Variable Fonts and Graphic Design

Hi! 

I'm currently studying about variable fonts and their application to the graphic designer work.

I'm not a programmer, but I would like to know if there is a possibility for developing an algorithm that controls the tone of the text.

I'm thinking about a control in a user interface that allows him to choose to have more or less tonal difference between the variable font used and the axes of width, weight, and so on, fit their choice. 

Thank you,
Ana Fernandes