added openGLVersion check as a silent operation, to avoid console

spamming when version check fails

libs_required/ACG/GL/gl.cc

@@ -126,7 +126,7 @@ bool checkExtensionSupported( const std::string& _extension )  {
 
 /** Check if OpenGL Version is greater or equal than the given values
 */
-bool openGLVersion( const int _major, const int _minor  )  {
+bool openGLVersion( const int _major, const int _minor, bool _verbose  )  {
 
   // Read OpenGL Version string
   std::string glVersionString = (const char*)glGetString(GL_VERSION);
@@ -148,8 +148,11 @@ bool openGLVersion( const int _major, const int _minor  )  {
   stream >> minor;
 
   if ( (_major > major) || ( (_major == major) && (_minor > minor))  ) {
+    if(_verbose)
+    {
       std::cerr << "OpenGL Version check failed. Required  : " << _major << "." << _minor << std::endl;
       std::cerr << "OpenGL Version check failed. Available : " << major << "." << minor << std::endl;
+    }
     return false;
   }
 

libs_required/ACG/GL/gl.hh

@@ -269,7 +269,12 @@ bool ACGDLLEXPORT checkExtensionSupported( const std::string& _extension ) ;
 
 /** Check if OpenGL Version is greater or equal than the given values
 */
-bool ACGDLLEXPORT openGLVersion( const int _major, const int _minor  );
+bool ACGDLLEXPORT openGLVersion( const int _major, const int _minor, bool verbose = true );
+
+/** Test if OpenGL Version is greater or equal than the given values
+ *  No output is generated, if the OpenGL version is less than the tested value
+*/
+inline bool ACGDLLEXPORT openGLVersionTest( const int _major, const int _minor  ){return openGLVersion(_major, _minor, false);}
 
 /// Store opengl core profile setting
 void ACGDLLEXPORT compatibilityProfile(bool _compatProfile);