CodeWalrus

I discovered about PICO-8 (http://www.pico-8.com/) months ago and Lexaloffle was kind enough to give me a code for alpha builds of it.

What's PICO-8? PICO-8 is a fantasy console project. Run in Lua and with SDL2, it aims to be run on computers and the Raspberry PI. It greets you with a Lua shell/CLI not too far from good old computers like C64 but that's not the only thing it includes. It includes a code editor (up to ~15KB lua code), a sprite editor (~256 different sprites), a map editor (one only map, 256*256, and the tileset is the spritesheet) and even sound/music editors.

(http://www.lexaloffle.com/gfx/pico8_boot_edit.gif) (Found on the site home)

It's quite easy to program with, I'm also going to add one mid-minor project done here in my list. I started programming on it because I was reminded of LuaFX or my days when learning programmation on my G100+. Projects or mockups on it looks already promising as even in the demos we have a simplistic raycaster!

Here's a quick thing I did with to get my hands on (twitter GIF/video): [LINK (https://twitter.com/Eiyeron/status/586091956360609793)].

It should be released as alpha for next LDJAM.

This looks really sweet! I love lua for smallish stuff like this, and I think it's a perfect language to use.

EDIT: I wonder if this would be able to be ported to the Nspire?

I asked about Lexaloffle for hypothetical power requirements. Looks like the host needs to bear 2 millions LUA's VM operations/s and drawing the sprites, maps and drawing commands without slowing down. It could be feasible but it'll be clocked down a lot. I'll eventually suggest him to try porting it on Nspire.

Wait, is this an OS? that is really awesome *.*

Quote from: Cumred_Snektron on April 16, 2015, 01:01:01 PM
Wait, is this an OS? that is really awesome *.*

It looks like it's more of a VM/emulator, kinda like computercraft or (less so) LÖVE.

Still cool! Also i noticed it will also be available for web, so that'll be cool too

Oh I overlooked that detail.

Quote from: Cumred_Snektron on April 16, 2015, 01:01:01 PM
Wait, is this an OS? that is really awesome *.*

Quote from: Ivoah on April 16, 2015, 01:24:22 PM

Quote from: Cumred_Snektron on April 16, 2015, 01:01:01 PM
Wait, is this an OS? that is really awesome *.*

It looks like it's more of a VM/emulator, kinda like computercraft or (less so) LÖVE.

Yeah, it bears both of these parts. You can mess with some files and folders in a cart repository. As in Voxatron, a saved file is actually a program with its data (map, sprite, sound, etc...). You'll be able to save them non compressed or compressed into a picture with a thumbnail.

Is it going to be opensource?

This looks really cool and I can't wait to try it.

Was the editor written in lua?

I don't really know. It's like a console, you don't really know what's inside. We have although something like a memory map to fiddle with some memory zones (like Maps or SPR data)

Quote from: CKH4 on April 16, 2015, 02:33:17 PM
This looks really cool and I can't wait to try it.

Try asking Lexaloffle then ;) But make sure you give feedback, alpha testing is crucial!

This looks really cool and fun to play with. I like such old school stuff. I don't do Lua but I am curious about what people will come up with. Maybe someone could port some old calc games to it? :P

But if this uses cartridges, then wouldn't it need like an usb peripheral or something?

Quote from: Cumred_Snektron on April 16, 2015, 04:46:15 PM
But if this uses cartridges, then wouldn't it need like an usb peripheral or something?

It doesn't use physical cartridges (I think, correct me if I'm wrong),  that's just the name the developer chose for the bundled programs/data.

Ah okay. That confused me for a bit.

Yeah, that looks pretty fun, can't wait to see it released.

I see why you can be excited to get your hands on, you LÖVE lua, right! ;)

(http://static.comicvine.com/uploads/original/14/145586/3231222-i+see+what+you+did+there.jpg)

Looks nice.
Definitly going to put that on one of my Pi's.

Quote from: Duke "Tape" Eiyeron on April 16, 2015, 04:10:05 PM

Quote from: CKH4 on April 16, 2015, 02:33:17 PM
This looks really cool and I can't wait to try it.

Try asking Lexaloffle then ;) But make sure you give feedback, alpha testing is crucial!

I can wait unless he actively wants alpha testers.

Quote from: Duke "Tape" Eiyeron on April 16, 2015, 04:10:05 PM
Try asking Lexaloffle then ;) But make sure you give feedback, alpha testing is crucial!

How would I contact him for an alpha version? I can test on a mac and nspire (linux :) )

I think you could do it via Twitter at https://twitter.com/lexaloffle but Twitter lacks any private message notifications if I recall correctly. Maybe he has a website?

Of course. (http://www.lexaloffle.com/)

Quote from: DJ Omnimaga on April 17, 2015, 11:30:15 AM
I think you could do it via Twitter at https://twitter.com/lexaloffle but Twitter lacks any private message notifications if I recall correctly. Maybe he has a website?

I don't have twitter

Quote from: Juju on April 17, 2015, 12:07:38 PM
Of course. (http://www.lexaloffle.com/)

Thanks, I found his email on the site.

Quote from: DJ Omnimaga on April 17, 2015, 11:30:15 AM
but Twitter lacks any private message notifications

Nope, I usually get correctly my PM in order and with notifications.

Ah strange, I never got them. On top of that, my old PMs got deleted >.<

Also I just checked Voxatron and it really looks cool O.O

Now if only we could get some of those old school developers interested in calculator-oriented forums to showcase their products, since people on calc forums are fans of old-school stuff, after all :P (especially CW which has a very large retro gaming userbase).

I wonder if PICO-8 itself could do voxels? I know that the TI-89 can do it at very decent frame rate even though it runs at 12 MHz, but that was in pure ASM or C.

You mean like 3d? won't that be very low res and not playable at all?

VOxels? Don't you have Voxatron for this? After all, voxels in the 89 is usually demoscene tricsk. THey won't be as flexible as you would need to uise them in a game. And it'll probably run quite slowly, but that's to test.

Quote from: DJ Omnimaga on April 18, 2015, 07:33:41 AMNow if only we could get some of those old school developers interested in calculator-oriented forums to showcase their products, since people on calc forums are fans of old-school stuff, after all :P (especially CW which has a very large retro gaming userbase).

Why not? Why not poking at them with one or two sticks then?

Yeah thats a good idea :P

Woo, PICO-8 alpha has been released!

Quote from: Cumred_Snektron on April 18, 2015, 09:00:42 AM
You mean like 3d? won't that be very low res and not playable at all?

One of the demos is a 2.5D (like DOOM) ray tracer that runs surprisingly quickly.

Quote from: DJ Omnimaga on April 18, 2015, 07:33:41 AM
Ah strange, I never got them. On top of that, my old PMs got deleted >.<

Also I just checked Voxatron and it really looks cool O.O

I was just about to say that.

Edit. Does anyone know the estimated release date?

What I am curious about is if PICO-8 will be free.

Quote from: CKH4 on April 18, 2015, 05:34:45 PM

Quote from: DJ Omnimaga on April 18, 2015, 07:33:41 AM
Ah strange, I never got them. On top of that, my old PMs got deleted >.<

Also I just checked Voxatron and it really looks cool O.O

I was just about to say that.

Edit. Does anyone know the estimated release date?

There are redemption codes for a alpha version on his twitter.

Quote from: DJ Omnimaga on April 18, 2015, 06:06:26 PM
What I am curious about is if PICO-8 will be free.

Well, the alpha is free, I hope the final product will be too.

I've been using the alpha and its the coolest thing I have ever seen / used ever. I wonder where he wants bug reports though.

Quote from: CKH4 on April 19, 2015, 05:44:05 AM
I've been using the alpha and its the coolest thing I have ever seen / used ever. I wonder where he wants bug reports though.

The only gripes I have are the lack of sqrt, pairs, and ipairs. sqrt can be worked around with x^(1/y), and there is an all function which works like pairs, but why change something that's already in lua?

Quote from: Ivoah on April 19, 2015, 10:06:28 PM

Quote from: CKH4 on April 19, 2015, 05:44:05 AM
I've been using the alpha and its the coolest thing I have ever seen / used ever. I wonder where he wants bug reports though.

The only gripes I have are the lack of sqrt, pairs, and ipairs. sort can be worked around with x^(1/y), and there is an all function which works like pairs, but why change something that's already in lua?

Because it wouldn't be fun. The interest point into PICO-8 is you have basically a fantasy retro console. YOu probably need to redo more or less all the work around and you usually don't need such things like sqrt in games (distance calculations stay the same when squared or not).

Well i wouldn't call the lack of basic functions "fun" but okay

That's not fun I know, right. But do you know how Doom calculated distance? Inverse square black magic
float Q_rsqrt( float number )
{
long i;
float x2, y;
const float threehalfs = 1.5F;

x2 = number * 0.5F;
y  = number;
i  = * ( long * ) &y;                       // evil floating point bit level hacking
i  = 0x5f3759df - ( i >> 1 );               // what the c?
y  = * ( float * ) &i;
y  = y * ( threehalfs - ( x2 * y * y ) );   // 1st iteration
//      y  = y * ( threehalfs - ( x2 * y * y ) );   // 2nd iteration, this can be removed

return y;
}

WHen you don't have the function/opcode, do something clever! :)

ah yes, i know that function. I use it in my particle systems too

Is there a way to fill a portion of the screen?

Quote from: CKH4 on April 20, 2015, 09:32:21 PM
Is there a way to fill a portion of the screen?

draw a solid rectangle

Sorry, I should have been more specific, I meant an irregular part of the screen.

I think I should be fine with the limitations if I ever attempted learning Lua for that console, because most games I do are RPGs and only requires basic math operations and no 3D.

I'm mainly confused as to why he removed a standard function and reimplemented it with a different name.

3d on this would be cool though :o

If you have the alpha load either of the music carts because fake 3d. Also there's a demo that looks like doom.

Eyup, the raycasting one. There aren't any textures though. Probably would be too slow.

Does anyone know how the data is stored when saving a cart as a png file?

Look at the pixels, it seems that he changes some parts of the colors on the carts. I would have prefered a SPORE-like storage, where the data were stored into PNG comment section.

I thought that the map/sprite data would be stored in the blank area in the middle so it could be seen, that would have been neat.

THe blank area is actually the thumbnail area. Press Fx (I don't remember which one) to PICO to store the current frame and when  you will save the cart, the thumbnail will be present. Just wait until I finish to post my project and you'll see a functionnal cart with thumbnail.

Ah, that's better than my idea :)

EDIT: I'm working on a game in PICO-8, I'll probably post when I'm done/have a working prototype

Theeere : (http://codewalr.us/index.php?action=dlattach;topic=409.0;attach=272;image)

fancy

Sooo, F6 to make a screenshot that will be stored on your desktop
F7 to store the current screen state to write it later on future picture carts ('save name.png")

Here's a (buggy) prototype of a game I'm working on

Another trick I read from the system, the first two text lines on the cart can be replaced for two commented lines (starting with --).

I thought it was only two

Quote from: pico8.txtThe first two lines of the program starting with '--' are drawn to the cart's label.

Corrected, I though we could be able to change the last one.

Hmmm. I should try to make something with this too

Gotta download it as well. Just saw a tweet on Lexaloffle's account saying something about how you can claim PICO-8 if you already bought Voxatron on Humble Bundle.

And earlier I didn't noticed the new 0.1.0 version. Neat, neat, neat.

And, does it add anything notable?

It's mostly bugfixes and about binary operators.

Ah. Binary operators are quite useful though

Will we need to buy PICO-8 in order to play games written in it?

At this moment you need to buy Voxatron to play games written in it i think.

Quote from: Cumred_Snektron on April 22, 2015, 04:36:35 PM
At this moment you need to buy Voxatron to play games written in it i think.

I have the PICO-8 alpha, and I haven't bought anything

ohh, where can you get it then?

He said something on twitter with redemption codes

Ah okay, i'll look into that :)

Or buy Voxatron and you'll be able to test PICO.

Eiyeron read only 4 posts back? :P

Getting through the already published carts, I checked out one which are already rocking hard aaand
- Hug Arena (http://www.lexaloffle.com/play/?pid=10022) looks as polished as a finished game
- Write Fite (http://www.lexaloffle.com/play/?pid=10024) does have a interesting gameplay but doesn't look like it was finished.

Both games are done for LDJAM which was last weekend or the previous one, I don't remember.

So you only need to buy it / get the alpha to devfor the game, it looks like

Lexaloffle released a huge list of keys on the Ludum dare website. I'm not sure if I should post the link, though, since it seems to be for Ludum Dare-ers only.

Ah okay. Shame.

Quote from: Strontium on April 22, 2015, 08:25:35 PM
Lexaloffle released a huge list of keys on the Ludum dare website. I'm not sure if I should post the link, though, since it seems to be for Ludum Dare-ers only.

He posted a link to the pastebin with all the keys on twitter, and that's what I used.

Would you mind sharing that? :P

http://pastebin.com/1viWQZ5X
http://pastebin.com/f5MZ2Nb3
http://pastebin.com/TGQqpJLC

Thanks, i'll see if i can use that if i get home :D

Something I've been working on since yesterday: (http://a.pomf.se/krcbgm.gif)
There is a bug when you zoom past {0,0,0}, haven't fixed it yet.

cartridge attached

That's very cool Ivoah, maybe I can use it with the ti basic 3d that I've been working on.

yeah that's awesome :D

Looks nice Ivoah. Does it run smoother in real life than in the screenshot?

Quote from: DJ Omnimaga on April 25, 2015, 09:56:52 PM
Looks nice Ivoah. Does it run smoother in real life than in the screenshot?

Yes.

EDIT: I found another bug, if left spinning for a while, the cube will start to get skinnier and taller. It's probably due to rounding.

Yup, to avoid such precision error IIRC you should use quaternions.

By the way, is this language entirely dependent on the computer speed or are there ways to throttle speed to have everything run at the same speed on every platform?

According to the docs, it should always run at 30 fps, unless your computer is too slow to render stuff at 30 fps, in that case the update function is ran twice at 15 fps.

Also, I wrote a script to import pictures into PICO-8, I should probably make a tutorial.

Ok but I was talking about execution speed, not the frame rate, unless you mean that a loop cannot loop more than 30 times per second?

Of course execution speed depends of your computer, but yeah, the update and draw functions are called 30 times a second.

Ok thanks. And there are timers, delay and wait commands to slow things down, right?

Today i finally got around to downloading it, and it looks very cool. Is it possible to edit code outside of pico-8 btw?

Yes, if you edit the .p8 file it should work.

ah yes, i've found the "folder" command :)

That's nice juju. Also is the music tracker built-in the software or is it a separate cartridge? And can music be edited outside PICO-8 such as Notepad?

The music tracker is built-in.

Cool to hear :). I'll see if I can try making a song with it at some point.

on an unrelated note, I found this:
https://gist.github.com/paniq/7814560e2b560b76911b (https://gist.github.com/paniq/7814560e2b560b76911b)

could probably be used for some fancy effects etc

Oh cool. This is becoming like calculators where everyone is hacking it too to find secrets :P

oh my god
I tried getting the code from a cart png with a text editor

I though it would just be some extensive metadata in the picture
I was wrong

the whole thing is encoded into the pixels themselves

Whoa.... how did they do that O.O

I think each byte of the cart is spread on the last 2 bits of every channel:

take for instance, the keyword "local"
hex: 6c 6f 63 61 6c
binary: 0110 1100 0110 1111 0110 0011 0110 0001 0110 1100

now for a gray pixel on the png:
hex: 66 66 66 FF
binary: 0110 0110 0110 0110 0110 0110 1111 1111

now for each pixel, spread a char on the end of each channel:
binary:
0110 0101 0110 0110 0110 0111 1111 1100
0110 0101 0110 0110 0110 0111 1111 1111
0110 0101 0110 0110 0110 0100 1111 1111
0110 0101 0110 0110 0110 0100 1111 1101
0110 0101 0110 0110 0110 0111 1111 1100
hex:
65 66 67 FC
65 66 67 FF
65 66 64 FF
65 66 64 FD
65 66 67 FC

the color change is so subtle you can't even see it, but the data is still there
with a picture of 160*205, you have 32800 pixels, that makes 32K of data for a cart

That's awesome O.O I love these kind of hidden secrets :D

Yeah, I looked at it the other day and found nothing. Thank you!

Quote from: Siapran on May 21, 2015, 02:44:15 PM
I think each byte of the cart is spread on the last 2 bits of every channel:

take for instance, the keyword "local"

Code Select Expand

hex: 6c 6f 63 61 6c
binary: 0110 1100 0110 1111 0110 0011 0110 0001 0110 1100

now for a gray pixel on the png:

Code Select Expand

hex: 66 66 66 FF
binary: 0110 0110 0110 0110 0110 0110 1111 1111

now for each pixel, spread a char on the end of each channel:

Code Select Expand

binary:
0110 0101 0110 0110 0110 0111 1111 1100
0110 0101 0110 0110 0110 0111 1111 1111
0110 0101 0110 0110 0110 0100 1111 1111
0110 0101 0110 0110 0110 0100 1111 1101
0110 0101 0110 0110 0110 0111 1111 1100
hex:
65 66 67 FC
65 66 67 FF
65 66 64 FF
65 66 64 FD
65 66 67 FC

the color change is so subtle you can't even see it, but the data is still there
with a picture of 160*205, you have 32800 pixels, that makes 32K of data for a cart

Or you can just ask Lexaloffle. That's a classic way to store data in picture : changing the less signifiant bits.

What if there's a secret message hidden in the original Walrii? O.O

I just wrote a little script to test this algorithm up, it indeed seems to work. I can see about 32K of memory with some Lua code in it.

Quote from: Siapran on May 21, 2015, 11:27:33 AM
oh my god
I tried getting the code from a cart png with a text editor

I though it would just be some extensive metadata in the picture
I was wrong

the whole thing is encoded into the pixels themselves

Seems like something I wanted to do on-calc a while back.

What surprises me though is how someone uploaded a cart a while ago, yet I couldn't see any different color difference between pixels of the same hue.

Hre's the base ram laout, found directly from the readme
0x0    gfx
0x1000 gfx2/map2 (shared)
0x2000 map
0x3000 gfx_props
0x3100 song
0x3200 sfx
0x4300 user-defined
0x5f00 draw state [,cart data] (1024 bytes incl. unused)
0x6000 screen (8k)


Quote from: DJ Omnimaga on May 21, 2015, 06:41:36 PM
What surprises me though is how someone uploaded a cart a while ago, yet I couldn't see any different color difference between pixels of the same hue.

The data is encoded in the 2 least signifiant bits of each channel, and a difference of 4 out of 255 in each color is pretty much imperceptible. Myself I was fooled, it's kind of incredible when you think about it.

Yeah I didn't see the color difference myself, which is why I was wondering lol when Ivoah posted that 3D cart. I was asking myself: "Where is the code? O.o" It's a good idea I think, providing that people use common sense and don't start distributing cartridges in JPEG format. :P

Quote from: DJ Omnimaga on May 22, 2015, 06:33:46 AM
Yeah I didn't see the color difference myself, which is why I was wondering lol when Ivoah posted that 3D cart. I was asking myself: "Where is the code? O.o" It's a good idea I think, providing that people use common sense and don't start distributing cartridges in JPEG format. :P

if you're looking for the differences, check the 10~ rows of pixels under the green cube, that is the zone mapped to the code
(http://codewalr.us/index.php?action=dlattach;topic=396.0;attach=289)
(use GIMP or something)

I actually maxed out the image gamma three times and I see it now :)

That is very interesting, what's the blue line through the cube for?

OH that's cool, really easy to see now

[spoiler=Some random code]

<?php$im = new Imagick($argv[1]);$it = $im->getPixelIterator();foreach($it as $row => $pixels) {  foreach ($pixels as $column => $pixel) {    $c = $pixel->getColor();    $cn = $pixel->getColor(true);    $mem[] = ((floor($cn['a']*255)&3)<<6)|(($c['r']&3)<<4)|(($c['g']&3)<<2)|(($c['b'])&3);  }  $it->syncIterator();}for($i=0x4300;$mem[$i]!=0&&$i<count($mem);$i++){  echo chr($mem[$i]);}?>

[/spoiler]

I said absolutely nothing. >.>

So yeah, it's pretty much what Siapran said, but the alpha channel's 2 least signifiant bits are the characters' 2 most signifiant bytes, that is, it goes first. The memory map should be pretty much what the doc said about it, and Lua code starts at 0x4300 and probably goes until 0x7F00. Finding a library that doesn't convert the 8-bit alpha channel value to 7-bit (GD) or 1-bit (non-normalized Imagick) was kinda tedious, though.