在C＃中实现类似jQuery的animate（）函数的功能

Question

I'm new to C# and using it to write my next game. Coming from a background in C++, Java and JavaScript, I'm excited to use C#'s anonymous functions to simplify tasks that weren't so simple in C++ and Java.

Particularly, I'd like to implement a system in my code that works similar to jQuery's animate() function: easing a set of variables from their initial values to a new set of values, and then executing a callback upon completion. I understand how to use anonymous functions and callbacks in C#, so that's no problem, but I'm not sure how I'd go about passing properties and their associated values to a function.

As an example, my goal would be something like this, to ease a player's x coordinate from the initial value to the target value of 500, while easing his scale value to 2.0f, over the course of 10.0 seconds:

game.animate( { player.x: 500, player.scale: 2.0f }, 10.0f, delegate() { Console.WriteLine("Callback has been called!"); }

(That won't compile, of course, but the point of the example is to describe the syntax I'm hoping to approximate.)

According to other Stack Overflow questions and answers, it's not possible to pass property references to functions in C#, so passing player.x and player.scale to the function would apparently be impossible in this way, which means I have to rethink my strategy for implementing this.

Is there any other way I could go about implementing a system like this, given C#'s constraints about passing property references to functions? Or do I need to just give up on this idea and use less flexible means of easing property values over time?

Answer 1

With a little experimentation and help from Shoe's comments, I came up with a solution.

First, the assumption is made that all properties will be floats. Secondly, each property (player.x, player.scale, etc.) will need an explicitly-defined setter (player.SetX(), player.SetScale(), etc.) which takes in a single float and returns void.

After that, the main code can be defined like so:

public delegate void PropertySetter(float newVal);

public void Animate(PropertySetter setter, float time, float valToSet, Action callback=null)
{
   // the implementation-specific code for interpolating values will go here.  and call "callback" when complete, if it's non-null.
}

And to use the Animate() function, all we need to do is call it like so:

Animate(player.SetX, 10.0f, 500.0f);
Animate(player.SetScale, 10.0f, 2.0f);

I'm going to change it later to allow those calls to happen in a single call, but this serves as a simple example.