static void draw_rectangle(unsigned val, uint8_t *dst, int dst_linesize, int segment_width,
                           int x, int y, int w, int h)
{
    int i;
    int step = 3;

    dst += segment_width * (step * x + y * dst_linesize);
    w *= segment_width * step;
    h *= segment_width;
    for (i = 0; i < h; i++) {
        memset(dst, val, w);
        dst += dst_linesize;
    }
}