struct Png{
    int width, height;
    png_byte color_type;
    png_byte bit_depth;

    png_structp png_ptr;
    png_infop info_ptr;
    png_byte **row_pointers;
};

void print_info(struct Png *image){
    printf("Ширина в пикселях: %d\n", image->width);
    printf("Высота в пикселях: %d\n", image->height);
    printf("Тип цвета: %u\n", image->color_type);
    printf("Глубина цвета: %u бит\n", image->bit_depth);
}

void draw_Circle(struct Png *image, int x0, int y0, int line_fat, int width_pixel, int Red, int Green, int Blue) {
    int x = 0;
    int radius = line_fat / 2;
    int y = radius;
    int start = y0 - radius;
    int end = y0 + radius;
    int delta = 1 - 2 * radius;
    int error;
    while(y >= 0) {
        png_byte *row = image->row_pointers[y0 + y];
        png_byte *ptr = &(row[(x0 + x) * width_pixel]);
        ptr[0] = Red;
        ptr[1] = Green;
        ptr[2] = Blue;

        png_byte *row1 = image->row_pointers[y0 - y];
        png_byte *ptr1 = &(row1[(x0 + x) * width_pixel]);
        ptr1[0] = Red;
        ptr1[1] = Green;
        ptr1[2] = Blue;

        png_byte *row2 = image->row_pointers[y0 + y];
        png_byte *ptr2 = &(row2[(x0 - x) * width_pixel]);
        ptr2[0] = Red;
        ptr2[1] = Green;
        ptr2[2] = Blue;

        png_byte *row3 = image->row_pointers[y0 - y];
        png_byte *ptr3 = &(row3[(x0 - x) * width_pixel]);
        ptr3[0] = Red;
        ptr3[1] = Green;
        ptr3[2] = Blue;
        error = 2 * (delta + y) - 1;
        while(start <= y0) {
            for (int i = abs(x - x0); i < (x + x0); i++) {
                png_byte *row4 = image->row_pointers[start];
                png_byte *ptr4 = &(row4[i * width_pixel]);
                ptr4[0] = Red;
                ptr4[1] = Green;
                ptr4[2] = Blue;

                png_byte *row5 = image->row_pointers[end];
                png_byte *ptr5 = &(row5[i * width_pixel]);
                ptr5[0] = Red;
                ptr5[1] = Green;
                ptr5[2] = Blue;
            }
            if(error > 0) {
                start++;
                end--;
            }
            break;
        }
        if(delta < 0 && error <= 0) {
            ++x;
            delta += 2 * x + 1;
            continue;
        }
        error = 2 * (delta - x) - 1;
        if(delta > 0 && error > 0) {
            --y;
            delta += 1 - 2 * y;
            continue;
        }
        ++x;
        delta += 2 * (x - y);
        --y;
    }
}

void paint_line(struct Png *image, int width_pixel, int x0, int y0, int x1, int y1, int line_fat, int Red, int Green, int Blue){
    int A, B, sign;
    A = y1 - y0;
    B = x0 - x1;
    if (abs(A) > abs(B)) sign = 1;
    else sign = -1;
    int signa, signb;
    if (A < 0) signa = -1;
    else signa = 1;
    if (B < 0) signb = -1;
    else signb = 1;
    int f = 0;
    png_byte *row = image->row_pointers[y0];
    png_byte *ptr = &(row[x0 * width_pixel]);
    ptr[0] = Red;
    ptr[1] = Green;
    ptr[2] = Blue;
    draw_Circle(image, x0, y0, line_fat, width_pixel, Red, Green, Blue);
    int x = x0, y = y0;
    if (sign == -1){
        do {
            f += A * signa;
            if (f > 0)
            {
                f -= B * signb;
                y += signa;
            }
            x -= signb;
            png_byte *row1 = image->row_pointers[y];
            png_byte *ptr1 = &(row1[x * width_pixel]);
            ptr1[0] = Red;
            ptr1[1] = Green;
            ptr1[2] = Blue;
            draw_Circle(image, x, y, line_fat, width_pixel, Red, Green, Blue);
        } while (x != x1 || y != y1);
    }
    else
    {
        do {
            f += B * signb;
            if (f > 0) {
                f -= A * signa;
                x -= signb;
            }
            y += signa;
            png_byte *row2 = image->row_pointers[y];
            png_byte *ptr2 = &(row2[x * width_pixel]);
            ptr2[0] = Red;
            ptr2[1] = Green;
            ptr2[2] = Blue;
            draw_Circle(image, x, y, line_fat, width_pixel, Red, Green, Blue);
        } while (x != x1 || y != y1);
    }
}