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--
-- All or portions of this file Copyright (c) Amazon.com, Inc. or its affiliates or
-- its licensors.
--
-- For complete copyright and license terms please see the LICENSE at the root of this
-- distribution (the "License"). All use of this software is governed by the License,
-- or, if provided, by the license below or the license accompanying this file. Do not
-- remove or modify any license notices. This file is distributed on an "AS IS" BASIS,
-- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
--
--
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-- audio area entity - to be attached to an area
-- reports a normalized (0-1) fade value depending on the listener's distance to the area

AudioAreaEntity = {
	type = "AudioAreaEntity",
	
	Editor = {
		Model = "Editor/Objects/Sound.cgf",
		Icon = "AudioAreaEntity.bmp",
	},
	
	Properties = {
		bEnabled = true,
		audioEnvironmentEnvironment = "",
		eiSoundObstructionType = AUDIO_OBSTRUCTION_TYPE_IGNORE,
		fFadeDistance = 5.0,
		fEnvironmentDistance = 5.0,
	},
	
	fFadeValue = 0.0,
	nState = 0, -- 0 = far, 1 = near, 2 = inside
	fFadeOnUnregister = 1.0,
	hEnvironmentID = nil,
	tObstructionType = {},
}

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function AudioAreaEntity:_ActivateOutput(sPortName, value)
	if (self.Properties.bEnabled) then
		self:ActivateOutput(sPortName, value);
	end
end

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function AudioAreaEntity:_UpdateParameters()
	-- Set the distances as the very first thing!
	self:SetFadeDistance(self.Properties.fFadeDistance);
	self:SetEnvironmentFadeDistance(self.Properties.fEnvironmentDistance);
	
	if (self.Properties.bEnabled) then
		self.hEnvironmentID = AudioUtils.LookupAudioEnvironmentID(self.Properties.audioEnvironmentEnvironment);
		if (self.hEnvironmentID ~= nil) then
			self:SetAudioEnvironmentID(self.hEnvironmentID);
		end
	else
		self:SetAudioEnvironmentID(INVALID_AUDIO_ENVIRONMENT_ID);
	end
end

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function AudioAreaEntity:_LookupObstructionSwitchIDs()
	-- cache the obstruction switch and state IDs
	self.tObstructionType = AudioUtils.LookupObstructionSwitchAndStates();
end

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function AudioAreaEntity:_SetObstruction()
	local nStateIdx = self.Properties.eiSoundObstructionType + 1;
	self:SetAudioObstructionCalcType(self.Properties.eiSoundObstructionType, self:GetDefaultAuxAudioProxyID());
	if ((self.tObstructionType.hSwitchID ~= nil) and (self.tObstructionType.tStateIDs[nStateIdx] ~= nil)) then
		self:SetAudioSwitchState(self.tObstructionType.hSwitchID, self.tObstructionType.tStateIDs[nStateIdx], self:GetDefaultAuxAudioProxyID());
	end
end

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function AudioAreaEntity:OnSpawn()
	self:SetFlags(ENTITY_FLAG_CLIENT_ONLY, 0);
end

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function AudioAreaEntity:OnLoad(load)
	self.Properties = load.Properties;
	self.fFadeOnUnregister = load.fFadeOnUnregister;
	self:_SetObstruction();
	self.nState = 0;
	self.fFadeValue = 0.0;
end

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function AudioAreaEntity:OnPostLoad()
	self:_UpdateParameters();
end

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function AudioAreaEntity:OnSave(save)
	save.Properties = self.Properties;
	save.fFadeOnUnregister = self.fFadeOnUnregister;
end

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function AudioAreaEntity:OnPropertyChange()
	self:_UpdateParameters();
	
	if (self.Properties.eiSoundObstructionType < AUDIO_OBSTRUCTION_TYPE_IGNORE) then
		self.Properties.eiSoundObstructionType = AUDIO_OBSTRUCTION_TYPE_IGNORE;
	elseif (self.Properties.eiSoundObstructionType > AUDIO_OBSTRUCTION_TYPE_MULTI) then
		self.Properties.eiSoundObstructionType = AUDIO_OBSTRUCTION_TYPE_MULTI;
	end
	
	self:ResetAudioRtpcValues(self:GetDefaultAuxAudioProxyID());
	self:_SetObstruction();
end

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function AudioAreaEntity:CliSrv_OnInit()
	self.nState = 0;
	self.fFadeValue = 0.0;
	self.fFadeOnUnregister = 1.0;
	self:SetFlags(ENTITY_FLAG_VOLUME_SOUND, 0);
	
	self:_UpdateParameters();
end

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function AudioAreaEntity:UpdateFadeValue(player, fFade, fDistSq)
	if (not(self.Properties.bEnabled) or (fFade == 0.0 and fDistSq == 0.0)) then
		if (self.fFadeValue ~= 0.0) then
			self:_ActivateOutput("FadeValue", 0.0);
		end
		self.fFadeValue = 0.0;
		do return end;
	end
	
	if (self.Properties.fFadeDistance > 0.0) then
		if (self.nState == 2) then
			if (self.fFadeValue ~= fFade) then
				self.fFadeValue = math.abs(fFade);
				self:_ActivateOutput("FadeValue", self.fFadeValue);
			end
		else
			local fLocalFade = 1.0 - (math.sqrt(fDistSq) / self.Properties.fFadeDistance);
			self.fFadeValue = math.max(0, fLocalFade);
			self:_ActivateOutput("FadeValue", self.fFadeValue);
		end
	end
end

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AudioAreaEntity.Server = {
	OnInit = function(self)
		self:CliSrv_OnInit();
	end,
	
	OnShutDown = function(self)
	end,
}

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AudioAreaEntity.Client = {
	OnInit = function(self)
		self:RegisterForAreaEvents(1);
		self:_LookupObstructionSwitchIDs();
		self:_SetObstruction();
		self:CliSrv_OnInit();
	end,
	
	OnShutDown = function(self)
		self.nState = 0;
		self:RegisterForAreaEvents(0);
	end,
	
	OnAudioListenerEnterNearArea = function(self, player, nAreaID, fFade)
		if (self.nState == 0) then
			self:_SetObstruction();
			self:_ActivateOutput("OnFarToNear", true);
		elseif (self.nState == 2) then
			self:_ActivateOutput("OnInsideToNear", true);
		end
		
		self.nState = 1;
		self.fFadeValue = 0.0;
		self:_ActivateOutput("FadeValue", self.fFadeValue);
	end,
	
	OnAudioListenerMoveNearArea = function(self, player, areaId, fFade, fDistsq)
		self.nState = 1;
		self:UpdateFadeValue(player, fFade, fDistsq);
	end,
	
	OnAudioListenerEnterArea = function(self, player, areaId, fFade)
		if (self.nState == 0) then
			-- possible if the listener is teleported or gets spawned inside the area
			-- technically, the listener enters the Near Area and the Inside Area at the same time
			-- however, in this case the AreaManager is responsible to first call OnEnterNear and then OnEnter so this is technically circumventing a possible bug :)
			self:_SetObstruction();
			self:_ActivateOutput("OnFarToNear", true);
		end
		
		self.nState = 2;
		self.fFadeValue = 1.0;
		self:_ActivateOutput("OnNearToInside", true);
		self:_ActivateOutput("FadeValue", self.fFadeValue);
	end,
	
	OnAudioListenerProceedFadeArea = function(self, player, areaId, fExternalFade)
		-- fExternalFade holds the fade value which was calculated by an inner, higher priority area
		-- in the AreaManager to fade out the outer sound dependent on the largest fade distance of all attached entities
		if (fExternalFade > 0.0) then
			self.nState = 2;
			self:UpdateFadeValue(player, fExternalFade, 0.0);
		else
			self:UpdateFadeValue(player, 0.0, 0.0);
		end
	end,
	
	OnAudioListenerLeaveArea = function(self, player, nAreaID, fFade)
		self.nState = 1;
		self:_ActivateOutput("OnInsideToNear", true);
	end,
	
	OnAudioListenerLeaveNearArea = function(self, player, nAreaID, fFade)
		self.nState = 0;
		self.fFadeValue = 0.0;
		self:_ActivateOutput("OnNearToFar", true);
		self:_ActivateOutput("FadeValue", self.fFadeValue);
	end,
	
	OnUnBindThis = function(self)
		self.nState = 0;
	end,
}

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-- Event Handlers
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function AudioAreaEntity:Event_Enable(sender)
	self.Properties.bEnabled = true;
	self:OnPropertyChange();
end

function AudioAreaEntity:Event_Disable(sender)
	self.Properties.bEnabled = false;
	self:OnPropertyChange();
end

AudioAreaEntity.FlowEvents =
{
	Inputs =
	{
		Enable = { AudioAreaEntity.Event_Enable, "bool" },
		Disable = { AudioAreaEntity.Event_Disable, "bool" },
	},
	
	Outputs =
	{
		FadeValue = "float",
		OnFarToNear = "bool",
		OnNearToInside = "bool",
		OnInsideToNear = "bool",
		OnNearToFar = "bool",
	},
}