19 replies to this topic

[stu]

I've ported Powermanga, a nice little addictive shmup, to the GP2X - it's pretty much feature complete at this point, although it's not 100% perfect - the sound effects seem to lag by up to a second, which is rather irritating. The port is based on version 0.80 (latest at time of writing), available from http://linux.tlk.fr/games/Powermanga/.

GP2X Download Links:
The game (ready to run)
The sourcecode (minus data files, which you can get from the above)
[CUT]
I've tried to adhere to the Common User Interface Recommendations as much as the default control scheme allows, and I guess it fits in rather nicely - directional controls plus a primary fire and a secondary powerup map rather well to handheld consoles ;-)

My first post here, as well as my first port to the GP2X :-) Hopefully more to come in the future!

Enjoy![/CUT]

[deadlychicken22]

Judging from the screenshots it looks like a good game, I will try to test it later tonight.

[BenRoshi]

There's an issue with the highscore entry (at least, I think there is...), and like you said there is a delay with the sound, but overall it works pretty good, I'm sure I'll be playing this plenty

[yaustar]

The lag with the sound is usually due to the sound buffer being too large in SDL_mixer. Try 64 or 128.

[thebooboo]

Also, what sample rate are you using? If the SFX are in mono at a lower sample rate this can speed things up

[Flavor]

The lag with the sound is usually due to the sound buffer being too large in SDL_mixer. Try 64 or 128.

Yup, this seems like a common problem for SDL ports. The PC versions usually set the buffer much higher, and it causes lags on the GP2X.

[stu]

Thanks for the feedback guys - it was an overly large SDL_Mixer buffer causing the sound delay. I reduced it from 4096 to 64 as recommended, and it's working great now!

There is still a bit of a problem with the high score entry - by default Powermanga expects standard key presses to enter a name, which doesn't work too well on the GP2X obviously :-p I created a simple mapping from the GP2X buttons to the characters A-G, so you can (sortof, very clumsily) enter a name now. I set the left dpad button to SDLK_Left instead of an alphabet character in the hopes of allowing you to back up and re-enter characters, but it doesn't seem to work.

I'm not going to try fix this as it stands - I'm rather going to try implement the standard up/down+enter letter cycle as used in arcades, which will be far more suited to a handheld. It might take some time to do however - deciphering source written in French when I don't speak a word of the language turns out to be rather tricky...

Anway, I've updated the downloads (game+source) at the file archive to include these two changes, so the game should be almost perfect at this point. I played up until level ~27 this evening without any problems, so I assume it's possible to complete the game.

Forgot about the sample rate question: All the sounds are either 11KHz or 22KHz mono, so no problems there. I originally thought that this was the cause of the problem and so checked them all, but they were fine as-is. I did however end up reencoding the music at 22KHz instead of 44KHz to see if that made a difference, but no such luck. Thankfully it was down to something as simple as a Mix_OpenAudio() parameter change :-)

Edited by stu, 02 August 2006 - 10:15 PM.

[ninjak]

The link in the archive is returning an empty file right now. Is it just waiting for the new version to be verified ?

[deadlychicken22]

8/1 = august first, i believe

[DaveC]

I have the version that says 8/2 and there seems to still be some sound lag. Also the rate of fire seems kind of sluggish. It wants to fire 1 bullet per second no matter if I hold fire or pump the button faster.

Looks great though and is very smooth. Thanks for the good work.

[stu]

Yeah it looks like the "Update File" functionality on the file archive seems to take some time before the link is actually updated. I've just redownloaded it now at work and it looks to be the correct version - the two extra high score files which I put in for the new version are in there. Let me know if there are still problems...

I have the version that says 8/2 and there seems to still be some sound lag. Also the rate of fire seems kind of sluggish. It wants to fire 1 bullet per second no matter if I hold fire or pump the button faster.

Looks great though and is very smooth. Thanks for the good work.

It is nice and smooth, and plays really well on the GP2X - I was surprised it worked so well actually! Are you certain there's still sound lag? I couldn't notice any when playing through it yesterday, but I could always try decreasing the buffer size still further and see if that helps.

With regards to the rate of fire, that's just how the game is :-) You get a slight increase in RoF (+damage) when you upgrade your ship to the next level (the very top powerup), but for the greatest effect you need to max out the default fire (so you'll have five bullets per shot) as well as the missile fire (which become homing missiles from ship level 2 onwards).

Having a fully maxed out ship towards the final levels is quite a sight to behold, but even then it can be difficult to withstand those later asteroid fields!

[DaveC]

Yeah it looks like the "Update File" functionality on the file archive seems to take some time before the link is actually updated. I've just redownloaded it now at work and it looks to be the correct version - the two extra high score files which I put in for the new version are in there. Let me know if there are still problems...

It is nice and smooth, and plays really well on the GP2X - I was surprised it worked so well actually! Are you certain there's still sound lag? I couldn't notice any when playing through it yesterday, but I could always try decreasing the buffer size still further and see if that helps.

I will try DL again maybe it is the older version? It says 8/2 on the file info.

It seems that when you shoot the bullet fires and the sound is played slightly later.

[deadlychicken22]

8/1 = august first, i believe

Yes, and today is 8/2 = August 2nd (soon to be 8/3 on the east coast of the U.S. of A.)

stu wrote today (8/1/2006) at 6:08pm EST:

Anway, I've updated the downloads (game+source) at the file archive to include these two changes, so the game should be almost perfect at this point. I played up until level ~27 this evening without any problems, so I assume it's possible to complete the game.

... just clearing things up

Looking back at my comment, I'm not really sure why I made it... I was tired and wasn't thinking clearly

Edited by deadlychicken22, 03 August 2006 - 07:02 PM.