J2ME Effects Library

[ovvyblabla]

Hi guys!

I've been working on a J2ME effects library called J2ME ARMY KNIFE. It features textured bitmap fonts, free-angle image rotations, image distortions (like wobble), image masking (including real-time dynamic masks) and more. Best of all, it's completely free!

Check it out at http://www.j2mearmyknife.com and tell me what you think!

[DevelopmentTeam]

Note: Usually we don't allow posts that has a link to any external website that sell or advertise J2ME developer APIs. But yours seems to be something that deserves its position here. Nice work.

Meanwhile, how about the fps on a real device like Nokia N70 especially for the Image rotation per angle. Do you do it dynamically or its magic?

[ovvyblabla]

There's no magic involved, just well-written code.

I ran the Free Rotate scene from the demo on a Nokia E50 (closest thing I have to a Nokia N70) and I think you will find the results I got very interesting.

Before I begin please keep in mind that, for each frame of the demo:

* the nine buffers (one for each image) must be cleared,
* the screen must be cleared,
* after the actual rotations take place and the results are stored in the buffers, said buffers must also be drawn on screen.

This is a significant overhead, especially when considering that images and buffers are stored internally as int arrays, for quick and dirty pixel manipulation, and that the results are drawn on a Graphics object - in this case the screen - using drawRGB.

Now, the results:

With the latest version of the library and the demo, the on-screen FPS counter shows 12 FPS. Since there are 9 items on screen, that's 108 rotations per second. With the overhead described above.

However, I also timed ONLY the rotation part of the code (with none of the overhead described above). I got 5 ms for each rotation, which means 200 rotations per second. Not only is this pretty fast, it's also closer to real-life performance, considering that in an actual game you will most likely draw the result on an Image object and reuse that object in subsequent frames (unlike the demo, which does not cache/reuse previous results at all).

In my opinion, this means that real-time in-game sprite rotation is more than feasible.

PS: The source sprite is 64x64. Smaller sprites will yield better results.

[DevelopmentTeam]

Thanks for the info. And nice work again.

200 rotations per second is really enough and even 50 will do for a good game. We have been trying to optimize our work image rotation library for sometime, and yours seems to be a good alternative. Anyway, we'll test it on few phones in next few days and let you know the results. Thanks for the good work...

[ovvyblabla]

Thanks!

Feel free to use the library in your projects if you want, it's free after all. I do have one thing to ask you if you do decide to use it: although you are not obligated to do so, I would appreciate an e-mail testimony so I can include it on the library website. You'll get more links back to your site, and the library will get an "endorsement", so everybody wins.

PS: My services are available for hire if you need help. I'm always looking to make new business acquaintances.

[shawnwilliams]

Hi
I am looking forward to buy a new mobile. This information about new mobiles are good specially applications for Sony Ericssion mobile phones because I have to buy Sony Ericssion.

[ishailin]

it's usefull ,

[channal1]

thank you ,good it is useful....