dev version of mine1k. some comments, might be helpful

README.md

Hi! Here's the source code to my minesweeper demake. it's just 1024 bytes!

Q: this looks longer than 1024 characters..?

Yes, this file is much longer. This is the commented "dev" version -- the human-readable version of the code that I wrote by hand. the final submission is the result of running this code through some minification scripts that rename the variables and remove comments and whitespace.

To view the final 1024-byte code, open the minified version, press play, and then press escape twice to open the code editor.

Note that the 1024-byte codesize is measured by the size of the compressed cartridge, not raw character count. that's why you see so much repeated code here -- it compresses well

For more details, see the pico1k 2022 jam page

Q: still, the minified version on pico-8-edu.com says 1028 compressed bytes

I custom-compressed the code using shrinko8 -- the tool tends to compress slightly better than pico-8 itself. So the mine1k.p8.rom file is exactly 1024 bytes, but when pico8 decompresses it and then recompresses it as best as it can, it ends up at 1028 bytes. both files are valid compressed pico8 encodings, but one of them is a little smaller!

sprites

the sprites in the game are stored in the code as strings, and converted into sprites during startup. see JadeLombax's tutorial for more info -- I used a modified version of the RLE sprite compressor shown there

comments

The comments were written as I worked, with only my future self in mind. I haven't edited them to try and explain things. so, this "commented source code" might not be that helpful to you! but maybe it's a little bit helpful, so here you go. feel free to leave a comment on the itch page or tweet at me if you have questions about this code

devlog

I wrote a bit about this code here

mine1k.lua

numfont={"⁶.\0008llll8\0","⁶.\0「、「「「<\0","⁶.\0008d`8ᶜ|\0","⁶.\0008d0`d8\0","⁶.\000044|00\0","⁶.\0|ᶜ<`d8\0","⁶.\0008ᶜ<ll8\0","⁶.\0|`0「「「\0","⁶.\0008l8ll8\0","⁶.\0008llx`8\0","⁶.$\0B<\0\0\0\0","⁶.$\0<B\0\0\0\0","⁶.~l²<\0\0\0\0","⁶!5f000\0¹²","⁶!5f00²³⁴\t"}

for i=1,177do o=ord("$²¹\n¹\n¹⁴-¹$²⁴²\r²\n³ ⁷$²⁴¹³\r\n³ ⁷$²%⁴³ ⁷$²⁴」\n³ ⁷$²⁴²\r²\n³ ⁷$²¹\n¹\n¹⁴³ ⁷,.³+E¹ᶜ1³ᵉ⁙ᵉ⁷ᶜ-¹³⁸¹▶¹⁸⁷ᶜ³²▮⁸⁷³²¹#¹²⁷ᶜ³²▮⁸⁷³¹/\rᶜ³²▮⁸⁷³¹/\rᶜ³²⁷³⁸⁷³¹/\rᶜ³ᵉ³⁸⁷³¹/\rᶜ³⁸\r²⁷³²¹#¹²⁷ᶜ³+³⁸¹▶¹⁸⁷ᶜ1³ᵉ⁙ᵉ⁷B³CB",i)for i=0,o\6do sset(⬅️%25,⬅️\25,o%6)⬅️+=1end end

-- note: can remove the +1 in direct ord since first char is \0

-- cls()
-- -- hexdump(0x5f00,32)
-- ?"\^!5f1061=78*,3=0562911" --pal
-- -- hexdump(0x5f00,32)
-- poke(0x5f2e,1) --pal persist
-- spr(0,0,32,16,16)
-- stop()

gmine={}
gnum={}
gflag={}
gvis={}
revq={}

::o::
?"\^1\^c"
ghold={}

mbtnr=~stat(34)&mbtn
mbtnp=stat(34)&~mbtn
mbtn=stat(34)&3
i=mid(stat(32)\8,15)+stat(33)\8*16-32
sr=0 --spooky #2
--sum into sr
for ii=1,8do
 jr=i+ord("•、。+-;<=",ii)-44
 if(abs(i%16-jr%16)<2and jr==jr%224)sr+=gflag[jr]
end

-- if not dead/won, and cell is inbounds, do mouse interaction
-- if death==999and jr==jr%224then -- dunno why this loses 3CB, should be good
if death==999and gflag[i]then
 -- LMB held: mark non-flag cells as preview-held
 jr=i --spooky #1
 if 0<1&mbtn then
  ghold[jr]=gflag[jr]<1 --spooky #1
 end
 -- LMB+RMB held: enter splatmode, and show 3x3 preview-hold
 if 2<mbtn then
  splat=999
  for ii=1,8do
   jr=i+ord("•、。+-;<=",ii)-44
   if(abs(i%16-jr%16)<2and jr==jr%224)ghold[jr]=gflag[jr]<1 -- (reason for spooky #1)
  end
 end
 -- LMB released, and not splatmode: reveal cell
 --   note: revq code deals already-revealed cells
 if 1&mbtnr>splat then
 -- if mbtnr&1>0and splat<1then
  add(revq,i)
 end
 -- RMB released, and not splatmode or revealed: flag cell
 if mbtnp&2>splat+gvis[i]then
 -- if mbtnp&2>0and splat<1and not gvis[i]then
  remain+=2*gflag[i]-1 -- could reverse this for next line; doesn't help currently
  gflag[i]=1-gflag[i]
 end
 -- either released, and in splatmode: splat! (if flag count matches minecount, and cell is already revealed)
 --   note: revq code deals already-revealed cells
 if splat&gvis[i]&mbtnr>0and sr==gnum[i]then --spooky #2
 -- if mbtnr>0and splat>0and sr==gnum[i]and gvis[i]then --note 999&3==3
  for ii=1,8do
   jr=i+ord("•、。+-;<=",ii)-44
   if(abs(i%16-jr%16)<2and jr==jr%224)add(revq,jr)
  end
 end
 -- none held: exit splatmode
 if 1>mbtn then
  splat=0
 end
end
-- if mbtnp>mbtnp*i then --mbtnp>0 and i<0 (bug: i==0 resets)
-- if mbtnp>0and abs(i%16-8)<2then -- same CB but bad ux. also needs elseif
if mbtnr>i+25&238then
 reset=8
end

-- levelgen
if reset>1then
reset=1
death=999
remain=0
time=0

for i=0,223do
 gmine[i]=0
 gflag[i]=0
 gnum[i]=0
 gvis[i]=0
 gvis[-i]=0
 if(rnd(9)>7)gmine[i]=1remain+=1
end

for i=0,223do
 hidden=remain-223 --spooky order. must be after last remain calc
 --sum into gnum
 for ii=1,8do
  jr=i+ord("•、。+-;<=",ii)-44
  if(abs(i%16-jr%16)<2and jr==jr%224)gnum[i]+=gmine[jr]
 end
end
end
time+=1/30

-- tophud
rect(0,0,223,15,3) --white --spooky: 0,223 is any 0,>=128
rect(0,14,223,15,1) --blue --spooky: 223 is any >=127
sspr(0,8,13,13,58,2)
?numfont[12-death\999],60,6

-- seg8 displays
for i=0,2do
 ?"\#9"..numfont[1+min(death,time)\10^i%10],117-6*i,3,4
 ?"\#9"..numfont[1+remain\10^i%10],15-6*i,3,4
end

-- reveal queue
for i=1,#revq do
 i=deli(revq,1)
 -- if tile is not flagged, reveal it
 if 1>gflag[i]then
  -- die to mines
  if 0<gmine[i]then
   ?"\as8i6c2.c3g2c" --⁷
   death=time
   reset*=8
  -- new reveals
  elseif 1>gvis[i]then
   ?"\ac0"
   reset=0
   hidden+=1
   if 0<hidden then
    ?"\acg"
    death=time-1000
   end
   if 1>gnum[i]then
    for ii=1,8do
     jr=i+ord("•、。+-;<=",ii)-44
     if(abs(i%16-jr%16)<2and jr==jr%224)add(revq,jr)
    end
   end
  end
  gvis[i]=3
 end
end

-- draw cells
for i=0,223do
 x=i%16*8 y=i\16*8+16
 ?"\^!5f1061=78*,3=0562911" --pal --spooky order
 ?"\^!5f2d1" --mouse. ⁶
 ?"\^!5f5e◝" --reset bitplanes

 -- if 0<gvis[i] or (dev_look and btn(4,1))then
 if 0<gvis[i]then
  -- if visible, draw empty space or mine
  if 0<gnum[i]then
   ?numfont[1+gnum[i]],x-1,y-1,ord("6741,2*5",gnum[i])
  end
  spr(gmine[i],x,y)
 elseif ghold[i]then
  -- preview-hold: show empty space
  spr(0,x,y)
 else
  -- otherwise: show solid block (maybe with flag)
  sspr(16,9*gflag[i],9,9,x-1,y-1)
 end
 ?"\^!5f5e☉" --bitplanes
 if gvis[i-16]<gvis[i]then
  rect(x,y,x+8,y,8) -- bitplane shadow
 end
 if gvis[i-1]<gvis[i]then
  rect(x,y,x,y+8,8) -- bitplane shadow
 end
end
-- y=stat(33)+4
-- rect(stat(32)-1,y,stat(32)+4,y,8) -- bitplane shadow
-- y+=1
-- rect(stat(32),y,stat(32)+4,y,8) -- bitplane shadow
-- y+=1
-- rect(stat(32)+1,y,stat(32)+3,y,8) -- bitplane shadow

--mouse
?"⁶.\0\0\0\0\0??゛",stat(32)-1,stat(33)-1,8 --shadow
?"\^!5f5e◝" --reset bitplanes
?"⁶.²⁵\t■!」⁶\0",stat(32)-1,stat(33)-1,1 --border
?"⁶.\0²⁶ᵉ゛⁶⁸\0",stat(32)-1,stat(33)-1,3 --white
-- pset(stat(32),stat(33),4)

-- smiley hitbox debug
-- for i=0,255do
--  x=i%16*8 y=i\16*8
--  i-=32
--  if i-7&(255-1-16)==224then -- check < 3 too
--   rect(x,y,x+7,y+7,5)
--  end
-- end
goto o