Solved

Vector class problem

Posted on 2004-03-20
5
699 Views
Last Modified: 2013-12-14
Hi

I have declared :

class Pixel
{
      byte R;
      byte G;
      byte B;
public:
      Pixel(){};
      Pixel(const Pixel&);
      void operator=(const Pixel&);
      friend class Frame;
      friend class Macroblock;
      friend class BMPHeader;
};


class Frame
{
      BMPHeader bmph;
      vector <Macroblock> mblk;
      vector <Pixel> pix;
      int vertmac;
      int hormac;
public:
      Frame(){};            //----------------do nothing constructor
      Frame(BMPHeader &,byte *);
      void createMBlk(void);
      void findMV(Frame &);
      void display(void);
      friend class Video;
};

Frame::Frame(BMPHeader& bmp,byte *buffer)
{
      bmph = bmp;
      pix.reserve(bmph.height*bmph.width);
      for (int j=(bmph.height-1);j>=0;j--)
      {
            for(int i=0;i<bmph.width;i++)
            {
                  int index;
                  switch(bmph.bitsperPixel)
                  {
                        case 24:pix[j*bmph.width+i].R = *buffer++;
                                    pix[j*bmph.width+i].G = *buffer++;
                                    pix[j*bmph.width+i].B = *buffer++;
                                    break;
                        case 16:return;
                                    index = GetWord(buffer);                                                                                                                       buffer += 2;
                                    pix[j*bmph.width+i] = bmph.palette[index];
                                    break;
                        case 8 :index = *buffer++;
 
                                    pix[j*bmph.width+i].R = bmph.palette[index].R;   //problem is here
                                    pix[j*bmph.width+i].G = bmph.palette[index].G;  
                                    pix[j*bmph.width+i].B = bmph.palette[index].B;
                                    break;
                        default:cout << "Color depth not supported";
                                    return;
                  }
            }
            if (bmph.width%4 != 0)
                  for(int i=4;i>bmph.width%4;i--)
                        buffer++;
      }
}



I get error: Access violation unhandled exception. Using VC++.

bmph.palette is also a vector of Pixel class

vector <Pixel> palette;

Please help. It is urgent.

Dhyanesh


0
Comment
Question by:dhyanesh
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 2
  • 2
5 Comments
 
LVL 48

Expert Comment

by:AlexFM
ID: 10643129
pix.reserve(bmph.height*bmph.width);

Use size instead of reserve. reserve doesn't add members to vector.

pix.size(bmph.height*bmph.width);

0
 
LVL 4

Author Comment

by:dhyanesh
ID: 10643177
AlexFM

The program does not compile.

It says

C:\Program Files\Microsoft Visual Studio\MyProjects\finalprj\Ver1.cpp(61) : error C2660: 'size' : function does not take 1 parameters

Also size() returns the size of the vector. I dont think it adds members.

Dhyanesh
0
 
LVL 48

Accepted Solution

by:
AlexFM earned 300 total points
ID: 10643200
Sorry, it was typo:

pix.resize(bmph.height*bmph.width);
0
 
LVL 30

Assisted Solution

by:Axter
Axter earned 200 total points
ID: 10643859
A more optimize method would be to define the size in the initialize list.
Example:
Frame::Frame(BMPHeader& bmp,byte *buffer)
: pix(bmph.height*bmph.width)
{
    bmph = bmp;
    //pix.resize(bmph.height*bmph.width);  //Now you don't need this

By declaring the size on the initialize list, the std::vector object gets initialize with the correct size right from the start.
0
 
LVL 4

Author Comment

by:dhyanesh
ID: 10644703
Thank you for your solution AlexFM.

Axter, I like your method as well but AlexFM was first with solution so I give him more points.

Dhyanesh
0

Featured Post

Free Tool: Port Scanner

Check which ports are open to the outside world. Helps make sure that your firewall rules are working as intended.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Many modern programming languages support the concept of a property -- a class member that combines characteristics of both a data member and a method.  These are sometimes called "smart fields" because you can add logic that is applied automaticall…
Update (December 2011): Since this article was published, the things have changed for good for Android native developers. The Sequoyah Project (http://www.eclipse.org/sequoyah/) automates most of the tasks discussed in this article. You can even fin…
The viewer will learn how to pass data into a function in C++. This is one step further in using functions. Instead of only printing text onto the console, the function will be able to perform calculations with argumentents given by the user.
The viewer will learn how to clear a vector as well as how to detect empty vectors in C++.

615 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question