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Portal’s physics engine rebuilt in 25KB—on a graphing calculator

arstechnica.com

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Re: Portal’s physics engine rebuilt in 25KB—on a graphing calculator

#41

Post by bcoates »

Evbn wrote: post #34
fatjokes wrote: post #26

> While programming for graphing calculators admittedly doesn’t give Marcolina’s work a wide reach Are they joking? Those TI 83's will be used by high school students in the US/Canada as long as TI has this chokehold on schools. They've outlasted god-knows how many versions of Mac's, PC's, Nintendos, Xboxes, PS's.

How is the TI-83 still a thing? iPod is superior in every way: CPU display size and color, flexibility, cost (well, if they produced a last-gen version for the down market, it would be)

Battery life. Durability.

Also, don't underestimate the value of a UI and hardware keyboard centered around a specific workflow. Calculators are almost the opposite of a tablet/phone, computers specialized to programming and user input, with communication and content consumption as an afterthought at most.

Re: Portal’s physics engine rebuilt in 25KB—on a graphing calculator

#42

Post by lloeki »

zephjc wrote: post #36
Jach wrote: post #2

Not quite--this is more a recreation of the Flash Portal clone. i.e. it's all 2D graphics and 2D physics. I got my hopes up for a moment, preparing to be awestruck. Since I have a TI-89, that's what I think of when I hear "graphing calculator". My TI-89 can do 3D stuff (for instance this fun maze generator game http://www.ticalc.org/pub/89/asm/games/amaz89.zip ), it would blow my mind to have anything close to a Port…

Technically, that's a raycasting engine (a la Doom and Wolf3D). The first implementation that I know of that was made into a game was Daedalus for the TI-85, back in 1997 http://www.ticalc.org/archives/files/fileinfo/11/1147.html

You ain't done nothing till you coded a 3d engine on a HP48 GX: 131x64 pixels and a 4-bit Saturn CPU. The timing tricks to extort four shades of gray from the monochrome screen were awesome.

http://en.wikipedia.org/wiki/Saturn_(microprocessor)

Re: Portal’s physics engine rebuilt in 25KB—on a graphing calculator

#43

Post by andrewcooke »

ygra wrote: post #40
yozmsn wrote: post #31

Oh how I wish I still had a usb-TI83 cable, still have the calculator just not the cord to plug it into my computer...

This one? http://www.amazon.com/☺/dp/B00006BXBS

ok, i have to ask - how do you get smiley-face amazon urls?

[update: huh, so it can be arbitrary text. what's it for?]

Re: Portal’s physics engine rebuilt in 25KB—on a graphing calculator

#45

Post by yozmsn »

ygra wrote: post #40
yozmsn wrote: post #31

Oh how I wish I still had a usb-TI83 cable, still have the calculator just not the cord to plug it into my computer...

This one? http://www.amazon.com/☺/dp/B00006BXBS

Yes, only I'm not spending $20 to play portal on a calculator...

Re: Portal’s physics engine rebuilt in 25KB—on a graphing calculator

#47

Post by ygra »

andrewcooke wrote: post #43
ygra wrote: post #40

Earlier quoted context omitted.

This one? http://www.amazon.com/☺/dp/B00006BXBS

ok, i have to ask - how do you get smiley-face amazon urls? [update: huh, so it can be arbitrary text. what's it for?]

I didn't want the original (very long) URL which included the product name at that place (the technical term might be SEO-friendly URLs). So I first replaced it by an underscore to keep it short and then tried whether I can put something nicer in there. This wasn't generated by Amazon ☺

Re: Portal’s physics engine rebuilt in 25KB—on a graphing calculator

#48

Post by geori »

jlgreco wrote: post #32
loeg wrote: post #29

Earlier quoted context omitted.

You can absolutely page in data from Flash memory as needed, it's just non-trivial (and not handled by the "OS"). On devices with flash memory as an extension of RAM (TI 83+, 89, and 89 titanium), this could help for read-only level data that isn't needed all of the time. Edit: Of course, Joltima targets the TI-83 (different from the 83+), which doesn't have any flash memory. Bravo, Justin Karneges.

You can also go the "App" route and make the whole thing an application that runs straight from flash. Advantages are you can use many flash pages so your application can be massive, and your program will be easier to launch/distribute. We have the App signing keys so these days this route is pretty simple. On the other hand you have to "allocate" ram to write to or scrounge for ram in predetermined areas in the addr…

Paging really, really sucks to manage on a TI calculator.

That being said, I loved working with the 32KB limit and optimizing every single byte out of my code. You got to learn all of the tricks like "XOR A" = 1 byte vs "LD A,0" = 2 bytes. However, some things sucked, like having to frequently write new sprite routines or tilemap scroller routines. I even ended up writing a logo style scripting language to handle animations in a RPG just to save a few KB.

Yes, this is clearly the 3% case for Knuth's quote, "... 97% of the time: premature optimization is the root of all evil"

Re: Portal’s physics engine rebuilt in 25KB—on a graphing calculator

#49

Post by ANTSANTS »

jlgreco wrote: post #18
gipsies wrote: post #13

Earlier quoted context omitted.

I remember playing a lot with my old TI-83. One of the most impressive games was DOOM: http://www.ticalc.org/archives/files/fileinfo/238/23843.html Best video I can find: https://www.youtube.com/watch?v=TuupoxmeQ6U Unfortunately I never had a TI-89. Would've been awesome if I had one back in the day, and then test these games: http://www.ticalc.org/archives/files/fileinfo/405/40593.html and http://www.ticalc.org/arch…

Ah yeah, good stuff. I was always partial to Gemini and Wolf on the 83+ ( http://www.ticalc.org/archives/files/fileinfo/247/24742.html , http://www.ticalc.org/archives/files/fileinfo/277/27767.html ). Wolf even had an on-calculator level editor!

Gemini blew the socks off of all my middle school friends, but I'm embarrassed by the amount of time I spent on Galaxian in math class. Maybe one of these days, I'll dig out my 83+ and complete the no laser, no death run that I was always aiming for, just for old time's sake.

In hindsight, I wish I had spent that time learning Z80 instead...

Re: Portal’s physics engine rebuilt in 25KB—on a graphing calculator

#50

Post by NanoWar »

rheide wrote: post #24

It's an awesome achievement, worthy of geek praise. But even if I'm being very generous I wouldn't call this a physics engine.

There is however another approach by the same guy. Called Zedd Physics Library: http://www.ticalc.org/archives/files/fileinfo/441/44185.html
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