Things I've done today

[davidn]

• Drew quite a lot of this stuff:
  


• Wrote procedures to save a compressed level format - instead of saving every value, it does what CDs do and saves them as strings of identical tiles - this can cause massive savings on blank spaces, which are recorded not as 208,992 zeroes but as "[repeat tile 0 208,992 times]"


• Realized that this method of loading was much slower - about four of five seconds a room, which wasn't crippling but was annoying


• Worked on improving the loading procedure as well, so that it completely skipped over stretches of blank tiles, calculating where it should land in the level array rather than stepping through (240000*SaveZ( "SaveVars" )+600*SaveY( "SaveVars" )+SaveX( "SaveVars" ) + Gap, then translated back into coordinates)


• Thanks to that, got even quite large rooms to load instantly!


• Realized that one day's work of patching up all of the above later, I'm now exactly where I started the day, except with level files that take up 2-4KB instead of 2MB. This could have been quite important in 1997

Still, I like the cave texture.

Comments

[premchaia_pre4]

It could also be quite important if you release a version people on constrained networks might play with downloadable levels, mobile being the classic example.

Everything old is new again.

Append: wait, what CDs do? Surely not for Redbook audio—are you talking about some other encoding that I don't recall? The main uses of RLE I recall involve BMP and… ZZT, the latter of which sounds quite plausible for you.

[davidn]

I couldn't remember the name of run-length encoding at the time - I meant at the byte level, where a CD changes from a pit to a land not to represent zeroes and ones directly but to indicate changes (except I remembered it wrongly and it's really nothing like what I implemented here).

I didn't realize that BMPs used any compressive encoding, I thought they just naively stored every pixel (hence a 640x480 one took up 1MB, a huge amount on my 386's hard drive).

[premchaia_pre4]

You mean a differential encoding except for the part where it's not due to lack of tea? Actually, albeit unrelatedly, non-single-bit delta encoding is used together with RLE in cases where linear runs are common and light decoding is needed: take the derivative of the original signal, and the linear runs become constant runs which you can conveniently RLE, and then integrate again on the receive side.

Edit: actually it's the opposite: the function from {zero, one} to {pit, land} is based on discretely integrating over GF(2), not differentiating, bah. TEA TIME.

And here my best hypothesis was that you'd meant to write “ZZT” and merely got the voiced/unvoiced consonants inverted in the verbal processing, thus turning the Z into a C and the T into a D!

Windows Bitmap format can use RLE but I think can also have raw data, so it presumably depends on the program that writes the file.

[rakarr.livejournal.com]

I think having level files that are 2-4KB instead of 2MB is fantastically worthwhile. We might, by and large, have so much space and internet speed that 2mb doesn't seem like much, but 2kb is still a thousand times smaller, and any improvement in size and loading efficiency is absolutely worthwhile. If more game developers bothered with that we might not need 3TB hard drives and huge amounts of memory. So, bravo. I'll definitely be asking your advice on efficiency if I ever make a game.

And I like the cave texture too!

[crassadon.livejournal.com]

It should be more purply