set(physics_internal_dir ${physics_dir}/internal)
set(physics2d_internal_dir ${physics_internal_dir}/chipmunk-impl)
set(physics3d_internal_dir ${physics_internal_dir}/bullet-impl)

set(physics2d_src_files ${physics_src_files}
  ${physics2d_internal_dir}/chipmunk-physics-actor-impl.cpp
  ${physics2d_internal_dir}/chipmunk-physics-adaptor-impl.cpp
  ${physics2d_internal_dir}/chipmunk-physics-debug-renderer.cpp
  ${physics2d_internal_dir}/chipmunk-physics-world-impl.cpp
  ${physics_internal_dir}/physics-adaptor-impl.cpp
  ${physics_internal_dir}/physics-world-impl.cpp
)

set(physics3d_src_files ${physics_src_files}
  ${physics3d_internal_dir}/bullet-physics-actor-impl.cpp
  ${physics3d_internal_dir}/bullet-physics-adaptor-impl.cpp
  ${physics3d_internal_dir}/bullet-physics-debug-renderer.cpp
  ${physics3d_internal_dir}/bullet-physics-world-impl.cpp
  ${physics_internal_dir}/physics-adaptor-impl.cpp
  ${physics_internal_dir}/physics-world-impl.cpp
)