dnl VKD3D_CHECK_VULKAN
AC_DEFUN([VKD3D_CHECK_VULKAN],[
VKD3D_CHECK_SONAME([vulkan], [vkGetInstanceProcAddr],,
                   [VKD3D_CHECK_SONAME([vulkan-1], [vkGetInstanceProcAddr],
                                       [AC_DEFINE_UNQUOTED([SONAME_LIBVULKAN], ["$ac_cv_lib_soname_vulkan_1"])],
                                       [VKD3D_CHECK_SONAME([MoltenVK], [vkGetInstanceProcAddr],
                                                           [AC_DEFINE_UNQUOTED([SONAME_LIBVULKAN],
                                                                               ["$ac_cv_lib_soname_MoltenVK"])],
                                                           [AC_MSG_ERROR([libvulkan and libMoltenVK not found.])],
                                                           [$VULKAN_LIBS])],
                                       [$VULKAN_LIBS])],
                   [$VULKAN_LIBS])
])