Separrate build of examples.

CMakeLists.txt

diff --git a/CMakeLists.txt b/CMakeLists.txt
index e7864e5..30cc854 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -4,18 +4,24 @@
 
 SET(CMAKE_CXX_STANDARD 11)
 
-option(TINYGLTF_BUILD_EXAMPLES "Build examples" ON)
+option(TINYGLTF_BUILD_LOADER_EXAMPLE "Build loader_example" ON)
+option(TINYGLTF_BUILD_GL_EXAMPLES "Build GL exampels(requires glfw, OpenGL, etc)" OFF)
+option(TINYGLTF_BUILD_VALIDATOR_EXAMPLE "Build validator exampe" OFF)
 
-if (TINYGLTF_BUILD_EXAMPLES)
+if (TINYGLTF_BUILD_LOADER_EXAMPLE)
   ADD_EXECUTABLE ( loader_example
     loader_example.cc
     )
+endif (TINYGLTF_BUILD_LOADER_EXAMPLE)
 
+if (TINYGLTF_BUILD_GL_EXAMPLES)
   ADD_SUBDIRECTORY ( examples/gltfutil )
   ADD_SUBDIRECTORY ( examples/glview )
-  ADD_SUBDIRECTORY ( examples/validator )
-endif (TINYGLTF_BUILD_EXAMPLES)
+endif (TINYGLTF_BUILD_GL_EXAMPLES)
 
+if (TINYGLTF_BUILD_VALIDATOR_EXAMPLE)
+  ADD_SUBDIRECTORY ( examples/validator )
+endif (TINYGLTF_BUILD_VALIDATOR_EXAMPLE)
 #
 # TinuGLTF is a header-only library, so no library build. just install header files.
 #