指向3D数组C ++的指针 [英] pointers to 3D arrays C++

问题描述

C ++：我有一个指向3D数组的指针的问题 - 我使用2D数组编写基本游戏，每个2D数组是一个单独的级别，这些级别被分组为一个称为地图的3D数组。

C++: I have a problem with pointers to 3D arrays - I'm writing a basic game with 2D arrays, each 2D array is a separate level and these levels are grouped into a 3D array called map.

如何指向我游戏的每一个关卡？我精简的代码：

How can I point to each 'level' of my game? My streamlined code:

#include<iostream>
using namespace std;

#define LEVEL  2
#define HEIGHT 3
#define WIDTH  3

bool map[LEVEL][HEIGHT][WIDTH] = { {{1, 0, 1},   
                                    {1, 0, 1},   
                                    {0, 0, 1}},

                                   {{1, 1, 0},   
                                    {0, 0, 0},   
                                    {1, 0, 1}} };
int main()
{
  // ideally this points to level#1, then increments to level#2 
  bool *ptrMap;

  for(int i=0; i<HEIGHT; i++)
  {
     for(int j=0; j<WIDTH; j++)
       cout << map[1][i][j];       // [*ptrMap][i][j] ?
     cout << endl;
  }
return 0;    
}

推荐答案

Assign,

bool *ptrmap= &map[0][0][0];// gives you level 0
cout<<*ptrmap; //outputs the first element, level 0
cout<<*(ptrmap+9);// outputs first element, level 1

如果不想要指针的线性增量，

If you do not want a linear increment of pointers,

i.e. map[0][0][0] as *ptrmap & map[1][0][0] as *(ptrmap + 9)

使用指针的指针来创建矩阵（例如bool *** ptrmap），然后创建一个临时指针来解引用。

, I suggest you use pointer of pointers to create the matrix (ex. bool ***ptrmap) and then create a temporary pointer to dereference it.

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