message: cmake: add global defines to enable useful macros
diff: @@ -224,6 +224,10 @@ macro(ocv_add_module _name)
  endif()
  if((NOT OPENCV_MODULE_${the_module}_IS_PART_OF_WORLD AND NOT ${the_module} STREQUAL opencv_world) OR NOT ${BUILD_opencv_world})
  project(${the_module})
  + add_definitions(
  + -D_USE_MATH_DEFINES # M_PI constant in MSVS
  + -D__STDC_CONSTANT_MACROS -D__STDC_LIMIT_MACROS # to use C libraries from C++ code (ffmpeg)
  + )
  endif()
  endif()
  endmacro()
  