What do you think you're doing, Dave?

从《雷神之锤III》的资料中，我在一些随机的帖子中偶然发现了这一点。该文件的完整源代码可以在这里找到。这是一种非常快速的求平方根倒数的方法。至于最好的评论呢?当然，这是一种常见的方法，但考虑到它附着在直线上，它的神奇之处在于它的伟大之处。

float Q_rsqrt( float number )
{
  long i;
  float x2, y;
  const float threehalfs = 1.5F;

  x2 = number * 0.5F;
  y  = number;
  i  = * ( long * ) &y;  // evil floating point bit level hacking
  i  = 0x5f3759df - ( i >> 1 ); // what the fuck?
  y  = * ( float * ) &i;
  y  = y * ( threehalfs - ( x2 * y * y ) ); // 1st iteration
  // y  = y * ( threehalfs - ( x2 * y * y ) ); // 2nd iteration, this can be removed

  #ifndef Q3_VM
  #ifdef __linux__
    assert( !isnan(y) ); // bk010122 - FPE?
  #endif
  #endif
  return y;
}

我不止一次使用过这个方法，当我对一个数学公式做了一些不明显的简化时，我不想记录:

//this formula is right, work out the math yourself if you don't believe me

long time; /* just seems that way */

用VB写的很好。我今天早上跑进了NET，得到了一个笑声…

''' <summary>
''' Represents an exception that was logged.  Since System.Exception implements IDictionary, it can't be
''' serialized, so I had to write this.  Pretty fucking stupid thing to have to do, System.Exception should
''' be serializable right out of the box, IMHO.
''' </summary>
''' <remarks></remarks>
Public Class LogException

.class {border:1px solid gold;} /*我可怜这个傻瓜*/