function init()
  mode(1)

  mountains = {}
  local val = 2
  for i=0,99 do
    val = mid(1,val+rnd(3)-1,4)
    mountains[i] = val
  end 

  ox=0
end

function update()
  cls()
  draw_mountains()

  if btn(KEY_RIGHT) then ox=(ox+1)%100 end
  if btn(KEY_LEFT) then ox=(ox-1)%100 end
end

function draw_mountains()
  color(COLOR_RED,COLOR_BLACK)
  for i=0,39 do
    local x=(ox+i)%100
    for j=29-mountains[x],29 do
      local chr="\143"
      if j==29-mountains[x] then
        if mountains[(x+1)%100] > mountains[x] then
          print("\214",i,j-1) --chr="\214"
        elseif mountains[(x+1)%100] < mountains[x] then
          chr="\215"
        end
      end
      print(chr,i,j)
    end
  end  
end