Ray Tracing for the TI-84 CE | Hacker News Reader

Ray Tracing for the TI-84 CE

github.com

227 pointsAndyJames49 comments

This is awesome. A bit of self-promotion: I, too, wrote a deliberately obtuse raytracer: https://github.com/chunky/sqlraytracer

Amazing!

Ray tracing at 5fph, not bad at all for the hardware. I am impressed that this is even possible with a calculator

With an eZ80 and color screen, it’s much more like a feature phone without a SIM card than a pure calculator.

Feature phones have been using low-end ARM for past 20 years, at least. The Z80 is a particularly old CPU.

The eZ80 is quite a different beast than the original Z80 though :)

About 3x quicker at the same frequency and the performance is comparable to a Z80 clocked at 150 MHz if fast memory

... according to wikipedia!

> comparable to a Z80 clocked at 150 MHz

Calculate like it's 1994.

That's enormously faster than I was getting on a 286-12 with POVRay, which was more like 0.05 fph.

When I saw that comment on /g/ about raytracincing on the TI-84 the other day, I just knew someone would post something like this here in a couple days.

This YouTuber did a simpler version years ago, this is a followup.

https://www.youtube.com/watch?v=todarS6XTPc

What’s /g/?

I think it's a 4chan board

I believe they are refering to the 4chan technology posting board. https://boards.4channel.org/g/

I believe they are refering to the 4chan technology posting board.

https://boards.4channel.org/g/

4chan's technology board. You will never find a more wretched hive of scum and villainy. We must be cautious.

I thought, well it's 2022, how bad can it be?

Well, to anybody else curious, it took 3 messages to find a hard N. I don't even know why anyone would use that word (unless they're openly racist and terribly uncreative at writing).

Trolling, I suppose.

An image board where people compare riced desktops.

fyi the word 'rice' in that context comes from a pretty bad pejorative.. https://en.wikipedia.org/wiki/Rice_burner

The only recent comment I could find about raytracing on calculators on /g/ mentions a TI-86, and was posted after this repo was created, but before it was posted on HN (I used a 4chan archive to search for the comment): https://boards.4channel.org/g/thread/85596005/2-cores-4-thre...

TIL: The TI-84 got an upgrade since I was in school. I guess it was time to trade in that best of 1985 technology for the best of 2005 :)

Looking at the newer models, it is pretty neat they can run Python. Some of my earliest programming experiences were playing with TI basic on my TI84 while bored in class so it is nice to see them stay relevant in that regard for today's students.

Python on the TI-84 series is run on a separate ARM Cortex-M0+ micro-controller with 256 KiB of Flash and 32 KiB of RAM, hooked to the ASIC with what appears to be a UART. In other words, it's just about the worst performing Python implementation in a graphical calculator to date: https://www.cemetech.net/forum/viewtopic.php?p=285853#285853 (alongside a rant about removal of C/ASM support, some points about it being outdated).

I have a hard time calling these "upgrades". I had a TI-83 (not Plus) in high school - the Plus gave us ROM, the TI-84 gave us USB, and the TI-84 CE gave us a color screen, which are all creature comforts at best. It's on par with what we'd think of "upgrades" circa Apple II -> Apple IIe.

I _would_ call moving from a TI-83 to the TI nSpire CAS an upgrade - there's a whole host of things that the nSpire can do which the TI-83 can't, like symbolic calculations and matrix math with complex values. I'd also bet it can emulate a TI-84 faster than a native TI-84.

I have a nSpire CAS. While those features are really, really good, it does have a significant flaw compared to older graphic calculators (including the TI-89, which is probably more of a predecessor to the nSpire CAS than the 84 is as the 89 also has CAS): actual boot up time.

The 84 and 89 are instant on while the nSpire has significant boot time. I guess you are suppose to leave it on but let it “sleep” like a modern smartphone, but the battery life is bad even when the screen is off. I’m not sure how the 84 CE compares, if it’s “just” and 84 with color or it’s something much more modern locked to running an 84 emulator.

The boot-up time is really a killer. I also just can not get used to the input/keyboard of the nSpire.

My actual workflow is to use DM42/HP-35s for anything I can do with those, and if it's more complicated, I'd rather launch Octave or MATLAB. I just can't make my nSpire work for me.

> I _would_ call moving from a TI-83 to the TI nSpire CAS an upgrade

Having used all of TI-83, TI-84, and TI nSpire, I can say that unless you need and are allowed to use the CAS portion of the nSpire, it is a downgrade in almost every way.

In calculus, I could be done with a calculation on the TI-83 before my classmates in on the nSpire even got to the relevant screen - the UI makes molasses look fast. It may have more features, but at least at high school levels, you just straight up don't need them.

Not really an upgrade... the Silver Edition (the earlier one) was just built better. I seem to remember a student who left one on the roof of his car when leaving school... It not only survived the fall, but was just fine the next day.

Not to mention the fact that the newer software (from which you cannot downgrade) introduced a significant lag / delay, even on the same hardware.

The silver edition is a power black hole. Mine would need to change battery every week.

GitHub claim this is 93% C and 3.8% C++, despite it being entirely in C++ (and a bit of ASM). I guess GitHub just consider that a .h file is a C file

Yes, github's language detection is definitely messed up, especially in the C language family. A while ago, a C or C++ source file would be detected as Objective-C if you had a variable called "id" (I think that's been fixed though).

To add to that, Github reads Arduino code as C++.

I know it's not truly this simple, but if the file extension is ".ino", I feel like your detection algorithm should be free to use that as a massive indication it is Arduino code.

…but Arduino code IS c++ code. I don’t believe a distinction would make much sense.

They should throw AI at this problem.

You can override it. I had to provide such an override so that my C++ module files would be reckognised as C++.

A .gitattributes file must be present with something like,

    *.ixx linguist-language=C++

More info here, https://github.com/github/linguist/blob/master/docs/override...

If you're nostalgic about your old engineering RPN calculator, or would just like to use your Ti-84+CE more efficiently, check out https://git.io/ti84rpn - it let's you quickly switch in and out of reverse polish notation mode.

The scene looks so familiar that I thought I had created it. A metal ball in a room with a red and blue wall. Where is it from?

I know our memories are terrible.

There are differences. In “my scene” there is only one metal ball, it’s floating, and the floor is white.

Here’s my scene from 2012. Someone tell me where I got this idea. I’m sure it’s not novel. Anyone know where it’s from?

https://www.joeldare.com/wiki/aoi:generating_fog

This type of scene is called a Cornell box, often used to test rendering capabilities.

https://en.wikipedia.org/wiki/Cornell_box

Yeah but could you do it on a TI-85 is the question

Oh my god.

and i thought there was no innovations in the TI84 space, the calculator hasn't changed in practically 2 decades

The CE released in 2015, and the community still looks pretty active: https://www.cemetech.net/

that poor calculator

Hey, if the TI-84 is too slow for you, you can always overclock it: https://www.youtube.com/watch?v=l06PlYNShpQ

It might have been interesting, but it was so annoying with all the time-wasting "fun" stuff, that I stopped watching. I bet they could have easily made that 12 minute video into a 4 or less minute video. The video makers basically don't care about their viewers and want to monetize their attention, pathetic.

I got as far in that video to where one of the guys shouts about his "meaningless victory".

Meaningless indeed. Thanks Linus Tech Tips.

I’ll defend LTT here: it’s supposed to be a fun video. Entertainment value is core to their videos, that’s what their audience comes for in the first place.

If you’re rather looking for short, to-the-point videos, you’ll be better served by Linus Media Group’s other channel, Techquickie.

I watched most-not-all of it and really enjoyed the build. Sure it could have been shorter, but also maybe they shouldn't be overclocking an 18 year old calculator just to play Doom. Who wouldn't want a water cooled calculator?

I did that with my ti89 when I was in highschool and I remember having clock it down during exams because I was getting obviously wrong results. It's obviously a pretty stupid thing to do with a calculator. I think I was able to go from 10 to 18 Mhz though.

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