Trivial but useful extension method

Don’t know why I didn’t write this before; it makes code very readable. Often when you write anything graphics related, you want to constrain coordinates to window edges (for example).

So a simple method:

    1: /// <summary>

    2: /// Ensure that the given number falls within the

    3: /// given min/max constraints.

    4: /// </summary>

    5: public static double Constrain( this double num,

    6:                         double min, double max )

    7: {

    8:     if (num < min)

    9:         return min;

   10:     else if (num > max)

   11:         return max;

   12:     else

   13:         return num;

   14: }

It’s just a Floor combined with a Ceiling, but it reads nicely:

    1: xform.X = dx.Constrain(-this.ActualWidth, 0 );

    2: xform.Y = dy.Constrain(-this.ActualHeight, 0 );

 

Avi

Comments

• Anonymous
  September 29, 2008
  Nice, but why not make it generic?public static T Constrain<T>(this T value, T min, T max) where T : IComparable<T>{ if (value.CompareTo(min)<0)   return min; else if (value.CompareTo(max)>0)   return max; else   return value;}
• Anonymous
  September 29, 2008
  Yep, even better!
• Anonymous
  September 04, 2009
  "It’s just a Floor combined with a Ceiling, but it reads nicely:" Your code dosen't read like that, whythe ifs? public static int Constraint(this int value, int min, int max) { return Math.Min(Math.Max(value,min), max); }