在3D结构中快速设置字节变量

问题描述

我有一个3d结构，其中包含Byte变量cCtrlVal.
我想在运行时将其尽快设置为255.
有5760个cCtrlVal实例.

目前，我正在遍历具有3个嵌套的for循环的矩阵.

有没有更好的方法来快速设置此变量?
提前谢谢.

:罗恩

Hi,

I have a 3d structure that contains a Byte variable cCtrlVal.
I would like to set this at runtime to 255 as fast as possible.
There are 5760 instances of cCtrlVal.

Currently I am looping through the matrix with 3 nested for loops.

This there a better quicker way to quick set this var?
Thanks in advance.

:Ron

struct typControlMatrix
	{
	BOOL bEnabled;
	BOOL bChanged;
	BOOL LastChange;
	BOOL AdjStripNo;
        BYTE cCtrlVal;
	enum enControlType eCtrlType;
	DWORD lCtrlNo;
	char sStripDesc[MAX_SCRIBBLE_STRIP_DESC];
	CString sCtrlVal;
	BOOL bDescChanged;
	int TrackPage;
	int CompRatioIndex ;
	DWORD lStripNo;
	int lParamNo;
	} m_tControlMatrix[128][5][9];

推荐答案

register int i, j, k;
  LARGE_INTEGER t[4];

  QueryPerformanceCounter(&t[0]);

  //-> 3 loops
  for (i=0; i<128; i++)
  {
    for (j=0; j<5; j++)
    {
      for (k=0; k<9; k++)
        m_tControlMatrix[i][j][k].cCtrlVal = 255;
    }
  }
  //<-
  QueryPerformanceCounter(&t[1]);

  QueryPerformanceCounter(&t[2]);
  //-> flat pointers
  register BYTE * p = &m_tControlMatrix[0][0][0].cCtrlVal;
  register BYTE * q = p + 5760 * sizeof(typControlMatrix);
  while (p < q)
  {
    *p = 255;
    p += sizeof(typControlMatrix);
  }
  //<-
  QueryPerformanceCounter(&t[3]);

  CString s;
  s.Format("3 loops: %I64d flat pointers: %I64d speed ratio %g ", (t[1].QuadPart-t[0].QuadPart), (t[3].QuadPart-t[2].QuadPart), ((double)(t[1].QuadPart-t[0].QuadPart))/(t[3].QuadPart-t[2].QuadPart));
  MessageBox(s, "Test");

输出:

The output:

3 loops: 195327 flat pointers: 67743 speed ratio 2.88335 

这篇关于在3D结构中快速设置字节变量的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！