Function bgfx_alloc_transform 

pub unsafe extern "C" fn bgfx_alloc_transform(
    _transform: *mut bgfx_transform_t,
    _num: u16,
) -> u32

Reserve matrices in internal matrix cache. @attention Pointer returned can be modified until bgfx::frame is called.

@param[out] _transform Pointer to Transform structure. @param[in] _num Number of matrices.

@returns Index in matrix cache.