File.cpp

#include "File.h"
#include <string>
#include <fstream>
#include <iostream>

// constructor
File::File(std::string fileName) {
    header = {};
    pixelArray = nullptr;

    if (!ReadFile(fileName)) {
        // file not read properly, explain error
        std::cout << "File read incorrectly." << std::endl;
    }
}

// destructor
File::~File() {
    // Free dynamically allocated memory for pixelArray
    if (pixelArray != nullptr) {
        for (int i = 0; i < header.height; ++i) {
            delete[] pixelArray[i];
        }
        delete[] pixelArray;
    }
}

// read file
bool File::ReadFile(std::string fileName) {
    // open file
    std::ifstream file(fileName, std::ios::binary);

    if (!file.is_open()) {
        std::cout << "Failed to open target file." << std::endl;
        return false;
    }

      // read header from file
    header = readHeader(file);

    // read pixels into pixel array
    pixelArray = readPixelArray(file, header.width, header.height);

    // close file
    file.close();

    return true;
}

// write file
bool File::WriteFile(std::string fileName) {
    // open file
    std::ofstream file(fileName, std::ios::binary);

    if (!file.is_open()) {
        std::cout << "Failed to open target file." << std::endl;
        return false;
    }

    // write header to file
    writeHeader(header, file);

    // write pixel array to file
    writePixelArray(pixelArray, file);

    if (pixelArray == nullptr) {
        return false;
    }

    // close file
    file.close();

    return true;
}

// read header
File::Header File::readHeader(std::ifstream& file) {
    Header header;

    // Read each component of the header
    file.read(reinterpret_cast<char*>(&header.idLength), sizeof(char));
    file.read(reinterpret_cast<char*>(&header.colorMapType), sizeof(char));
    file.read(reinterpret_cast<char*>(&header.dataTypeCode), sizeof(char));
    file.read(reinterpret_cast<char*>(&header.colorMapOrigin), sizeof(short));
    file.read(reinterpret_cast<char*>(&header.colorMapLength), sizeof(short));
    file.read(reinterpret_cast<char*>(&header.colorMapDepth), sizeof(char));
    file.read(reinterpret_cast<char*>(&header.xOrigin), sizeof(short));
    file.read(reinterpret_cast<char*>(&header.yOrigin), sizeof(short));
    file.read(reinterpret_cast<char*>(&header.width), sizeof(short));
    file.read(reinterpret_cast<char*>(&header.height), sizeof(short));
    file.read(reinterpret_cast<char*>(&header.bitsPerPixel), sizeof(char));
    file.read(reinterpret_cast<char*>(&header.imageDescriptor), sizeof(char));

    return header;
}

// write header to file
void File::writeHeader(Header header, std::ofstream& file) {
    // write each component of the header
    file.write(reinterpret_cast<char*>(&header.idLength), sizeof(char));
    file.write(reinterpret_cast<char*>(&header.colorMapType), sizeof(char));
    file.write(reinterpret_cast<char*>(&header.dataTypeCode), sizeof(char));
    file.write(reinterpret_cast<char*>(&header.colorMapOrigin), sizeof(short));
    file.write(reinterpret_cast<char*>(&header.colorMapLength), sizeof(short));
    file.write(reinterpret_cast<char*>(&header.colorMapDepth), sizeof(char));
    file.write(reinterpret_cast<char*>(&header.xOrigin), sizeof(short));
    file.write(reinterpret_cast<char*>(&header.yOrigin), sizeof(short));
    file.write(reinterpret_cast<char*>(&header.width), sizeof(short));
    file.write(reinterpret_cast<char*>(&header.height), sizeof(short));
    file.write(reinterpret_cast<char*>(&header.bitsPerPixel), sizeof(char));
    file.write(reinterpret_cast<char*>(&header.imageDescriptor), sizeof(char));
}

File::Pixel** File::readPixelArray(std::ifstream& file, int width, int height) {
    // create 2D array of pixels
    Pixel** pixelArray = new Pixel*[width];

    // read pixels row as many pixels of w/h
    for (int i = 0; i < width; ++i) {
      pixelArray[i] = new Pixel[height];
      file.read(reinterpret_cast<char*>(pixelArray[i]), sizeof(Pixel) * height);
    }

    return pixelArray;
}


void File::writePixelArray(Pixel** pixelArray, std::ofstream& file) {
    for (int i = 0; i < header.height; ++i) {
        file.write(reinterpret_cast<char*>(pixelArray[i]), sizeof(Pixel) * header.width);
    }
}

File::Header File::getHeader() {
    return header;
}