Add multiplayer-bomber example.

[Yarwin]

closes: #903
A demo adapted from: https://github.com/godotengine/godot-demo-projects/tree/master/networking/multiplayer_bomber

I took few liberties, mostly related to caching references to nodes in the scene tree by using OnReady, using signals instead of parsing tree in process, and declaring gamestate autoload as engine singleton.

[GodotRust]

API docs are being generated and will be shortly available at: https://godot-rust.github.io/docs/gdext/pr-910

[ValorZard]

Still getting this error on this pull request:

  <C++ Error>    Condition "true" is true. Continuing.
  <C++ Source>   modules/multiplayer/scene_replication_interface.cpp:782 @ on_delta_receive()

Additionally, for some reason the tile map isn't showing up properly

E 0:00:21:0723   create_tile: Cannot create tile. The tile is outside the texture or tiles are already present in the space the tile would cover.
  <C++ Error>    Condition "!room_for_tile" is true.
  <C++ Source>   scene/resources/2d/tile_set.cpp:4963 @ create_tile()

On further testing, this additional error popped up, which is probably a typo

E 0:00:10:0292   get_state: Property '.:player_idx' not found.
  <C++ Error>    Condition "!valid" is true. Returning: ERR_INVALID_DATA
  <C++ Source>   modules/multiplayer/multiplayer_synchronizer.cpp:167 @ get_state()

[Yarwin]

ah, my bad – I forget to update property in the editor in the gdext project (done it only on a copy outside the repo 😬)

output.mp4

[ValorZard]

Update: everything works now, but the missing tilemap issue is still there

[Yarwin]

I changed some assets in cases where their source couldn't be properly determined and added proper information about license otherwise;

I couldn't determine source of explosion.png and rock_bit.png but I do believe they were created specifically for this example.

[Yarwin]

It seems that adding this example breaks check.sh. Running it fails at cargo clippy stage with following errors:

gdext$ ./check.sh
> cargo fmt --all -- --check
> cargo clippy --all-targets --no-default-features -- -D clippy::suspicious -D clippy::style -D clippy::complexity -D clippy::perf -D clippy::dbg_macro -D clippy::todo -D clippy::unimplemented -D warnings

(…)
error[E0432]: unresolved imports `godot::classes::PhysicsRayQueryParameters2D`, `godot::classes::TileMap`
 --> examples/multiplayer-bomber/rust/src/bomb.rs:8:30
  |
8 | use godot::classes::{Area2D, PhysicsRayQueryParameters2D, TileMap};
  |                              ^^^^^^^^^^^^^^^^^^^^^^^^^^^  ^^^^^^^ no `TileMap` in `classes`
  |                              |
  |                              no `PhysicsRayQueryParameters2D` in `classes`

error[E0432]: unresolved imports `godot::classes::IMultiplayerSpawner`, `godot::classes::MultiplayerSpawner`
  --> examples/multiplayer-bomber/rust/src/bomb_spawner.rs:11:22
   |
11 | use godot::classes::{IMultiplayerSpawner, MultiplayerSpawner};
   |                      ^^^^^^^^^^^^^^^^^^^  ^^^^^^^^^^^^^^^^^^ no `MultiplayerSpawner` in `classes`
   |                      |
   |                      no `IMultiplayerSpawner` in `classes`

error[E0432]: unresolved imports `godot::classes::ENetMultiplayerPeer`, `godot::classes::MultiplayerApi`
  --> examples/multiplayer-bomber/rust/src/game_state.rs:16:22
   |
16 | use godot::classes::{ENetMultiplayerPeer, Engine, Marker2D, MultiplayerApi};
   |                      ^^^^^^^^^^^^^^^^^^^                    ^^^^^^^^^^^^^^ no `MultiplayerApi` in `classes`
   |                      |
   |                      no `ENetMultiplayerPeer` in `classes`

error[E0432]: unresolved imports `godot::classes::AcceptDialog`, `godot::classes::ItemList`, `godot::classes::LineEdit`, `godot::classes::MultiplayerApi`, `godot::classes::Panel`
  --> examples/multiplayer-bomber/rust/src/lobby.rs:14:5
   |
14 |     AcceptDialog, Button, Control, IControl, ItemList, Label, LineEdit, MultiplayerApi, Os, Panel,
   |     ^^^^^^^^^^^^                             ^^^^^^^^         ^^^^^^^^  ^^^^^^^^^^^^^^      ^^^^^ no `Panel` in `classes`
   |     |                                        |                |         |
   |     |                                        |                |         no `MultiplayerApi` in `classes`
   |     |                                        |                no `LineEdit` in `classes`
   |     |                                        no `ItemList` in `classes`
   |     no `AcceptDialog` in `classes`

error[E0432]: unresolved imports `godot::classes::AnimationPlayer`, `godot::classes::CharacterBody2D`, `godot::classes::ICharacterBody2D`, `godot::classes::MultiplayerApi`, `godot::classes::MultiplayerSynchronizer`
  --> examples/multiplayer-bomber/rust/src/player.rs:16:5
   |
16 |     AnimationPlayer, CharacterBody2D, ICharacterBody2D, Label, MultiplayerApi,
   |     ^^^^^^^^^^^^^^^  ^^^^^^^^^^^^^^^  ^^^^^^^^^^^^^^^^         ^^^^^^^^^^^^^^ no `MultiplayerApi` in `classes`
   |     |                |                |
   |     |                |                no `ICharacterBody2D` in `classes`
   |     |                no `CharacterBody2D` in `classes`
   |     no `AnimationPlayer` in `classes`
17 |     MultiplayerSynchronizer,
   |     ^^^^^^^^^^^^^^^^^^^^^^^ no `MultiplayerSynchronizer` in `classes`

error[E0432]: unresolved imports `godot::classes::AnimationPlayer`, `godot::classes::CharacterBody2D`
 --> examples/multiplayer-bomber/rust/src/rock.rs:3:22
  |
3 | use godot::classes::{AnimationPlayer, CharacterBody2D};
  |                      ^^^^^^^^^^^^^^^  ^^^^^^^^^^^^^^^ no `CharacterBody2D` in `classes`
  |                      |
  |                      no `AnimationPlayer` in `classes`

error[E0432]: unresolved imports `godot::classes::HBoxContainer`, `godot::classes::IHBoxContainer`
 --> examples/multiplayer-bomber/rust/src/score.rs:4:22
  |
4 | use godot::classes::{HBoxContainer, IHBoxContainer, Label};
  |                      ^^^^^^^^^^^^^  ^^^^^^^^^^^^^^ no `IHBoxContainer` in `classes`
  |                      |
  |                      no `HBoxContainer` in `classes`

error[E0433]: failed to resolve: could not find `unsafe_inherits_transitive_MultiplayerSpawner` in `class_macros`
  --> examples/multiplayer-bomber/rust/src/bomb_spawner.rs:62:20
   |
62 | #[class(init, base=MultiplayerSpawner)]
   |                    ^^^^^^^^^^^^^^^^^^ could not find `unsafe_inherits_transitive_MultiplayerSpawner` in `class_macros`

error[E0433]: failed to resolve: could not find `unsafe_inherits_transitive_CharacterBody2D` in `class_macros`
  --> examples/multiplayer-bomber/rust/src/player.rs:23:20
   |
23 | #[class(init, base=CharacterBody2D)]
   |                    ^^^^^^^^^^^^^^^ could not find `unsafe_inherits_transitive_CharacterBody2D` in `class_macros`

error[E0433]: failed to resolve: could not find `unsafe_inherits_transitive_CharacterBody2D` in `class_macros`
 --> examples/multiplayer-bomber/rust/src/rock.rs:7:20
  |
7 | #[class(init, base=CharacterBody2D)]
  |                    ^^^^^^^^^^^^^^^ could not find `unsafe_inherits_transitive_CharacterBody2D` in `class_macros`

error[E0433]: failed to resolve: could not find `unsafe_inherits_transitive_HBoxContainer` in `class_macros`
  --> examples/multiplayer-bomber/rust/src/score.rs:26:20
   |
26 | #[class(init, base=HBoxContainer)]
   |                    ^^^^^^^^^^^^^ could not find `unsafe_inherits_transitive_HBoxContainer` in `class_macros`

error[E0412]: cannot find type `MultiplayerSpawner` in module `godot::classes`
  --> examples/multiplayer-bomber/rust/src/bomb_spawner.rs:62:20
   |
62 | #[class(init, base=MultiplayerSpawner)]
   |                    ^^^^^^^^^^^^^^^^^^ not found in `godot::classes`

error[E0412]: cannot find type `CharacterBody2D` in module `godot::classes`
  --> examples/multiplayer-bomber/rust/src/player.rs:23:20
   |
23 | #[class(init, base=CharacterBody2D)]
   |                    ^^^^^^^^^^^^^^^ not found in `godot::classes`

error[E0412]: cannot find type `CharacterBody2D` in module `godot::classes`
 --> examples/multiplayer-bomber/rust/src/rock.rs:7:20
  |
7 | #[class(init, base=CharacterBody2D)]
  |                    ^^^^^^^^^^^^^^^ not found in `godot::classes`

error[E0412]: cannot find type `HBoxContainer` in module `godot::classes`
  --> examples/multiplayer-bomber/rust/src/score.rs:26:20
   |
26 | #[class(init, base=HBoxContainer)]
   |                    ^^^^^^^^^^^^^ not found in `godot::classes`

Some errors have detailed explanations: E0412, E0432, E0433.
For more information about an error, try `rustc --explain E0412`.
error: could not compile `multiplayer-bomber` (lib) due to 15 previous errors
warning: build failed, waiting for other jobs to finish...
error: could not compile `multiplayer-bomber` (lib test) due to 15 previous errors

=====================
gdext: checks FAILED.
=====================

I'm not sure how should I proceed in this case.

[Yarwin]

closed in favor of godot-rust/demo-projects#1