Hello everyone,
I had a problem by dealing with the display function in opengl.
Well, the problem goes as following:

I would like to use a function inside display function of opengl, and having a variable in that function which can be changed interactively, could be by keyboard function,but in here I couldn't right now achieve this since I always have a good result when the variable is setting to zero but whenever I change it the displayed picture starts falshing and flashing just like when you don't use
at the end of your rendering procedure

Could any one give me an advice or explaine what is the alternative solution could be?

By the way: the variable that I tried to change it, effects directly on an array the is used to render the result between


Comments, new suggestions are really appreciated

sorry for the repetition, I am don't know how can I remove it yet.