but factorio appears to just drop frames instead of allowing tearing to happen, even with vsync off...

That's because of borderless fullscreen, the rendered image is not presented to screen directly, but is sent to desktop compositing manager, which then presents it with v-sync anyway. With ...

16.6ms is eons in computer-speak, about 50 million cpu cycles at 3ghz.... Instead of dropping a fame that can't be drawn wouldn't it be more visually pleasing to have a subroutine hold on to whatever the current/last frame data was, and constantly feed that at 60 fps whether or not you can ...

Without pretending to know exactly how SDL and GPU's work... why do frames that can't be rendered in time get dropped?

Shouldn't the game be writing (ideally, only the changed pixels) to some sort of frame buffer that is constantly updated as the screen is polled? My understanding of screen ...

Without pretending to know exactly how SDL and GPU's work... why do frames that can't be rendered in time get dropped?

Shouldn't the game be writing (ideally, only the changed pixels) to some sort of frame buffer that is constantly updated as the screen is polled? My understanding of screen tearing ...