Topic: True bi-directional communication

Hey everyone

It's been a little quiet round these parts for a while So, as it's something I always kinda wondered about in the past, I was wondering whether anyone had looked at much true bi-directional javascript? I'm familiar with ajax systems, but as I understand it, these require a separate XMLHttpRequest for each request from the client?

Anyway, I was just wondering if anyone had looked at them much. I'm thinking about throwing up my server again (been down for...quite a while...) and wanted to use it for some experimentation!

Wrayal

P.s. I was very fond of the 20 liners and the couple of games of pong we had...does anyone fancy another round of either? ^_^

Unfortunately as of today clients can't keep an open connection to the server, but severs can stream data to the clients thanks to SSE : server sent events. See the IRC-ish chat we did a year ago using XHR and SSE. It's really simple to use.

... or is it really impossible to use SSE from A to B and not from B to A at the same time ... grrr must resist, NDA, no, no talking....

OTOH, I also liked the 20 liners and the pong I had with InI back in the days. I could do something like that. It's just not the best period of the year for that now : Xmas holiday, flying to France soon, then back to Norway and moving to a new flat.



(Edited by poi on 12-11-2007 22:29)

Naught poi :P Though I'm guessing as it's an NDA thing it's a future opera thing as opposed to a clever JS trick?

What's the generally accepted way for clients then? Is it XMLHttpRequest? I'm sorry, I've never plunged that deeply into Ajax...also, what is the latency? Would it be useful for say, multiplayer games? Also, I remember a pool game some time ago that was multiplayer, though I cannot remember the name of the site....are you familiar with it? What system did that use?

Yup, clients are doomed to use XHR to poke the server every now and then. As for the latency it's hard to tell, it depends on the distance to the server, the type of connections ( esp. on mobile ), ... I don't have numbers but I'm sure it's not suitable for a fast paced multiplayer game. Turn based or slow paced games are no problem though.

The pool game was by Scott Porter, the guy behind the unfortunately dead www.javascript-games.org. Behind quite old I assume it was based on a good'ole trick like a 1px frame or an hidden iframe.

Actually, just a sec ago I found this: http://www.webreference.com/new/020228.html ^_^ Seems he used XHR. I guessed a fast paced game was out of the question, but still...it'd be interesting to see what could be done. I'm still intrigued what could be done in terms of 3d with enough effort - I saw a lot of games, especially from you poi, that demonstrated some impressive 3d graphics (raycasters, voxel systems), though a lot of them were constrained by size. I wonder what could be done if speed were the only object? And then, whether that could be applied to a multiplayer game.

Javascript MMORPG anyone? :P

Actually, I think there's at least two 2D MMORPGs and one fast paced 2D MMO-Platformer that I've seen. Nothing I've got bookmarked however, so I can't give any links. Nothing fully featured in 3D that I have seen yet, however. I expect with OpenGL ES based 3D Canvas from Mozilla and a custom higher level 3D Canvas from Opera we will see something emerging soon though.


Actually having browsers moving in on the Flash gaming scene is one of the reasons I really want to see ECMAScript 4 in browsers. ES4 and a good hardware accelerated graphics API (Persistent mode X3D, SVG | Immediate mode 3D Canvas, 2D Canvas) or even ES4 rendering to some raster format and using the data: protocol should make graphics manipulation significantly faster than with ES3.

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var Liorean = {
abode: "http://codingforums.com/",
profile: "http://codingforums.com/member.php?u=5798"};

wrayal: Thanks. My latest tests shows that PS1 or N64 type of graphisms are doable in JavaScript, in a public build of Opera 9.5, FireFox 3 or Safari 3, so I might finally be able to make my dream game in JavaScript : Descent.

liorean: any clue about this fast paced 2D MMO platformer ?

I'm also looking forward to ES4. Code should cleaner and faster.

As for 3D Canvas, I like the idea of using pixel shaders, but there's no way to get such a low level and bound-to-one-API DOM API working on all platforms ( Wii, DS, phones, TVs, ... PCs ). Therefore I'm not sure what direction is better : low level or high level.

Poi: really? PS/N64 standard? Wow, I must have missed a lot recently (uni seems to eat time...) I suspect I shall have to watch very carefully - this all seems fantastic. Some truly incredible games could be created this way it would seem.

liorean: As poi says, it'd be very interesting to hear more about these, especially the platformer!

ok, you certainly can't have hundreds of polygons, but on a recent computer it seems possible to push a few dozen textured polygons withouth even using 3D Canvas.

If you do any 20liners, count me in.

BTW, poi, I can't seem to access your website. I wanted to play with your recent 5k raycaster...

Finally, I can't remember my old password. Yay for registering new accounts! XD

Hmmm. Again InI, and what's that pong thing? Something like PS pong? Twenty liners I found links, but...
P01, your domain is down(!). Anyone has a link to the mentionned pong thing?

I'm not InI, I'm ironwallaby, but this time with that awesome underscore.

Kid me not : first thing, I can't read. Secondly, I am ALF myself, in disguise. And last but not least, I know you are Spiderman.
But I will keep it our secret for 10 gazillion dollars ONLY!

(If, on the other hand, you have a link to some javascript pong match, and I like what I see, we can sort this out by dueling).

back onto the original topic:
is anyone familar with the comet "model"?

Especially long polling seems to be a doable idea, even with today's clients...

Nice of you, nurse Tyberius - I love comets, stars and constellations but...

Our topic starter for today had the following request :

quote:

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P.s. I was very fond of the 20 liners and the couple of games of pong we had...does anyone fancy another round of either? ^_^

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I do.

iron_wallaby + argo navis: my 4k FPS is on http://www.3dtomb2.com . I'm late with the payment of my own domain ( www.p01.org ). I crashed at a friend's place before moving to a new apartment in january, and am visiting my family in France, so all my account/paper stuff are buried deep down in a carton somewhere. I should sort this out before something really annoying happen

Tyberius Prime: Flushing whitespaces to keep a connection alive feels a bit wrong but that's the price to pay today to have "lasting" connections.

Thanks for the link. Play time!

How about we start a new 20 line compo on the first? Seems like as good a time as any, after the holidays...

What about a christmas special? Anything goes.

side note: my site is back up. Pheww, for one moment I feared I'd have to fight a domain squatting.