waitable blockly scripts. new waitForSeconds block

eslint.config.js

@@ -18,5 +18,14 @@ export default defineConfig([
     languageOptions: {
       globals: globals.browser,
     },
+    rules: {
+      "padding-line-between-statements": [
+        "warn",
+        { blankLine: 'always', prev: '*', next: 'block' },
+        { blankLine: 'always', prev: 'block', next: '*' },
+        { blankLine: 'always', prev: '*', next: 'block-like' },
+        { blankLine: 'always', prev: 'block-like', next: '*' },
+      ]
+    },
   },
 ])

src/blockly/actions/consoleLog.ts

@@ -5,7 +5,7 @@ Blockly.Blocks['console_log_action'] = {
     init(this: Blockly.Block) {
         this.appendValueInput('VALUE')
             .setAlign(Blockly.inputs.Align.RIGHT)
-            .setCheck('ObjectType')
+            // .setCheck('String')
             .appendField('print');
         this.setInputsInline(false)
         this.setPreviousStatement(true, null);

src/blockly/actions/index.ts

@@ -1,2 +1,3 @@
 export * from './consoleLog';
 export * from './physics';
+export * from './waitSeconds';

src/blockly/actions/waitSeconds.ts

@@ -0,0 +1,22 @@
+import * as Blockly from "blockly";
+import { javascriptGenerator } from "blockly/javascript";
+
+Blockly.Blocks['wait_seconds_action'] = {
+    init(this: Blockly.Block) {
+        this.appendDummyInput()
+            .appendField('Wait')
+            .appendField(new Blockly.FieldNumber(1, 0, 3600, 0.1), 'SECONDS')
+            .appendField('seconds');
+        this.setPreviousStatement(true, null);
+        this.setNextStatement(true, null);
+        this.setTooltip('Pause execution for N seconds');
+        this.setColour(120);
+    }
+};
+
+javascriptGenerator.forBlock['wait_seconds_action'] = function (block) {
+    const seconds = block.getFieldValue('SECONDS');
+    return `yield wait(${seconds});\n`;
+};
+
+export { };

src/blockly/generateCode.ts

@@ -12,7 +12,7 @@ export function generateCode(workspace: Blockly.WorkspaceSvg): string {
                 body += javascriptGenerator.blockToCode(next, true);
                 next = next.getNextBlock();
             }
-            body = javascriptGenerator.prefixLines(body, javascriptGenerator.INDENT);
+            body = javascriptGenerator.prefixLines(body, javascriptGenerator.INDENT.repeat(2));
 
             // const args = Array.from(block.getFields())
             //     .filter(field => field.name !== undefined)
@@ -23,12 +23,10 @@ export function generateCode(workspace: Blockly.WorkspaceSvg): string {
 
             result += `onGameEvent(
   '${block.type.replace(/_event$/, '')}',
-function(context) {
-    // console.dir({context, api, object, objectType});
+  function*(context) {
     if (context.object && (context.object.id !== object.id))
       return;
-    ${body}
-}
+${body}  },
 );
 `;
         }

src/components/scriptEditor/ScriptEditorView.tsx

@@ -45,8 +45,8 @@ const TOOLBOX: Blockly.utils.toolbox.ToolboxDefinition = {
             colour: '20',
             contents: [
                 { kind: 'block', type: 'console_log_action' },
-                { kind: 'block', type: 'text_print' },
                 { kind: 'block', type: 'physics_apply_impulse_action' },
+                { kind: 'block', type: 'wait_seconds_action' },
             ],
         },
         {

src/model/GameScheduler.ts

@@ -0,0 +1,63 @@
+export type YieldCommand =
+    | { type: 'waitSeconds'; seconds: number }
+    | { type: 'waitFrames'; frames: number }
+    | { type: 'waitUntil'; condition: () => boolean };
+
+type Coroutine =
+    & { gen: Generator<YieldCommand, void, void> }
+    & (| { wakeType: 'time'; remaining: number }
+        | { wakeType: 'frames'; remaining: number }
+        | { wakeType: 'condition'; test: () => boolean });
+
+export class GameScheduler {
+    private coroutines: Coroutine[] = [];
+
+    tick(deltaTime: number): void {
+        const next: Coroutine[] = [];
+        for (const co of this.coroutines) {
+            if (this.isReady(co)) this.step(co, next);
+            else next.push(this.countdown(co, deltaTime));
+        }
+        this.coroutines = next;
+    }
+
+    startCoroutine(gen: Generator<YieldCommand, void, void>): void {
+        const result = gen.next();
+        if (!result.done)
+            this.coroutines.push(this.make(gen, result.value));
+    }
+
+    reset(): void { this.coroutines = []; }
+
+    private isReady(co: Coroutine): boolean {
+        switch (co.wakeType) {
+            case 'time': return co.remaining <= 0;
+            case 'frames': return co.remaining <= 0;
+            case 'condition': return co.test();
+        }
+    }
+
+    private countdown(co: Coroutine, deltaTime: number): Coroutine {
+        switch (co.wakeType) {
+            case 'time': return { ...co, remaining: co.remaining - deltaTime };
+            case 'frames': return { ...co, remaining: co.remaining - 1 };
+            default: return co;
+        }
+    }
+
+    private step(co: Coroutine, list: Coroutine[]): void {
+        const result = co.gen.next();
+        if (!result.done) list.push(this.make(co.gen, result.value));
+    }
+
+    private make(gen: Generator<YieldCommand, void, void>, cmd: YieldCommand): Coroutine {
+        switch (cmd.type) {
+            case 'waitSeconds':
+                return { gen, wakeType: 'time', remaining: cmd.seconds };
+            case 'waitFrames':
+                return { gen, wakeType: 'frames', remaining: cmd.frames };
+            case 'waitUntil':
+                return { gen, wakeType: 'condition', test: cmd.condition };
+        }
+    }
+}

src/model/gameFactory.ts

@@ -1,8 +1,9 @@
 import type { Game, RuntimeGameScene, RuntimeScene, World } from "../types";
-import type { GameEventHandler, GameEventContext, InternalGameEventBus } from "../types/runtime/gameBus";
+import type { GameEventContext, GameEventHandler, InternalGameEventBus } from "../types/runtime/gameBus";
 import { clone } from "../utils";
 import { populateRuntimeScene } from "../utils/runtime";
 import { ObjectApi } from "../utils/runtime/objectApi";
+import type { GameScheduler, YieldCommand } from "./GameScheduler";
 
 export class GameEventBus {
     private handlers = new Map<string, GameEventHandler[]>();
@@ -66,25 +67,41 @@ export class GameFactory {
         world: World,
         scene: RuntimeGameScene,
         eventBus: GameEventBus,
-
+        scheduler: GameScheduler,
     ): void {
 
+        const handlerWrappers = new WeakMap<Function, (ctx: GameEventContext) => void>();
+
+        const wait = (seconds: number): YieldCommand => ({ type: 'waitSeconds', seconds });
+        const waitFrames = (frames: number): YieldCommand => ({ type: 'waitFrames', frames });
+        const waitUntil = (condition: () => boolean): YieldCommand => ({ type: 'waitUntil', condition });
+
         const internalBus: InternalGameEventBus = {
-            onGameEvent: eventBus.on.bind(eventBus),
-            offGameEvent: eventBus.off.bind(eventBus),
+            onGameEvent(event, genFn) {
+                const wrapper: GameEventHandler = (ctx) => scheduler.startCoroutine(genFn(ctx) as Generator<YieldCommand, void, void>);
+                handlerWrappers.set(genFn, wrapper);
+                eventBus.on(event, wrapper);
+            },
+            offGameEvent(event, genFn) {
+                const wrapper = handlerWrappers.get(genFn);
+                if (wrapper) {
+                    eventBus.off(event, wrapper);
+                    handlerWrappers.delete(genFn);
+                }
+            },
         };
 
         try {
             Object.values(world.objectTypes)
                 .filter((ot) => ot.javascript)
                 .forEach((ot) => {
-                    const gameScript = eval(`(function gameScript({onGameEvent, offGameEvent }, {api, object, objectType}) {${ot.javascript}})`);
+                    const gameScript = eval(`(function gameScript({onGameEvent, offGameEvent, wait, waitFrames, waitUntil}, {api, object, objectType}) {${ot.javascript}})`);
 
                     Object.values(scene.objects)
                         .filter((o) => o.typeId == ot.id)
                         .forEach((o) => {
                             const api = new ObjectApi(o, ot, world, scene);
-                            gameScript(internalBus, { api, object: o, objectType: ot });
+                            gameScript({ ...internalBus, wait, waitFrames, waitUntil }, { api, object: o, objectType: ot });
                         })
                 });
         }

src/state/gameState.ts

@@ -3,6 +3,7 @@ import type { WorldState } from "./worldState";
 import type { Game, Pos3, RuntimeGameScene } from "../types";
 import type { CameraProps } from "@react-three/fiber";
 import { GameEventBus, GameFactory } from "../model/gameFactory";
+import { GameScheduler } from "../model/GameScheduler";
 import type { GameEventContext } from "../types/runtime/gameBus";
 
 export class GameState {
@@ -14,6 +15,7 @@ export class GameState {
     public scene: RuntimeGameScene;
 
     private eventBus: GameEventBus;
+    private scheduler: GameScheduler;
 
     private startAutoSave() {
         return reaction(
@@ -46,11 +48,12 @@ export class GameState {
 
         const eventBus = new GameEventBus();
         this.eventBus = eventBus;
+        this.scheduler = new GameScheduler();
 
         this._stopAutoSave = this.startAutoSave();
         makeAutoObservable(this);
 
-        GameFactory.evalGameScripts(rawWorld, this.scene, eventBus);
+        GameFactory.evalGameScripts(rawWorld, this.scene, eventBus, this.scheduler);
     }
 
     public emitEvent(event: string, context: Omit<GameEventContext, 'world' | 'scene'> = {}) {
@@ -126,6 +129,7 @@ export class GameState {
         if (this.isPaused)
             return;
 
+        this.scheduler.tick(deltaTime);
         this.time += deltaTime;
 
         if (this.isFirstTick) {

src/types/runtime/gameBus.ts

@@ -8,7 +8,9 @@ export type GameEventContext = {
 
 export type GameEventHandler = (context: GameEventContext) => void;
 
+export type GeneratorEventHandler = (context: GameEventContext) => Generator<unknown, void, void>;
+
 export type InternalGameEventBus = {
-    onGameEvent: (event: string, handler: GameEventHandler) => void;
-    offGameEvent: (event: string, handler: GameEventHandler) => void;
+    onGameEvent: (event: string, handler: GeneratorEventHandler) => void;
+    offGameEvent: (event: string, handler: GeneratorEventHandler) => void;
 }