message: add CMake macro for setting ISPC-side preprocessor definitions
diff: @@ -79,6 +79,15 @@ MACRO (INCLUDE_DIRECTORIES_ISPC)
  SET(ISPC_INCLUDE_DIR ${ISPC_INCLUDE_DIR} ${ARGN})
  ENDMACRO ()
  +# ##################################################################
  +# add macro ADD_DEFINITIONS_ISPC() that allows to specify
  +# ISPC pre-processor definitions
  +# ##################################################################
  +SET(ISPC_DEFINITIONS "")
  +MACRO (ADD_DEFINITIONS_ISPC)
  + SET(ISPC_DEFINITIONS ${ISPC_DEFINITIONS} ${ARGN})
  +ENDMACRO ()
  +
  MACRO (OSPRAY_ISPC_COMPILE)
  SET(ISPC_ADDITIONAL_ARGS "")
  SET(ISPC_TARGETS ${OSPRAY_ISPC_TARGET_LIST})
  @@ -158,6 +167,7 @@ MACRO (OSPRAY_ISPC_COMPILE)
  OUTPUT ${results} ${ISPC_TARGET_DIR}/${fname}_ispc.h
  COMMAND ${CMAKE_COMMAND} -E make_directory ${outdir}
  COMMAND ${ISPC_EXECUTABLE}
  + ${ISPC_DEFINITIONS}
  -I ${CMAKE_CURRENT_SOURCE_DIR}
  ${ISPC_INCLUDE_DIR_PARMS}
  --arch=${ISPC_ARCHITECTURE}
  