Fixed Android app black screen issue when reopening after incomplete …

…closing (#3227)

* Fixed black screen issue when resuming the app on Android

Partly explained here: #3127

* Fix APP_CMD_TERM_WINDOW for Android

src/rcore.c

@@ -720,8 +720,8 @@ void android_main(struct android_app *app)
  char arg0[] = "raylib"; // NOTE: argv[] are mutable
  CORE.Android.app = app;
 
- // NOTE: We get the main return for exit()
- int ret = main(1, (char *[]) { arg0, NULL });
+ // NOTE: Return from main is ignored
+ (void)main(1, (char *[]) { arg0, NULL });
 
  // Request to end the native activity
  ANativeActivity_finish(app->activity);
@@ -731,19 +731,13 @@ void android_main(struct android_app *app)
  int pollEvents = 0;
 
  // Waiting for application events before complete finishing
- while (!CORE.Android.app->destroyRequested)
+ while (!app->destroyRequested)
  {
  while ((pollResult = ALooper_pollAll(0, NULL, &pollEvents, (void **)&CORE.Android.source)) >= 0)
  {
- if (CORE.Android.source != NULL) CORE.Android.source->process(CORE.Android.app, CORE.Android.source);
+ if (CORE.Android.source != NULL) CORE.Android.source->process(app, CORE.Android.source);
  }
  }
-
- // WARNING: Make sure you free resources properly and no other process is running from Java code or other.
- // NOTE: You can use JNI to call a NativeLoader method (which will call finish() from the UI thread)
- // to handle the full close from Java, without using exit(0) like here.
-
- exit(ret); // Close the application directly, without going through Java
 }
 
 // NOTE: Add this to header (if apps really need it)
@@ -5897,21 +5891,28 @@ static void AndroidCommandCallback(struct android_app *app, int32_t cmd)
  case APP_CMD_TERM_WINDOW:
  {
  // Dettach OpenGL context and destroy display surface
- // NOTE 1: Detaching context before destroying display surface avoids losing our resources (textures, shaders, VBOs...)
- // NOTE 2: In some cases (too many context loaded), OS could unload context automatically... :(
- eglMakeCurrent(CORE.Window.device, EGL_NO_SURFACE, EGL_NO_SURFACE, EGL_NO_CONTEXT);
- eglDestroySurface(CORE.Window.device, CORE.Window.surface);
+ // NOTE 1: This case is used when the user exits the app without closing it. We detach the context to ensure everything is recoverable upon resuming.
+ // NOTE 2: Detaching context before destroying display surface avoids losing our resources (textures, shaders, VBOs...)
+ // NOTE 3: In some cases (too many context loaded), OS could unload context automatically... :(
+ if (CORE.Window.device != EGL_NO_DISPLAY)
+ {
+ eglMakeCurrent(CORE.Window.device, EGL_NO_SURFACE, EGL_NO_SURFACE, EGL_NO_CONTEXT);
+
+ if (CORE.Window.surface != EGL_NO_SURFACE)
+ {
+ eglDestroySurface(CORE.Window.device, CORE.Window.surface);
+ CORE.Window.surface = EGL_NO_SURFACE;
+ }
+
+ CORE.Android.contextRebindRequired = true;
+ }
+ // If 'CORE.Window.device' is already set to 'EGL_NO_DISPLAY'
+ // this means that the user has already called 'CloseWindow()'
 
- CORE.Android.contextRebindRequired = true;
  } break;
  case APP_CMD_SAVE_STATE: break;
  case APP_CMD_STOP: break;
- case APP_CMD_DESTROY:
- {
- // NOTE 1: Call ANativeActivity_finish again to free resources unconditionally.
- // NOTE 2: You can deallocate other things that are NativeActivity related here.
- ANativeActivity_finish(CORE.Android.app->activity);
- } break;
+ case APP_CMD_DESTROY: break;
  case APP_CMD_CONFIG_CHANGED:
  {
  //AConfiguration_fromAssetManager(CORE.Android.app->config, CORE.Android.app->activity->assetManager);