Exposed physics frame count and idle frame count

[AndreaCatania]

Exposed:

uint64_t get_physics_frames() const;
uint64_t get_idle_frames() const;

[Calinou]

Out of curiosity, what's the difference between get_idle_frames() and the current get_frames_drawn()? Also, it'd be good to regenerate the documentation XML using --doctool . and document the new methods.

That said, thanks for adding get_physics_frames() 🙂

[Xrayez]

Ninja'd me, I wanted to create a PR just for this recently but procrastinated. Those are used internally by input actions timestamps, I'm currently working on a proof-of-concept PR for godotengine/godot-proposals#104 so this should help me debug the development via script.

[AndreaCatania]

@Calinou frames_draw is advanced each time a frame is renderized: https://github.com/godotengine/godot/blob/master/main/main.cpp#L2035-L2047
If the rendering is disabled it doesn't advance.

While idle_frames (and also physics_frames) are advanced each frame not matter what (and each physics frame).

[akien-mga]

Thanks!