PICO-8 snippets

neighboring_tiles.lua

-- four directions, 16 tokens
for i=0,1,0.25 do
 local x,y=cos(i),sin(i)
end

-- eight directions, 24 tokens
for i=0.125,1,0.125 do
 local x,y=flr(cos(i)+.5),flr(sin(i)+.5)
end

random.lua

--random int between 0,h
function rand(h) --exclusive
    return flr(rnd(h))
end
function randi(h) --inclusive
    return flr(rnd(h+1))
end

--random int between l,h
function randb(l,h) --exclusive
    return flr(rnd(h-l))+l
end
function randbi(l,h) --inclusive
    return flr(rnd(h+1-l))+l
end

seeded_random.lua

// before any srand() calls have happened
oldSeed=rnd(-1)

// begin deterministic stuff
srand(1)
for i=1,100 do
   somethingWhichUsesRnd()
end

// reset seed to something unpredictable
srand(oldSeed)

string_index.lua

t={"apple","orange","line"}
a="1"

t.__index=function(self,key)
 local k=tonum(key)
 if k>0 and k<=#self then -- this is needed since we don't have rawget()
  return self[k]
 else
  return nil
end
setmetatable(t,t)

printh(t[a]) -- good, prints "apple"

try_catch.lua

function try(t,c,f)
    local co=cocreate(t)
    local s,m=true
    while s and costatus(co)!="dead" do
        s,m=coresume(co)
        if not s then
            c(m)
        end
    end
    if f then
        f()
    end
end

cls()

try(function()
    print("hi ")
    --print("hi " .. nil)
end,
function(e)
    print("an error occurred:\n"..e)
end,
function()
    print("finally")
end)