// ------------------------------------------------------------------------
  // This program is complementary material for the book:
  //
  // Frank Nielsen
  //
  // Visual Computing: Geometry, Graphics, and Vision
  //
  // ISBN: 1-58450-427-7
  //
  // Charles River Media, Inc.
  //
  //
  // All programs are available at www.charlesriver.com/visualcomputing/
  //
  // You may use this program for ACADEMIC and PERSONAL purposes ONLY. 
  //
  //
  // The use of this program in a commercial product requires EXPLICITLY
  // written permission from the author. The author is NOT responsible or 
  // liable for damage or loss that may be caused by the use of this program. 
  //
  // Copyright (c) 2005. Frank Nielsen. All rights reserved.
  // ------------------------------------------------------------------------
   
  // ------------------------------------------------------------------------
  // File: multidim-indexremapping.cpp
  // 
  // Description: Conversions between 1D and dD array indices of arrays.
  // ------------------------------------------------------------------------
  
  include <stdafx.h>
  
  using namespace std;
  
  // Array dimensions
  
  const int d1=12, d2=21, d3=8, d4=30;
  int D1,D2,D3,D4;
  
  int marray[d4][d3][d2][d1];
  
  void Error();
  
  void FillArray()
  {
  int i1, i2, i3, i4;
  
  for(i4=0;i4<d4;i4++)
          for(i3=0;i3<d3;i3++)
          for(i2=0;i2<d2;i2++)
          for(i1=0;i1<d1;i1++)
                  marray[i4][i3][i2][i1]=rand();
  }
  
  int _tmain(int argc, _TCHAR* argv[])
  {
  int *larray=(int*)&marray[0][0][0][0];
  int k,k1,k2,k3,k4,n,el1,el2;
  
  cout<<"Visual Computing: Geometry, Graphics, and Vision (ISBN:1-58450-427-7)"<<endl;
  cout<<"Demo program\n\n"<<endl;
  
  cout<<"Index remapping demo for arrays.\n\n"<<endl;
  
  srand(2005);
  
  FillArray();
  
  D1=1;
  D2=d1*D1;
  D3=d2*D2;
  D4=d3*D3;
  n=d4*D4;
  
  cout<<"Number of elements:"<<n<<endl;
  
  for(int nbtest=0;nbtest<100;nbtest++)
  {
  k1=rand()\%d1;
  k2=rand()\%d2;
  k3=rand()\%d3;
  k4=rand()\%d4;
  
  cout<<"Multidimensional index to linear index mapping:"<<endl;
  
  cout<<"\tMulti-dimensional array["<<k4<<"]"<<"["<<k3<<"]["<<k2<<"]["<<k1<<"]="<<marray[k4][k3][k2][k1]<<endl;
  k=k4*D4+k3*D3+k2*D2+k1*D1;
  cout<<"\tLinear array["<<k<<"]="<<larray[k]<<endl;
  
  el1=marray[k4][k3][k2][k1];
  el2=larray[k];
  if (el1!=el2) {Error();break;}
  
  cout<<"\nLinear index to multidimensional index mapping:"<<endl;
  k=rand()\%n;
  cout<<"\tLinear array["<<k<<"]="<<larray[k]<<endl;
  el2=larray[k];
  
  k4=k/D4;
  k=k-k4*D4; 
  
  k3=k/D3;
  k=k-k3*D3;
  
  k2=k/D2;
  k=k-k2*D2;
  
  k1=k;
  cout<<"\tMulti-dimensional array["<<k4<<"]"<<"["<<k3<<"]["<<k2<<"]["<<k1<<"]="<<marray[k4][k3][k2][k1]<<endl;
  cout<<"-------------------------------------------\n\n\n";
  
  el1=marray[k4][k3][k2][k1];
  
  if (el1!=el2) {Error();break;}
  }
  
  char line[256];
  cout<<"Press Return key"<<endl;
  gets(line);
  
  return 0;
  }
  
  void Error()
  {
  cout<<"Should not happen. There is an error here!"<<endl;
  }