ray

dir = fs.getDir(shell.getRunningProgram()).."/"
blittleEnabled = true
function fillBox(x1,y1,x2,y2,col)
  win.setBackgroundColor(col)
  for x=x1,x2 do
    for y=y1,y2 do
      win.setCursorPos(x,y)
      win.write(" ")
    end
  end
end
if not fs.exists(dir.."blittle") then
  shell.run("pastebin","get","ujchRSnU",dir.."blittle")
end
os.loadAPI(dir.."blittle")
level = {}
local native = term.native()
nX,nY = term.getSize()
if blittleEnabled then
  win = (blittle.createWindow(term.current(),1,1,nX,nY,true))
end
function math.round(nNum)
  return math.floor(nNum+0.5)
end
function loadLevel(path)
  file = {}
  f = fs.open(dir..path,"r")
  line = true
  while line do
    line = f.readLine()
    file[#file+1] = line
  end
  f.close()
  level = {}
  for i=1,#file[1] do
    level[i] = {}
  end
  for y=1,#file do
    for x=1,#file[y] do
      char = string.sub(file[y],x,x)
      if char == "0" then
        char = colors.white
      elseif char == "1" then
        char = colors.orange
      elseif char == "2" then
        char = colors.magenta
      elseif char == "3" then
        char = colors.lightBlue
      elseif char == "4" then
        char = colors.yellow
      elseif char == "5" then
        char = colors.lime
      elseif char == "6" then
        char = colors.pink
      elseif char == "7" then
        char = colors.gray
      elseif char == "8" then
        char = colors.lightGray
      elseif char == "9" then
        char = colors.cyan
      elseif char == "a" then
        char = colors.purple
      elseif char == "b" then
        char = colors.blue
      elseif char == "c" then
        char = colors.brown
      elseif char == "d" then
        char = colors.green
      elseif char == "e" then
        char = colors.red
      elseif char == "f" then
        char = colors.black
      elseif char == " " then
        char = false
      end
      level[x][y] = char
    end
  end
end
loadLevel("/level1")
xPos = 3
yPos = 3
yaw = 0
rayInc = 1
rayDist = 100
w,h = win.getSize()
rayDirections = {}
yawOffset = 0
for i=0,90 do
  rayDirections[i] = {
    [1] = (0)+(i/90),
    [2] = (-1)+(i/90),
  }
end
for i=90,180 do
  rayDirections[i] = {
    [1] = (1)-((i-90)/90),
    [2] = (0)+((i-90)/90),
  }
end
for i=180,270 do
  rayDirections[i] = {
    [1] = (0)-((i-180)/90),
    [2] = (1)-((i-180)/90),
  }
end
for i=270,360 do
  rayDirections[i] = {
    [1] = (-1)+((i-270)/90),
    [2] = (0)-((i-270)/90),
  }
end
rayShadow = true
function castRay(rayYaw)
  while rayYaw > 360 do
    rayYaw = rayYaw - 360
  end
  while rayYaw < 0 do
    rayYaw = rayYaw + 360
  end
  rayX = xPos
  rayY = yPos
  rayYaw = math.round(rayYaw)
  for len=1,rayDist do
    rayY = rayY + (rayDirections[rayYaw][2]/10)
    rayX = rayX + (rayDirections[rayYaw][1]/10)
    if rayShadow then
      if not rayPixels[math.round(rayX)] then
        rayPixels[math.round(rayX)] = {}
      end
      if math.round(rayX) > 0 and math.round(rayX) <= #level and math.round(rayY) > 0 and math.round(rayY) <= #level then
        if level[math.round(rayX)][math.round(rayY)] then
          rayPixels[math.round(rayX)][math.round(rayY)] = level[math.round(rayX)][math.round(rayY)]
        else
          rayPixels[math.round(rayX)][math.round(rayY)] = colors.white
        end
      end
    end
    --rayY = rayY + (rayDirections[rayYaw][2]/10)
    --rayX = rayX + (rayDirections[rayYaw][1]/10)
    if math.round(rayX) > 0 and math.round(rayX) <= #level and math.round(rayY) > 0 and math.round(rayY) <= #level then
      if level[math.round(rayX)][math.round(rayY)] then
        return len,level[math.round(rayX)][math.round(rayY)]
      end
    end
  end
  return false
end
xRaw = 2
yRaw = 2
h2 = math.round(h/2)
fovMultiplier = 1
fov = w/fovMultiplier
function redraw()
  win.setVisible(false)
  xPos = math.round(xRaw*5)/5
  yPos = math.round(yRaw*5)/5
  rayPixels = {}
  xDraw = 0
  win.setBackgroundColor(colors.white)
  win.clear()
  fillBox(1,h/2,w,h+1,colors.lightGray)
  for i=yaw-(fov/2),yaw+(fov/2),fovMultiplier do
    size,col = castRay(math.round(i))
    if size then
      if size > (h*2) then
        size = h*2
      end
      size = (h/2)-(size/6)
      fillBox(xDraw,(h/2)-size,xDraw+(fovMultiplier-1),(h/2)+size,col)
    end
    xDraw = xDraw + fovMultiplier
  end
  win.setVisible(true)
  for x=1,#level do
    for y=1,#level[x] do
      if level[x][y] then
        paintutils.drawPixel(x,y,level[x][y])
        if rayPixels[x] then
          if rayPixels[x][y] then
            term.setBackgroundColor(colors.lightGray)
            term.setTextColor(rayPixels[x][y])
            term.setCursorPos(x,y)
            write(".")
          end
        end
      else
        paintutils.drawPixel(x,y,colors.gray)
        if rayPixels[x] then
          if rayPixels[x][y] then
            term.setTextColor(rayPixels[x][y])
            term.setCursorPos(x,y)
            write(".")
          end
        end
      end
    end
  end
  term.setBackgroundColor(colors.lightBlue)
  term.setCursorPos(xPos,yPos)
  term.setTextColor(colors.white)
  pointYaw = yaw + 45
  if pointYaw >= 0 and pointYaw < 90 then
    write("^")
  elseif pointYaw >= 90 and pointYaw < 180 then
    write(">")
  elseif pointYaw >= 180 and pointYaw < 270 then
    write("v")
  elseif pointYaw >= 270 and pointYaw < 450 then
    write("<")
  end
end
while true do
if yaw > 360 then
  yaw = 0
elseif yaw < 0 then
  yaw = 360
end
redraw()
term.setCursorPos(1,h)
term.setBackgroundColor(colors.lightGray)
write(tostring(yaw))
e,k = os.pullEvent("key")
if k == keys.left then
  yaw = yaw - 10
elseif k == keys.right then
  yaw = yaw + 10
elseif k == keys.w then
  yRaw = yRaw + rayDirections[yaw][2]/5
  xRaw = xRaw + rayDirections[yaw][1]/5
elseif k == keys.s then
  yRaw = yRaw - rayDirections[yaw][2]/5
  xRaw = xRaw - rayDirections[yaw][1]/5
elseif k == keys.a then
  if yaw > 270 then
    yRaw = yRaw + rayDirections[yaw-90][2]/5
    xRaw = xRaw + rayDirections[yaw-90][1]/5
  else
    yRaw = yRaw - rayDirections[yaw+90][2]/5
    xRaw = xRaw - rayDirections[yaw+90][1]/5
  end
elseif k == keys.d then
  if yaw > 270 then
    yRaw = yRaw - rayDirections[yaw-90][2]/5
    xRaw = xRaw - rayDirections[yaw-90][1]/5
  else
    yRaw = yRaw + rayDirections[yaw+90][2]/5
    xRaw = xRaw + rayDirections[yaw+90][1]/5
  end
elseif k == keys.up then
  yaw = yaw - 1
elseif k == keys.down then
  yaw = yaw + 1
elseif k == keys.enter then
  break
end
end