Workaround for promise continuations not executing (#63)

Author: ryantrem

Modules/@babylonjs/react-native/EngineHook.ts

@@ -66,7 +66,48 @@ export function useEngine(): Engine | undefined {
                     }
                 }
 
-                setEngine(engine = new NativeEngine());
+                engine = new NativeEngine();
+
+                // NOTE: This is a workaround for https://github.com/BabylonJS/BabylonReactNative/issues/60
+                let heartbeat: NodeJS.Timeout | null;
+                const startHeartbeat = () => {
+                    if (!heartbeat) {
+                        heartbeat = setInterval(() => {}, 10);
+                    }
+                };
+                const stopHeartbeat = () => {
+                    if (heartbeat) {
+                        clearInterval(heartbeat);
+                        heartbeat = null;
+                    }
+                }
+                startHeartbeat();
+
+                let renderLoopCount = 0;
+
+                const originalRunRenderLoop: (...args: any[]) => void = engine.runRenderLoop;
+                engine.runRenderLoop = function(...args: any[]): void {
+                    originalRunRenderLoop.apply(this, args);
+                    if (++renderLoopCount == 1) {
+                        stopHeartbeat();
+                    }
+                }
+
+                const originalStopRenderLoop: (...args: any[]) => void = engine.stopRenderLoop;
+                engine.stopRenderLoop = function(...args: any[]): void {
+                    if (--renderLoopCount == 0) {
+                        startHeartbeat();
+                    }
+                    originalStopRenderLoop.apply(this, args);
+                }
+
+                const originalDipose = engine.dispose;
+                engine.dispose = function() {
+                    originalDipose.apply(this);
+                    stopHeartbeat();
+                };
+
+                setEngine(engine);
             }
         })();
 

README.md

@@ -115,30 +115,33 @@ After having run the above commands, you can also open `Apps/Playground/ios/Play
 
 ### **Building the NPM Package**
 
-An NPM package can be built in two different ways: as source, and as binaries. Source is useful if you want to debug the Babylon React Native source in the context of the project consuming it, though configuration is a bit more involved. Binaries are useful in that they simplify configuration in the consuming app, though they cannot be debugged so easily. The binary package is what is published to [npmjs.org](https://www.npmjs.com/package/@babylonjs/react-native).
+If you want to test using a local build of the NPM package with your own React Native app, you can do so with a `gulp` command on a Mac (this requires a Mac as it builds binaries for both iOS and Android).
 
-#### Source Package
+```
+cd Package
+npm install
+gulp pack
+```
 
-If you want to test using a local build of the source-based NPM package with your own React Native app, you can do so with the `npm pack` command on either Mac or Windows.
+The NPM package will be built into the `Package` directory where the `gulp` command was run. Once the local NPM package has been built, it can be installed into a project using `npm`.
 
 ```
-cd Apps/Playground/node_modules/@babylonjs/react-native
-npm pack
+cd <directory of your React Native app>
+npm install <root directory of your BabylonReactNative clone>/Package/Assembled/babylonjs-react-native-0.0.1.tgz
 ```
 
-This will produce a zipped local NPM source-based package that can be installed into a React Native application for testing purposes. Note that when testing a source based package for iOS, the XCode project needs to be generated with `CMake` as described [above](#ios).
+### **Debugging in Context**
 
-#### Binary Package
-
-If you want to test using a local build of the binary-based NPM package with your own React Native app, you can do so with a `gulp` command on a Mac (this requires a Mac as it builds binaries for both iOS and Android).
+If you want to consume `@babylonjs/react-native` as source in your React Native app (for debugging or for iterating on the code when making a contribution), you can install the package source directory as an npm package.
 
 ```
-cd Package
-npm install
-gulp pack
+cd <directory of your React Native app>
+npm install <root directory of your BabylonReactNative clone>/Modules/@babylonjs/react-native
+cd ios
+pod install
 ```
 
-This will produce a zipped local NPM binary-based package that can be installed into a React Native application for testing purposes.
+This will create a symbolic link in your `node_modules` directory to the `@babylonjs/react-native` source directory. For iOS the XCode project needs to be generated with `CMake` as described [above](#ios) and added to your `xcworkspace`.
 
 ## Security