Arkanoid (wip) - following the Pico-8 Hero video series

arkanoid.p8

pico-8 cartridge // http://www.pico-8.com
version 16
__lua__

function center(width)
 return (screen_width / 2) - (width / 2)
end

function _init()
 cls()

 screen_width = 127
 x_zero = 0
 y_zero = 8

 pad = {
  sl = 1,
  sc = 2,
  sr = 1,
  len = 5, -- change this dynamically during update
  x = screen_width / 2, -- set this dynamically during update
  y = screen_width - 16,
  h = 8,
  dx = 0,
 }
 pad.x = center(pad.len * 8)
 pad.w = pad.len * 8

 ball = {
  x = center(0),
  y = pad.y - 2,
  dx = 1,
  dy = -1,
  r = 2,
  c = 7,
 }

 bricks = {}

 game = {
  state = 1,
  lives = 3,
  points = 0,
  hiscore = 0,
 }

 states = {
  splash = 1,
  game = 2,
  gameover = 3,
 }

end

colors = {8,9,10,11,12,14}
numblocks = 0

function buildbricks()

 for row=1,#colors do
  for col=1,8 do
   local _b = {
    v = true,
    w = 12,
    h = 4,
    c = colors[row],
   }
   _b.y = (_b.h+2) * (row + 2)
   _b.x = (_b.w+2) * (col - .5)

   -- increment numblocks count
   numblocks += 1

   add(bricks,_b)
  end
 end
end

function collide(box, projx, projy)
 if projy - ball.r > box.y + box.h
 or projy + ball.r < box.y
 or projx - ball.r > box.x + box.w
 or projx + ball.r < box.x
 then return false end

 return true
end

function collide_side(box)
 local slope = ball.dy / ball.dx
 local cx, cy
 if ball.dx == 0 then
  return false
 else
  if ball.dy == 0 then
   return true
  elseif slope > 0 and ball.dx > 0 then
   cx = box.x - ball.x
   cy = box.y - ball.y
   return cx > 0 and cy/cx < slope
  elseif slope < 0 and ball.dx > 0 then
   cx = box.x - ball.x
   cy = box.y + box.h - ball.y
   return cx > 0 and cy/cx >= slope
  elseif slope > 0 and ball.dx < 0 then
   cx = box.x + box.w - ball.x
   cy = box.x + box.h - ball.y
   return cx < 0 and cy/cx <= slope
  else
   cx = box.x + box.w - ball.x
   cy = box.y - ball.y
   return cx < 0 and cy/cx >= slope
  end
 end
end

function update_splash()
 if btnp(5) then
  startgame()
 end
end

function update_gameover()
 if btnp(5) then
  startgame()
 end
end

function startgame()
 -- reset stuff
 game.state = states.game
 game.lives = 3
 game.points = 0
 pad.x = center(pad.len * 8)
 buildbricks()
end

function update_game()
 local projx, projy

 if btn(0) then
  pad.dx = -2.5
 end
 if btn(1) then
  pad.dx = 2.5
 end
 if not btn(0) or btn(1) then
  pad.dx /= 1.4
 end
 pad.x += pad.dx
 pad.x = mid(0, pad.x, screen_width - pad.w)

 projx = ball.x + ball.dx
 projy = ball.y + ball.dy

 if projx > (screen_width - ball.r) or projx < (x_zero + ball.r) then
  projx = mid( (x_zero + ball.r), projx, screen_width - ball.r)
  ball.dx = -ball.dx
  sfx(0)
 end
 -- if projy > (screen_width - ball.r) or projy < (y_zero + (ball.r*2)) then
 if projy < (y_zero + (ball.r*2)) then
  projy = mid(y_zero + ball.r, projy, screen_width - ball.r)
  ball.dy = -ball.dy
  sfx(0)
 end

  -- handle collision with pad
 if collide(pad,projx,projy) then
  game.points += 1
  if collide_side(pad) then
   ball.dx = -ball.dx
  else
   ball.dy = -ball.dy

   local padmid = pad.x + (pad.len * 4)
   -- if left side of paddle, x-
   if ball.x < padmid then
    ball.dx = -1
   end

   -- if right side of paddle, x+
   if ball.x > padmid then
    ball.dx = 1
   end

  end
  sfx(1)
 end

  -- handle collision with brick
 for b=1,#bricks do
  local _b = bricks[b]
  if _b.v and collide(_b,projx,projy) then
   if collide_side(_b) then
    ball.dx = -ball.dx
   else
    ball.dy = -ball.dy
   end

   sfx(2)
   game.points += 10
   _b.v = false
   numblocks -= 1
  end
 end


 -- update position
 ball.x = projx
 ball.y = projy

 if projy > (screen_width - ball.r) then
  -- off bottom, lose life
  game.lives -= 1
  if game.lives < 0 then
   -- game over!
   game.state = 3
   sfx(3)
   if game.points > game.hiscore then
    game.hiscore = game.points
   end
  else
   new_ball()
  end
 end

end

function new_ball()
-- stuff
 ball.x = pad.x + (pad.w/2)
 ball.y = pad.y - 2
 ball.dx = 1
 ball.dy = -1
end

function draw_splash()
 cls(5)
 local str = "press ❎ to start"
 print(str, center(#str * 4), 64, 7)
end

function draw_gameover()
 -- cls(8)
 local str
 rectfill(0, 60, 128, 68, 0)
 str = "game over!"
 print(str, center(#str * 4), 62, 10)
 str = "press ❎ to try again"
 print(str, center(#str * 4), 72, 7)
 str = "hi-score: "..game.hiscore
 print(str, center(#str * 4), 82, 11)
end

function draw_game()
 cls(1)

 -- top bar
 rectfill(0, 0, screen_width, y_zero, 0)
 print("lives: "..game.lives, 1, 2, 7)
 local score_txt = "score: "..game.points
 print(score_txt, screen_width - (#score_txt * 4), 2, 7)

 -- paddle
  -- left
  spr(pad.sl, pad.x, pad.y, 1, 1)
  -- center
  for i=1,pad.len - 2 do
   spr(pad.sc, pad.x+(i*8), pad.y)
  end
  -- right
  spr(pad.sr, pad.x+((pad.len-1)*8), pad.y, 1, 1, true) -- flipped


 -- ball
 circfill(ball.x + ball.r, ball.y + ball.r, ball.r, 0) -- shadow
 circfill(ball.x,ball.y,ball.r,ball.c) -- fg

 -- bricks
 for b=1,#bricks do
  local _b = bricks[b]
  if _b.v then
   rectfill(_b.x + 2, _b.y + 2, _b.x + _b.w + 2, _b.y + _b.h + 2, 0) -- shadow
   rectfill(_b.x, _b.y, _b.x + _b.w, _b.y + _b.h, _b.c)
  end
 end
end


function _update60()
 if game.state == states.splash then
  update_splash()
 elseif game.state == states.game then
  update_game()
 else
  update_gameover()
 end
end

function _draw()

 if game.state == states.splash then
  draw_splash()
 elseif game.state == states.game then
  draw_game()
 else
  draw_gameover()
 end


end

__gfx__
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__sfx__
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