I'll probably get negative reputation for asking this question but I'm stuck and need help. I need to do a nice and smooth easing between two values, the result being displayed in a textbox. For example, my textbox is showing "125" and have to grow smoothly to "25000" in 2.5 seconds with a nice quadratic acceleration and deceleration curve. I'm not good at C# and I'm used to "hack" pieces of code I can find on the web and build them together to do what I need but, for this, I can't find anything I've been able to use so far. Is there anyone who can be kind enough to give me instructions, links or, even better a working piece of code to do this? Thank you very much Vince.
I've found that the simplest way to do this is with quadratic formulas (as you have already figured out). There are online calculators that can give you a parabolic equation using three points, and when taking (0, 125), (2.5, 25000), and (5, 125) we get an equation of y = -3980x^2 + 19900x + 125. Translated into C#, this gives us:
var foo = -3980 * Math.Power(bar, 2) + 19900 * bar + 125;
After that, we can use a for loop and a small sleep time to transition smoothly from bar = 0 to bar = 2.5.