Flappy CC

-- Flappy Bird clone

-- XXX scoring doesn't work at irregular frametimes (i.e. only 10/20 work)
local ftTarget = 1/10
local score = 0

local pillars = {}

if not term.isColor() then
  error("this program requires an advanced computer", 0)
end

local old
if not term.current().isVisible then
  old = term.redirect(window.create(term.current(), 1, 1, term.getSize()))
end

-- CC maxes out at 20fps
if ftTarget < 1/20 then
  ftTarget = 1/20
end

-- half the gap size in characters
local gapsize = 4
local width, height = term.getSize()
local pillarCount = math.floor(width / 10)

local halfHeight = math.floor(height * 0.5)
-- x is x-coordinate on screen
-- height is the y-coordinate at which the center of the gap is
local function drawPillar(x, y)
  x = math.floor(x)
  -- draw the top bit
  local tby, bty = y - gapsize, y + gapsize
  for i=1, height, 1 do
    if i < tby or i > bty then
      term.setCursorPos(x, i)
      term.blit("  ", "5d", "5d")
    end
  end
end

local birdX = math.floor(width / 2)
local function drawBird(y)
  term.setCursorPos(birdX, y)
  -- flip/flip/noflip
  term.blit(" \x84\x90", "3f1", "443")
  term.setCursorPos(birdX, y+1)
  -- flip/flip/noflip
  term.blit("  \x81", "331", "443")
end

local birdY, birdV = math.floor(height / 2), 0
local gapH, gapL = math.ceil(height * 0.25 + 0.5), math.floor(height * 0.75)
local pillarGap = math.ceil(width / pillarCount)

local function drawObjects()
  term.current().setVisible(false)
  term.setBackgroundColor(colors.lightBlue)
  term.clear()
  for i=1, #pillars, 1 do
    drawPillar(pillars[i].x, pillars[i].gap)
  end
  drawBird(math.floor(birdY))
  term.setTextColor(colors.black)
  term.setCursorPos(1, 1)
  term.write("Score: " .. tostring(score))
  term.current().setVisible(true)
end

local function tickObjects()
  birdV = birdV - 5*ftTarget
  birdY = birdY - (birdV * ftTarget * 10)
  if #pillars < pillarCount then
    if #pillars == 0 or pillars[#pillars].x < width - pillarGap then
      pillars[#pillars+1] = {x = width, gap = math.random(gapH, gapL)}
    end
  end
  for i=#pillars, 1, -1 do
    pillars[i].x = pillars[i].x - 10*ftTarget
    if pillars[i].x < -1 then
      table.remove(pillars, i)
    elseif pillars[i].x >= birdX and pillars[i].x <= birdX + 1 then
      local tby, bty = pillars[i].gap - gapsize, pillars[i].gap + gapsize
      if birdY < tby or birdY > bty then
        birdV = 2
        repeat
          birdV = birdV - 5*ftTarget
          birdY = birdY - (birdV * ftTarget * 10)
          drawObjects()
          os.sleep(ftTarget)
        until birdY > height + 10
        if old then term.redirect(old) end
        term.setBackgroundColor(colors.black)
        term.setTextColor(colors.white)
        term.clear()
        term.setCursorPos(1,1)
        error("died; score " .. score, 0)
      elseif pillars[i].x == birdX then
        score = score + 1
      end
    end
  end
end

-- target 10fps
local tid
local function tickInput()
  local sig, id, x, y = os.pullEvent()
  if sig == "timer" and id == tid then
    tid = os.startTimer(ftTarget)
    tickObjects()
  elseif sig == "mouse_click" or sig == "monitor_touch" or
      (sig == "key" and id == keys.space) then
    birdV = 2
  end
end

tickObjects()
drawObjects()
term.setTextColor(colors.black)
term.setCursorPos(3, 3)
term.write("press space, click, or tap")
repeat
  local sig, id = os.pullEventRaw()
until (sig == "key" and id == keys.space) or sig == "mouse_click"
  or sig == "monitor_touch"
tid = os.startTimer(0.1)
birdV = 2

while true do
  tickInput()
  drawBird(math.floor(birdY))
  drawObjects()
end