Function android_main

hello-vulkan/app/src/main/cpp/vk_main.cpp:124–155

* Entry point required by the Android Glue library. * This can also be achieved more verbosely by manually declaring JNI functions * and calling them from the Android application layer. */

 * and calling them from the Android application layer.
 */
void android_main(struct android_app* state) {
  VulkanEngine engine{};
  vkt::HelloVK vulkanBackend{};

  engine.app = state;
  engine.app_backend = &vulkanBackend;
  state->userData = &engine;
  state->onAppCmd = HandleCmd;

  android_app_set_key_event_filter(state, VulkanKeyEventFilter);
  android_app_set_motion_event_filter(state, VulkanMotionEventFilter);

  while (!state->destroyRequested) {
    android_poll_source* source;
    auto result = ALooper_pollOnce(engine.canRender ? 0 : -1, nullptr, nullptr,
                                   (void**)&source);
    if (result == ALOOPER_POLL_ERROR) {
      LOGE("ALooper_pollOnce returned an error");
      std::abort();
    }

    if (source != nullptr) {
      source->process(state, source);
    }

    HandleInputEvents(state);

    if (engine.canRender) {
      engine.app_backend->render();
    }
  }
}