These packages contain BOTH the single-precision and double-precision
floating-point builds. By default you get the single-precision floating-point
builds. The double-precision floating point libraries all have "-float64" in
their filenames and SONAME tags and the pkgconfig and the cmake files. To use
the double-precision libraries:

  - Compile with -DBT_USE_DOUBLE_PRECISION
  - Link with -lBulletXXX-float64 instead of -lBulletXXX

If using pkgconfig you get both of these by switching

  pkg-config --whatever bullet

to

  pkg-config --whatever bullet-float64

Similarly, if using CMake, instead of invoking

  BulletConfig.cmake

you should invoke

  BulletConfig-float64.cmake

 -- Dima Kogan <dkogan@debian.org>, Tue, 30 Oct 2018 17:30:55 -0700