Troubleshooting/Blam

This is a little bit technical. If you just want a solution go here, or scroll to the bottom of the section.

Causes

Blam at startup

This problem has been traced to the overflow of a particular text buffer -- the one that lists the OpenGL extensions in the startup.txt file. If your version of Oni just crashed on startup, take a look at that file (it's in your Oni folder). At the end, there should be a rather big list of available OpenGL extensions. If the list cuts off abruptly, that means that startup failed during its writing.

When Oni was written, the OpenGL extension list dump was much shorter, and the developers did not allow for a larger dump. Modern graphics cards almost always cause this overflow. Fortunately, there is a patch (see "Solutions" below) for the PC and the Mac.

Other text buffer overflows

There are other occasions when Oni dumps large amounts of text, and when the dumped text is larger than the buffer Bungie set up for it, you'll have an overflow, and Oni will crash.

Examples

debugger.txt - another debug log located in the Oni folder

other debug logs enabled with the -debugfiles command line argument

console output in Developer Mode

Debug logs

What you should remember about them :

• Some debug logs that can cause crashes are only enabled if you choose to do so. (See -debugfiles under command line argument.)
• You can't disable the default debug logs (debugger.txt and startup.txt), so this cannot prevent the startup Blam. See the "Solution Links" below for patches for this.
• Some other logs (debug files and console output) are either disabled in the executable you're using, or they're (re)enabled and in that case you may experience a crash.

Non-text buffer overflows

There are fixed-size buffers that are not handled by Ian's patch, but can cause overflow just fine.

Movie buffer

See here for details.

You shouldn't encounter these situations if you play Oni "normally".

Out of range errors

There are a number of situations where Oni will "Blam" that have little to do with buffers. Most often, the engine will attempt to address a region in memory but fail to find the expected data.

Pathfinding

Oni can generate too many pathfinding nodes if a pathfinding grid is inconsistent with the environment (rare)

Switching between characters

Oni will crash if you chr_focus to a character that's not drawn

Conflicts

Oni will crash if you fire a gun while in control of an active AI

Oni will crash if you "talk" to a neutral AI while in control of it

(it's a bit more complicated, but who cares?)

Inexistent stuff

Oni will crash if you call an inexistent function with the strong syntax.

You shouldn't encounter these situations if you play Oni "normally".

About the Solutions

Ian's patch

Ian Patterson (a professional coder, and the creator of OniTools, among other stuff) located the routine that writes to fixed-size text buffers (in startup.txt and elsewhere). Rather than making the problematic buffers larger or dynamic (adjusted at runtime), he completely disabled them. Thus he made the English version of Oni run without a "Blam" on startup on Windows XP with the most common GFX hardware/drivers.

Then he proceeded with creating a universal patch that makes the appropriate changes not only to the English Oni.exe, but also to the executables of a number of other releases (German, Spanish...). For all those versions, the patch completely disables the problematic fixed-size buffers, making it possible to run Oni on XP with "those recent GFX cards that have too many OpenGL extensions".

Ian's patch also makes the executable able to run no matter what its name is (the original Oni.exe will not work if you rename it).

There are, however, a few issues.

Problems

One problem is that people who want to have a look at files like debugger.txt can't do so

(well, that's only a problem for fanatic reverse engineers who want to figure out "how Oni works"...)

A bigger problem is that Ian's patch prevents Oni from dumping output to the console in Developer Mode

(well, that has only become a problem after we got aware of the Developer Mode functionality)

Solutions

reenable the needed buffers (except the GL extension buffer)

make them larger, or dynamic, to avoid overflow

Recent driver fixes

The present status of Ian's patch is unofficial. Although Ian suggested to Take2 and Godgames to release an official patch, there was no response. However, action has been taken by GFX card manufacturers. Since Oni is not the only game for which the GL extension problem arises, the recent drivers provide a set of options that limits the list of GL extensions "seen" by the game. That's an alternative way to prevent Oni from crashing at startup, but it's highly manufacturer-dependent.

Nvidia

from your driver's interface, create an application profile for Oni.exe with "extension limit" set to ON.

ATI

Solution Links

Ian's patch

• Ian's patch (ZIP) (patches several Oni versions, not only the English one)
• instructions and troubleshooting (ignore the line "send me a copy of your oni.exe in this forum thread, and I'll try and add support for that version")
• patched English version (RAR)
• a very useful thread on Oni Central Forum (about Ian's patch and the "Blam" issue in general)
• Ian's patch on Script10K's page
• Ian's patch on Ian's page

Beyond Ian's patch

See here for a beefed-up Oni.exe featuring :

• a slightly modified Ian's patch
  • executable can be renamed (retained)
  • no GL extensions dumped at startup (retained)
  • dev console and other debug logs (reenabled)
• the Developer Mode