Yeah, it does suck. But hey, it's the best we have at the moment.

My main complaint with J2ME is that the standard is too conservative; it needs to grow some balls. For example, hell, alpha-ized images aren't even in the MIDP 1.0 standard... they definitely should be as MIDP 2.0 support is total shit (i.e. barely any affordable phones in North America that support it).

Speed? Yeah, I'll complain about it too. However, that's what makes it fun: shoehorning inefficient code onto a small machine. :)

REPOST

Well, on some high-end pones (Symbian OS, Linux, WinCE, Palm OS) you can use C++.
Of cause you have other problems - Palm OS (Treo) and Linux phones have low market penetration, WinCE.. hmm, I just don't llike it, and Symbian OS in the process of closing itself from small third party developers (Symbian Signed programm and ability of the operators to lock the phone from outside applications in the next OS version)

I agree it's challenging. The main reason that people moan about J2ME are

- It's limited - which is of course reasonable, considering the severe limitations of the devices - it does tend to go with the lowest spec phone - MIDP2 is better of course.
- It's not compatible enough between devices.

In fact I don't think you're easily going to find a system which allows you to deploy the same build of a game to different devices. This is because they all have different screen resolutions, colour depths and other capabilities.

On such a small screen, developers have to think of exactly how many pixels will be used for what - therefore on different devices, the game may even have to play differently, because of the inherent limitations of a small screen.

In fact as long as you stick to the standard and don't do anything too rediculous, J2ME does work compatibly between devices. It's just that isn't that useful. Most games want to use device-specific features, and push the edge of what that particular device can do in some way.

The API itself is very small and fairly clean - pretty much a subset of J2SE, with some of the strange bits removed, and the really arcane bits (AWT etc) just gone entirely. Yet useful things are still there like threading and collections.

True, some people moan about lack of floating point, but these devices are typically FPU-less so they would be terribly slow anyway.

Carmack is of course doing things rather more ambitious than most with his. He's trying to write software 3d engines in J2ME - which is ambitious in the most.

Perhaps he's played "Frag Island" - a J2SE "port" of Quake which uses software rendering - and realised that it's actually rather fast.

Mark

There's nothing wrong with J2ME per se, it's just that:
a) it's often running on very limited devices (no hardware divide!)
b) the JVM is not always well implemented (MIDP2 TiledLayer anyone?)
c) the framerate is often limited by the LCD screen, which is often a very cheap part (to keep costs down) that can only cope with 10fps for example.

But, the biggest problem is that J2ME has a lot of overhead (up to 1K overhead for each class) which goes against the constraints imposed by limited devices (i.e. low memory), which leads to developers not using classes (all my recent work only use three classes: the midlet, a canvas and a runnable) as well as not using other language features (class constants for instance).

To be fair, J2ME/MIDP1 was never designed for games (but MIDP2 is an attempt, although a bit late, to address this) and developers have coerced games into the system, overcoming the problems previously stated.

Skizz

Quote:Original post by markr
Carmack is of course doing things rather more ambitious than most with his. He's trying to write software 3d engines in J2ME - which is ambitious in the most.

I think he said he's making a 2D RPG version of Doom...

Well, I just got a new phone (Ericsson k700i, although apparently the model is some months old) and I was impressed to see that it can run java apps with textured full-3D graphics at a decent frame rate (not quite what you'd call 'fluid' but definitely playable). Talking to the guy at the phone shop he seemed to think that MIDP 2.0 was standard on phones these days - I'm aware that Australia is somewhat ahead of most of the world in uptake of new technology *cough*brag*cough* but from that, I would have thought that MIDP 2.0 phones were relatively common, and given that it might take three months to write a game to run well on MIDP 2.0, by the time the game is released it'll be even more widespread.

Anyone have market penetration figures for higher-end phones?