This because video-drivers might need to make changes to their
context, which for most video-drivers has to be done in the same
thread as the window was created; main thread in our case.
/* Failed to switch blitter, let's hope we can return to the old one. */
if(BlitterFactory::SelectBlitter(cur_blitter)==nullptr||!VideoDriver::GetInstance()->AfterBlitterChange())usererror("Failed to reinitialize video driver. Specify a fixed blitter in the config");
DEBUG(driver,1,"Successfully switched to %s.",repl_blitter);
if(!this->AfterBlitterChange()){
/* Failed to switch blitter, let's hope we can return to the old one. */
if(BlitterFactory::SelectBlitter(cur_blitter)==nullptr||!this->AfterBlitterChange())usererror("Failed to reinitialize video driver. Specify a fixed blitter in the config");
}
/* Clear caches that might have sprites for another blitter. */