Saturday, November 14, 2009

Thoughts: DrawIndexedVertices[UP] may be our problem...

I've been talking to martin_sw about a few things Cxbx related a few days ago. Eventually we got around to talking about speed and corruption issues (for Panzer, Robotech Battlecry, and BattleStar Galactica appear to suffer from this). One interesting detail that came up was our implementation of EmuIDirect3DDevice8_DrawIndexedVertices. He says that if this function is used in any games we are emulating and speed/graphics issues occur, this function is likely the problem as it really needs optimization and stuff. I've never actually looked into how the Draw[Indexed]Vertices[UP] functions work on a real Xbox, and just assumed sir Caustik had that taken care of. Just in case you didn't know Draw[Indexed]Vertices[UP] is not a part of PC standard Direct3D. It's an Xbox extension and as far as I know, Draw[Indexed]Primitive[UP] is really redirected to Draw[Indexed]Vertices[UP]. I can do some simple tests to see what may be causing our problems.

I can hear you saying, "Do you have anything interesting to show us??". Hold on, I'm getting to that; okay, fine... lol. I got Robotech Battlecry to go in-game again. I still didn't get around to fixing the random problem yet, but someone from (IIRC) made a SSE2 optimized version of Cxbx r-153. It started up Robotech Battlecry about 4 times in a row without problems. I did make a few in-game screenshots for you (since I couldn't last time). They are highly distorted, but here they are:

Even through the frame rates are decent, you can't really do anything in-game because it crashes almost immediately. Since it was a release build I tested, I wasn't able to track the problem. I can already tell it's an internal problem in the CxbxKrnl. I tried to make a youtube video of this, but it looks like fraps can't correctly record this game (everything is just a few blue lines). Oh well...

So as you can see, the problem is getting pretty dire (haha). So I'll start testing some scenarios with DrawIndexedVertices[UP] on Cxbx and then try them on my real debug Xbox. Well, had to have some kind of update, heh heh....



  1. Take it easy man you will fix that with a lot of time ;).

  2. From Colombia, I have pcsx2 emulator (PS2) for pc, and I would love to have a xbox emulator for my pc, go Caustik, cxbx'll be the best emulator, ;)