function fade(progress)
	for xx=0,15 do
		for yy=0,15 do
			circfill(xx*8+4,yy*8+4,8*(1-progress)+sin((yy)/15),0)
		end
	end
end

function fade(progress)
p=progress*152
for i=8,2,-2 do
grid(i)
p-=38
end
end

function grid(mx)
for y=0,15 do
for x=0,15 do
l=min(2*flr((p-(x+y))/2),mx)/2
if l>0 then
rect(x*8+4-l,y*8+4-l,x*8+3+l,y*8+3+l,0)
end
end
end
end

function fade(p)
	if not _░_ then
		--shuffle rnd-id
		_░_={}
		for i=0,255 do
			add(_░_,i)
			add(_░_,deli(_░_),rnd(i)+1)
		end
	end

	local i,s=1/(256+1) --make an extra loop
	poke(0x5f55,0x0)
	rectfill(8,0,23,15,0) --init sprite{1,2,17,18}
	poke(0x5f55,0x60)
	while p>0 do
		s=_░_[p\i+1] or 0
		sset(s\16%16+8,s%16,7)
		p-=i
	end
	pal(7,0)
	local s={1,2,17,18} --sprite-id table
	local p,q
	for i=0,255 do
		local p,q,r=unpack(_░_,i+1,i+4)
		spr(s[p%4+1],i%16*8,i\16%16*8,1,1,(q or 1)%2==0,(r or 2)%2==0)
	end
	pal()
end

function fade(progress)
  for i=0, 3 do
    for j=0, 3 do
      for k=0, 4 do
        sset((i%2)+(j%2)*2+(k%2)*4+120,((i+1)\2)+(j\2)*2+(k\2)*4+56,5-#tostr(i*4+j > progress*16))
      end
    end
    sset(i*2+121,56,5-#tostr(progress < 0.6))
  end
  pal(1,0)
  for i=0, 15 do
    for j=0, 15 do
      spr(127,i*8,j*8)
    end
  end
  pal()
end

function fade(progress)
  local px,py,dx,dy=123,59,0,-1
  for i=56,63 do
   for j=120,127 do
    sset(j,i,0)
    assert(sget(j,i)==0)
   end
  end  
  while progress>0 do
    sset(px,py,1)
    if(sget(px-dy,py+dx)==0) then
     px,py,dx,dy=px-dy,py+dx,-dy,dx
    else
     px,py=px+dx,py+dy    
    end
    progress-=1/64
  end

  pal(1,0)
  spr(0,0,0,16,16)
  for i=0, 15 do
    for j=0, 15 do
      spr(127,i*8,j*8)
    end
  end
  pal()
end

function fade(progress)
 --disable transparency
 palt(0)
 -- set screen as sprite source
 poke(0x5f54,0x60)
 -- zoom out screen
 local x,w
 x=(64*progress+0.5)&127
 w=(128*(1-progress)+0.5)&127
 sspr(0,0,128,128,x,x,w,w)
 -- set spritesheet back to normal
 poke(0x5f54,0x00)
 -- enable inverted draw
 poke(0x5f34,0x2)
 --inverted rectangle black border
 rectfill(x,x,x+w-1,x+w-1,0 | 0x1800)
end