Some oddities

Stealthy71088 · Post by **Stealthy71088** » Thu Dec 02, 2010 20:30

So I was playing through the original keen 1 today, trying to see if I could beat the game without firing a shot. In the first level, at the very end standing on the first set pink tiles above the ground, I saw two yorps get stuck in the wall like vorticons, one on the left side of the pink tile on the ground, and one on the left side of the red tile at the top of the bridge. I've never seen that before. Is this common knowledge?

Something else I remembered playing keen 4 but I keep forgetting to post on here- in Crystalus, there is one mad mushroom on the left hand side of the main level, at about mid height. This mushroom likes to sit there and do its normal bouncing routine, but if you sit there and wait long enough, it will jump, land on top of the jump throughable ground above it, and just start bouncing off that ground. The weirdest thing is that there is candy directly above that platform, at just the right height for the mushroom to jump through it on the high jumps. (as mushrooms in keen4 are known to do) Its almost as if the developers deliberately programmed for that glitch.

MOM4Evr · Post by **MOM4Evr** » Thu Dec 02, 2010 22:02

Yeah, I've seen both of those. But good question about the second one. Anybody know under exactly what circumstances the second one happens? Because it doesn't happen always.

Grimson · Post by **Grimson** » Thu Dec 02, 2010 22:14

But good question about the second one. Anybody know under exactly what circumstances the second one happens? Because it doesn't happen always.

It does, you just have to wait long enough.

Stealthy71088 · Post by **Stealthy71088** » Fri Dec 03, 2010 0:03

I guess what I'm curious about is why does it happen? And why does it take so long to work? Is it bouncing different heights each time?

I've never seen it happen in the cave of descendants, but I'm pretty sure the way its set up, it should happen there too.

Grimson · Post by **Grimson** » Fri Dec 03, 2010 9:36

I've never seen it happen in the cave of descendants, but I'm pretty sure the way its set up, it should happen there too.

Yup, happens there as well.

kuliwil · Post by **kuliwil** » Sat Dec 04, 2010 9:01

I hadn't thought that it was a glitch at all!

But yeah, good question about variable jump heights!

K1n9_Duk3 · Post by **K1n9_Duk3** » Sun Dec 05, 2010 20:13

It might be due to an integer overflow in a timer variable. Let's say the shroom moves up a pixel every 10 frames. If the timer reaches, for example, 255 and is increased again, it will be set to 0 (assuming the timer is a 1-byte variable). This will cause the shroom to move up about 5 frames too soon, thus making it jump higher and reach the higher platform.

I'm sure this is not exactly what happens in Keen 4, but it explains a possible cause.

Post by **KeenRush** » Sun Dec 05, 2010 23:35

That bug with yorps has never happened to me, in all my years of Keen 1 playing (or then I've just never noticed it). But I don't doubt it, the enemies are likely to share pieces of coding...

As for the mad mushroom, I've noticed that happening in Crystalus and the Cave but I didn't know that it will always happen if one keeps waiting. Neat. Maybe it's a rounding 'error' with a variable so that at some point the height of the jump becomes 1 pixel too high and that's enough to make them get on the higher platform (if it's not a bug, it's a pretty nicely hidden feature).

Post by **Levellass** » Sun Dec 12, 2010 7:15

Never noticed the Yorp bug before. It needs snapshotting and posting on keenwiki.

If what we have is a timer bug, then it should be predictable, it should always take x jumps before the error occurs. Possibly also it's a sprite clipping error.

Nospike · Post by **Nospike** » Sun Dec 12, 2010 10:03

Well, since I've got new sprites for Botafloria, the stuck yorp bug sometimes happens. It's strange, because only the sprite image got changed, the hitbox is intact... so it probably isn't a problem with the sprite itself.

Post by **Levellass** » Tue Dec 21, 2010 7:47

Possibly if you change the Yorp searching\stunned spees from zero to a very small positive value, such as $0002W, that might trigger the 'hit wall' response?

Nospike · Post by **Nospike** » Tue Dec 21, 2010 15:25

Yeah, I changed the duration of the searching animation.

davidchatman · Post by **davidchatman** » Tue Jul 12, 2011 4:57

I want to know the answer of second question.

Gridlock · Post by **Gridlock** » Tue Jul 12, 2011 5:03

I've noticed that the gravity of the Mad Mushroom seems to change sometimes. The jumping and falling speed often seems to go from fairly slow to a lot faster and vice-versa. It's rather subtle, and it took me years to notice, but I bet it has something to do with that oddity.

Also, has anyone noticed that if you save and load in the last part of Crystalus (after the door) that the camera often gets messed up and you can see the bottom EDGE OF MAP blocks and random garbage below them?

Stealthy71088 · Post by **Stealthy71088** » Tue Jul 12, 2011 21:06

Saw that one on my first playthrough. I was little and didn't understand what was meant by map.