BitmapImageGenerator.cpp

#include "BitmapImageGenerator.h"


BitmapImageGenerator::BitmapImageGenerator() {

}

void BitmapImageGenerator::generateBitmapImage(unsigned char *image, int height, int width, char *imageFileName)
{
    unsigned char *fileHeader = createBitmapFileHeader(height, width);
    unsigned char *infoHeader = createBitmapInfoHeader(height, width);
    unsigned char padding[3] = {0, 0, 0};
    int paddingSize = (4 - (width * bytesPerPixel) % 4) % 4;

    FILE *imageFile = fopen(imageFileName, "wb");

    fwrite(fileHeader, 1, fileHeaderSize, imageFile);
    fwrite(infoHeader, 1, infoHeaderSize, imageFile);

    int i;
    for (i = 0; i < height; i++)
    {
        fwrite(image + (i * width * bytesPerPixel), bytesPerPixel, width, imageFile);
        fwrite(padding, 1, paddingSize, imageFile);
    }
    fclose(imageFile);
}
unsigned char* BitmapImageGenerator::createBitmapFileHeader(int height, int width)
{
    int fileSize = fileHeaderSize + infoHeaderSize + bytesPerPixel * height * width;

    static unsigned char fileHeader[] = {
        0, 0,       /// signature
        0, 0, 0, 0, /// image file size in bytes
        0, 0, 0, 0, /// reserved
        0, 0, 0, 0, /// start of pixel array
    };

    fileHeader[0] = (unsigned char)('B');
    fileHeader[1] = (unsigned char)('M');
    fileHeader[2] = (unsigned char)(fileSize);
    fileHeader[3] = (unsigned char)(fileSize >> 8);
    fileHeader[4] = (unsigned char)(fileSize >> 16);
    fileHeader[5] = (unsigned char)(fileSize >> 24);
    fileHeader[10] = (unsigned char)(fileHeaderSize + infoHeaderSize);

    return fileHeader;
}

unsigned char* BitmapImageGenerator::createBitmapInfoHeader(int height, int width)
{
    static unsigned char infoHeader[] = {
        0, 0, 0, 0, /// header size
        0, 0, 0, 0, //1/ image width
        0, 0, 0, 0, /// image height
        0, 0,       /// number of color planes
        0, 0,       /// bits per pixel
        0, 0, 0, 0, /// compression
        0, 0, 0, 0, /// image size
        0, 0, 0, 0, /// horizontal resolution
        0, 0, 0, 0, /// vertical resolution
        0, 0, 0, 0, /// colors in color table
        0, 0, 0, 0, /// important color count
    };

    infoHeader[0] = (unsigned char)(infoHeaderSize);
    infoHeader[4] = (unsigned char)(width);
    infoHeader[5] = (unsigned char)(width >> 8);
    infoHeader[6] = (unsigned char)(width >> 16);
    infoHeader[7] = (unsigned char)(width >> 24);
    infoHeader[8] = (unsigned char)(height);
    infoHeader[9] = (unsigned char)(height >> 8);
    infoHeader[10] = (unsigned char)(height >> 16);
    infoHeader[11] = (unsigned char)(height >> 24);
    infoHeader[12] = (unsigned char)(1);
    infoHeader[14] = (unsigned char)(bytesPerPixel * 8);

    return infoHeader;
}

BitmapImageGenerator::~BitmapImageGenerator() {


}