浏览器中的3D街机：我们如何在React + Redux上制作游戏

哈Ha！在那些不太遥远的年代，在我进入“程序员”学院的第一年，我喜欢问同学们一个问题：“你为什么还要去这里学习？” 当然，我没有对答案进行准确的统计，但是我确实记得：一半以上的人想做游戏。大多数以这种方式回答的人并没有为大量的不同类型的“数学家”和“物理学家”做好准备，在前两年的学习中我们不知所措。并非所有人都能幸存-到五个人满为患的第二年结束时，有三个残缺不全。

不久前，我们的前端团队有机会尝试扮演gamedev的角色。简而言之，任务是这样的：制作一个真实的3D游戏，以便您只需打开浏览器即可玩。甚至移动。即使在webview中。

, , , — React + Redux, « », , , .

RnD , : « CodeFest — . — ». , , , . Gods in the sky.

CodeFest .

MMO TPS , , . , , , . CodeFest. , .

2 , , 2 . , , .

: -, — , . , N , — 1 . , — 15 . , , 16-. , , :

1. 30 . CodeFest, — , «». , .
2. «» . , :
   
   • 90 CPU;
   • 120 ;
   • 270 /c — , 675 /c — .
3. 4,2 /c. , . — UDP WebRTC, . .
4. . 2 , , , . , - Node.js , .

, , ( ?), , , , . .

, . , «». — .

:

, , , . , , 5 , , 40 .

-. , , — . React Redux. c 3D-, , Gods in the sky, three.js.

, .

:

, Node.js. :

• , - ( , IE11);
• access-;
• html- .

SSR . kubernetes , . , . , , , , ( ). . Nginx.

. TS, AppState, :

interface AppState {
    gameState: GameState;
    gameObjects: GameObjects;
    data: Data;
    requests: RequestsState;
}

requests — , — . , — . .

data — , , , , «». .

GameState :

1. stage: 'factoids' | 'citySelect' | 'flyShow' | 'game' | 'results'; — . :

   
   
   • ;
   • ;
   • ;
   • ;
   • .
   
   

2. elapsedTime: number; — , , .

   
   

, factoids flyShow, , — elapsedTime. 0, . , . , , , . , . … - , .

, , :

interface GameObjects {
    user: UserInGame;
    gifts: { [id: string]: GiftInGame; };
    boosts: { [id: string]: Boost; };
    bombs: { [id: string]: Bomb; };
}

, : , , . — .

GameObjects — . , FPS . GPU 100 . Redmi Note 7 40 FPS ( ). MI 5S 30 FPS, 20 , .

, . .

- Redux, — . Redux , . ? Redux, .

, . , . «» ( . behavior — ). , .

. — tick, . , . tick . :

• , , , . , , , .
• ( Redux-), .
  , «» .
• , gameObjects, . , «», .

25 ( ).

. ( ), React, . - , «- » ( , , ).

. pixabay.com

, FPS- 13. , , - MI 5S, FPS- — 5-6, . .

: performance — , . , , .

FPS=30 , :

• Redux FPS * ~[ ] ~= 750 , , .
• React’ FPS * ~2 * ~[ ] .
• three.js , , WebGL . , .
• (.. 150 ) 4-6 , .. .
• CSS- .
• , FPS 2-4 ( , «» ).
• React.memo, - , .

React :

• * ~2 , connect. connect — - HOC, , .
• , React – (render pass), CPU, GPU.

: React.memo , , «», , DOM-, .

, React + Redux, .

Redux

Redux — . ~1 , . ~1, - — . -, , GameObjects , :

export function setNextGameObjects(payload: GameObjects) {
    return {
        type: 'SET_NEXT_GAME_OBJECTS' as const,
        payload,
    };
}

GameObjects :

1. , . SET_NEXT_GAME_OBJECTS.
2. , , GameObjects. Redux , - . SET_NEXT_GAME_OBJECTS.

:

let state = store.getState().gameObjects;
for (const action of this.collectedActions) {
    state = gameObjectsFakeStateReducer(state, action);
}
store.dispatch(setNextGameObjects(state));

collectedActions — , . — , .

— ~25 10 : ~2 . , gameObjectsFakeStateReducer . 25 . , .

? , perf-. 3 :

1. ES2018, ~50 < ES2018 (, Firefox — ). , spread.
2. Object.assign 300 .
3. 500 , « » .

, , , — ES2018, . Firefox.

№3 , … . .

Object.assign. gameObjectsFakeStateReducer gameObjectsFastStateReducer, - :

switch (action.type) {
    case 'PARTIAL_GIFT_STATE_PATCH':
        if (!state.gifts[action.payload.id]) {
            return state;
        }
        Object.assign(state.gifts[action.payload.id], action.payload);
        break;
    // case, default ...
}

? , . , . 25 1 2-4 ( CPU). :

«» , , Redux 10 . , - , , connect gameObjects. , .

React

React . — DOM. , , — reselect, React.memo/React.PureComponent, shouldComponentUpdate . .

, , ~2, — 5. , React , .. DOM .

batch React + Redux. , — . , ?

, , connect . , .

. , <ScoreBoard />,

1. ;
2. , .
   

React.PureComponent, connect mapStateToProps. elapsedTime score. Score , elapsedTime — . elapsedTime - render. , FPS, shouldComponentUpdate. HOC’a connect — shouldComponentUpdate .

, «» , :

1. shouldComponentUpdate, elapsedTime ( ). , HOC’a connect.
2. mapStateToProps . , , . connect’a.
3. useSelector. , .. . , , , .
4. — connect, — . , . ScoreBoard .

— ! ScoreBoard’a connect, , . mapStateToProps , .

, connect. , — - - canvas-, three.js (, , .). render , :

return <div id="map" className={s.map} ref={mapRef} />;

return <canvas id="scene" className={s.scene} ref={sceneRef} />;

, DOM — . , React . , componentDidUpdate, . , componentDidUpdate :

public componentDidUpdate() {
    const { geoPos, orientedRotationQuanternion } = this.props;
    const { map } = this.state;
    map.setQuat(orientedRotationQuanternion);
    map.setCenter([geoPos[0], geoPos[1]], { animate: false });
    map.setZoom(getMapZoomFromHeight(geoPos[2]), { animate: false });
}

, componentDidUpdate . :

1. connect. , mapStateToProps;
2. public shouldComponentUpdate() { return false; } — «» «»;
3. Redux ( ) useStore ;
4. (store.subscribe(() => { /* … */}));
5. ;
6. !

:

store.subscribe(() => {
    const state = store.getState();
    const { map } = this.state;
    const { geoPos, orientedRotationQuanternion } = state.gameObjects.user;

    map.setQuat(orientedRotationQuanternion);
    map.setCenter([geoPos[0], geoPos[1]], { animate: false });
    map.setZoom(getMapZoomFromHeight(geoPos[2]), { animate: false });
}); 

, , .

, - , .

. — React Tree Reconcilation + Commit

React Tree Reconcilation + Commit

React + Redux , :

• , , , «» React , ;
• ;
• « », , ;
• , .

, . , . , . ? .

:

1. , , , , . , .
2. , React’ 30 . : .
3. , .
4. . . , .
5. .
6. Performance — . CPU — , Intel i9.
7. - : 12–20 – . , .
8. , . , , . , .
9. , , . IE11 , . 70- Edge 18- ( ).
10. WebGL . - , , -, Firefox linux, . . — . -, . , , « », .

, :

1. Firefox. . , WebGL, — spread. FPS Firefox , Chrome. , , .
2. IPhone. Safari IE6 220 . , , . , , . . — - .
3. . . . , , (, , ). .
4. . , , . , , , «» .
5. ( ), – , . .

, , . iOS, Android Web .