UnrealEngineUWP/Engine/Source/Runtime/Launch/Private/Android/LaunchAndroid.cpp

// Copyright 1998-2015 Epic Games, Inc. All Rights Reserved.

#include "LaunchPrivatePCH.h"
#include <string.h>
#include <jni.h>
#include <pthread.h>
#include "AndroidJNI.h"
#include "AndroidEventManager.h"
#include "AndroidInputInterface.h"
#include <android/log.h>
#include <android_native_app_glue.h>
#include <cstdio>
#include <sys/resource.h>
#include <dlfcn.h>
#include "AndroidWindow.h"
#include <android/sensor.h>
#include "Core.h"

// Function pointer for retrieving joystick events
// Function has been part of the OS since Honeycomb, but only appeared in the
// NDK in r19. Querying via dlsym allows its use without tying to the newest
// NDK.
typedef float(*GetAxesType)(const AInputEvent*, int32_t axis, size_t pointer_index);
static GetAxesType GetAxes = NULL;

// List of default axes to query for each controller
// Ideal solution is to call out to Java and enumerate the list of axes.
static const int32_t AxisList[] =
{
	AMOTION_EVENT_AXIS_X,
    AMOTION_EVENT_AXIS_Y,
	AMOTION_EVENT_AXIS_Z,
    AMOTION_EVENT_AXIS_RZ,
    AMOTION_EVENT_AXIS_LTRIGGER,
    AMOTION_EVENT_AXIS_RTRIGGER,
	AMOTION_EVENT_AXIS_GAS,
    AMOTION_EVENT_AXIS_BRAKE,

	//These are DPAD analogs
    //AMOTION_EVENT_AXIS_HAT_X,
    //AMOTION_EVENT_AXIS_HAT_Y,
};

// map of all supported keycodes
static TSet<uint16> MappedKeyCodes;

// List of gamepad keycodes to ignore
static const uint16 IgnoredGamepadKeyCodesList[] =
{
	AKEYCODE_VOLUME_UP,
	AKEYCODE_VOLUME_DOWN
};

// List of desired gamepad keycodes
static const uint16 ValidGamepadKeyCodesList[] =
{
	AKEYCODE_BUTTON_A,
	AKEYCODE_DPAD_CENTER,
	AKEYCODE_BUTTON_B,
	AKEYCODE_BUTTON_X,
	AKEYCODE_BUTTON_Y,
	AKEYCODE_BUTTON_L1,
	AKEYCODE_BUTTON_R1,
	AKEYCODE_BUTTON_START,
	AKEYCODE_MENU,
	AKEYCODE_BUTTON_SELECT,
	AKEYCODE_BACK,
	AKEYCODE_BUTTON_THUMBL,
	AKEYCODE_BUTTON_THUMBR,
	AKEYCODE_BUTTON_L2,
	AKEYCODE_BUTTON_R2,
	AKEYCODE_DPAD_UP,
	AKEYCODE_DPAD_DOWN,
	AKEYCODE_DPAD_LEFT,
	AKEYCODE_DPAD_RIGHT
};

// map of gamepad keycodes that should be ignored
static TSet<uint16> IgnoredGamepadKeyCodes;

// map of gamepad keycodes that should be passed forward
static TSet<uint16> ValidGamepadKeyCodes;

// -nostdlib means no crtbegin_so.o, so we have to provide our own __dso_handle and atexit()
extern "C"
{
	int atexit(void (*func)(void)) { return 0; }

	extern void *__dso_handle __attribute__((__visibility__ ("hidden")));
	void *__dso_handle;
}

extern void AndroidThunkCpp_InitHMDs();
extern void AndroidThunkCpp_ShowConsoleWindow();

// Base path for file accesses
extern FString GFilePathBase;

/** The global EngineLoop instance */
FEngineLoop	GEngineLoop;

bool GShowConsoleWindowNextTick = false;

static void AndroidProcessEvents(struct android_app* state);

//Event thread stuff
static void* AndroidEventThreadWorker(void* param);

// How often to process (read & dispatch) events, in seconds.
static const float EventRefreshRate = 1.0f / 20.0f;

//Android event callback functions
static int32_t HandleInputCB(struct android_app* app, AInputEvent* event); //Touch and key input events
static void OnAppCommandCB(struct android_app* app, int32_t cmd); //Lifetime events
static int HandleSensorEvents(int fd, int events, void* data); // Sensor events

bool GHasInterruptionRequest = false;
bool GIsInterrupted = false;

// Android sensor data management
static ASensorManager * SensorManager = NULL;
// Accelerometer (includes gravity), i.e. FMotionEvent::GetAcceleration.
static const ASensor * SensorAccelerometer = NULL;
// Gyroscope, i.e. FMotionEvent::GetRotationRate.
static const ASensor * SensorGyroscope = NULL;
static ASensorEventQueue * SensorQueue = NULL;
// android.hardware.SensorManager.SENSOR_DELAY_GAME
static const int32_t SensorDelayGame = 1;
// Time decay sampling rate.
static const float SampleDecayRate = 0.85f;
// Event for coordinating pausing of the main and event handling threads to prevent background spinning
static FEvent* EventHandlerEvent = NULL;

// Wait for Java onCreate to complete before resume main init
static volatile bool GResumeMainInit = false;
static volatile bool GEventHandlerInitialized = false;
extern "C" void Java_com_epicgames_ue4_GameActivity_nativeResumeMainInit(JNIEnv* jenv, jobject thiz)
{
	GResumeMainInit = true;

	// now wait for event handler to be set up before returning
	while (!GEventHandlerInitialized)
	{
		FPlatformProcess::Sleep(0.01f);
		FPlatformMisc::MemoryBarrier();
	}
}

static volatile bool GHMDsInitialized = false;
static TArray<IHeadMountedDisplayModule*> GHMDImplementations;
void InitHMDs()
{
	if (FParse::Param(FCommandLine::Get(), TEXT("nohmd")) || FParse::Param(FCommandLine::Get(), TEXT("emulatestereo")))
	{
		return;
	}

	// Get a list of plugins that implement this feature
	GHMDImplementations = IModularFeatures::Get().GetModularFeatureImplementations<IHeadMountedDisplayModule>(IHeadMountedDisplayModule::GetModularFeatureName());

	AndroidThunkCpp_InitHMDs();

	while (!GHMDsInitialized)
	{
		FPlatformProcess::Sleep(0.01f);
		FPlatformMisc::MemoryBarrier();
	}
}

static void InitCommandLine()
{
	static const uint32 CMD_LINE_MAX = 16384u;

	// initialize the command line to an empty string
	FCommandLine::Set(TEXT(""));

	// read in the command line text file from the sdcard if it exists
	FString CommandLineFilePath = GFilePathBase + FString("/UE4Game/") + (!FApp::IsGameNameEmpty() ? FApp::GetGameName() : FPlatformProcess::ExecutableName()) + FString("/UE4CommandLine.txt");
	FILE* CommandLineFile = fopen(TCHAR_TO_UTF8(*CommandLineFilePath), "r");
	if(CommandLineFile == NULL)
	{
		// if that failed, try the lowercase version
		CommandLineFilePath = CommandLineFilePath.Replace(TEXT("UE4CommandLine.txt"), TEXT("ue4commandline.txt"));
		CommandLineFile = fopen(TCHAR_TO_UTF8(*CommandLineFilePath), "r");
	}

	if(CommandLineFile)
	{
		char CommandLine[CMD_LINE_MAX];
		fgets(CommandLine, ARRAY_COUNT(CommandLine) - 1, CommandLineFile);

		fclose(CommandLineFile);

		// chop off trailing spaces
		while (*CommandLine && isspace(CommandLine[strlen(CommandLine) - 1]))
		{
			CommandLine[strlen(CommandLine) - 1] = 0;
		}

		FCommandLine::Append(UTF8_TO_TCHAR(CommandLine));
	}
}

//Main function called from the android entry point
int32 AndroidMain(struct android_app* state)
{
	FPlatformMisc::LowLevelOutputDebugString(L"Entered AndroidMain()");

	// Force the first call to GetJavaEnv() to happen on the game thread, allowing subsequent calls to occur on any thread
	FAndroidApplication::GetJavaEnv();

	// adjust the file descriptor limits to allow as many open files as possible
	rlimit cur_fd_limit;
	{
		int result = getrlimit(RLIMIT_NOFILE, & cur_fd_limit);
		//FPlatformMisc::LowLevelOutputDebugStringf(TEXT("(%d) Current fd limits: soft = %lld, hard = %lld"), result, cur_fd_limit.rlim_cur, cur_fd_limit.rlim_max);
	}
	{
		rlimit new_limit = cur_fd_limit;
		new_limit.rlim_cur = cur_fd_limit.rlim_max;
		new_limit.rlim_max = cur_fd_limit.rlim_max;
		int result = setrlimit(RLIMIT_NOFILE, &new_limit);
		//FPlatformMisc::LowLevelOutputDebugStringf(TEXT("(%d) Setting fd limits: soft = %lld, hard = %lld"), result, new_limit.rlim_cur, new_limit.rlim_max);
	}
	{
		int result = getrlimit(RLIMIT_NOFILE, & cur_fd_limit);
		//FPlatformMisc::LowLevelOutputDebugStringf(TEXT("(%d) Current fd limits: soft = %lld, hard = %lld"), result, cur_fd_limit.rlim_cur, cur_fd_limit.rlim_max);
	}

	// setup joystick support
	// r19 is the first NDK to include AMotionEvenet_getAxisValue in the headers
	// However, it has existed in the so since Honeycomb, query for the symbol
	// to determine whether to try controller support
	{
		void* Lib = dlopen("libandroid.so",0);
		if (Lib != NULL)
		{
			GetAxes = (GetAxesType)dlsym(Lib, "AMotionEvent_getAxisValue");
		}

		if (GetAxes != NULL)
		{
			FPlatformMisc::LowLevelOutputDebugStringf(TEXT("Controller interface supported\n"));
		}
		else
		{
			FPlatformMisc::LowLevelOutputDebugStringf(TEXT("Controller interface UNsupported\n"));
		}
	}

	// setup key filtering
	static const uint32 MAX_KEY_MAPPINGS(256);
	uint16 KeyCodes[MAX_KEY_MAPPINGS];
	uint32 NumKeyCodes = FPlatformMisc::GetKeyMap(KeyCodes, nullptr, MAX_KEY_MAPPINGS);

	for (int i = 0; i < NumKeyCodes; ++i)
	{
		MappedKeyCodes.Add(KeyCodes[i]);
	}

	const int IgnoredGamepadKeyCodeCount = sizeof(IgnoredGamepadKeyCodesList)/sizeof(uint16);
	for (int i = 0; i < IgnoredGamepadKeyCodeCount; ++i)
	{
		IgnoredGamepadKeyCodes.Add(IgnoredGamepadKeyCodesList[i]);
	}

	const int ValidGamepadKeyCodeCount = sizeof(ValidGamepadKeyCodesList)/sizeof(uint16);
	for (int i = 0; i < ValidGamepadKeyCodeCount; ++i)
	{
		ValidGamepadKeyCodes.Add(ValidGamepadKeyCodesList[i]);
	}

	// wait for java activity onCreate to finish
	while (!GResumeMainInit)
	{
		FPlatformProcess::Sleep(0.01f);
		FPlatformMisc::MemoryBarrier();
	}

	// read the command line file
	InitCommandLine();
	FPlatformMisc::LowLevelOutputDebugStringf(TEXT("Final commandline: %s\n"), FCommandLine::Get());

	EventHandlerEvent = FPlatformProcess::GetSynchEventFromPool(false);
	FPlatformMisc::LowLevelOutputDebugString(L"Created sync event");
	FAppEventManager::GetInstance()->SetEventHandlerEvent(EventHandlerEvent);

	// ready for onCreate to complete
	GEventHandlerInitialized = true;

	// Initialize file system access (i.e. mount OBBs, etc.).
	// We need to do this really early for Android so that files in the
	// OBBs and APK are found.
	IPlatformFile::GetPlatformPhysical().Initialize(nullptr, FCommandLine::Get());

#if 0
	for (int32 i = 0; i < 10; i++)
	{
		sleep(1);
		FPlatformMisc::LowLevelOutputDebugStringf(TEXT("[Patch %d]"), i);

	}
	FPlatformMisc::LowLevelOutputDebugStringf(TEXT("[Patch] : Dont Patch \n"));
#endif

	// initialize the engine
	GEngineLoop.PreInit(0, NULL, FCommandLine::Get());

	// initialize HMDs
	InitHMDs();

	UE_LOG(LogAndroid, Display, TEXT("Passed PreInit()"));

	GLog->SetCurrentThreadAsMasterThread();

	GEngineLoop.Init();

	UE_LOG(LogAndroid, Log, TEXT("Passed GEngineLoop.Init()"));

	// tick until done
	while (!GIsRequestingExit)
	{
		FAppEventManager::GetInstance()->Tick();
		if(!FAppEventManager::GetInstance()->IsGamePaused())
		{
			GEngineLoop.Tick();

			float timeToSleep = 0.05f; //in seconds
			sleep(timeToSleep);
		}

#if !UE_BUILD_SHIPPING
		// show console window on next game tick
		if (GShowConsoleWindowNextTick)
		{
			GShowConsoleWindowNextTick = false;
			AndroidThunkCpp_ShowConsoleWindow();
		}
#endif
	}

	UE_LOG(LogAndroid, Log, TEXT("Exiting"));

	// exit out!
	GEngineLoop.Exit();

	return 0;
}



static void* AndroidEventThreadWorker( void* param )
{
	struct android_app* state = (struct android_app*)param;

	FPlatformProcess::SetThreadAffinityMask(FPlatformAffinity::GetMainGameMask());

	FPlatformMisc::LowLevelOutputDebugString(L"Entering event processing thread engine entry point");

	ALooper* looper = ALooper_prepare(ALOOPER_PREPARE_ALLOW_NON_CALLBACKS);
	ALooper_addFd(looper, state->msgread, LOOPER_ID_MAIN, ALOOPER_EVENT_INPUT, NULL,
		&state->cmdPollSource);
	state->looper = looper;

	FPlatformMisc::LowLevelOutputDebugString(L"Prepared looper for event thread");

	//Assign the callbacks
	state->onAppCmd = OnAppCommandCB;
	state->onInputEvent = HandleInputCB;

	FPlatformMisc::LowLevelOutputDebugString(L"Passed callback initialization");

	// Acquire sensors
	SensorManager = ASensorManager_getInstance();
	if (NULL != SensorManager)
	{
		// Register for the various sensor events we want. Some
		// may return NULL indicating that the sensor data is not
		// available in the device. For those empty data will eventually
		// get fed into the motion events.
		SensorAccelerometer = ASensorManager_getDefaultSensor(
			SensorManager, ASENSOR_TYPE_ACCELEROMETER);
		SensorGyroscope = ASensorManager_getDefaultSensor(
			SensorManager, ASENSOR_TYPE_GYROSCOPE);
		// Create the queue for events to arrive.
		SensorQueue = ASensorManager_createEventQueue(
			SensorManager, state->looper, LOOPER_ID_USER, HandleSensorEvents, NULL);
	}

	FPlatformMisc::LowLevelOutputDebugString(L"Passed sensor initialization");

	//continue to process events until the engine is shutting down
	while (!GIsRequestingExit)
	{
//		FPlatformMisc::LowLevelOutputDebugString(L"AndroidEventThreadWorker");

		AndroidProcessEvents(state);

		sleep(EventRefreshRate);		// this is really 0 since it takes int seconds.
	}

	UE_LOG(LogAndroid, Log, TEXT("Exiting"));

	return NULL;
}

//Called from the separate event processing thread
static void AndroidProcessEvents(struct android_app* state)
{
	int ident;
	int fdesc;
	int events;
	struct android_poll_source* source;

	while((ident = ALooper_pollAll(-1, &fdesc, &events, (void**)&source)) >= 0)
	{
		// process this event
		if (source)
		{
			source->process(state, source);
		}
	}
}

pthread_t G_AndroidEventThread;

struct android_app* GNativeAndroidApp = NULL;

void android_main(struct android_app* state)
{
	FPlatformMisc::LowLevelOutputDebugString(L"Entering native app glue main function");
	
	GNativeAndroidApp = state;
	check(GNativeAndroidApp);

	pthread_attr_t otherAttr; 
	pthread_attr_init(&otherAttr);
	pthread_attr_setdetachstate(&otherAttr, PTHREAD_CREATE_DETACHED);
	pthread_create(&G_AndroidEventThread, &otherAttr, AndroidEventThreadWorker, state);

	FPlatformMisc::LowLevelOutputDebugString(L"Created event thread");

	// Make sure glue isn't stripped.
	app_dummy();

	//@todo android: replace with native activity, main loop off of UI thread, etc.
	AndroidMain(state);
}

extern bool GAndroidGPUInfoReady;

//Called from the event process thread
static int32_t HandleInputCB(struct android_app* app, AInputEvent* event)
{
//	FPlatformMisc::LowLevelOutputDebugStringf(L"INPUT - type: %x, action: %x, source: %x, keycode: %x, buttons: %x", AInputEvent_getType(event), 
//		AMotionEvent_getAction(event), AInputEvent_getSource(event), AKeyEvent_getKeyCode(event), AMotionEvent_getButtonState(event));

	if (AInputEvent_getType(event) == AINPUT_EVENT_TYPE_MOTION)
	{
		int action = AMotionEvent_getAction(event);
		int actionType = action & AMOTION_EVENT_ACTION_MASK;
		size_t actionPointer = (size_t)((action & AMOTION_EVENT_ACTION_POINTER_INDEX_MASK) >> AMOTION_EVENT_ACTION_POINTER_INDEX_SHIFT);
		bool isActionTargeted = (actionType == AMOTION_EVENT_ACTION_POINTER_DOWN || actionType == AMOTION_EVENT_ACTION_POINTER_UP);

		// trap Joystick events first, with fallthrough if there is no joystick support
		if (((AInputEvent_getSource(event) & AINPUT_SOURCE_CLASS_JOYSTICK) != 0) &&
				(GetAxes != NULL) &&
				(actionType == AMOTION_EVENT_ACTION_MOVE))
		{
			const int axisCount = sizeof(AxisList)/sizeof(int32_t);
			int device = AInputEvent_getDeviceId(event);

			for (int axis = 0; axis < axisCount; axis++)
			{
				float val = GetAxes( event, AxisList[axis], 0);
				FAndroidInputInterface::JoystickAxisEvent( device, AxisList[axis], val);
			}
		}
		else
		{
			TArray<TouchInput> TouchesArray;
			
			TouchType type = TouchEnded;

			switch (actionType)
			{
			case AMOTION_EVENT_ACTION_DOWN:
			case AMOTION_EVENT_ACTION_POINTER_DOWN:
				type = TouchBegan;
				break;
			case AMOTION_EVENT_ACTION_MOVE:
				type = TouchMoved;
				break;
			case AMOTION_EVENT_ACTION_UP:
			case AMOTION_EVENT_ACTION_POINTER_UP:
			case AMOTION_EVENT_ACTION_CANCEL:
			case AMOTION_EVENT_ACTION_OUTSIDE:
				type = TouchEnded;
				break;
			}

			size_t pointerCount = AMotionEvent_getPointerCount(event);

			if (pointerCount == 0)
			{
				return 1;
			}

			ANativeWindow* Window = (ANativeWindow*)FPlatformMisc::GetHardwareWindow();
			if (!Window)
			{
				return 0;
			}

			int32_t Width = 0 ;
			int32_t Height = 0 ;

			if(Window)
			{
				FAndroidWindow::CalculateSurfaceSize(Window, Width, Height);
			}

			// make sure OpenGL context created before accepting touch events.. FAndroidWindow::GetScreenRect() may try to create it early from wrong thread if this is the first call
			if (!GAndroidGPUInfoReady)
			{
				return 1;
			}
			FPlatformRect ScreenRect = FAndroidWindow::GetScreenRect();

			if(isActionTargeted)
			{
				if(actionPointer < 0 || pointerCount < (int)actionPointer)
				{
					return 1;
				}

				int pointerId = AMotionEvent_getPointerId(event, actionPointer);
				float x = FMath::Min<float>(AMotionEvent_getX(event, actionPointer) / Width, 1.f);
				x *= (ScreenRect.Right - 1);
				float y = FMath::Min<float>(AMotionEvent_getY(event, actionPointer) / Height, 1.f);
				y *= (ScreenRect.Bottom - 1);

				UE_LOG(LogAndroid, Verbose, TEXT("Received targeted motion event from pointer %u (id %d) action %d: (%.2f, %.2f)"), actionPointer, pointerId, action, x, y);

				TouchInput TouchMessage;
				TouchMessage.Handle = pointerId;
				TouchMessage.Type = type;
				TouchMessage.Position = FVector2D(x, y);
				TouchMessage.LastPosition = FVector2D(x, y);		//@todo android: AMotionEvent_getHistoricalRawX
				TouchesArray.Add(TouchMessage);
			}
			else
			{
				for (size_t i = 0; i < pointerCount; ++i)
				{
					int pointerId = AMotionEvent_getPointerId(event, i);

					float x = FMath::Min<float>(AMotionEvent_getX(event, i) / Width, 1.f);
					x *= (ScreenRect.Right - 1);
					float y = FMath::Min<float>(AMotionEvent_getY(event, i) / Height, 1.f);
					y *= (ScreenRect.Bottom - 1);

					UE_LOG(LogAndroid, Verbose, TEXT("Received motion event from pointer %u (id %d) action %d: (%.2f, %.2f)"), i, action, AMotionEvent_getPointerId(event,i), x, y);

					TouchInput TouchMessage;
					TouchMessage.Handle = AMotionEvent_getPointerId(event, i);
					TouchMessage.Type = type;
					TouchMessage.Position = FVector2D(x, y);
					TouchMessage.LastPosition = FVector2D(x, y);		//@todo android: AMotionEvent_getHistoricalRawX
					TouchesArray.Add(TouchMessage);
				}
			}

			FAndroidInputInterface::QueueTouchInput(TouchesArray);

#if !UE_BUILD_SHIPPING
			if ((pointerCount >= 4) && (type == TouchBegan))
			{
				bool bShowConsole = true;
				GConfig->GetBool(TEXT("/Script/Engine.InputSettings"), TEXT("bShowConsoleOnFourFingerTap"), bShowConsole, GInputIni);

				if (bShowConsole)
				{
					GShowConsoleWindowNextTick = true;
				}
			}
#endif
		}

		return 1;
	}
	else if (AInputEvent_getType(event) == AINPUT_EVENT_TYPE_KEY)
	{
		int keyCode = AKeyEvent_getKeyCode(event);

		FPlatformMisc::LowLevelOutputDebugStringf(L"Received keycode: %d", keyCode);

		//Trap Joystick events first, with fallthrough if there is no joystick support
		if (((AInputEvent_getSource(event) & (AINPUT_SOURCE_GAMEPAD | AINPUT_SOURCE_DPAD)) != 0) && (GetAxes != NULL) && ValidGamepadKeyCodes.Contains(keyCode))
		{
			if (IgnoredGamepadKeyCodes.Contains(keyCode))
			{
				return 0;
			}

			int device = AInputEvent_getDeviceId(event);
			bool down = AKeyEvent_getAction(event) != AKEY_EVENT_ACTION_UP;
			FAndroidInputInterface::JoystickButtonEvent( device, keyCode, down);
			FPlatformMisc::LowLevelOutputDebugStringf(L"Received gamepad button: %d", keyCode);
		}
		else
		{
			FPlatformMisc::LowLevelOutputDebugStringf(L"Received key event: %d", keyCode);

			// only handle mapped key codes
			if (!MappedKeyCodes.Contains(keyCode))
			{
				return 0;
			}

			FDeferredAndroidMessage Message;

			Message.messageType = AKeyEvent_getAction(event) == AKEY_EVENT_ACTION_UP ? MessageType_KeyUp : MessageType_KeyDown; 
			Message.KeyEventData.unichar = keyCode;
			Message.KeyEventData.keyId = keyCode;
			Message.KeyEventData.modifier = AKeyEvent_getMetaState(event);
			Message.KeyEventData.isRepeat = AKeyEvent_getAction(event) == AKEY_EVENT_ACTION_MULTIPLE;
			FAndroidInputInterface::DeferMessage(Message);

			// allow event to be generated for volume up and down, but conditionally allow system to handle it, too
			if (keyCode == AKEYCODE_VOLUME_UP || keyCode == AKEYCODE_VOLUME_DOWN)
			{
				if (FPlatformMisc::GetVolumeButtonsHandledBySystem())
				{
					return 0;
				}
			}
		}

		return 1;
	}

	return 0;
}

static void onNativeWindowResized(ANativeActivity* activity, ANativeWindow* window)
{
	FAppEventManager::GetInstance()->EnqueueAppEvent(APP_EVENT_STATE_WINDOW_CHANGED,window);
}



//Called from the event process thread
static void OnAppCommandCB(struct android_app* app, int32_t cmd)
{
	FPlatformMisc::LowLevelOutputDebugStringf(L"OnAppCommandCB cmd: %u", cmd);

	switch (cmd)
	{
	case APP_CMD_SAVE_STATE:
		/**
		* Command from main thread: the app should generate a new saved state
		* for itself, to restore from later if needed.  If you have saved state,
		* allocate it with malloc and place it in android_app.savedState with
		* the size in android_app.savedStateSize.  The will be freed for you
		* later.
		*/
		// the OS asked us to save the state of the app
		UE_LOG(LogAndroid, Log, TEXT("Case APP_CMD_SAVE_STATE"));
		FAppEventManager::GetInstance()->EnqueueAppEvent(APP_EVENT_STATE_SAVE_STATE);
		break;
	case APP_CMD_INIT_WINDOW:
		/**
		 * Command from main thread: a new ANativeWindow is ready for use.  Upon
		 * receiving this command, android_app->window will contain the new window
		 * surface.
		 */
		// get the window ready for showing
		UE_LOG(LogAndroid, Log, TEXT("Case APP_CMD_INIT_WINDOW"));
		FAppEventManager::GetInstance()->HandleWindowCreated(app->pendingWindow);
		break;
	case APP_CMD_TERM_WINDOW:
		/**
		 * Command from main thread: the existing ANativeWindow needs to be
		 * terminated.  Upon receiving this command, android_app->window still
		 * contains the existing window; after calling android_app_exec_cmd
		 * it will be set to NULL.
		 */
		// clean up the window because it is being hidden/closed
		UE_LOG(LogAndroid, Log, TEXT("Case APP_CMD_TERM_WINDOW"));
		FAppEventManager::GetInstance()->EnqueueAppEvent(APP_EVENT_STATE_WINDOW_DESTROYED, NULL);
		
		break;
	case APP_CMD_LOST_FOCUS:
		/**
		 * Command from main thread: the app's activity window has lost
		 * input focus.
		 */
		// if the app lost focus, avoid unnecessary processing (like monitoring the accelerometer)
		UE_LOG(LogAndroid, Log, TEXT("Case APP_CMD_LOST_FOCUS"));
		FAppEventManager::GetInstance()->EnqueueAppEvent(APP_EVENT_STATE_WINDOW_LOST_FOCUS, NULL);
		if (NULL != SensorQueue)
		{
			if (NULL != SensorAccelerometer)
				ASensorEventQueue_disableSensor(SensorQueue, SensorAccelerometer);
			if (NULL != SensorGyroscope)
				ASensorEventQueue_disableSensor(SensorQueue, SensorGyroscope);
		}
		break;
	case APP_CMD_GAINED_FOCUS:
		/**
		 * Command from main thread: the app's activity window has gained
		 * input focus.
		 */
		// bring back a certain functionality, like monitoring the accelerometer
		UE_LOG(LogAndroid, Log, TEXT("Case APP_CMD_GAINED_FOCUS"));
		FAppEventManager::GetInstance()->EnqueueAppEvent(APP_EVENT_STATE_WINDOW_GAINED_FOCUS, NULL);
		if (NULL != SensorQueue)
		{
			if (NULL != SensorAccelerometer)
			{
				ASensorEventQueue_enableSensor(SensorQueue, SensorAccelerometer);
				ASensorEventQueue_setEventRate(SensorQueue, SensorAccelerometer, SensorDelayGame);
			}
			if (NULL != SensorGyroscope)
			{
				ASensorEventQueue_enableSensor(SensorQueue, SensorGyroscope);
				ASensorEventQueue_setEventRate(SensorQueue, SensorGyroscope, SensorDelayGame);
			}
		}
		break;
	case APP_CMD_INPUT_CHANGED:
		UE_LOG(LogAndroid, Log, TEXT("Case APP_CMD_INPUT_CHANGED"));
		break;
	case APP_CMD_WINDOW_RESIZED:
		/**
		 * Command from main thread: the current ANativeWindow has been resized.
		 * Please redraw with its new size.
		 */
		UE_LOG(LogAndroid, Log, TEXT("Case APP_CMD_WINDOW_RESIZED"));
		FAppEventManager::GetInstance()->EnqueueAppEvent(APP_EVENT_STATE_WINDOW_RESIZED );
		break;
	case APP_CMD_WINDOW_REDRAW_NEEDED:
		/**
		 * Command from main thread: the system needs that the current ANativeWindow
		 * be redrawn.  You should redraw the window before handing this to
		 * android_app_exec_cmd() in order to avoid transient drawing glitches.
		 */
		UE_LOG(LogAndroid, Log, TEXT("Case APP_CMD_WINDOW_REDRAW_NEEDED"));
		FAppEventManager::GetInstance()->EnqueueAppEvent(APP_EVENT_STATE_WINDOW_REDRAW_NEEDED );
		break;
	case APP_CMD_CONTENT_RECT_CHANGED:
		/**
		 * Command from main thread: the content area of the window has changed,
		 * such as from the soft input window being shown or hidden.  You can
		 * find the new content rect in android_app::contentRect.
		 */
		UE_LOG(LogAndroid, Log, TEXT("Case APP_CMD_CONTENT_RECT_CHANGED"));
		break;
	case APP_CMD_CONFIG_CHANGED:
		/**
		 * Command from main thread: the current device configuration has changed.
		 */
		UE_LOG(LogAndroid, Log, TEXT("Case APP_CMD_CONFIG_CHANGED"));
		break;
	case APP_CMD_LOW_MEMORY:
		/**
		 * Command from main thread: the system is running low on memory.
		 * Try to reduce your memory use.
		 */
		UE_LOG(LogAndroid, Log, TEXT("Case APP_CMD_LOW_MEMORY"));
		break;
	case APP_CMD_START:
		/**
		 * Command from main thread: the app's activity has been started.
		 */
		UE_LOG(LogAndroid, Log, TEXT("Case APP_CMD_START"));
		app->activity->callbacks->onNativeWindowResized  = onNativeWindowResized; //currently not handled in glue code.
		FAppEventManager::GetInstance()->EnqueueAppEvent(APP_EVENT_STATE_ON_START);
	
		break;
	case APP_CMD_RESUME:
		/**
		 * Command from main thread: the app's activity has been resumed.
		 */
		UE_LOG(LogAndroid, Log, TEXT("Case APP_CMD_RESUME"));

		FAppEventManager::GetInstance()->EnqueueAppEvent(APP_EVENT_STATE_ON_RESUME);

		break;
	case APP_CMD_PAUSE:
		/**
		 * Command from main thread: the app's activity has been paused.
		 */
		UE_LOG(LogAndroid, Log, TEXT("Case APP_CMD_PAUSE"));
		FAppEventManager::GetInstance()->EnqueueAppEvent(APP_EVENT_STATE_ON_PAUSE);

		break;
	case APP_CMD_STOP:
		/**
		 * Command from main thread: the app's activity has been stopped.
		 */
		UE_LOG(LogAndroid, Log, TEXT("Case APP_CMD_STOP"));
		FAppEventManager::GetInstance()->EnqueueAppEvent(APP_EVENT_STATE_ON_STOP);
		break;
	case APP_CMD_DESTROY:
		/**
		* Command from main thread: the app's activity is being destroyed,
		* and waiting for the app thread to clean up and exit before proceeding.
		*/
		UE_LOG(LogAndroid, Log, TEXT("Case APP_CMD_DESTROY"));
		FAppEventManager::GetInstance()->EnqueueAppEvent(APP_EVENT_STATE_ON_PAUSE);
		break;
	}

	if ( EventHandlerEvent )
		EventHandlerEvent->Trigger();
}

static int HandleSensorEvents(int fd, int events, void* data)
{
	// It's not possible to discern sequencing across sensors in
	// Android. So we average out all the sensor events on one cycle
	// and post a single motion sensor data point. We also need
	// to synthesize additional information.
	FVector current_accelerometer(0, 0, 0);
	FVector current_gyroscope(0, 0, 0);
	int32 current_accelerometer_sample_count = 0;
	int32 current_gyroscope_sample_count = 0;
	static FVector last_accelerometer(0, 0, 0);

	if (NULL != SensorAccelerometer || NULL != SensorGyroscope)
	{
		ASensorEvent sensor_event;
		while (ASensorEventQueue_getEvents(SensorQueue, &sensor_event, 1) > 0)
		{
			if (ASENSOR_TYPE_ACCELEROMETER == sensor_event.type)
			{
				current_accelerometer.X += sensor_event.acceleration.x;
				current_accelerometer.Y += sensor_event.acceleration.y;
				current_accelerometer.Z += sensor_event.acceleration.z;
				current_accelerometer_sample_count += 1;
			}
			else if (ASENSOR_TYPE_GYROSCOPE == sensor_event.type)
			{
				current_gyroscope.X += sensor_event.vector.pitch;
				current_gyroscope.Y += sensor_event.vector.azimuth;
				current_gyroscope.Z += sensor_event.vector.roll;
				current_gyroscope_sample_count += 1;
			}
		}
	}

	if (current_accelerometer_sample_count > 0)
	{
		// Do simple average of the samples we just got.
		current_accelerometer /= float(current_accelerometer_sample_count);
		last_accelerometer = current_accelerometer;
	}
	else
	{
		current_accelerometer = last_accelerometer;
	}

	if (current_gyroscope_sample_count > 0)
	{
		// Do simple average of the samples we just got.
		current_gyroscope /= float(current_gyroscope_sample_count);
	}

	// If we have motion samples we generate the single event.
	if (current_accelerometer_sample_count > 0 ||
		current_gyroscope_sample_count > 0)
	{
		// The data we compose the motion event from.
		FVector current_tilt(0, 0, 0);
		FVector current_rotation_rate(0, 0, 0);
		FVector current_gravity(0, 0, 0);
		FVector current_acceleration(0, 0, 0);

		// Buffered, historical, motion data.
		static FVector last_tilt(0, 0, 0);
		static FVector last_gravity(0, 0, 0);

		// We use a low-pass filter to synthesize the gravity
		// vector.
		static bool first_acceleration_sample = true;
		if (!first_acceleration_sample)
		{
			current_gravity
				= last_gravity*SampleDecayRate
				+ current_accelerometer*(1.0f - SampleDecayRate);
		}
		first_acceleration_sample = false;

		// Calc the tilt from the accelerometer as it's not
		// available directly.
		FVector accelerometer_dir = -current_accelerometer.GetSafeNormal();
		float current_pitch
			= FMath::Atan2(accelerometer_dir.Y, accelerometer_dir.Z);
		float current_roll
			= -FMath::Atan2(accelerometer_dir.X, accelerometer_dir.Z);
		current_tilt.X = current_pitch;
		current_tilt.Y = 0;
		current_tilt.Z = current_roll;

		// And take out the gravity from the accel to get
		// the linear acceleration.
		current_acceleration = current_accelerometer - current_gravity;

		if (current_gyroscope_sample_count > 0)
		{
			// The rotation rate is the what the gyroscope gives us.
			current_rotation_rate = current_gyroscope;
		}
		else if (NULL == SensorGyroscope)
		{
			// If we don't have a gyroscope at all we need to calc a rotation
			// rate from our calculated tilt and a delta.
			current_rotation_rate = current_tilt - last_tilt;
		}

		// Finally record the motion event with all the data.
		FAndroidInputInterface::QueueMotionData(current_tilt,
			current_rotation_rate, current_gravity, current_acceleration);

		// Update history values.
		last_tilt = current_tilt;
		last_gravity = current_gravity;

		// UE_LOG(LogTemp, Log, TEXT("MOTION: tilt = %s, rotation-rate = %s, gravity = %s, acceleration = %s"),
		//	*current_tilt.ToCompactString(),
		//	*current_rotation_rate.ToCompactString(),
		//	*current_gravity.ToCompactString(),
		//	*current_acceleration.ToCompactString());
	}

	// Indicate we want to keep getting events.
	return 1;
}

//Native-defined functions

//This function is declared in the Java-defined class, GameActivity.java: "public native void nativeConsoleCommand(String commandString);"
extern "C" void Java_com_epicgames_ue4_GameActivity_nativeConsoleCommand(JNIEnv* jenv, jobject thiz, jstring commandString)
{
	const char* javaChars = jenv->GetStringUTFChars(commandString, 0);

	new(GEngine->DeferredCommands) FString(UTF8_TO_TCHAR(javaChars));

	//Release the string
	jenv->ReleaseStringUTFChars(commandString, javaChars);
}

// This is called from the Java UI thread for initializing VR HMDs
extern "C" void Java_com_epicgames_ue4_GameActivity_nativeInitHMDs(JNIEnv* jenv, jobject thiz)
{
	for (auto HMDModuleIt = GHMDImplementations.CreateIterator(); HMDModuleIt; ++HMDModuleIt)
	{
		(*HMDModuleIt)->PreInit();
	}

	GHMDsInitialized = true;
}

extern "C" void Java_com_epicgames_ue4_GameActivity_nativeSetAndroidVersionInformation(JNIEnv* jenv, jobject thiz, jstring androidVersion, jstring phoneMake, jstring phoneModel, jstring osLanguage )
{
	const char *javaAndroidVersion = jenv->GetStringUTFChars(androidVersion, 0 );
	FString UEAndroidVersion = FString(UTF8_TO_TCHAR( javaAndroidVersion ));

	const char *javaPhoneMake = jenv->GetStringUTFChars(phoneMake, 0 );
	FString UEPhoneMake = FString(UTF8_TO_TCHAR( javaPhoneMake ));

	const char *javaPhoneModel = jenv->GetStringUTFChars(phoneModel, 0 );
	FString UEPhoneModel = FString(UTF8_TO_TCHAR( javaPhoneModel ));

	const char *javaOSLanguage = jenv->GetStringUTFChars(osLanguage, 0);
	FString UEOSLanguage = FString(UTF8_TO_TCHAR(javaOSLanguage));

	FAndroidMisc::SetVersionInfo( UEAndroidVersion, UEPhoneMake, UEPhoneModel, UEOSLanguage );
}

bool WaitForAndroidLoseFocusEvent(double TimeoutSeconds)
{
	return FAppEventManager::GetInstance()->WaitForEventInQueue(EAppEventState::APP_EVENT_STATE_WINDOW_LOST_FOCUS, TimeoutSeconds);
}