itch.io

So it's taken some time, but after using the brick-wall method (banging my head against it until it works) I've finally managed to get a working save-safe (mostly) efficient storage metod that can store up to 10 characters. 11 or more characters will cause an overflow, so I've taken the liberty of putting a sanity check in for that.

I wanted to stick to my original rules (1-53, 1 is capital 'A', 27 is lowercase 'a' and 53 is space), meaning I needed 6 bits per character; after doing a little tinkering with binary (specifically trying to come up with a way to handle bitflags for saves) I came up with a method that seems to be working, but has some overhead (2-4 bits) caused by  endianness that I'm not sure how to fix.

Anyway, here's the code (Size: 710)

nums={3,34,44,41,40,41,45,48,9,9}
local fmt=string.format
--Size counting starts on next line
function combine(tab)
 local out=0
    if #tab > 10 then trace"Error: Input table too big."end
 for i=1,#tab do
        if tab[i] then
            if tab[i]>53 then tab[i]=53 end
            out=out+tab[i]
            out=out<<6
     end
    end
 return out
end
function bytify(num)
 local out={}
    local i=1
    while num>0 do
        out[i]=num & 0xFF
     num=(num >> 8) // 1
        i=i+1
    end
    return out
end
function rebuild(tab)
 local out=0
    for i=#tab,1,-1 do
        if tab[i] then
            out = (out << 8)
         out = out + (tab[i]&0xFF)
        end
    end
    return out
end
function retable(num)
 local out={}
 local i=0
    while num>0 do
     if num>0 then
         out[i]=num&0x3F
      num=(num>>6)//1
        end
        i=i+1
    end
    local n={}
    for i=1,#out do
     n[#out-(i-1)]=out[i]
    end
 return n
end
--Size counting stops at end of previous line
--Debug Stuff but shows how to use the code
trace("Starting name:\n "..table.concat(nums,','))
val1 = combine(nums)
trace("Integer out:\n "..fmt("%0X",val1))
val2 = bytify(val1)
trace("Bytes out:\n "..table.concat(val2,","))
val3 = rebuild(val2)
trace("Integer confirm:\n "..fmt("%0X",val3))
val4 = retable(val3)
trace("Confirm:\n "..table.concat(val4,','))

And a little proof that it's working (as best as I can make it work with my current skills):

This works in tandem with some of my above code (specifically this:

ltrs="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz "
function str2num(str)
 local s={}
 for i=1,#str do
  s[i]=ltrs:find(str:sub(i,i))
 end
    return s
end

to convert the name string into a table. I haven't done the opposite conversion yet, but it wouldn't be that difficult, and you could even forgo the string step altogether if you operated strictly on a table and used a "name()" function or equivalent to convert the table into a string for use in your game.