void plat_hline(int x1, int x2, int y)
{
    uint8_t *left = screen->pixels + screen->pitch * y;
    uint8_t *right = left + x2 * 4;
    left += x1 * 4;
    while(left < right)
    {
        *(uint32_t*) left = fgcol;
        left += 4;
    }
}