It uses the (`const T &&... p_args`) forward reference, to avoid copying the
memory in case it's an rvalue, or pass a reference in case it's an lvalue.
This is an example:
```c++
PagedAllocator<btShapeBox> box_allocator;
btShapeBox* box = box_allocator.alloc( btVector3(1.0, 1.0, 1.0) );
```
* Specialization constants used to disable anything not needed to draw
* Added softshadow and projector support on mobile.
This new approach ensures mobile shaders are smaller and more efficient, but relies on more pipeline versions compiled on demand.
As a result, random stalls can ocur like in Godot 3.x. These will be solved by using background compilation and fallbacks eventually (but needs to be tested first).
Key, touch and joystick events will be passed directly from the UI thread to Godot, so they can benefit from agile input flushing.
As another consequence of this new way of passing events, less Java object are created at runtime (`Runnable`), which is good since the garbage collector needs to run less.
`AndroidInputHandler` is introduced to have a smaller cross-thread surface. `main_loop_request_go_back()` is removed in favor just inline calling `send_window_event()` at the most caller's convenience (i.e., leveraging the new `p_deferred`` parameter as appropriate).
Lastly, `get_mouse_position()` and `get_mouse_button_state()` now just call through `Input` to avoid the need of sync of mouse data tracked on the UI thread.
If enabled, key/touch/joystick events will be flushed just before every idle and physics frame.
Enabling this can greatly improve the responsiveness to input, specially in devices that need to run multiple physics frames per each idle frame, because of not being powerful enough to run at the target frame rate.
This will only work for platforms using input buffering (regardless event accumulation). Currenly, only Android does so, but could be implemented for iOS in an upcoming PR.
New contributors added to AUTHORS:
@angad-k, @Bhu1-V, @Blackiris, @ellenhp, @fabriceci, @follower,
@foxydevloper, @Geometror, @hilfazer, @hoontee, @Janglee123,
@Razoric480, @SirQuartz, @theoway.
Thanks to all contributors and donors for making Godot possible!
Input buffering is implicitly used by event accumulation, but this commit makes it more generic so it can be enabled for other uses.
For desktop OSs it's currently not feasible given main and UI threads are the same).
