btTransform and OpenGL

[vaxon]

Just another stupid question from a newbie here
Is there a sort of "OpenGL-optimized" version of btTransform.
Bullet uses (row-major) internal data storage for btTransform (and btMatrix3x3).
So we have to call getOpenGLMatrix() to export it to a temporary column-major matrix to be later passed to OpenGL.
Would it be possible to have bullet use column-major matrices in the first place and map them to an OpenGL float* (reinterpret_cast) to eliminate the copying?
Would it give us any performance gain?
Just wondering if anybody has already experimented with it and if it's possible.

Thanks,
V.

[Erwin Coumans]

I wouldn't worry about the minor conversion cost, your application CPU cycles are most likely happening elsewhere.

OpenGL uses a 4x4 matrix. Bullet uses a 3x3 matrix and a position vector, it is different. In Bullet 3.x we are using a quaternion and position, so we still need the conversion anyway.

[vaxon]

Thanks!