I have a general question about creating a drawing application, the language could be C++ or ObjectiveC with OpenGL. I would like to hear what are the best methods and practices for storing strokes data. Think of the many iPad apps that allow you to draw with your finger (or a stylus) or any other similar function on a desktop app.

To summarize, the data structure must:

• be highly responsive to the movement
• store precise values (close in space / time)
• usable for rendering the strokes with complex textures (textures based on the dynamic of the stroke etc)
• exportable to a text file for saving/loading