Real-Time Physics Simulation Forum

Re: Disable bullet serializer

2010-11-30T05:33:55+00:00

i created a new thread for the mingw-w64 patch which also has a patch to fix compilation issues on linux.

http://bulletphysics.org/Bullet/phpBB3/ ... f=9&t=6045

Statistics: Posted by simulacrum — Tue Nov 30, 2010 5:33 am

Re: Disable bullet serializer

2010-11-30T01:30:42+00:00

no problem.
its the same as the problem mentioned here: http://bulletphysics.org/Bullet/phpBB3/ ... +precision

compiling under a 64bit platform works fine but when using mingw-w64 there are 'precision errors' due to line 69 of btAlignedAllocator.cpp:

Code:

(alignment - (unsigned long)(real + sizeof(void *))) & (alignment-1);

and elsewhere in the code (such as btSerializer)

the problem is that the width of 'long' is 32bits under mingw-w64 whereas most of the time its 64bits which is why it compiles fine everywhere else. Since pointers are 64bits wide casting real + sizeof(void*) can easily go over the unsinged long width in mingw-w64, hence the error.

In short its easily fixed by replacing 'unsigned long' with 'uintptr_t' under systems that provide stdint.h which windows doesnt so win64 needs ULONG_PTR instead. I've already changed it with the necessary #ifdef's getting the system values from cmake and it compiles without problem on mingw-w64, vs2008, and gcc 4.4 under linux.

i should have a patch ready sometime today for the 2.77 release. i'll checkout the latest dev version too, though i dont know if this was fixed already.

hope this helps.
goran

Statistics: Posted by simulacrum — Tue Nov 30, 2010 1:30 am

Re: Disable bullet serializer

2010-11-29T21:56:37+00:00

It would be good to fix your compile problems. Can you provide the errors?

Thanks,
Erwin

Statistics: Posted by Erwin Coumans — Mon Nov 29, 2010 9:56 pm

Disable bullet serializer

2010-11-27T02:38:36+00:00

Hello,

Im using bullet with my own cmakefiles derived from the original ones but the serializer wouldn't compile on win7 64, most likely due to my own fault. Since I wont be needing the embedded serializer i decided to #ifdef serialization and their data structures out.
Disabling the serializer doesn't really save much. Performance is the same and the compiled library files are only marginally smaller. But if anyone else wants to disable it, whether because they dont need it or provide their own physics format, then using the patch below on the released 2.77 sources should add an option in the cmake configuration to disable the serializer.

Patch tested on 64 bit linux without demos and extras enabled.

(since a cant attach .patch or .txt files i had to zip it up)

optional-serializer.patch.zip

Statistics: Posted by simulacrum — Sat Nov 27, 2010 2:38 am