()
function seed_pool:init(addr_start,addr_end,routine,negencode)
 if (negencode) self.neg_max=(%addr_start)>>16 addr_start+=2
 local seeds={}
 routine(seeds,addr_start,addr_end)

 self.seeds=seeds
 self.is_seed={}
 for s in all(seeds) do
  self.is_seed[s] = true
 end
end

function seed_pool:choose()
 if self.neg_max then
  while true do
   local r = rnd(self.neg_max)
   if (not self.is_seed[r]) return r
  end
 end

 return rnd(self.seeds)
end

function _delta_4b(seeds,s,e)
 local acc=0
 while s < e do
  local byte=@s
  local nb0=byte>>20
  local nb1=(byte&0xf)>>16
  if nb0==0 then acc+=0x0.000f else acc+=nb0 add(seeds,acc) end
  if nb1==0 then acc+=0x0.000f else acc+=nb1 add(seeds,acc) end
  s+=1
 end
end

function _naive_16b(seeds,s,e)
 while s < e do
  add(seeds,%s)
  s+=2
 end
end