BMPDownloader.cpp

#include "BMPDownloader.h"
#include "Exceptions.h"

#include <iostream>

Color ColorFromInts(IntColor int_color) {
    double blue = static_cast<double>(int_color.blue) / static_cast<double>(Color::MaxIntValue);
    double green = static_cast<double>(int_color.green) / static_cast<double>(Color::MaxIntValue);
    double red = static_cast<double>(int_color.red) / static_cast<double>(Color::MaxIntValue);
    return {blue, green, red};
}

void BMPDownloader::OpenFile() {
    input_file_.open(path_, std::ios_base::binary);
    if (!input_file_) {
        std::string message = "File by path " + std::string(path_) + " can't be opened";
        throw OpeningFileException(message);
    }
    std::cout << "File " << path_ << " opened" << '\n';
}

void BMPDownloader::CloseFile() {
    input_file_.close();
    std::cout << "File " << path_ << " closed" << '\n';
}

template <typename T>
void BMPDownloader::ReadIn(T &input) {
    input_file_.read(reinterpret_cast<char *>(&input), sizeof(input));
}

void BMPDownloader::SaveBMPToImage(Image &image) {
    BMPFileHeader file_header;
    ReadIn(file_header);
    if (file_header.file_type != required_type_) {
        throw ReadingFileException("File's format is not .bmp");
    }
    image.SetFileHeader(file_header);

    BMPImageHeader image_header;
    ReadIn(image_header);
    if (image_header.bit_count != required_bit_count_) {
        throw ReadingFileException("File is not 24-bit");
    }
    image.SetImageHeader(image_header);

    input_file_.seekg(image.GetOffsetData(), input_file_.beg);

    if (image.GetWidth() < 0) {
        throw ReadingFileException("Image width can't be negative");
    }
    bool flipped_image = (image.GetHeight() < 0);
    if (flipped_image) {
        image.SetHeight(abs(image.GetHeight()));
    } else {
        image.SetHeight(image.GetHeight());
    }
    image.SetWidth(image.GetWidth());
    for (size_t i = 0; i < static_cast<size_t>(image.GetHeight()); ++i) {
        for (size_t j = 0; j < static_cast<size_t>(image.GetWidth()); ++j) {
            IntColor int_color;
            ReadIn(int_color);
            Color color = ColorFromInts(int_color);
            if (flipped_image) {
                image.SetPixel(i, j, color);
            } else {
                image.SetPixel(static_cast<size_t>(image.GetHeight()) - 1 - i, j, color);
            }
        }
        input_file_.ignore((4 - (image.GetWidth() * 3) % 4) % 4);
    }
    std::cout << "Image from " << path_ << " downloaded" << '\n';
}