PSP shmup development

[Tychom]

No doubt most people have noticed homebrew code is now around and working on PSPs running the 1.0 version bios (i.e. early model Japanese ones).

Well I noticed this morning on PSP Hacker the posting of some Hello World code - a basic demo program showing off some basic 2D functionality. That immediately got me interested in looking deeper. Going through the code itself it turns out to be nothing really out of the ordinary to anyone who's worked with 2d graphics libs or consoles themselves.

A bit of research and it turns out compiling the demo is as easy as downloading and installing the PS2 Development environment from PS2 Dev and elf2pbp in order to finish everything off.

Anyway I spent the day reading up on stuff, looking at other demo code for how to do controller input etc and still there's nothing untoward here - at least right now. Right now you see there's very little exposed of the platform below, the people looking into the hardware don't even seem to have come across a the symbol for a working malloc-like system call yet (though perhaps Mr Mirakichi who's been doing the emu releases has). 3D functionality isnt exposed yet, all that you can really do is read controller input and read/write to memory addresses (i.e. the video ram), a few basic display, initialisation and file system calls are available.

But, it's enough already to write 2D games which is oh so not so bad at all

I've started on a basic game to get my feet wet. It's a sort of Robotron clone - 8-way movement, 8-way firing. So far today I got my sprites working (wrote a converter to read in bmps and write some static unsigned short arrays) and have my ship moving happily around blasting it's heart out

Next thing to do is get my enemies in there and sort out collision detection on them followed quickly by having them fire back.

Should I not lose interest in the project ( ) then hopefully once the basics are down I'll make it all a bit more manic - set the arenas out with just 1-3 enemies spewing out boss/mini-boss like insane patterns



Is anyone else looking into this? it could really be an exciting platform, certainly once homebrew is working on 1.5s and onwards.

[licksweets]

have an engine which I assure you works on the psp, but needs heavy optimisation. meanwhile it also compiles in win32 opengl and runs at full speed. models are done by me the programmer, and this is just an object / bullet test and no more. pictures taken from an avi which I can't post over 56k in a hurry

http://lmx.50megs.com/

[Tychom]

That looks like it should be really good

How will you be adapting the 3D engine to the PSP? afaik none of the graphics libraries have been deciphered yet so I assume you have access to an SDK?


Anyway just put in font handling and a crappy background so at least we have something. Hopefully by the end of the day I can finish a quick & dirty alpha blending function to help out with the sprites and also put together a better background. After all it's looks that count.

[Tychom]

Some improvement, certainly enough for one night..

.

I'm just hoping the psp can keep up with my crappy coding, a ton of badly alpha blended bullets could bring it to a crawl :/

[gingerj]

What language you using? Btw that’s really impressive to be able to do such stuff, when I hear people doing such great things its a real motivator to do some sort of compiled language learning so I too can join people on their shmup crusades. Right now though I'm stuck up to my eye balls in ASP books and my main assignment for my diploma so I can't do anything as yet.

Go any tips for aspiring newbies....

[Tychom]

It's done in straight C, there's really not much in the way of libraries (certainly there are no graphics libraries around) so it's all done with writing to a large array in memory. Basically the whole thing is making sure you're writing to the right place

Fiddled a bit with the controls so it's now possible to download a very early version with digital & analog control set up.

I now have to put in the enemy ships, make them fire at me, move around etc etc.

[licksweets]

I collect devkits of redundant consoles such as saturn, PS1, gameboy, and one day a machine bought from a liquidator of a uk dev company had renderware, ds and psp sdks installed, but licences had expired. but simple look at psp sdk shows graphics lib is just like openGL, so used that and friend with psp devkit at work says my game ran (slowly) after adding display setup and kernel calls. with the library list coming from homebrew devrs then my engine should work with that, but I honestly reckon win32 opengl is the best platfrm due to speed issues atm. engine works on ps2linux kit which is what I shall concentrate on next.

but recommend using opengl style, as it's due to be used on PS3 now, yay

edit: btw, i have not access to sdks anymore, nor would have leaked them as it would have had consequences for me and my contacts. which is why the win32 version is more advanced, and more than likely the version i may release

[Tychom]

Added in enemy bullets, patterns & a few basic AI routines yesterday & today - It hadnt occured to me before starting this project that there wouldnt be any trigonometric functions available nor something as simple as sqrt() :p let's hope library writers clear that up in time.

Anyway hopefully I can do collision detection tomorrow and add in a few more patterns, for now here's a vid for the curious, shows it running at least with enemies basically spawning in and out, firing off circular waves, tracking the player etc etc: http://www.tychom.org/PSP/demo_1.avi (4MB, Divx 5.11).

[velocity7]

Holy shit.

Now that's stuff I want to be able to code. On PC. o_o

[MelGibson]

Thats really great.... now add some cool gfx, parallax scrolling and it will be awesome and kick ass

[Tychom]

Added some minor stuff like difficulty levels, player-bullet on enemy collision detection. Also have detection on the player semi working but need to work on a life stock, probably a bomb too because the game is too damned hard right now :p hence disabled so I can test things out.

Anyway, better vid now up here (pre difficulty levels, basically just a bit improved on the last). And also the thing itself here though of course you can't die (plus there's other 'bugs' too ).

[janrodricks]

I tried to load your game onto my PSP and I got a message saying "The game could not be started. (80020001)". Any idea why?

By the way, from the pictures, that looks really awesome. I had been getting into C++ about a year ago, and around the time the PSP was coming out I started thinking about how possible it is to make your own games. I guess you're proof that its not that hard

[Tychom]

You'll see that error if you try to run it on a non 1.0 firmware PSP, i.e. right now homebrew code can only be run on the Japanese PSPs that havent been updated to 1.5 (US PSPs are all at 1.5 from the start).

[janrodricks]

Oh damn. I can't wait till they figure out how to get around that. I think I'll get back to learning programming when they do

[YourMumsLesbianLover]

I still have Japanese v1.0 firmware on my PSP

It's quite a buzz seeing people making homebrew games on the PSP. It could be awesome if Sony were to support such efforts.

I guess they are blocking homebrew code to stop hacks intended for piracy, and potentially code that could fuck up peoples PSPs. I hope that Sony will at least veto the best stuff and stick it on their PSP site for download. It would be a shame for all these passionate gamers and coders' efforts to be confined to a handful of PSPs.

It would be damn nice if the PSP had a touch screen and a version of Flash