object erh_compass : player_tools {
	// greebo: Gets called upon addition to the inventory
	void inventory_item_init(entity userEntity, float overlayHandle, string overlayName);	

	// Gets called when the player switches to another inventory item
	void inventory_item_unselect(entity userEntity, float overlayHandle);

	// Gets called when this item is selected in the inventory
	void inventory_item_select(entity userEntity, float overlayHandle);

	// Gets called to update the HUD (not each frame!)
	void inventory_item_update(entity userEntity, float overlayHandle);

	// Updates the HUD variables
	void updateCompass(entity userEntity);

	// greebo: Call this function in a new thread. It will update the compass HUD each frame.
	void updateLoop(entity userEntity);

	// Member variables
	vector 	_playerAngles;
	float	_compcwise;
	float	_compccwise;

	// The GUI overlay handle (containing the compass model)
	float	_overlayHandle;

	// The thread number of the update loop
	float	_updateThreadNum;
};


void erh_compass::updateCompass(entity userEntity)
{
	vector pa;
	vector temp=userEntity.getViewAngles();
	vector visdir;
	pa = (getEntityKey("ent")).getOrigin()-userEntity.getEyePos();
	visdir_x=sys.cos(temp_x)*sys.cos(temp_y);
	visdir_y=sys.cos(temp_x)*sys.sin(temp_y);
	visdir_z=-sys.sin(temp_x);
	visdir=sys.vecNormalize(visdir);
	pa=sys.vecNormalize(pa);
	_playerAngles=sys.VecToAngles(visdir)-sys.VecToAngles(pa);
	if (_playerAngles_x>180)
	{
		_playerAngles_x=_playerAngles_x-360;
	}
	else if (_playerAngles_x < -180)
	{
		_playerAngles_x=_playerAngles_x+360;
	}
	float yaw = _playerAngles_y+90;
	// Clamp the pitch to [COMPASS_MIN_PITCH .. COMPASS_MAX_PITCH]
	float playerPitchClamped = _playerAngles_x;

	if (playerPitchClamped > 0)	{
		playerPitchClamped = COMPASS_MAX_PITCH * playerPitchClamped/90;
	}
	else {
		playerPitchClamped = COMPASS_MIN_PITCH * -playerPitchClamped/90;
	}

	float modelPitch = -playerPitchClamped * sys.cos(yaw);
	float modelRoll = playerPitchClamped * sys.sin(yaw);
	userEntity.setGuiFloat(_overlayHandle, "modelYaw", -yaw);
	userEntity.setGuiFloat(_overlayHandle, "modelPitch", modelPitch);
	userEntity.setGuiFloat(_overlayHandle, "modelRoll", modelRoll);
}

void erh_compass::updateLoop(entity userEntity)
{
	// Update the compass GUI each frame
	eachFrame
	{
		updateCompass(userEntity);
	}
}

void erh_compass::inventory_item_init(entity userEntity, float overlayHandle, string overlayName)
{
	_overlayHandle = overlayHandle;

	updateCompass(userEntity);
}

void erh_compass::inventory_item_select(entity userEntity, float overlayHandle)
{
	_overlayHandle = overlayHandle;

	// Disable the default inventory
	userEntity.setGuiFloat(userEntity.getInventoryOverlay(), "Inventory_ItemVisible", 0);

	// Make the compass GUI visible
	userEntity.setGuiFloat(_overlayHandle, "CompassVisible", 1);

	// Start a new thread 
	_updateThreadNum = thread updateLoop(userEntity);
}

void erh_compass::inventory_item_unselect(entity userEntity, float overlayHandle)
{
	_overlayHandle = overlayHandle;

	// Kill the update loop
	sys.terminate(_updateThreadNum);

	// Disable the compass
	userEntity.setGuiFloat(_overlayHandle, "CompassVisible", 0);

	// Enable the default inventory again
	userEntity.setGuiFloat(userEntity.getInventoryOverlay(), "Inventory_ItemVisible", 1);
}

void erh_compass::inventory_item_update(entity userEntity, float overlayHandle)
{
	updateCompass(userEntity);
}