descent

[Mark (Killzat)]

^^ Sorry, I meant by comparison to ARM...

[Digby]

Volition-fan,<br><br>On the Pocket PC it isn't the number of polygons that is the bottleneck, it's the size of the polygon.  This is because the rasterization is occuring in software and you're limited by the how fast you can fill the interior of the polygon.<br><br>

[MirekCz]

I'm not so sure if you're right Digby. Of course, polygon size does matter, but as far as I remember (from my cyrix p150 tests), PPC has got a better memory bandwitch and therefore it should handle for ex. quake better then an almost similar clocked cyrix. Of course the 16bpp screen mode is a bit of a bottleneck because of twice the size of a comparable 8bpp mode used for 3d gaming during early "pentium time". We do have a nice advantage thru which is fast access to video memory, it is faster then using a PCI or (god bless us) ISA card.<br>As far as I know the biggest bottleneck is the lack of a decent FPU for processing math calculations.<br>Of course software rendering won't allow you to write doom3 or anything, but with a decent fpu running quake1 at a good fps rate (24+) shouldn't be a problem. And we also might get better colors while using a 16bpp mode (unfortunetly downgraded to 12bpp by most (all?) IPAQ's)

[Digby]

Mirek,<br>I wasn't making a comparison between the Pocket PC and a PC.  I'm saying that with software 3D implementations, the bottleneck is the fill rate of the rasterizer.  <br><br>If you don't believe it's the fill rate, then what do you think IS the bottleneck?<br><br>

[MirekCz]

Digby:it's just like with 3d accels, it depends. if you have a lot of small triangles you will pretty fast lose all your time on calculating new vertex positions etc, but on the other hand few large polygons can kill you off because of fillrate. There are a lot of tricks to prevent it (sorting polygons front to back and using a c-buffer(or s-buffer) for ex.) which might give you excellent results in avoiding overdraw, unfortunetly again, if you have a lot of small triangles it won't help you.<br>My point is that PPCs memory bus is quite a speedy one comparing to older PCs but lack of a decent FPU kills it all. Quake2 used to work fine on a P200 and look how poorly it works on PPCs, and rewriting everything to fixedpoint math won't allow you to achieve good results either, althrought it will bring a huge performace increase.<br>My point pretty much is that with a decent fpu we would be able to achieve at least p100 game quality in terms of world complexity/fps rate, althrought with 16bpp color which increases image quality by a decent factor (and with PPCs small screen you won't see large ugly looking pixels either) and there were some great 3d games on a p100...

[mark (killzat)]