message: updates to avoid CMake warnings
diff: project(ospray_studio)
  cmake_minimum_required(VERSION 3.1)
  +if(POLICY CMP0074)
  + cmake_policy(SET CMP0074 NEW) # since 3.12
  +endif()
  +
  set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR})
  set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR})
  set(CMAKE_LIBRARY_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR})
  @@ -25,7 +29,8 @@ set(CMAKE_CXX_STANDARD 17)
  ## Find dependencies ##
  -find_package(OpenGL REQUIRED)
  +set(OpenGL_GL_PREFERENCE "LEGACY")
  +find_package(OpenGL 2 REQUIRED)
  find_package(glfw3 REQUIRED)
  set(CMAKE_THREAD_PREFER_PTHREAD TRUE)
  set(THREADS_PREFER_PTHREAD_FLAG TRUE) # for gcc6
  