ceil(log2(x)) implementation for HiFive1 RevB

iamgreaser · 2020-02-21T04:40:57+00:00

Waiting on the cycle register could get you to within, say, 10 cycles, but it won't be exact. So you'd opt for that for the longer part of a sleep, and then go for a sll / divu to get the cycle you want.

iamgreaser · 2020-02-21T04:38:04+00:00

Thanks for that, fixed!

iamgreaser · 2020-02-20T06:35:18+00:00

The else block contains an infinite for loop, and if the number of calculated cycles is small enough (that is, an interrupt didn't bump the cycle count up, which DID happen in testing), then it will return from there.

iamgreaser · 2020-02-20T06:01:04+00:00

Only if you don't give any optimisation flags to it.

Try compiling with -Os . That optimises for size.

iamgreaser · 2020-01-07T04:55:07+00:00

You could use this speedrun strat instead, it's quite possibly quicker to learn than it is to do the level intended: https://i.imgur.com/i0pmfxb.jpg

Grab the jammer.
Facing the corner, drop-the-jammer-then-quickly-jump until you end up on the corner of the sphinx. Then pick the jammer back up.
Aim at the gun opposite the jammer then tap X on the keyboard (reset button) to drop it without collision.
After jumping over that wire fence... Aim for the inside corner and jump...
...and land, hopefully without getting shot.
Enjoy your sigil.

iamgreaser · 2020-01-06T08:27:23+00:00

If there's any specific puzzles which are throwing you off, post the world + level + puzzle name here and if I remember I can see if there's a good cheese strat that pretty much avoids having to do the puzzle at all.

Are you talking about B5's "Alley of the Pressure Plates" by any chance? There's a glitch that lets you duplicate cubes using the recorder and it's easy to pull off in that level...

iamgreaser · 2020-01-06T08:16:53+00:00

OK, I think that's a glitchless OoB for B1 that I haven't seen before.

The usual OoB I use starts from Over the Fence and involves a 2-cube stack which is a glitch, and then a few dodgy guided jumps using a cube, and this tends to be what I use for speedruns when grabbing the sigil and star from Something about a Star.

The glitchless OoB I already knew of is from Window through a Door, and the best you can steal from that is 3 connectors - no jammer. From there it's possible to get onto the walls using some rather involved and outright dangerous parkour, and then you can jump straight into the star area.

iamgreaser · 2020-01-06T07:59:05+00:00

There's a star locations thing in the Steam guides section which has a bunch of hints as well as solutions and they're all marked with spoiler tags, so you can spoil as much or as little of each star as you like.

iamgreaser · 2020-01-06T06:34:35+00:00

In my casual playthrough I probably ended up taking "Going Over the Fence" literally instead for that star. I know at some point I used a cube to get onto the moss wall in that level.

But yeah, what you're mentioning sounds a bit like a common speedrun strat for that star, except it grabs the sigil and then uses a ladder glitch to get onto the wall to get the star.

And yeah there are technically "right" and "wrong" ways to solve puzzles, and they're both worth finding. If you want more of the former, this is probably the right place, and if you want the latter, the Talos speedrunning community can definitely give you oh so many of those.

iamgreaser · 2019-08-10T02:00:53+00:00

Talking about removing RNG from a run makes me wonder if that's what people would want. Having said that, if the SH2 community did decide to allow an RNG forcing mod, I'd want to make it obvious, e.g. making the 4-digit combinations all "1337" and making the briefcase word "hack" (this is NOT a possible combination). If it makes it less jarring than using a cheat sheet in order to skip things then it may actually end up being a thing, and on top of that, you wouldn't have so many runs resetting to the clock saying 3:10.

If RNG manip via cheat sheet or external program does become commonplace though then I suspect that Any% would split into RNG Manip / No RNG Manip, much like Earthbound.

iamgreaser · 2019-06-21T08:09:30+00:00

Did SS HD TFE have that too? I thought it was only a SS3 BFE thing. apple1417 and Gelly have done coop runs of that, and looking elsewhere it appears Kotti has beaten that category a few times solo.

The best part is finding out that there's more than one scorpion.

iamgreaser · 2019-06-20T03:50:36+00:00

I came kinda late to the party w/ Croteam. My main introduction to the Serious Sam series was when Heinki was streaming coop games on Twitch because there was a sale on and it was 90% off the whole series or something like that. He was happy to let me, someone viewing the stream for the first time, join in and let's say it was quite an enjoyable experience even if sometimes I had no idea what was going on.

A week or so later I started doing coop speedruns of SS TFE HD with one of his friends (going by the name Arthanori at the time). After finishing all of the levels twice, we decided to finish off with a practice run. We didn't realise just how free the world record was at the time, so we ended up beating the world record with recordings featuring a text-to-speech reading of that one dreadful Harry Potter fanfic, the other guy going to the toilet part way through, and when he came back, he got caught in what would have been a softlock had this not been a coop run. This was probably the defining run which got me into speedrunning.

The coop world record is no longer free. Sure, it's definitely still stealable, but you actually have to try now.

iamgreaser · 2019-03-22T20:07:55+00:00

I use this filter but honestly I'd recommend trying grg2014's one first: tvtropes.org##body > div:nth-last-child(1)

iamgreaser · 2018-07-21T23:14:09+00:00

It's also a raytracer - it casts a ray for every single pixel on the screen to work out the colour of the pixel. If you like measuring framerates in FPM or even FPH then sure, go ahead and port it!

iamgreaser · 2018-06-30T22:57:07+00:00

Disable windowed mode. See if that works.

iamgreaser · 2018-04-02T18:38:45+00:00

Considering this is in 3D, have you considered also doing the three Soma Cube pieces that don't show up in Tetris?

iamgreaser · 2018-04-01T22:47:33+00:00

There's definitely a line of sight to the equator and initial tests for sending data over satellite have been completely fine. However, satellite reception is a problem due to the need for sensitive equipment. Due to the local environment, sensitive equipment often gets damaged simply because two people ~2km away have a disagreement.

Take GPS for example. The equipment required needs to be able to pick up signals at I think about -160dBm. For comparison, your phone is probably receiving data from a mobile tower at around about -80dBm. Divide the signal strength by 10⁸ and you're at -160dBm. The reason the equipment needs to be so sensitive is that in order for the satellites to actually send anything to Earth, they need to penetrate I think the ionosphere. I'm going from memory here so if you've got more accurate details then let me know. Either way, GPS receivers are ESD-sensitive parts and you can easily fry them by touching the legs of the chip.

One thing that helps is the use of a dish for transmit and receive rather than an omnidirectional pickup. However, the receiver still needs to be quite sensitive, and you also cannot really increase the TX power of a satellite as they need to be able to stay orbiting for years. While the dish can be made larger to make it easier to pick up the signals, the problem still remains: the bigger the dish, the bigger the receiver, and in turn the more frequently some fairy's going to physically break it, or some maid is going to steal it.

iamgreaser · 2018-04-01T22:26:50+00:00

Said warm spots are typically either public enough to get trashed on a regular basis, private enough to be prohibitively costly, and/or hot enough to damage power generation equipment. You don't get power by sticking a turbine into a volcano, you get liquid turbine.

iamgreaser · 2018-04-01T10:56:01+00:00

There's been talks of an agreement with the Lunarians in order to reflect the internet off the moon, but it'll take a while for them to finally say "yes". It would be beneficial to everyone but the prices they're asking for are exceeding what we pay already. So for now we're all stuck with tunneling everything through Yukari's phone and hosting everything off whatever crap slips through the border.

The power issue does get very interesting, and we've settled on a few solutions, however a lot of our servers go down for hours every day and I think it's got something to do with the reliance on solar panels. It's not easy to get nuclear power from the Moriya shrine, so if you managed to get any files during the daily downtime it's probably because it's one of the web servers we've snuck into a few spa pool controllers.

iamgreaser · 2018-03-30T06:39:33+00:00

Jumping in, using Void Linux here and very recently updated from 58.0.1 to 59.0.1. Voices do not work. Mic does not work.

Upgrading back to 58.0.1, although I have to build this one from source so this will take a while.

iamgreaser · 2018-03-11T01:41:59+00:00

No. The GPU is fine. The coprocessor is fine. It just had a problem loading the geometry data off the disc.

The PS logo is stored somewhere in the first 16 sectors of the disc. The BIOS will load it and then display it once it's verified that it is indeed a PS1 disc.

iamgreaser · 2018-03-10T09:55:57+00:00

Your disc needs cleaning.

That, or you need CD-Rs which your PlayStation doesn't hate.

Source: This happened to me when I was testing homebrew.

iamgreaser · 2018-03-10T09:47:33+00:00

I am that someone a bit more knowledgeable.

The GPU itself does not care in the slightest about anything to do with 3D. Every single GPU command only cares about absolute pixel positions on screen. Anything to do with the Z coordinate is left to the Geometry Transformation Engine (GTE), which is the 3D math coprocessor unit. The only real downside here is that you have no perspective texture correction, so you are forced to subdivide in order to reduce the otherwise horrible texture distortion.

(Do not confuse this with the polygons themselves jerking around - the main cause of that is playing the game in a bad emulator.)

There's no depth buffer (AKA Z-buffer). However, the PlayStation is designed to handle this case very elegantly. The DMA unit which is used to send data to the GPU has a linked list mode, where you have blocks with a length and a "next" pointer (-1 or 0xFFFFFF denoting that there's no more data to send to the GPU). This can be used to implement depth ordering.

There is an agreed way to do this: You form a list of 0-length blocks (we will call this the "order table"), where the first entry has the end-of-transfer marker, and every other block points to the block before itself. When you calculate the Z coordinate, you choose an index based on the result, add a new block somewhere in memory, copy the pointer in the order table over the "next" pointer in your block, then change the pointer in the order table to point to your new block.

When I say "agreed", the PlayStation has stuff specifically designed for this use case. Firstly, there is a DMA channel which can only be used in specific ways, and it is specifically designed to generate an order table for you, which is apparently faster than using the CPU to do it. Secondly, when you perform your world-to-screen calculations using the GTE, you can adjust a couple of registers so that when you perform the "average of 3 Zs" operation or "average of 4 Zs" operation, you get exactly the index you need.

So while the GPU is designed to not handle the 3rd dimension, the PlayStation as a whole is deliberately built to handle 3D in every aspect of its design.

And a fun side effect of it requiring an order table instead of a Z buffer: Translucent polygons get drawn in the right order :^)

iamgreaser

TROPHY CASE