Added unuse(), identity check

include/shader.hpp

@@ -20,6 +20,9 @@ public:
   void clean_up(){glDeleteShader(ID);}
   // use/activate the shader
   void use();
+  void unuse();
+  // check identity of shader
+  bool is(const std::string vertexPath, const std::string fragmentPath) const;
   // utility uniform functions
   void setBool(const std::string &name, bool value) const;
   void setInt(const std::string &name, int value) const;
@@ -31,6 +34,10 @@ public:
 
   //TODO: make this private
   unsigned int ID; //shader program ID
+
+private:
+  std::string _vertexPath;
+  std::string _fragmentPath;
 };
 
 #endif