4 replies to this topic

[Headkaze]

I have a method that takes two enums and returns a delegate based on their values.

ie.

public static EaseDelegate GetEaseFunction(EaseCategory easeCategory, EaseType easeType)
{
switch (easeCategory)
{
  case EaseCategory.Linear:
   switch (easeType)
   {
	case EaseType.EaseIn:
	 return new EaseDelegate(Linear.EaseIn);
	case EaseType.EaseOut:
	 return new EaseDelegate(Linear.EaseOut);
	case EaseType.EaseInOut:
	 return new EaseDelegate(Linear.EaseInOut);
	case EaseType.EaseNone:
	 return new EaseDelegate(Linear.EaseNone);
   }
   break;
  ...
}
}

Note that in the above extract "Linear" is a static class and "EaseIn", "EaseOut" etc. are static methods. EaseDelegate is a delegate matching the method signatures in the class.

Now I need two methods that do the reverse; return the enum value based on the class and method of the delegate.

public static EaseCategory GetEaseCategory(EaseDelegate easeFunction)
{
// return ???
}
public static EaseType GetEaseType(EaseDelegate easeFunction)
{
// return ???
}

[Headkaze]

This is what I've have so far and a few variations thereof. Am I on the right track?

public static EaseCategory GetEaseCategory(EaseDelegate easeFunction)
{
if (easeFunction.GetType() == typeof(Linear))
  return EaseCategory.Linear;
else if (easeFunction.GetType() == typeof(Quadratic))
  return EaseCategory.Quadratic;
return EaseCategory.Sine;
}
public static EaseType GetEaseType(EaseDelegate easeFunction)
{
if (easeFunction.Method.GetType() == new EaseDelegate(Linear.EaseIn).Method.GetType())
  return EaseType.EaseIn;
else if (easeFunction.Method.GetType() == new EaseDelegate(Linear.EaseOut).Method.GetType())
  return EaseType.EaseOut;
return EaseType.EaseNone;
}

[Headkaze]

I thought I had it with

if (easeFunction.GetType().IsInstanceOfType(typeof(Linear)))

To check if the object was an instance of Linear. Not so.

Still at a loss here.

Here is my delegate declaration

public delegate double EaseDelegate(double start, double end, double duration, double elapsedTime);

And here is the Ease class

public static class Easing
{
public static class Linear
{
  public static double EaseNone(double t, double b, double c, double d)
  {
   return c * t / d + b;
  }
  public static double EaseIn(double t, double b, double c, double d)
  {
   return c * t / d + b;
  }
  public static double EaseOut(double t, double b, double c, double d)
  {
   return c * t / d + b;
  }
  public static double EaseInOut(double t, double b, double c, double d)
  {
   return c * t / d + b;
  }
}
}

Now if I pass in Easing.Linear.EaseIn as a "EaseDelegate easeFunction" parameter shouldn't easeFunction be an object? So why I can't I use "if(easeFunction is Linear)". I get "the expression is never of the provided type". I get the same if I use "if(easeFunction is Easing)".

Edited by Headkaze, 10 October 2012 - 11:17 AM.

[Anthracis]

Hi,

the delegate type provides you with all the necessary information. Especially the "Method"-property is helpful for your need.
Its "DeclaringType" gives you the type where your delegate function is defined and with the "Name"-Property you receive the name of the actual method.

So your two methods could look like this:

[source lang="csharp"] public static EaseCategory GetEaseCategory(EaseDelegate easeFunction) { if (easeFunction.Method.DeclaringType == typeof(Linear)) return EaseCategory.Linear; else if (easeFunction.Method.DeclaringType == typeof(Quadratic)) return EaseCategory.Quadratic; return EaseCategory.Sine; } public static EaseType GetEaseType(EaseDelegate easeFunction) { if (easeFunction.Method.Name == "EaseIn") return EaseType.EaseIn; else if (easeFunction.Method.Name == "EaseOut") return EaseType.EaseOut; return EaseType.EaseNone; } [/source]

Hope this helps with your problem.

[Headkaze]

Thanks Anthracis.