The N800 has a 3D accelerator, right?
 

Is anyone making any headway on writing drivers for that?

Kinda itching for some on-the-go FFVII.

Re: The N800 has a 3D accelerator, right?
 

It does, but it wouldn't be very useful. It doesn't support an 800x480 screen, and there isn't enough bandwidth for it to be useful anyway, if I recall correctly.

Re: The N800 has a 3D accelerator, right?
 

Then whats the point of even having it ? IS it a separate chip, or integrated into some other thing that was already used ?

Re: The N800 has a 3D accelerator, right?
 

The powervr 3d accelerator is part and parcel with the SoC used in the devices. It's part of the CPU, ram, dsp, .... unfortunately it was designed with cell phones in mind and has maybe a 640x480 buffer. Even if you could use it the LCD is hamstrung by a bandwidth issue that would limit it's usefulness.

Re: The N800 has a 3D accelerator, right?
 

The processor used in the tablets is an OMAP2 ARM(EL) processor manufactured by Texas Instruments. This chip is used in a wide variety of mobile devices and is a "packaged" chip meaning it's not just a CPU. It's a CPU with onboard ram, included video chip, 3d accelerator, hardware mpeg processing, java bytecode interpreter etc. However, not all these features are used on every device.

On our tablets, the 3d and the video chip are not utilized because they don't support a screen of the resolution the tablets have. The LCD is handled by a third party (Epson) chip.

Also missing is drivers for the hardware Java interpreter (Jazelle) but this is due to a licensing issue if I remember correctly.

Re: The N800 has a 3D accelerator, right?
 

Rubbish, the PowerVR will quite happily support our screen resolution. In fact I was talking to a Nokian at LinuxTag who had been using it on the N8x0. It uses a shared SDRAM frame buffer afaik, so the frame size is not limited. It does use internal memory for some things (like a Z-buffer, tile buffer), at least that's what it says in the few docs which are available, so this will set some limit to the number of items on the display. Not related to the screen/frame size though.

With regard to the driver, it's buggy and messy and won't be released as it would be be troublesome to support (that's my impression); to get it rewritten into a better form would cost money.

There is certainly an LCD controller bandwidth limitation, but this doesn't stop the PowerVR from performing complex 3D transformations, etc., just limits your maximum screen update rate.

Some of us started looking at the driver (there's an old 2.6.10 (iirc) driver for the PowerVR in the OMAP2430 floating around), but I at least have been busy doing other things.

Re: The N800 has a 3D accelerator, right?
 

Hmm, bandwidth issues with the possibility of only 640x480?

Without knowing any details whatsoever, you could circumvent that by drawing to an XSP 480 x 240 pixel buffer surely? Failing that, just use the hardware to setup transforms; models; etc and slowly writing them to a buffer somewhere would still be useful.

The E90 happily utilizes PowerVR. http://www.youtube.com/watch?v=Q-mEgsr4qcs - screen is 800 x 352

Re: The N800 has a 3D accelerator, right?
 

I would preffer clutter on XSP instead of clutter on 800x480.

Re: The N800 has a 3D accelerator, right?
 

Its generally agreed that if we can get the powervr engine up and running we can discuss details later, there are many powerful things you can do once you have the ability to to transformation and lighting. it doesnt actually matter if its fullscreen or not.

Games people dont care about lower resolution;
I challenge most people to be able to tell the difference between 640*480 and 800*480 (liqbase can show you)

I know the hardware is capable and I hope someone can manage to advance this.

Re: The N800 has a 3D accelerator, right?
 

It's possible that the PowerVR chip could be utilized somehow, but the reason the external Epson LCD controller is used for the display still seems to be that in practice the built-in controller of the OMAP chip isn't up for more than 640x480.. from http://focus.ti.com/pdfs/wtbu/TI_omap2420.pdf page four: "5 Mbit internal SRAM supporting a VGA display". (It also says other interesting things as "Video out supporting an external TV display" btw...)

There's a nice picture and description in this link btw: http://focus.ti.com/general/docs/wtb...contentId=4671