PocketMatrix

So I have noticed there isn't very much talk about DirectX on WM5 based devices. I've been using it and aside from a few minor hacks you have to do in order to get it working on all devices, I really like it!

Some SmartPhones seem to have video acceleration (namely the Samsung Blackjack) so that makes things interesting as well. Although, I noticed that the Blackjack's CPU is a TI-OMAP processor which features video acceleration on-chip.

Do SmartPhone's/PocketPC's have a seperate video chip or is it done on board the CPU or... what?

I'm not using it, but have considered it. The main reason I haven't seriously considered it yet is because I want to support PPC2003 devices. Once everything is finished and happily working with older devices I will look at building in support for DirectX for newer devices.

What are the hacks you hinted at? Do you primarily just use it for faster blitting to screen?

Well it's just a little tricky setting up the primary/back buffer.

You create the direct draw object, get the caps and from there you can see if a backbuffer with flipping is supported. Well some phones (like the MotoQ) will say that indeed it is supported until you try to actually create the surfaces and then it fails. So the way around that is to create a primary surface and a seperate back buffer and then do a blt copy over each frame of the back buffer to the primary surface as opposed to using the hardware flipping capability.

Ok, so do you render all your graphics with your own code? How extensive use do you make of the DirectX drawing capabilities? I had a look a while back and from memory it didn't seem to support much more than drawing a surface onto another, or did I miss something?

Ya aside from blitting, you have to do it all yourself BUT the blitting will take advantage of hardware capabilities when present which makes a big difference.

How much of a performance increase do you get with one blit? I doubt its anything over what GAPI can do.

For example on the treo my GAPI blit is around 3ms.

I doubt anyone will be using it until WM5 devices are more widespread, which will be a few more years, a lot of people are still using 2003 devices and older.

mm40, do you have any actual stats on 2003 usage? I would have thought that there were now more WM5 devices in use than 2003, although I actually still use a 2003 device

I don't personally know anything about legitimate statistics on OS usage, but if I were to guess I'd say that more Smartphone users were probably using WM5, but more non-phone PDA users were still running WM2003- devices. I have two WM PDAs, one running WM2003 and the other WM2002.