PPMImageLoader.h

#ifndef __PPM_IMAGELOADER_H_
#define __PPM_IMAGELOADER_H_

#include "ImageLoader.h"
#include <stdexcept>
#include <iostream>
#include <fstream>
#include <sstream>

/**
 * @brief This class is used to load an image in the ASCII PPM format 
 * 
 */
class PPMImageLoader: public ImageLoader {

    public:
        PPMImageLoader() {

        }

        void load(std::string filename) {
            std::ifstream fp;
            std::string str;
            int i,j;
            int r,g,b;
            int factor;

            fp.open(filename.c_str());
            
            if (!fp.is_open())
                throw std::invalid_argument("File not found!");

            std::cout << "Image file opened" << std::endl;

            //read line by line and ignore comments
            std::stringstream input;
            std::string line;

            while (std::getline(fp,line)) {
                if ((line.length()>0) && (line[0]!='#')) {
                    input << line << std::endl;
                }
            }
            fp.close();


            //read in the word P3

            input >> str;


            //now read in the width and height

            input >> width >> height;

            //read in the factor
            input >> factor;

            image = new GLubyte[3*width*height];

            for (i=0;i<height;i++)
            {
                for (j=0;j<width;j++)
                {
                    input >> r >> g >> b;
                    image[3*((height-1-i)*width+j)] = r;
                    image[3*((height-1-i)*width+j)+1] = g;
                    image[3*((height-1-i)*width+j)+2] = b;
                    // << "r=" << (int)r << ", g=" << (int)g << ",b=" << (int)b << endl;
                }
            }
            //fp.close();
        }
    
};

#endif