-- Update this according to however much you enlarge your window.
-- scale = 2 works for a double-sized window.
local scale = 2

local RNG24 = {}
local RNG26 = {}
local RNG   = {}
local bit = 0
local RNGoffset = -70
local RNGend = 14592
local RNGpos = -70
RNG24[RNGoffset] = 4660
RNG26[RNGoffset] = 120
RNG[RNGoffset] = 134

for i=RNGoffset+1,RNGend do
  RNG24[i] = math.floor((RNG24[i-1]+bit)/2)+32768*math.fmod(RNG24[i-1]+bit,2)
  RNG26[i] = math.fmod(RNG26[i-1]+109, 256)
  RNG[i] = math.fmod(math.floor(math.fmod(RNG24[i],256)*RNG26[i]/16),256)
  bit = math.fmod(math.floor(math.fmod(RNG24[i],256)*RNG26[i]/4),4)
end

function search_RNGpos()
  local cur24 = mainmemory.read_u16_le(0x0024)
  local cur26 = mainmemory.read_u8(0x0026)
  RNGpos = RNGoffset
  for i=RNGoffset, 256 do
    if(RNG26[i]==cur26) then
      for j=i, RNGend, 256 do
        if(RNG24[j]==cur24) then
          RNGpos = j
          break
        end
      end
      break
    end
  end
end

function draw_RNGgraph(x,y,width,height)
  gui.drawRectangle(x,y,width,height,0x50FFFFFF)
  gui.drawLine(x+36,y+height+2,x+36,y-2,0xFFFFFFFF)
  gui.text(scale*200,scale*216,string.format("%5d/%5d",RNGpos,RNGend))
  gui.text(scale*2,scale*172,string.format("RNG:     %3d",RNG[RNGpos]))
  for i=0,width do
    local color = 0x8020FF00
    local curRNG = RNG[(RNGpos+i-36)%14592]
    if curRNG==0 then
      color = 0xFF30FFFF -- 1/128 Item Drop
      curRNG=256
    elseif curRNG==128 then
      color = 0xFF30FFFF -- 1/128 Item Drop
    -- elseif curRNG==255 then
      -- color = 0xFFFF0080 -- MAX
      -- curRNG=256
    -- elseif curRNG<=12 then
      -- color = 0xFF5050FF -- SMAAAASH!!
      -- curRNG=256
    -- elseif curRNG>184 then
      -- color = 0x90FF3000 -- No enemies
    -- end
    elseif curRNG<=12 then
      color = 0xFF5050FF -- SMAAAASH!!
      curRNG=256
    end
    gui.drawLine(x+i,y+height,x+i,y+height-math.floor(curRNG/256*height),color)
  end
end


function watch_pos()
  -- use 0x9B26 for Mother 2
  local xadr = 0x9875
  gui.text(scale*150,scale*144,string.format("X-Pos: %5d \n",mainmemory.read_u16_le(xadr+2)))
  gui.text(scale*150,scale*151,string.format("X-Sub: %5d \n",mainmemory.read_u16_le(xadr-0)))
  gui.text(scale*150,scale*158,string.format("Y-Pos: %5d \n",mainmemory.read_u16_le(xadr+6)))
  gui.text(scale*150,scale*165,string.format("Y-Sub: %5d \n",mainmemory.read_u16_le(xadr+4)))

  -- This legend takes up a ton of space on the screen. >_>
  --
  --color = "#00ff80ff"
  --gui.text(scale*208, scale*146, "No use", color)
  --color = "#FF5050FF"
  --gui.text(scale*208, scale*154, "SMAAAASH!!", color)
  --color = "#0080FFFF"
  --gui.text(scale*208, scale*162, "No enemies", color)
  --color = "#FFFF30FF"
  --gui.text(scale*208, scale*170, "1/128 Item", color)

  --9ae0 and 9ae4 for mother 2, I think (original script got 2-byte values here, which isn't quite right)
  m = mainmemory.read_s32_le(0x9831)
  gui.text(scale*2,scale*144,"Money:    "..m)
  atm = mainmemory.read_s32_le(0x9835)
  gui.text(scale*2,scale*151,"ATM:      "..atm)
  ss = mainmemory.read_s16_le(0x9AE6)
  gui.text(scale*2,scale*158,"Skip S.:  "..ss)
  dr = mainmemory.read_s16_le(0xABE5)
  gui.text(scale*2,scale*165,"Drop   :  "..dr)
  --These don't seem to work correctly in EarthBound
  --
  --gui.text(scale*66,scale*163,"EnemyHP: "..mainmemory.read_u16_le(0xA431), color)
  --gui.text(scale*66,scale*170,"Ness HP: "..mainmemory.read_u16_le(0x9CC5), color)
  gui.text(scale*2,scale*216,emu.framecount())
end

event.onframeend(function()
  search_RNGpos()
  draw_RNGgraph(0,182,255,32)
  watch_pos()
end, "Draw RNG")