e2101.cpp

游戏开发数据结构Data Structures for Game Programmers

// =======================================================
//  Chapter 21, Example 1
//  RLE Compression
// =======================================================
#include <stdlib.h>
#include <stdio.h>
#include <iostream.h>
#include <string.h>
#include "Array.h"
#include "RLE.h"



int GetFileSize( char* p_filename )
{
    FILE* file = fopen( p_filename, "rb" );
    unsigned long int size = 0;

    // skip to the end of the file
    fseek( file, 0, SEEK_END );

    // retrieve the size
    size = ftell( file );    

    // close the file
    fclose( file );

    // return the size.
    return size;
}

void main()
{
    Array<char> original( 1 );
    Array<char> uncompressed( 1 );
    RLE<char> compressed;

    // filename
    char filename[80];

    // index
    int index;

    // get the file name
    cout << "Enter file name: ";
    cin >> filename;

    // resize the array so that the file will fit.
    original.Resize( GetFileSize( filename ) );

    // read the file in
    original.ReadFile( filename );

    // compress the array into an RLE
    compressed.Compress( original );

    // save the RLE to disk
    strcat( filename, ".rle" );
    compressed.SaveData( filename );

    // show statistics
    cout << "Original File Size: " << compressed.m_size << endl;
    cout << "Compressed File Size: " << compressed.m_runs * 2 << endl;
    cout << "Compression Ratio: ";
    cout << (float)(compressed.m_size) / (float)(compressed.m_runs * 2);
    cout << endl;

    // decompress the RLE into the second array.
    compressed.Decompress( uncompressed );


    // check to see if the arrays match
    cout << "Checking Array Integrity..." << endl;
    for( index = 0; index < compressed.m_size; index++ )
    {
        if( original[index] != uncompressed[index] )
        {
            cout << "ERROR, DECOMPRESSION UNSUCCESSFUL!!" << endl;
            return;
        }
    }

    cout << "Arrays match!" << endl;
}