ATI Rage Mobility (Mach64) DRI Issue

finite · 07-19-2006, 11:09 AM

I've managed to get open source DRI working in linux for on my Compaq Armada M700 with the above graphics card. Yay!

However, there seems to be a serious problem with certain polygons not being rendered. I've searched all over the place for an answer, and thought I'd ask here before submitting bug reports to the DRI folk.

Essentially, in any OpenGL app, every odd polygon that touches the edge of the screen isn't rendered, leaving a tell-tale hole where it should be. Here are a few example screenshots:

bzflag
neverball
neverball again
(You may also notice in the large text in bzflag that every letter is cut in half... only one of the two polygons is being rendered)

Seems like somewhere along the pipeline, polygons are being culled (perhaps they are thought to be off-screen?) that shouldn't be.

Anyone seen this problem with the DRI drivers (mach64 or otherwise)? Any suggestions on where I should go from here?

Here are the contents of the relevant xorg.conf sections. They're the basically the bare minimum to get dri working:

Code:

Section "Module"
    Load       "dbe"
    SubSection  "extmod"
      Option    "omit xfree86-dga"   # don't initialise the DGA extension
    EndSubSection
    Load        "freetype"

    Load       "dri"
    Load       "glx"
EndSection

Section "Device"
    Identifier  "My Video Card"
    Driver      "ati"
EndSection

Section "DRI"
   Mode 0666
EndSection

RCL · 08-06-2006, 02:09 PM

I have the same problem with DRI drivers for ATI Rage Pro LT card. I guess the bug is in mach64 driver.

When compiling my own OpenGL program, I noticed the following problems:

1) Only the first triangle is drawn from display lists (it's used for printing fonts).

2) When large polygon which is partially offscreen is being drawn, it's incorrectly clipped. Visible part of it contains "holes" and texture coordinates are sometimes set to random values.

The drivers installed come from Debian unstable/testing distribution. This is what glxinfo says:

Code:

OpenGL vendor string: Gareth Hughes, Leif Delgass, José Fonseca
OpenGL renderer string: Mesa DRI Mach64 [Rage Pro] 20051019 AGP 2x
OpenGL version string: 1.2 Mesa 6.4.2