A friend a work showed me he's gp2x, I was very impressed with it, i'm very atracted to the home brew side of things. Currently I do a lot of DX on my PC but would like to get back to the "to the metal" coding I used to do on my Amiga A500.


So, some simple questions. ( i've read the faq's )

1) Can I dump linux once my app is running, and so have full access to the chips?

2) I've read in the docs, the ARM asm doc talks about a vector unit, is it there one in the gp2x? ( don't look like it )

3)What funcs does the 2d chip do? Is it just a very basic blitter style chip?

4) Whats the best dev enviroment, Linux or Windows. I'm more of a windows man but experiance has taught me that systems with linux always have poor windows dev enviroments.

5) Any one done a 3d engine using the second CPU as the GPU? When I first read about the gp2x it struck me that the reason for two cpu's was so one can be used to emulate graphics chips while the other emulates the cpu, but from what I read when running in the linux enviroment the second cpu is out of bounds.

The reason I asked about 3d engine was I was thinking of doing one. I've written software renderers before, may years ago on 386/486 using modeX. They were a bit simple, no texture or z buffering.

Yes, but there is no complete package out there yet for you to use to help you do this.

no

It also has some stuff to help with video decoding

Either one works fine

A number of people are poking at 3D engines. There has been discussion of doing some or all of such an engine on the second CPU but I don't know of anybody demonstrating it in use that way.

This isn't true. You can use the second CPU if you want. It is not completely simple to work with though.

If you really want to, but it isn't necessary 99% of the time.



No vector unit or FPU on the gp2x



Yes, it also supports all 256 rwops needed for WinCE to have full hardware accelleration. No fancy alpha or anything though.



You can use whatever you like, from VS2005 to vi. There is no official dev environment.



No-one was written one yet. The main issue is bandwidth, as the 940t only has 4k+4k cache and the main bus is shared between all the peripherals. Accessing the 940t with or without linux is much the same.

The video decoder and post-processor are completely separate from the 2d accelerator.

You doesn't have to. You really doesn't have to dump Linux to access hardware directly.



No, unfortunatelly no but... there are some tricks.



What "2d chip"?

The MMSP2 (the chipset inside the GP2x) has multiple hardware coprocessors. From memory they are: 2D accelerator, videoprocessor, videopostprocessor and
image signal processor.

For now only the 2D accelerator was figured to an extent and videopostprocessor to smaller one. The rest is just waiting to be utilized...



Well... it's matter of taste. I'm using Vim personally for everything. Yes - it's that good.



No it isn't. But keep in a mind Linux is a full system with features like privileges, memory protection and premptive task switching. Problem with the second cpu is that it doesn't have a MMU so can not be easily used from user space. But there are workarounds for that. For an example the video decoding in current firmware is already using it and under Linux.



Then you will find the GP2x hardware joyfull to work with.

For teh 3D engine, there is the port of yeti3D, a very powerful 3D engine with software rendering only. It was first ported to the GP32 and is very impressive.
pro version for the gp32 : http://www.angelsoftware.org/index.php?200...d---pro-version

port of yeti 3D for the gp2x (ask your friend to try it)
http://www.gp2x.de/cgi-bin/cfiles.cgi?0,0,0,0,46,1247

some people were looking for the owner of the pro version to buy a licence, dunno if they found him.

Hi, downloaded Yeti and ported to a dumb windows app.
I've fixed the update to 30 fps. Go grab the zip here. ( hope its ok to add links in this forum ).

Anyway, Yeti looks real good, the API is a bit odd, shame the developers have gone AWOL.

I hope i've not broken any licence stuff here.

www.maddoggames.com/gp2x/sw_renderer.zip

P.s. I'm a pro games coder, you may want to pop over to my portfolio. When I get a gp2x I hope to help out. So far it all looks real cool.

http://www.maddoggames.com/maddoggames/portfolio.html

The rest of the site is a bit old, so don't take much notice, i'm think of redoing it a bit and use it as my gp2x portal.

Wow, this is impressive, I hope you will make something good for the gp2x, maybe a game using yeti, i dunno. are you going to make commercial game, if coding is your job i assume it is normal to give you a "reward".
I will pay 20€ for a commercial game if it worth it (can you make a rpg ?)

Wow! Some seriously impressive stuff there. Hope you find time to work on GP2x. Have you spoken to Craigix from GBAX yet? He's been having a lot of communication with commercial devlopers.

Hope to see more of your stuff around here

Very impressive stuff there , welcome to the fold btw, it's always great to see another talented dev intrested in the GP2X .

Thanks guys, i'm not looking to do any commercial games for the gp2x. I'm looking to use it as a diversion from the console work I do.

I'm a low level engine coder which is why i'm looking at doing a 3d engine. Basic idea is something that will also run on windows to help development and to run the second cpu as a GPU. I'm quite busy this coming month but as soon as i've got a plan and a gp2x I'll rework my web site and post.

Till then keep up the good work, looks like this is going to be fun.

Looks like this is going to be very interesting, i can't wait

I'm betting the version of Yeti you downloaded was the GPL version, so as long as you make your source available to anyone who requests it you're not violating anything. (Share and share alike. )Some people might get a little uppity if there's not also a source tarball for download but it's not a license requirement and those people are dicks anyway.

Welcome to the community and have a wonderful stay.

Really cool to have another talented coder onboard ;D

Amazing stuff indeed.