Hi to all
Thank for all to help me,

I want to ask about linking the files ,

now I have files ( with extension .cpp and .h ) , which contain on class of OpenGL code to drawing rectangle.

I can make object from them in main body. But now I want to call it and use in my window which I created.


Unfortunate, if I do that ,it cause error .


If we can help me .

Thank you