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HIVE PICO-8 Tutorial

§6

6a: map, sprites & palette swapping

cloudly.p8

function _draw()
  --bg
  cls(1)
  circfill(84,20,5,10)
  rectfill(0,90,127,127,0)
  --map
  palt(0, false)
  palt(1, true)
  pal(13,0)
  map(0,0,0,0,16,16)
  palt()
  pal()
  --cloud
  spr(0,50,0,4,4)
end

function _update()

end

6b: simple timers & palette cycling

cloudly.p8

cloudx=128
cloud=0
flash=false
flashdown=100

function _draw()
  --bg
  cls(flash and 3 or 1)
  circfill(84,20,5,10)
  rectfill(0,90,127,127,flash and 14 or 0)
  --map
  palt(0, false)
  palt(1, true)
  if not flash then
    pal(13,0)
  end
  map(0,0,0,0,16,16)
  palt()
  pal()
  --cloud
  if flash then
    pal(6,7)
    pal(13,7)
  end
  pal()
  spr(cloud,cloudx,0,4,4)
  flash=false
end

function _update()
  --cloudcode
  cloudx-=.3333
  if cloudx < -32 then
    cloudx=128+RND(20)
    cloud=flr(rnd(3))*4
  end

  --flash counter
  flashdown-=1
  if flashdown <= 0 then
    flash=true
    flashdown=rnd()<.4 and rnd(100) or rnd(20)
  end
end

6c: custom functions & powers of recursion

cloudly.p8

cloudx=128
cloud=0
flash=false
flashdown=100

function _draw()
  --bg
  cls(flash and 3 or 1)
  circfill(84,20,5,10)
  rectfill(0,90,127,127,flash and 14 or 0)
  --map
  palt(0, false)
  palt(1, true)
  if not flash then
    pal(13,0)
  end
  map(0,0,0,0,16,16)
  if flash and rnd()<.2 then
    spr(218,rnd(120)+4,72+rnd(44),1,3)
  end
  palt()
  pal()
  --cloud
  if flash then
    pal(6,7)
    pal(13,7)
    lightning(cloudx+16,20)
  end
  pal()
  spr(cloud,cloudx,0,4,4)
  flash=false
end

function _update()
  --cloudcode
  cloudx-=.3333
  if cloudx < -32 then
    cloudx=128+RND(20)
    cloud=flr(rnd(3))*4
  end

  --flash counter
  flashdown-=1
  if flashdown <= 0 then
    flash=true
    flashdown=rnd()<.4 and rnd(100) or rnd(20)
  end
end

function lightning(x,y)
  local newx=x+(rnd(2)-1)*16
  local newy=y+(rnd(2)-.3)*10
  line(x,y,newx,newy,rnd(7)+8)
  if newy<110 then
    lightning(newx,newy)
    if rnd()<.1 then
      lightning(newx,newy)
    end
  end
end